1965 was the first year Pontiac used the "thin wall" casting technology for their engine blocks. This does allow better thickness control where it's needed, but it uses less iron too. They "improved" the intake ports in the cylinder heads in 1965 too, requiring a different intake manifold and gaskets.
The only reason I found out about that was after cleaning and inspecting my latest engine. The rear main did not take, and when I went back in to change it the bottom of the pan had a lot of debris in it again. My machinist told me it was from the cam / lifter faces, because of the lack of zinc in most modern oils. Running ZDDP in it every oil change now.
Street car would have had antifreeze rather than straight water, and that would have been apparent with draining the oil out. (the dreaded milkshake) If the oil had no evidence of coolant, the crack wasn't leaking. (at least any more than a drip or so) Another sign of coolant in the oil is the undersides of the valve covers will have a white slime. I've seen more than my fair share of failed cams and lifters. The fact that anyone is successful in using flat tappet cams, especially in this day and age of the components cast with dubious materials and machined with maximum profit margin in mind and zero quality control is astounding. All it takes is one lobe ground with insufficient taper (stone needed a redress) or a lifter with insufficient crown or a lifter bore that has a tight spot or a bit of grit caught between the lifter and it's bore and it's going to fail. We use the correct break in oils, run low ratio rockers when we can, fire up carefully controlled on our dyno with zero idle time and right up to 3000 and still lose the odd flat tappet cam. We've even had a case on a Chev small block where everything went well on the dyno but it lost a cam within about 10,000 KM, and this was a typical "RV" build, nothing crazy in terms of spring pressure and a relatively mild cam. It's a gamble.
I have not been a professional auto mechanic for more than 30 years, but yes, I have seen plenty of one lobe and lifter failures, even on Pontiac. I have seen the failure on all brands of General Motors, Fords , and Chryslers. I don't discount your failure analysis of coolant leaking down one lifter bore, but I suspect it has more to do with the case hardening on the camshaft and/or bad radius grinding on the lifter and possibly poor grinding on the lobe taper. In all reality, the failures I saw back in the day were all on high mileage engines, but high mileage was 75k to 150k miles at the time, and poor oil change intervals may have been a major factor.
I don't disagree just wondering why the water didn't also take out the exhaust lobe and lifter as well, the crack is even closer to or at least right over it? Or do you think the water was only leaking from the highest point which is more directly over the intake set?
That sounds plausible. Find any coolant in the oil/ pan? Yeah I know it was hot tank but make sure to physically swab the oil passages out clean, before it goes back together ; )
Every cam shaft failure I've experienced had only one lobe worn down. In my opinion there are several factors that can cause these failures. It looks to me the lifter was still spinning judging from the wear pattern. I believe the most common reason is the motor oil being manufactured today. With all the environmental "concerns" and the wide spread use of roller cams, they have reduced a lot of the ingredients that gave flat tappet cams longer life. There can also be soft spots in the iron that can cause failure over time. The lifter bore can be slightly off causing the lifter to ride on one side of the cam lobe more than the other side. The break in process if not properly done can cause this type of failure. I've seen brand new cams wipe a lobe immediately at start up. There are so many things that can cause this type of failure you would be hard pressed to know 100% what caused this lobe failure.
There have been so many flat tappet failures lately I'm afraid to use the flat tappet cam I just bought. Since I'm rebuilding a just rebuilt engine that had a lobe round off and a second just barely rounding. My machinist said, you're going to try a flat tappet again, why not a roller? I've been a mechanic for 40+ years and not seen big issues until recently. Even ZDDP doesn't seem to be a factor. Poor machine work possibly. So on to the cam failure and reasons videos!
Thanks Jimmy, for what it is worth, i have not had one fail yet. proper preparation, clean start up and break in, the right oil, and avoid heavy valve spring pressures on start up. AG
There would usually be a slight rust stain if the crack was leaking. I don’t think your theory is what caused lifter/cam failure. Lifter failures have been rampant since oils changed and parts are suspect anymore. I myself never had a lifter failure until one engine I built lost just one..a 454 Chev with a hyd cam. The owner replaced the cam and lifters himself after that incident so I don’t know why the first one failed. He did the initial start up and running.
As sensitive as flat tappets are with spinning in their bore and on top of the lobe, the zinc fortified oil, along with the proximity of the coolant path, I’d say you’re spot on
My client managed to break the camshaft in his engine, 428 Cobra Jet, into 5 pieces. Destroyed the cam tunnel and #3 main webbing. Flat tappet cam goodbye!
@arturozarate1752 I will never run another flat tappet cam. Roller cam is the best option today with modern oils and sub-par flat tappet lifter issues. To me it's not worth the headache.
I've heard that 1 in 5, 20% of brand new cams are garbage outta the box...!!! No one seems to know why except that there's no quality control and there is way too much stuff being manufactured in China...!!! Thanks for sharing... Keep up your awesomeness...
That theory makes the most sense. Engines aren't always perfectly level, so it would make sense for some coolant to drip in the direction of that lifter rather than the most forward.
I had several cams that got chewed up. Ford 352, 292 . I've seen pushrods right through the rocker arms come in on California 318 Dodge.. Flattened lobes on Chevy and concave lifter's.. And in the "80"'s the GM conversion diesel 🙄 remember those. We had many come in that was shelled. Cam broken in three pieces and cracks in cylinder walls crankshafts in pieces piston skirts destroyed. S shaped rods. The list goes on and on. You see I did 52yrs service on all and everything. And built engines from 80-88, the stories I could tell are endless.
Back in the late 60's the automotive machine shop where I worked did similar repairs to engine blocks and heads. We called it cold lacing, dirll a hole, tap in, thread in a plug, grind it flush and drill another hole in the crack and half the first plut, repeat until the crack is no more. It holds up very well. Granted, if a rod goes through the side of the block, it is not meant for repairing catastrophic breaks. I have heard the process called pinning and cold welding. I guess it depends on the name of the manufacturer or what people refer to it as. No need to discard a block where water froze and cracked the bottom of a water jacket. That is an oddity to me how the Pontiac block cracked in that vicinity. I have never seen or heard of anything like this. Thanks for the Pontiac videos.
In 30 years I've never seen this in a GM engine. Hemi's are quite another matter! I've seen 2 that had lobes worn like that in different engines. Kinda upsetting as I owned the first one, the second belonged to a friend.
Maybe. The area around the lifter bore too on Pontiacs I’ve seen is slightly raised and it would have channeled water away. That lifter was definitely turning by the way it wore, plus any water would have been immediately flushed away on start up. While the crack may have aggravated the problem, I still say it’s a lifter bore, cam lobe, or tappet machining issue. However, you just proved the importance of magnafluxing a block! These old castings need thorough inspection.
I dunno. I had a Mopar 383 with a new camshaft and lifters run a lobe and lifter after 5 years. Valve springs were new single spring and damper to match the camshaft and it always regular oil changes. The heads had K-line guides and were reconditioned before it was all installed. The oil pump pickup tube was 1/2" with the block drilled, and the mains were just stock half grooved and the big ends bearings replaced. Point is all the areas you'd expect were great, the oil pressure never low, but it ran a lobe. A real lot of idling in traffic though. But yeah only one lifter and lobe, all the rest were 100%. How?
I had a 396 BB Chevy lose one lifter and one cam lobe that disenegrated and everything else was fine. Unfortunately for me the shrapnel scared a cylinder wall deeply.
I've seen lobes grind down for several reasons but I will say Never by the process you're describing, you could always pose that question to Nunzi 's Automotive who was one of the defacto experts with everything Pontiac. Well at least from the 1960's and beyond.
I run 7 psi radiator caps on everything. The more pressure the more likelihood of leaks. If the water temp gets over 210 I’m pulling over to see what’s up. Therefore no need for the higher pressure radiator cap.
