I am so glad there are still people like you that believe in quality and treating customers how you would like to be treated. I have tried hiring some people to do some work and they either do not show up or they half ass the work or they charge a fortune. Keep doing what you do!
I may be reading your comment wrong but it sounds like you're expecting top tier work for mediocre prices. Of course the lowest bidder is going to do shoddy work... if they show up at all.
@@aaadamt964It’s more nuanced than that. There are tradesmen who don’t charge top dollar, yet still do quality work. While these folks typically won’t be the LOWEST bidder, they will do a quality job at a reasonable price. The lowest bidder will occasionally be a (misguided) new guy trying to build a business. That guy might also do a good job at a below-market price. The rest of the lowest bidders are usually just hacks looking for a quick buck. They’ll promise the moon and deliver a shiny pile of steaming dog shit.
Well, in either case, aluminum block or Cast iron, the bore grows .002 to .0025. So your oil clearance will increase by .001 to .00125. But since the crank diameter will grow the same amount for a cast iron crank, and even a little more for a steel crank, the net change in oil clearance will be pretty much nil, maybe .0001 up or down. So I don't think you should change your line hone dimensions at all. Just my opinion as a retired engineer and metallurgist. A very interesting experiment, thank you for doing it. It got my brain working.🤔
Thanks for checking this. I've measured several LC9 blocks at 200* and they were .0017-.0018" larger than at 80*. So I make sure main clearance is .0015" at 80* and it makes high oil pressure cold. But when oil and coolant temps are at 200* oil pressure is in the mid 40s at 800rpms and 95-100 at 7500 rpms. I measured a few stock cranks but don't remember their expansion numbers :(
Yes sir Mr.Daniel thank goodness there’s still quality people that do quality work instead of only worrying about quantity. Thanks for all these videos and sharing your knowledge with us.
It's nice that you take the time to make these kinds of educational videos. Also that you don't know in advance what the results of your experiments are going to be.
Makes sense. Aluminum expands more and faster than cast iron. The whole reason we need MLS head gaskets when swapping iron heads for aluminum. Good video to illustrate this. Thanks for bringing attention to it. As always, great and very useful content man.
well theres also the steel maincap on aluminum block so differnt expansion rates to consider and then there how much thicked to the bearings get when they heat up soo many factors to think of with engines alot of people dont even know about
That is a very interesting and surprising result. I re-torqued cylinder head bolts cold, then set valve lash. Cold being room temp and one head bolt at a time. This 4 cylinder import was alum. on cast iron and never had a customer loose a head gasket. They also didn’t have torque to yield bolts either. 300k miles was not uncommon for life. Very interesting! Thanks.
Thanks for taking the time to give us this great info. Would be interesting to see how much the lifter bores expand also. Looking forward to seeing how much the crankshaft expands 👍
Interesting on aluminum expansion, remind me of my air compressor with aluminum rods I had to hone the rod a little bit bigger because when it heated up it would end up with not enough clearance.
I would never think that a roughly 100 degree temperature change would make it grow that much. I figured at most it would grow 0.0005". Thanks for doing this.
This temperature expansion is actually a major issue in the manufacturing of cams. Even just from room temperature on a normal day to a hot day (~70-115) can add a few tenths on the journal size on a larger cam. So after grind you'd have to wait for the part to normalize to QA area. Did a big project at a company that made cams for the OEMs and we had to add a temperature scale at the automated gauging to prevent making u/s parts in hot days after they cooled down. Good stuff man!
Nice demo. I think many of us could have made an educated call on some increase happening but not able to put number to it. I expected a bigger difference between the cast iron and aluminum blocks, but either way, with a bore size having a range of 8 tenths or so it would be easy to go out of spec on a warm engine. It would be nice to see if the crankshaft journal expansion would take up the extra space, as well as how much variation in expansion there is block to block. Thanks.
As a retired Mechanical Engineer and car nut, I would expect the crankshaft will grow at about the same rate being steel. Steel vs Aluminum block will be interesting, A 1/2 a thou is a half a thou. Good science, great content, love the chicken.
I scuffed a rear main on a 400 SBC dirt late model engine, so after that I started running .0035 to .004” at position 5, thrust and bearing always looked good on future builds. That was a gas engine running about 220-230 oil temp.
that was really cool...!..dont remember see'n/or hear'n from anyone who has ever done that..!..i now know why VW pined there main berrings in the the bugs..!..there were alumium cases..!..screw'd around with them since i was 6 yo..!..thanks Daniel...great topic...!..learn something new...every day...!