That is an interesting failure for certain Alan. As a 35 years mechanic, I believe you may be correct. The lifter only needs to not turn for a minute to start to gall up and then start turning again. Now the damage has begun and does not heal itself. Coolant and oil can be a goopy sludge that can slow lifter rotation without stopping it entirely.
I had a very similar thing happen to me with a very rare (to me actually) 4 bolt main 400sbc that I still have but not gotten the chance to have it looked at any further then taking the top off and removing cam / lifters . (Almost 20 years ago now) I was only able to suspect that the intake seal failed .a damning event to occur to me ,and since then my life has gotten the best of me such as becoming a paraplegic in 2011 where my health has kept me from everything else I have . So much has happened since, I doubt ill ever get back to ,just so much.
I'm not saying you're wrong, but I've seen that sort of failure before. I've also been wrong before! The wear pattern suggests to me the lifter was rotating when the wear occurred. If the lifter wasn't turning, it strikes me that there would likely be a wear pattern biased to one side of the lifter instead of being symmetrically worn to the centre. Back in the 80's, in the Holden 253 v8's, this failure was common & many cam & lifter sets were replaced under warranty. Often, the complaint would be a gradual loss of power with increasing tappet rattle. In the motors I repaired or witnessed, the lifter had a wear pattern just like yours, but some actually wore through the bottom of the lifter. The factory blamed soft cam lobes due to incorrect hardening, but I can't help wondering if the cause might have been an occasional soft lifter. Especially when the damage was sometimes confined to only 1 lobe & not always the same one. Food for thought?
@@goldsgarage8236 Sure is. I don't know if you're familiar with Holdens, they're our primary G.M. product. Similar(ish) to U.S. vehicles, but for the most part, smaller. And a couple of years behind in development. Hope I was able to shed a bit more light on your puzzle. May your knuckles stay un-busted!
I've ran STP Oil Treatment & DELO for years in High Output Engines & NEVER A Failure !! Bracket Racing & Dirt Track !! I'll also give a Shout Out to Brad Penn 20-50 !! 😉👍🏻
Was there any water in the oil at disassembly? No metal in pan at breakdown? Was the lock and stitch done prior to your diassembly ? Todays oil changes have so little zinc even an old cam and lifter set can fail. See Lake Speed Jr's accessment on today's oils and why failures are occuring.
Water or bad parts, either is plausible. I don't see where anyone has suggested that the internals of the lifter might be seized from rust. Hydraulic lifters operate with *sort of* zero lash. If it was truly zero, then there would be no room for oil. In reality, the lifter "relaxes" when the valve is closed, which allows oil between lifter and cam. Try disassembling the lifter. On the other hand, modern car parts are known to be crap.
Shop rate and time, plus the stitches. We use the Irontite taper plugs. Drill a hole, run the tapered tap in, a little red loctite and run the plug in tight, trim it off, then drill for the next one, following the crack while at the same time the hole intersects the previous plug, and so on and so on. Taps are thin (under 1/4 inch) and brittle so you take your time. Pretty easy to burn up a couple of hours doing the repair.
I'm sure it's expensive. There was a process outlined in a magazine in the '90's I read how to do it. You can actually do it yourself. You basically drill holes along the crack (one at a time) and tap the hole, screw in a peg or pin with sealer, cut it off, drill another hole in front and tap partially into the pin you just installed, repeating to just past the end of the crack, 'stitching' or pinning the crack. Then grind all the tops flush. You can actually 'stipple' the surface to make it look like it was never touched if it's on the outside. It's a tedious process. Originally used on old boilers and steam locomotives.
I repaired a crack in the original flat head 4cyl engine in my ‘41 Willys pick up with lock-n-stitch my self in 2021 it cost $400 US to get their tooling and the pins. 100 pins was $140 US
@@cabotbroughton7458 That's not too bad. I think depending on the machine shop you're looking at over $1000 to start. Depending how cheap you want to go, you can perform the operation with basic shop tools, (drill bits, stop collar, taps, bolts, hammer and peens or punches). That's all machinists used a hundred years ago to perform a repair.
I am a retired journeyman mechanic. I overhauled hundreds of engines. I worked at a Cadillac dealership. You theory may be possible, but I doubt it. Water seeping out of the water jacket into the oil would have caused the oil to reach with it turning it into a grey sludge. This would have become obvious after a short time. What I have seen are dished out valve lifters due to a couple of reasons. Cadillac had this problem in one of their engines causing dishing on the cam lobes and lifter bases. The fix for this was simply changing to another grade of oil. From SE to SF oil (this was in the 1980s). Another thing I have seen was poor or irregular hardening of a lifter base causing premature wear on the cam lobe. What happened to our engine is hard to say without a forensic examination. Guessing or other people's opinions really aren't going to solve your issue.
was the head gasket ok? no bent pushrod? not the usual suspects like too long of a bolt bottomed out in the blind hole putting pressure on the block causing the crack? packed up valve spring would be my guess.
I knew it would happen by your start-up, and I'm sure you did not show it all... Here is a tip: when you are ready to finally start your engine for break in, turn your cranck backward to 25 degrees before TDC. Engine will start right up. Go immediately to 2000rpm for 20minutes. No playing around with tune. Use a 40w oil or 20w-50 for breakin oil. Its all about running for 20 minutes at 2000rpm. Oil must pump up pressure within 29 seconds. Damage start at 30 seconds. Change oil after the 20 minutes etc etc. Run again for 30 minuteskeeping rpm up and then play with tune a little, etc etc. Change oil a third time and run again varying rpms from 2000 to 3500 for 20 minutes, then tune timing and carb.... I use Driven breakin oil and run that third oil change in engine for dyno and/or the first 500 miles... There are many great oils out there but I use Driven Breaking oil for first three oil changes and the fourth oil change is Driven Synthetic Blend 20w-50 or 15w-40 with Davis Vizards "oil extreme addative". Adds 8hp on dyno and lubricates so well I have to adjust idle down becuse it speeds up idle when added because it reduces friction so well. - Regards
@@autonomous_collective Failure was confined to just one lobe & just one lifter. All others appeared in good shape. This indicates prob wasn't with initial start up or running in proceedure. Prob was most likely a faulty lifter, a bent or otherwise sticking valve, coil bind or a too long valve guide getting bashed by the spring cap causing the lobe to simply behead itself. That lifter may have been stuck fully or nearly fully extended because of a tiny piece of foreign junk that eventually dislodged while the engine racked up a zillion miles running on 7 cylinders. Careful run in is vital, but that doesn't seem to be evidently causal in this case.
seen this on 400 pontiacs several times possible sludge broke off and got between lobe and lifter and wore the harden surface off the cam lobe or long idle time not enough oil splash from crankshaft in that area
If the oil wasn't a milkshake the crack wasn't leaking. I also doubt water or coolant which is much thinner than oil is going to wash away enough oil in the lifter valley to cause that. An easy test would be to pour a quart of oil in the lifter valey and then drip water on the repaired section and see what happens. My money says the water stays on top of the oil and is mixed up upon starting the engine.
I had an engine that ate the #6 intake lobe twice on new cams. I put a used cam in it and it survived. That was 1994. The engine went on to race for another 20+ years and is still running. I have no idea why there was an issue with that lobe repeatedly. The engine is affectionately known as Bracket Betty and has several hundred passes on it at the drag strip. She’s fairly potent with runs in 10’s with a full bodied (fiberglass hood) Duster.
Would be interesting to know how that bore spec'd out. Too much clearance, too little or perpendicularity could all be factors. May not have been an issue with a slower ramp profile cam.
@@The340kingBerry Cams, I have no experience with. Crower was nicknamed "crazy" by myself for the insane lifts. I could only guess that a weak valvespring allowed some oscillation on that particular lobe with a particular amount of duration.
Thank You Alan, In my 50 years as a mechanic I've never seen this in a Pontiac. The 1971 Chevy 307 I had in a Malibu wore out # 6 exhaust lobe and lifter at 59000. and 100009.0 miles. I have heard of this from others. Probably a casting or machining defect. I know a 307 from the factory was kind of sick, small valves, low compression, 2 barrel. A friend of mine worked in a machine shop and someone never came and picked up their 307 + .030, he called it a 311. 12 1/2 to 1 compression. I used 461X Corvette heads ported, Holley Strip Dominator, 750 Holley off of Jeff Bodines Nascar, Ultradynes largest flat tappet cam. Long main studs with the main caps machined flat with 3/4" straps. People didn't believe it was a 307. It ran 6.90's in the 1/8 mile in a 2900 lb. car consistently with a powerglide and a Dana 60 back in the 90's,, :)
Back in the early 60s, My Mother was driving a '51 Mercury 2 door. We stopped at an intersection and the motor was running fine. When she gave it gas to pull away, the engine bucked, snorted and died. When Dad tore it down, the camshaft had broken into 3 pieces. No other damage, a new cam and it was back in service.
This lifter issue is becoming one of the greatest mysteries of the past 20 years. Everyone seems to have a theory but nobody knows 100% what is going on. Many people say "just go roller" but flat tappets still have a place in many low dollar simple rebuilds for nostalgic cars. Would be great to get this issue resolved.
not gonna happen.......everyone has basically thrown their hands into the air. The last OEM flat tappet engine was the jeep 4.0L that was discontinued almost 20 years ago. Aftermarket gets the overflow from OEM production and OEM production has moved on. My personal theory is that since most manufacturing machine shops have gone 100% CNC that they are just hiring low skill "button pushers" to run the machines. Back when a machinist had to turn those knobs and watch that dial indicator he was basically doing QA testing as he went along. Now "oh the cnc just makes the parts.....and we don't need to check it because its always perfect". At work we get parts all the time(not automotive related) that are screwed up by 'world class' machine shops who one makes 6 figure casting molds for a major automaker and another who makes machine guns for the US Military. EVERYONE is phoning it in now.
There is sn answer, but no one want to accept it. I was in the business 30yrs, but that's just my word. The finish on the bottom of the lifters is too course - the surface finish is no longer held to the finer micro it once was. This "attacks" the lobe on startup, and the oil film isn't this enough to protect at the height of the peaks of the courser finish. I've dusted the bottom of flat tappets for decades, just enough to take down the peaks, and had zero lifter failures.
@Motor-City-Mike Your answer makes perfect sense. I've been a mechanic since the mid-80s, rebuilt over 50 motors without a problem till 2 years ago, wiped out 2 flat tappet cams on initial break-in. Could you please explain your method of dusting the lifter?
Geez, IT"S THE LIFTERS. It looks like a 20+ year issue because everybody CONFLATES multiple problems. In the beginning it was the OIL that was the problem and (generally speaking) the lifters were 'OK' after people figured out about the oil, the LIFTERS quality totally went in the tank. ALL the quality lifter MFR's GAVE UP. They don't NEED to focus on them because the OE's haven't used HFT's for over 35+ years and the replacement market is getting ever smaller. The ones that did make good quality HFT lifters just quit. Johnson (not the current Topline) the OTHER Johnson in Taylor, MI made an OUTSTANDING HFT product as recent as 2016/17 (I think) but got out of the HFT biz (which is another story unto itself). Which is a real shame. They were the ONLY modern MFR making a great product . Now there are NONE left. Buy OLD STOCK.
I've changed cams that too had lifter failures like this one. I just feel the materials used for cam/lifters were poor quality. A flat tappet lifter does rotate when operating, and it just rotated to get the failure you see.
I don't know who I am, however it doesn't appear that the lifter quit turning because it is soup bowled. Considering the lifter has an even wear tells me that it was spinning.
I agree, I would inspect every lobe and lifter for proper tapper and I would rockwell test each lobe and lifter because there is a lot of China junk out there with name brand labels.. one other issue, too. I have seen people forgetting to install the cam retainer, and then the cam walks, resulting in the same issue.
I bought a 1964 Buick Special with the 225 V6 with a bad cam/lifter looked just like this one. It sounded like a rod-knock. I installed a re-ground cam ($19 in 1976) and lifters and the only other part which was showing any wear... the oil pump. The filter got almost all the grime and I drove that car for several years without another failure. Still don't know what happened, aside from the previous owner didn't change the oil like he should have. After 20k miles, I did take it down to rebuild and didn't see any damage from before.
My parents both worked skilled trades in Flint, Michigan GM plants. My mother was in the Engine plant on Van Slyke street. I remember her telling me about when induction hardening machine for the camshafts went down. They stoped the line to repair it. Then, supervisors came down and ordered it to run regardless of whether the camshaft were hardened or not. She and the other staff pointed out those cams were going to fail in the field. The managers response was, “ Run it, we’ll fit them when the cars end up returned to the dealers after they are sold “
My friend had an 81 Cutlass from brand new with a (267?) V8 that barely made 25,000 kms before the case hardening on the camshaft and lifters failed and ground off several lobes. Took it to the dealer and they were well aware of the fault, but did nothing to fix it. He wore the cost of the parts and we fixed it.
It's not unusual for block castings to have cracks in certain areas. Sometimes it's completely benign and doesn't matter. It looks like the first lifter would be impacted as well. The laws of physics dictate that any coolant leakage would run past that 'well' area by the tappet bosses and end up in the crankcase. Liquid will flow to flow down the path of least resistance. A wide open drainback is easier to follow than a one -two thou bore clearance You can tell if it was spinning by looking at the lifter side (linear scoring). I'm assuming the block was like that before it was torn down the first time. Was there a bad lifter in that location in the past? An oil analysis would tell you for certain if there was coolant in the oil. I would suspect something else. As far as your hypothesis, maybe it's correct but you'd never be able to prove it now that it's fixed. My opinion is I don't think it was that bad if you needed a Magnaflux to find it. Should have been able to see some traces by eye. Even a UV dye test would tell if it was bad enough to actually leak, Magnaflux just says theres a crack, not whether it's a problem. Magnaflux is expensive because they have to generally suspect where a crack is. Anytime I went to a machine shop they said unless you think or 'know' you have a crack, forget about it. That could have been a freezing crack, though not very likely on the inside, but I think it was there a long time. Maybe just from manufacture. It's in a strange place. Being dished the lifter looks like it was spinning just getting 'eaten'.
I think your diagnosis, is correct. With the coolant being 200 degrees, it would more than likely wash some of the oil film away also, with the possibility of rust, and pitting.
If I had to guess years ago steel was hardened with anthrocite coal which was the best way to heat treat steel but no more anthrocite coal and now steel is heat treated with propane gas or bituminous coal that no where near gets hot enough that's why you put brake rotors on a car and the next day they have rust on them where rotors made years ago could sit for 6 months or longer and no rust on them!!!!
My guess is the engine froze at some point. I've pushed 700 plus HP and split blocks up thru the mains, but never in that area. I've also broken off lifter bores & use braces in all my builds. If enough water was entering the crankcasevto damage the lifter/cam lobe, you would have seen it in the oil. Flat tapped lifters fail.
Back in 1988 I was working at quality Chevrolet and engines were coming in cracked along the lifter valley they were replacing them right and left they were not seasoning their engine blocks
I put a comp cam kit in a 350 with everything brand new with their cam lube and within a minute of starting the engine it was making a hell of a noise on cylinder 6 exhaust lobe and filled the engine bearings full of metal and destroyed the crankshaft and wiped out all the cam bearings and I turned it into comp and they said it was my fault and wouldn’t refund my 500$ it cost for the kit so I won’t ever buy another damn thing from that sorry ass company again and will tell everyone that same thing to stay away from them.
A scrubbed cam lobe and lifter on a newly-built engine is usually attributed to cam break-in lube being applied to the sides of the lifter rather than the bottom only. Engine oil only on the sides of the lifters.
That's as good a theory as any. As you say, if the lifter is not spinning the cam is dead. I don't know the Pontiac oiling system but on a Ford oiling system that lifter is the last place to get oil so if its similar it may also have something to do with it.
ENGINE BREAK IN..... WHAT DO YOU THINK? Chevy engines have an oil bypass valve in the spin on oil filter adapter. Nobody knows how often this bypass occurs. If you block off this bypass by removing it and installing a quarter inch pipe plug you will now get 100 percent oil filtration. You must use a strong oil filter with a thick canister such as Baldwin. NOW by using this theory when breaking in a flat tappet camshaft engine and something goes wrong any debris will go directly into the oil filter instead of bypassing and causing damage to other PLEASE TELL ME WHAT YOU THINK.
Good question Steve. Under a controlled situation such as a break in, sure, as long as you can keep your eye on the oil pressure. remember, that most oil filters, except racing oil filters also have an internal bypass.AG
I like Your line of Thinking , effect & probable cause through good visual inspection using magna fluxing equipment and knowledge & experience ! Thank You for the great insight 🇺🇸🇵🇷🦊👍
Its a GM engine,, renowned for wiping cam lobes. I have seen and or done numerous ones in Chevs, Holden V8s, some Holden 6s, and a 327 Pontiac. And it seems these days cam lobes disapear more often in all makes. Fords have a bigger dia lifter and are less likely to do this. Though I have seen them OEM take a lobe as well.
I respectfully disagree on this one Mr Gold. I just don't think the coolant would displace the oil between the lifter and lifter bore, or not enough to stop the lifter from rotating anyway. There are countless good vids on multiple potential lifter failure causes. My "opinion" on these failures is in the area of improperly crowned lifters and or lobe taper, and lesser so but possibly poor material. Remember back in the 1980's we slapped cams and lifters in motors with little to no break in with rarely a failure. Now we do all the "by the book" tricks and still see failures. I did an experiment a year ago and broke all the rules. New cam (Comp xtreme energy solid flat), a good used set of EDM lifters, heavy double valve springs and no break in. A year later, couple hundred hours on it and working well. What I did do was checked the crown on each lifter, checked lobe taper, cranked and confirmed rotation of all before and at startup. One caveat, the cam and lifter were manufactured over ten years ago. Although going forward I would be very cautious buying any cam or lifters. I don't know who to trust anymore.
Whatever the cam was that the previous person installed had a failed heat treat, and/or was not ran in correctly. This is also something typical when people run today's motor oils in an 1965 engine. Today's oils are formulated for emissions controlled engines. Thus, they have a lot less zinc in them. Thus, a combination of reduced zinc, poorly broken in camshaft with perhaps a poor heat treat, presto, this was the first lobe that failed. Once the wear is not right between the camshaft and the lifter bottom, the lifter stops spinning around. This only compounds the problem. I'm not agreeing with your water seepage idea because these engines have so much oil flying around that unless he let sit for a year, the lifter getting stuck from corrosion is pretty unlikely. Get the camshaft from a quality camshaft company such as Comp Cams, and be sure you break it in properly. Use a good break in oil, and recommend that they use a racing oil since they will have more zinc in them as they are not supposed to be used in a modern street engine with the emissions controls. The Valvoline VR 1 is a great one as well as Redline and Mobil 1 racing oils.
Your explanation on magna fluxing is in the wrong order. You have to magnetize the metal before applying the particles. You don't apply the particles first.
I`ve seen many camshaft failures in my 50 yrs of building engines and most of them are not the parts fault. In the early days on grocery getters it was poor maintenence, in spec stock car motors it was abuse, exssesive spring pressure and interference problems. I had a friend of mine who fancied himself an engine builder pull one of his motors off a dyno and it looked like the cam had 4 fuel pump lobes.... I laughed my butt off.
might of said ok agree with you. BUT yep there it is.. why would it miss the ex side. so nope can not agree with this.... i would say... just a bad lifter. some how wasnt harded enough or to soft of mix for it. something with lifter itself.
I'm an old guy to and in my days I've learned that " shit happens ".
Good point, thanks for commenting. AG
Great video and analysis!! I never knew what magnaflux was or how a crack could be repaired. Thank you for educating your audience!!!
You can use certain anti perspirants and food coloring in the right order with great success.
1965 was the first year Pontiac used the "thin wall" casting technology for their engine blocks. This does allow better thickness control where it's needed, but it uses less iron too. They "improved" the intake ports in the cylinder heads in 1965 too, requiring a different intake manifold and gaskets.
Had alot of problems with flat tappet cams some time back
Zinc. Zinc zinc
The only reason I found out about that was after cleaning and inspecting my latest engine. The rear main did not take, and when I went back in to change it the bottom of the pan had a lot of debris in it again. My machinist told me it was from the cam / lifter faces, because of the lack of zinc in most modern oils. Running ZDDP in it every oil change now.
In Germany we even use NOS oil cans in old OHV US engines
Street car would have had antifreeze rather than straight water, and that would have been apparent with draining the oil out. (the dreaded milkshake) If the oil had no evidence of coolant, the crack wasn't leaking. (at least any more than a drip or so) Another sign of coolant in the oil is the undersides of the valve covers will have a white slime.
I've seen more than my fair share of failed cams and lifters. The fact that anyone is successful in using flat tappet cams, especially in this day and age of the components cast with dubious materials and machined with maximum profit margin in mind and zero quality control is astounding. All it takes is one lobe ground with insufficient taper (stone needed a redress) or a lifter with insufficient crown or a lifter bore that has a tight spot or a bit of grit caught between the lifter and it's bore and it's going to fail.
We use the correct break in oils, run low ratio rockers when we can, fire up carefully controlled on our dyno with zero idle time and right up to 3000 and still lose the odd flat tappet cam. We've even had a case on a Chev small block where everything went well on the dyno but it lost a cam within about 10,000 KM, and this was a typical "RV" build, nothing crazy in terms of spring pressure and a relatively mild cam.
It's a gamble.
Agreed. If it's expected to live, change over to a roller. I've experienced the same and more so in the past five years of my 25 years.
I think you called it! Fine work
I have not been a professional auto mechanic for more than 30 years, but yes, I have seen plenty of one lobe and lifter failures, even on Pontiac.
I have seen the failure on all brands of General Motors, Fords , and Chryslers. I don't discount your failure analysis of coolant leaking down one lifter bore, but I suspect it has more to do with the case hardening on the camshaft and/or bad radius grinding on the lifter and possibly poor grinding on the lobe taper. In all reality, the failures I saw back in the day were all on high mileage engines, but high mileage was 75k to 150k miles at the time, and poor oil change intervals may have been a major factor.
Thanks for watching and commenting. AG
I don't disagree just wondering why the water didn't also take out the exhaust lobe and lifter as well, the crack is even closer to or at least right over it? Or do you think the water was only leaking from the highest point which is more directly over the intake set?
That sounds plausible. Find any coolant in the oil/ pan? Yeah I know it was hot tank but make sure to physically swab the oil passages out clean, before it goes back together ; )
Every cam shaft failure I've experienced had only one lobe worn down. In my opinion there are several factors that can cause these failures. It looks to me the lifter was still spinning judging from the wear pattern. I believe the most common reason is the motor oil being manufactured today. With all the environmental "concerns" and the wide spread use of roller cams, they have reduced a lot of the ingredients that gave flat tappet cams longer life. There can also be soft spots in the iron that can cause failure over time. The lifter bore can be slightly off causing the lifter to ride on one side of the cam lobe more than the other side. The break in process if not properly done can cause this type of failure. I've seen brand new cams wipe a lobe immediately at start up. There are so many things that can cause this type of failure you would be hard pressed to know 100% what caused this lobe failure.
Had an 010 SBC that cracked in the valley, found it by sealing the block, pressurising it with air and spraying soapy water on it.
There have been so many flat tappet failures lately I'm afraid to use the flat tappet cam I just bought. Since I'm rebuilding a just rebuilt engine that had a lobe round off and a second just barely rounding. My machinist said, you're going to try a flat tappet again, why not a roller?
I've been a mechanic for 40+ years and not seen big issues until recently. Even ZDDP doesn't seem to be a factor. Poor machine work possibly.
So on to the cam failure and reasons videos!
Thanks Jimmy, for what it is worth, i have not had one fail yet. proper preparation, clean start up and break in, the right oil, and avoid heavy valve spring pressures on start up. AG
There would usually be a slight rust stain if the crack was leaking. I don’t think your theory is what caused lifter/cam failure. Lifter failures have been rampant since oils changed and parts are suspect anymore. I myself never had a lifter failure until one engine I built lost just one..a 454 Chev with a hyd cam. The owner replaced the cam and lifters himself after that incident so I don’t know why the first one failed. He did the initial start up and running.
As sensitive as flat tappets are with spinning in their bore and on top of the lobe, the zinc fortified oil, along with the proximity of the coolant path, I’d say you’re spot on
I managed to brake my cam in my last race motor into 3 pieces
My client managed to break the camshaft in his engine, 428 Cobra Jet, into 5 pieces. Destroyed the cam tunnel and #3 main webbing. Flat tappet cam goodbye!
@@arturozarate1752 I got lucky and the cam was the only damage. I got really lucky.
@arturozarate1752 I will never run another flat tappet cam. Roller cam is the best option today with modern oils and sub-par flat tappet lifter issues. To me it's not worth the headache.
@@I_like_turtles_67 agreed.👍
I've heard that 1 in 5, 20% of brand new cams are garbage outta the box...!!! No one seems to know why except that there's no quality control and there is way too much stuff being manufactured in China...!!! Thanks for sharing... Keep up your awesomeness...
Thanks for the nice comment Kurtis. AG
That theory makes the most sense. Engines aren't always perfectly level, so it would make sense for some coolant to drip in the direction of that lifter rather than the most forward.
Thanks for your thoughts Happy. AG
I had several cams that got chewed up. Ford 352, 292 . I've seen pushrods right through the rocker arms come in on California 318 Dodge.. Flattened lobes on Chevy and concave lifter's.. And in the "80"'s the GM conversion diesel 🙄 remember those. We had many come in that was shelled. Cam broken in three pieces and cracks in cylinder walls crankshafts in pieces piston skirts destroyed. S shaped rods. The list goes on and on. You see I did 52yrs service on all and everything. And built engines from 80-88, the stories I could tell are endless.
Thanks for the info Desert. You have a lot of real life experience. AG
That makes sense to me, my initial thought was a lifter bore issue. I'd double check those bores to make sure the new lifter is going to ride right.
Thanks for the comment, we are going roller on this one. It's going together right now. AG
I'm on board with your theory. Glad you saved it.
Thanks Rotax. AG
Back in the late 60's the automotive machine shop where I worked did similar repairs to engine blocks and heads. We called it cold lacing, dirll a hole, tap in, thread in a plug, grind it flush and drill another hole in the crack and half the first plut, repeat until the crack is no more. It holds up very well. Granted, if a rod goes through the side of the block, it is not meant for repairing catastrophic breaks. I have heard the process called pinning and cold welding. I guess it depends on the name of the manufacturer or what people refer to it as. No need to discard a block where water froze and cracked the bottom of a water jacket. That is an oddity to me how the Pontiac block cracked in that vicinity. I have never seen or heard of anything like this. Thanks for the Pontiac videos.
Thanks you! AG
I've seen many cams fail from too much spring pressure
Never considered water contamination before, but absolutely valid concern.
Thanks for your comment. AG
In 30 years I've never seen this in a GM engine. Hemi's are quite another matter! I've seen 2 that had lobes worn like that in different engines. Kinda upsetting as I owned the first one, the second belonged to a friend.
Thanks for the info Will, It is a strange one for sure. AG
I only use NOS or even good used cams from the 1970s and 80s and I only trust NOS lifters from not later than 1997
Maybe. The area around the lifter bore too on Pontiacs I’ve seen is slightly raised and it would have channeled water away. That lifter was definitely turning by the way it wore, plus any water would have been immediately flushed away on start up.
While the crack may have aggravated the problem, I still say it’s a lifter bore, cam lobe, or tappet machining issue.
However, you just proved the importance of magnafluxing a block! These old castings need thorough inspection.
For sure, thanks Pablo. AG
I dunno. I had a Mopar 383 with a new camshaft and lifters run a lobe and lifter after 5 years. Valve springs were new single spring and damper to match the camshaft and it always regular oil changes. The heads had K-line guides and were reconditioned before it was all installed. The oil pump pickup tube was 1/2" with the block drilled, and the mains were just stock half grooved and the big ends bearings replaced. Point is all the areas you'd expect were great, the oil pressure never low, but it ran a lobe.
A real lot of idling in traffic though. But yeah only one lifter and lobe, all the rest were 100%. How?
Good question Paul. AG
I had a 396 BB Chevy lose one lifter and one cam lobe that disenegrated and everything else was fine. Unfortunately for me the shrapnel scared a cylinder wall deeply.
looks identical to my cam failure 1981 z-28 stock cam
I've seen lobes grind down for several reasons but I will say Never by the process you're describing, you could always pose that question to Nunzi 's Automotive who was one of the defacto experts with everything Pontiac. Well at least from the 1960's and beyond.
Thanks for the comment Alfred. AG
I run 7 psi radiator caps on everything. The more pressure the more likelihood of leaks. If the water temp gets over 210 I’m pulling over to see what’s up. Therefore no need for the higher pressure radiator cap.
Sounds like a great strategy, thanks AG
Harder metal will win some big cam manufacturers use cheap metal to increase profits
I understand what you are saying. and part of it makes sense. But it is odd that it did not effect the number 1 exhaust lifter and cam lobe as well.
Good point David, i cannot explain that. AG
Should check the cylinders for cracks also . A lot of Old pontiacs liners are getting thin !
Your theory on the cam and lifter sounds good but what caused the crack?
Thanks Rick, we don't really know the history of it. AG
That is an interesting failure for certain Alan. As a 35 years mechanic, I believe you may be correct. The lifter only needs to not turn for a minute to start to gall up and then start turning again. Now the damage has begun and does not heal itself. Coolant and oil can be a goopy sludge that can slow lifter rotation without stopping it entirely.
Thanks for commenting Dale. AG
I had a very similar thing happen to me with a very rare (to me actually) 4 bolt main 400sbc that I still have but not gotten the chance to have it looked at any further then taking the top off and removing cam / lifters . (Almost 20 years ago now) I was only able to suspect that the intake seal failed .a damning event to occur to me ,and since then my life has gotten the best of me such as becoming a paraplegic in 2011 where my health has kept me from everything else I have . So much has happened since, I doubt ill ever get back to ,just so much.
Sorry to hear, thanks for watching and commenting Tory. AG
I'm not saying you're wrong, but I've seen that sort of failure before. I've also been wrong before! The wear pattern suggests to me the lifter was rotating when the wear occurred. If the lifter wasn't turning, it strikes me that there would likely be a wear pattern biased to one side of the lifter instead of being symmetrically worn to the centre. Back in the 80's, in the Holden 253 v8's, this failure was common & many cam & lifter sets were replaced under warranty. Often, the complaint would be a gradual loss of power with increasing tappet rattle. In the motors I repaired or witnessed, the lifter had a wear pattern just like yours, but some actually wore through the bottom of the lifter. The factory blamed soft cam lobes due to incorrect hardening, but I can't help wondering if the cause might have been an occasional soft lifter. Especially when the damage was sometimes confined to only 1 lobe & not always the same one. Food for thought?
Thanks John, good point about it still spinning. Holden? Is that Australia?
@@goldsgarage8236 Sure is. I don't know if you're familiar with Holdens, they're our primary G.M. product. Similar(ish) to U.S. vehicles, but for the most part, smaller. And a couple of years behind in development. Hope I was able to shed a bit more light on your puzzle. May your knuckles stay un-busted!
probably just had enough flex to prevent lifter from spinning correctly
I've ran STP Oil Treatment & DELO for years in High Output Engines & NEVER A Failure !! Bracket Racing & Dirt Track !!
I'll also give a Shout Out to Brad Penn 20-50 !! 😉👍🏻
Thanks Waylon. AG
Exact thing happened to my 79 W72
Was there any water in the oil at disassembly? No metal in pan at breakdown? Was the lock and stitch done prior to your diassembly ? Todays oil changes have so little zinc even an old cam and lifter set can fail. See Lake Speed Jr's accessment on today's oils and why failures are occuring.
Thanks for the question Durward. No evidence on the break down. The crack was detected by the machine shop by magnetic particle inspection. AG
Here of late I have seen multiple flat tappet failures that never occurred before, I am leaning towards oil
By the Way I enjoy your vids
Water or bad parts, either is plausible. I don't see where anyone has suggested that the internals of the lifter might be seized from rust. Hydraulic lifters operate with *sort of* zero lash. If it was truly zero, then there would be no room for oil. In reality, the lifter "relaxes" when the valve is closed, which allows oil between lifter and cam. Try disassembling the lifter. On the other hand, modern car parts are known to be crap.
Thanks for your comment Mike. AG
makes sense to me , how much does a procedure like that cost?
Shop rate and time, plus the stitches. We use the Irontite taper plugs. Drill a hole, run the tapered tap in, a little red loctite and run the plug in tight, trim it off, then drill for the next one, following the crack while at the same time the hole intersects the previous plug, and so on and so on. Taps are thin (under 1/4 inch) and brittle so you take your time. Pretty easy to burn up a couple of hours doing the repair.
I'm sure it's expensive. There was a process outlined in a magazine in the '90's I read how to do it. You can actually do it yourself. You basically drill holes along the crack (one at a time) and tap the hole, screw in a peg or pin with sealer, cut it off, drill another hole in front and tap partially into the pin you just installed, repeating to just past the end of the crack, 'stitching' or pinning the crack. Then grind all the tops flush. You can actually 'stipple' the surface to make it look like it was never touched if it's on the outside. It's a tedious process. Originally used on old boilers and steam locomotives.
I repaired a crack in the original flat head 4cyl engine in my ‘41 Willys pick up with lock-n-stitch my self in 2021 it cost $400 US to get their tooling and the pins. 100 pins was $140 US
@@cabotbroughton7458 That's not too bad. I think depending on the machine shop you're looking at over $1000 to start. Depending how cheap you want to go, you can perform the operation with basic shop tools, (drill bits, stop collar, taps, bolts, hammer and peens or punches). That's all machinists used a hundred years ago to perform a repair.
The forced use of 0 weight oil hasn't helped this problem.
I am a retired journeyman mechanic. I overhauled hundreds of engines. I worked at a Cadillac dealership. You theory may be possible, but I doubt it. Water seeping out of the water jacket into the oil would have caused the oil to reach with it turning it into a grey sludge. This would have become obvious after a short time. What I have seen are dished out valve lifters due to a couple of reasons. Cadillac had this problem in one of their engines causing dishing on the cam lobes and lifter bases. The fix for this was simply changing to another grade of oil. From SE to SF oil (this was in the 1980s). Another thing I have seen was poor or irregular hardening of a lifter base causing premature wear on the cam lobe. What happened to our engine is hard to say without a forensic examination. Guessing or other people's opinions really aren't going to solve your issue.
Thanks for your point of view Dave. AG
Howards can brakes in a 351 c so far so good has about 300 miles on it purs like a kitten
Correct, assuming all else was fine, your theory is correct.
That makes sense to me. If you take away lube and add water instead, something bad is going to happen.
Thanks Kent. AG
My experience comes from the armchair engineering academy soooo.......... I dunno. You're probably correct.
was the head gasket ok? no bent pushrod? not the usual suspects like too long of a bolt bottomed out in the blind hole putting pressure on the block causing the crack? packed up valve spring would be my guess.
Did the coolant level go down. Did you do a oil analysis.. what did engine oil look like..
The engine looks good inside, except for the one cam lobe. Unfortunately, we don't know much about the history. AG
Curious was there any evidence of rust or discoloration in that lifter bore or any other telltale signs the lifter couldn’t snip normally?
Not when I opened it, but time has passed since it was running. AG
I knew it would happen by your start-up, and I'm sure you did not show it all... Here is a tip: when you are ready to finally start your engine for break in, turn your cranck backward to 25 degrees before TDC. Engine will start right up. Go immediately to 2000rpm for 20minutes. No playing around with tune. Use a 40w oil or 20w-50 for breakin oil. Its all about running for 20 minutes at 2000rpm. Oil must pump up pressure within 29 seconds. Damage start at 30 seconds. Change oil after the 20 minutes etc etc. Run again for 30 minuteskeeping rpm up and then play with tune a little, etc etc. Change oil a third time and run again varying rpms from 2000 to 3500 for 20 minutes, then tune timing and carb.... I use Driven breakin oil and run that third oil change in engine for dyno and/or the first 500 miles... There are many great oils out there but I use Driven Breaking oil for first three oil changes and the fourth oil change is Driven Synthetic Blend 20w-50 or 15w-40 with Davis Vizards "oil extreme addative". Adds 8hp on dyno and lubricates so well I have to adjust idle down becuse it speeds up idle when added because it reduces friction so well. - Regards
Tip: buy Comp Cams DLC Coated Lifters.... Make sure you pay the extra for a hardened cam.
NOTE: the crack is another issue. I believe it had nothing to do with your failure... I would have to see and examine engine during tear-down.
@@autonomous_collective
Failure was confined to just one lobe & just one lifter. All others appeared in good shape. This indicates prob wasn't with initial start up or running in proceedure.
Prob was most likely a faulty lifter, a bent or otherwise sticking valve, coil bind or a too long valve guide getting bashed by the spring cap causing the lobe to simply behead itself.
That lifter may have been stuck fully or nearly fully extended because of a tiny piece of foreign junk that eventually dislodged while the engine racked up a zillion miles running on 7 cylinders.
Careful run in is vital, but that doesn't seem to be evidently causal in this case.
Thanks for the info. AG
Could you do some brazing over the crack repair to make sure it's sealed up?
Not necessary. There are UA-cam videos on that process. Pretty impressive system
Parkerizing on cam might jave failed if it is not done right. May not have spelled it correctly. Heat treating also... AG.
I only seen a failed camshaft on You tube .
seen this on 400 pontiacs several times possible sludge broke off and got between lobe and lifter and wore the harden surface off the cam lobe or long idle time not enough oil splash from crankshaft in that area
Thanks for your thoughts Dave. AG
I had a motor eat a cam lobe once it was because the valve wasn't touching the valve seat and it rode on the lobe all the time
Thanks for sharing Michael. Never heard of that before also. AG
I am surprised a corrosion trail wasn't discovered ?
Interesting ! Thanks -
Thanks for watching and commenting. AG
Ido know one thing , it doesn't take much coolant to hydralock a lifter
Correct, thanks Tory. AG
Once cracked. I Ditch em
You don't say how many miles on it.your explanation sounds good.weird place for a crack
The engine definitely had some miles on it but we don't know how many for sure. AG
Pontiac Ford an Chevy v,8 was bad for cam shafts but never seen any Mopar with bad cams but small block Chevy's were bad replaced lot of them
Oil analysis
Good suggestion Jeffrey, AG
If the oil wasn't a milkshake the crack wasn't leaking. I also doubt water or coolant which is much thinner than oil is going to wash away enough oil in the lifter valley to cause that. An easy test would be to pour a quart of oil in the lifter valey and then drip water on the repaired section and see what happens. My money says the water stays on top of the oil and is mixed up upon starting the engine.
Thanks for your thoughts bdd. You might be right. AG
I think you are correct
Thanks Hank. AG
Todays lifters are made in china out of butter I use nothing but roller cams now.
That's one way to fix it. We are going roller on this one. AG
plausible..i l
I had an engine that ate the #6 intake lobe twice on new cams. I put a used cam in it and it survived. That was 1994. The engine went on to race for another 20+ years and is still running. I have no idea why there was an issue with that lobe repeatedly. The engine is affectionately known as Bracket Betty and has several hundred passes on it at the drag strip. She’s fairly potent with runs in 10’s with a full bodied (fiberglass hood) Duster.
Would be interesting to know how that bore spec'd out. Too much clearance, too little or perpendicularity could all be factors. May not have been an issue with a slower ramp profile cam.
What brand(s) was the cams?
@vilefly the first was a Berry Cams and the second was a Crower.
@@The340kingBerry Cams, I have no experience with. Crower was nicknamed "crazy" by myself for the insane lifts. I could only guess that a weak valvespring allowed some oscillation on that particular lobe with a particular amount of duration.
Thanks 340, 10's is quick, enjoy the ride. AG
Thank You Alan, In my 50 years as a mechanic I've never seen this in a Pontiac. The 1971 Chevy 307 I had in a Malibu wore out # 6 exhaust lobe and lifter at 59000. and 100009.0 miles. I have heard of this from others. Probably a casting or machining defect. I know a 307 from the factory was kind of sick, small valves, low compression, 2 barrel. A friend of mine worked in a machine shop and someone never came and picked up their 307 + .030, he called it a 311. 12 1/2 to 1 compression. I used 461X Corvette heads ported, Holley Strip Dominator, 750 Holley off of Jeff Bodines Nascar, Ultradynes largest flat tappet cam. Long main studs with the main caps machined flat with 3/4" straps. People didn't believe it was a 307. It ran 6.90's in the 1/8 mile in a 2900 lb. car consistently with a powerglide and a Dana 60 back in the 90's,, :)
I've built 4 , it's a shame so many 307 blocks were sh.t canned . Number 6 gets the most heat .
Thanks for your comments. AG
Back in the early 60s, My Mother was driving a '51 Mercury 2 door. We stopped at an intersection and the motor was running fine. When she gave it gas to pull away, the engine bucked, snorted and died. When Dad tore it down, the camshaft had broken into 3 pieces. No other damage, a new cam and it was back in service.
That's a great car story. Thanks 74. AG
This lifter issue is becoming one of the greatest mysteries of the past 20 years. Everyone seems to have a theory but nobody knows 100% what is going on.
Many people say "just go roller" but flat tappets still have a place in many low dollar simple rebuilds for nostalgic cars. Would be great to get this issue resolved.
not gonna happen.......everyone has basically thrown their hands into the air. The last OEM flat tappet engine was the jeep 4.0L that was discontinued almost 20 years ago. Aftermarket gets the overflow from OEM production and OEM production has moved on. My personal theory is that since most manufacturing machine shops have gone 100% CNC that they are just hiring low skill "button pushers" to run the machines. Back when a machinist had to turn those knobs and watch that dial indicator he was basically doing QA testing as he went along. Now "oh the cnc just makes the parts.....and we don't need to check it because its always perfect". At work we get parts all the time(not automotive related) that are screwed up by 'world class' machine shops who one makes 6 figure casting molds for a major automaker and another who makes machine guns for the US Military. EVERYONE is phoning it in now.
There is sn answer, but no one want to accept it.
I was in the business 30yrs, but that's just my word.
The finish on the bottom of the lifters is too course - the surface finish is no longer held to the finer micro it once was.
This "attacks" the lobe on startup, and the oil film isn't this enough to protect at the height of the peaks of the courser finish.
I've dusted the bottom of flat tappets for decades, just enough to take down the peaks, and had zero lifter failures.
@Motor-City-Mike Your answer makes perfect sense. I've been a mechanic since the mid-80s, rebuilt over 50 motors without a problem till 2 years ago, wiped out 2 flat tappet cams on initial break-in. Could you please explain your method of dusting the lifter?
@@jeffhesse8415 Hey Jeff, ( just a little comment to trigger a UA-cam notice to me - I'd like to hear this myself) :-)
Geez, IT"S THE LIFTERS. It looks like a 20+ year issue because everybody CONFLATES multiple problems. In the beginning it was the OIL that was the problem and (generally speaking) the lifters were 'OK' after people figured out about the oil, the LIFTERS quality totally went in the tank. ALL the quality lifter MFR's GAVE UP. They don't NEED to focus on them because the OE's haven't used HFT's for over 35+ years and the replacement market is getting ever smaller. The ones that did make good quality HFT lifters just quit. Johnson (not the current Topline) the OTHER Johnson in Taylor, MI made an OUTSTANDING HFT product as recent as 2016/17 (I think) but got out of the HFT biz (which is another story unto itself). Which is a real shame. They were the ONLY modern MFR making a great product . Now there are NONE left. Buy OLD STOCK.
I've changed cams that too had lifter failures like this one. I just feel the materials used for cam/lifters were poor quality. A flat tappet lifter does rotate when operating, and it just rotated to get the failure you see.
I don't know who I am, however it doesn't appear that the lifter quit turning because it is soup bowled. Considering the lifter has an even wear tells me that it was spinning.
You are correct
That's what I was thinking too. You can look at the bad tappet a see if there are scratches up and down the body if it was stationary, not rotating.
Rotating just enough to wear all the way a-round.
I agree, I would inspect every lobe and lifter for proper tapper and I would rockwell test each lobe and lifter because there is a lot of China junk out there with name brand labels.. one other issue, too. I have seen people forgetting to install the cam retainer, and then the cam walks, resulting in the same issue.
Just bad heat treat then?
I bought a 1964 Buick Special with the 225 V6 with a bad cam/lifter looked just like this one. It sounded like a rod-knock. I installed a re-ground cam ($19 in 1976) and lifters and the only other part which was showing any wear... the oil pump. The filter got almost all the grime and I drove that car for several years without another failure. Still don't know what happened, aside from the previous owner didn't change the oil like he should have. After 20k miles, I did take it down to rebuild and didn't see any damage from before.
Thanks for sharing your experience James. AG
My parents both worked skilled trades in Flint, Michigan GM plants. My mother was in the Engine plant on Van Slyke street. I remember her telling me about when induction hardening machine for the camshafts went down. They stoped the line to repair it. Then, supervisors came down and ordered it to run regardless of whether the camshaft were hardened or not. She and the other staff pointed out those cams were going to fail in the field. The managers response was,
“ Run it, we’ll fit them when the cars end up returned to the dealers after they are sold “
That's a great story John. I think these things do happen a lot more than we realize. AG
My friend had an 81 Cutlass from brand new with a (267?) V8 that barely made 25,000 kms before the case hardening on the camshaft and lifters failed and ground off several lobes. Took it to the dealer and they were well aware of the fault, but did nothing to fix it. He wore the cost of the parts and we fixed it.
Sam Story today with China crap
“water isn’t a very good lubricant”😂😂😂😂
It's not unusual for block castings to have cracks in certain areas. Sometimes it's completely benign and doesn't matter. It looks like the first lifter would be impacted as well. The laws of physics dictate that any coolant leakage would run past that 'well' area by the tappet bosses and end up in the crankcase. Liquid will flow to flow down the path of least resistance. A wide open drainback is easier to follow than a one -two thou bore clearance You can tell if it was spinning by looking at the lifter side (linear scoring).
I'm assuming the block was like that before it was torn down the first time. Was there a bad lifter in that location in the past? An oil analysis would tell you for certain if there was coolant in the oil. I would suspect something else.
As far as your hypothesis, maybe it's correct but you'd never be able to prove it now that it's fixed. My opinion is I don't think it was that bad if you needed a Magnaflux to find it. Should have been able to see some traces by eye. Even a UV dye test would tell if it was bad enough to actually leak, Magnaflux just says theres a crack, not whether it's a problem. Magnaflux is expensive because they have to generally suspect where a crack is. Anytime I went to a machine shop they said unless you think or 'know' you have a crack, forget about it. That could have been a freezing crack, though not very likely on the inside, but I think it was there a long time. Maybe just from manufacture. It's in a strange place. Being dished the lifter looks like it was spinning just getting 'eaten'.
I think your diagnosis, is correct. With the coolant being 200 degrees, it would more than likely wash some of the oil film away also, with the possibility of rust, and pitting.
Thanks for the comment James. AG
If I had to guess years ago steel was hardened with anthrocite coal which was the best way to heat treat steel but no more anthrocite coal and now steel is heat treated with propane gas or bituminous coal that no where near gets hot enough that's why you put brake rotors on a car and the next day they have rust on them where rotors made years ago could sit for 6 months or longer and no rust on them!!!!
Thanks for the info Dennis. AG
My guess is the engine froze at some point. I've pushed 700 plus HP and split blocks up thru the mains, but never in that area. I've also broken off lifter bores & use braces in all my builds. If enough water was entering the crankcasevto damage the lifter/cam lobe, you would have seen it in the oil. Flat tapped lifters fail.
Back in 1988 I was working at quality Chevrolet and engines were coming in cracked along the lifter valley they were replacing them right and left they were not seasoning their engine blocks
I put a comp cam kit in a 350 with everything brand new with their cam lube and within a minute of starting the engine it was making a hell of a noise on cylinder 6 exhaust lobe and filled the engine bearings full of metal and destroyed the crankshaft and wiped out all the cam bearings and I turned it into comp and they said it was my fault and wouldn’t refund my 500$ it cost for the kit so I won’t ever buy another damn thing from that sorry ass company again and will tell everyone that same thing to stay away from them.
What does a politician and a flat cam lobe have in common.........campaign
A scrubbed cam lobe and lifter on a newly-built engine is usually attributed to cam break-in lube being applied to the sides of the lifter rather than the bottom only. Engine oil only on the sides of the lifters.
Thanks for the comment Kev. AG
@@goldsgarage8236 You agree with that?
Big John at delta cams knows whats going on with flat tappet lifters.
That's as good a theory as any. As you say, if the lifter is not spinning the cam is dead. I don't know the Pontiac oiling system but on a Ford oiling system that lifter is the last place to get oil so if its similar it may also have something to do with it.
Thanks for commenting. AG
ENGINE BREAK IN..... WHAT DO YOU THINK? Chevy engines have an oil bypass valve in the spin on oil filter adapter. Nobody knows how often this bypass occurs. If you block off this bypass by removing it and installing a quarter inch pipe plug you will now get 100 percent oil filtration. You must use a strong oil filter with a thick canister such as Baldwin. NOW by using this theory when breaking in a flat tappet camshaft engine and something goes wrong any debris will go directly into the oil filter instead of bypassing and causing damage to other PLEASE TELL ME WHAT YOU THINK.
Good question Steve. Under a controlled situation such as a break in, sure, as long as you can keep your eye on the oil pressure.
remember, that most oil filters, except racing oil filters also have an internal bypass.AG
I like Your line of Thinking , effect & probable cause through good visual inspection using magna fluxing equipment and knowledge & experience ! Thank You for the great insight 🇺🇸🇵🇷🦊👍
Thanks for the comment Ferdinand. AG
Its a GM engine,, renowned for wiping cam lobes. I have seen and or done numerous ones in Chevs, Holden V8s, some Holden 6s, and a 327 Pontiac. And it seems these days cam lobes disapear more often in all makes.
Fords have a bigger dia lifter and are less likely to do this. Though I have seen them OEM take a lobe as well.
Thanks for the comment Ldn. AG
I respectfully disagree on this one Mr Gold. I just don't think the coolant would displace the oil between the lifter and lifter bore, or not enough to stop the lifter from rotating anyway. There are countless good vids on multiple potential lifter failure causes. My "opinion" on these failures is in the area of improperly crowned lifters and or lobe taper, and lesser so but possibly poor material. Remember back in the 1980's we slapped cams and lifters in motors with little to no break in with rarely a failure. Now we do all the "by the book" tricks and still see failures. I did an experiment a year ago and broke all the rules. New cam (Comp xtreme energy solid flat), a good used set of EDM lifters, heavy double valve springs and no break in. A year later, couple hundred hours on it and working well. What I did do was checked the crown on each lifter, checked lobe taper, cranked and confirmed rotation of all before and at startup. One caveat, the cam and lifter were manufactured over ten years ago. Although going forward I would be very cautious buying any cam or lifters. I don't know who to trust anymore.
Thanks for your input Bobby. AG
Whatever the cam was that the previous person installed had a failed heat treat, and/or was not ran in correctly. This is also something typical when people run today's motor oils in an 1965 engine. Today's oils are formulated for emissions controlled engines. Thus, they have a lot less zinc in them. Thus, a combination of reduced zinc, poorly broken in camshaft with perhaps a poor heat treat, presto, this was the first lobe that failed. Once the wear is not right between the camshaft and the lifter bottom, the lifter stops spinning around. This only compounds the problem.
I'm not agreeing with your water seepage idea because these engines have so much oil flying around that unless he let sit for a year, the lifter getting stuck from corrosion is pretty unlikely.
Get the camshaft from a quality camshaft company such as Comp Cams, and be sure you break it in properly. Use a good break in oil, and recommend that they use a racing oil since they will have more zinc in them as they are not supposed to be used in a modern street engine with the emissions controls. The Valvoline VR 1 is a great one as well as Redline and Mobil 1 racing oils.
Thanks for your comments Lloyd. AG
Your explanation on magna fluxing is in the wrong order. You have to magnetize the metal before applying the particles. You don't apply the particles first.
Correct, thanks AG
I`ve seen many camshaft failures in my 50 yrs of building engines and most of them are not the parts fault. In the early days on grocery getters it was poor maintenence, in spec stock car motors it was abuse, exssesive spring pressure and interference problems. I had a friend of mine who fancied himself an engine builder pull one of his motors off a dyno and it looked like the cam had 4 fuel pump lobes.... I laughed my butt off.
Good point, thanks Ed. AG
I'm a master engine builder
Great video 👍👍👍
might of said ok agree with you. BUT yep there it is.. why would it miss the ex side. so nope can not agree with this.... i would say... just a bad lifter. some how wasnt harded enough or to soft of mix for it. something with lifter itself.
Thanks for the comment. You make a good point. AG
Don’t believe your theory. I believe the problem is in the lifter. Poor machining of the lifter body… most likely. My opinion.
Thanks Scott, you might be right. AG