@@timothybayliss6680 not all of them were magnesium...& i was try'n to keep the reply "generalized"...!..the break down of the "metals" in the "original" vw cases...has yet to be dupelacated by any aftermarket manufacture...to date...!...dont belive me...read Gean Berg's tech artical on type one cases..."if" u r a big vw expert..?..u should know who he was...!...i was just try'n to keep the reply generalized & simple....& also....the majority of the mteal in the type one case.....is "aluminum"...!...with the exception of the few years that were "magnesium"...!...& if u want to be so perfict...they werent "ALL" magnesium...the germans had metal experts design the formula of "metals" in the vw case...!..like i said...listen to Gean Berg...!..he knew better than "both" of us...!..!..& he had the tests done to "prove" it..!..
Aluminum ls 800 hp sprint car motor. .0017 clearance. Its 80 psi at 1000 rpm cold and 40 when hot. Always worried something was wrong. Thanks for doing this test. Makes me feel better
I have been keeping an aluminum Ford Can-Am 498 running for a while. When I opened it I could see the center main was just grabbing the crankshaft. The indicator measured .0005 runout on the journal which I see as normal for these heavy crankshafts. I knew it should be opened however I had no time. It had been running so I did what I could by adding .002 shim between the block and cap. Now I know that's not the right way to do it but we've got to go and the next time it's down we'll look at it. Besides I did gain clearance. After the racing, we looked it over and it was still trying to grab the crankshaft. The crankshaft still had .0005 runout at the center. Like you, I measured the mains cold and hot from the tank. Same .002" growth. -- I told the crew to preheat the engine before starting figuring that could do it. The next time in, still the same. The cold clearance was .0025/7. The center bearing was still didn't look that great so the crank was ground 11 under and 12 on the center main. I really didn't care what clearance it was, I was looking at what it was telling me. It's running fine and yet to come back. -- I fought the piston clearance as well as they were sticking when it came in. Two sets later and were at .0095". I know, but again. Everyone before me has been wrong with this piece. I'm just listening to what it's telling me.
I worked in a machine shop that repaired and ground mill rolls. I couldn't believe how much the size would change with temperature on some of the rolls. Also when doing a new bearing journal how much we could get the roll to grow with heat to shrink fit the journal.
Great videos!! You can calculate the change in dimensions for Aluminum and Cast Iron/Steel. Cast iron/steel will grow .000006" per degree F. Aluminum will grow .000012" per degree F. This is very handy when you are assembling Press fits. You can easily calculate how much to heat or cool parts to create slip fits and make assembly a breeze. I didn't pull this out of thin air.....it comes straight out of the AERA Machinist's text book.
I run my spray wash at 90c. I've measured blocks and cranks after. I've seen bores grow 2thou. Cranks grow thou to thou and a half. Alloy blocks with alloy main caps main tunnel grow 3thou
If the crank grows (diameter wise) just like the block bore diameter does, then the clearances hypothetically will somewhat stay the same. I've never washed the crank and block to see how much they grow separately with heat in them! Enjoy your videos very much! thanks
Just a question, but isnt the international standard for machine shops that they should be at 68 degrees f ambient temperature for measurements, not "normalized to the outside" temperature..?
The coefficient of thermal expansion for grey cast iron is about half that of aluminum. With that being said on the aluminum block half of the bore should grow twice as much as the iron block resulting in about 25% more overall growth. His experiment results make sense.
Not surprising at all and thank you for this. Different materials have different expansion/contraction rates. Not only to be considered for block clearances but also when determining valve lash and other tolerances. Cold and hot lash can vary greatly. For example, a ZL-1 all-aluminum Rat-motor valve lash should be different than that of an all cast-iron engine or one of a cast- iron block with aluminum heads given the exact same mechanical cam. I'm generally a Ford guy and have always taken this into consideration when building and tuning engines. Factory-installed Ford Boss 429 cast iron blocks topped by dry-deck aluminum heads have different valve lash specs than a 429 SCJ all-cast iron wedge engine using the exact same mechanical camshaft. Measure twice under different conditions.
First of your a wealth of info and lately iv'e been binge watching your video's. I got to ask though, do you lift weights or are you huge from lifting iron blocks .all day!! and farming work?
@@powellmachineinc Its sure working, your forearms are huge too!! You look wicked tall so 316lbs wasn't all that bad.. Anyways keep up the great videos...
Really surprised the aluminum block grew that much. Will be interesting to see how much a crank grows. If it grows anywhere that much, then the block growth is a non issue.
Very interesting. They both grew. Now, how do you account when building a cold aluminum block yet allow for hot clearance and not be so tight the crank won’t turn until hot?
Very few good things about a iron block.. To me the best is they can take alot more heat... Ran a iron block at 280 degrees for 10 laps an never hurt it ( big race running 2nd )... Motor ran the rest of the season with 7 wins... Can never do that with aluminum...
Pulled in at 270° many times and even pitted next to a guy that pulled in at over 270 and he had his guys pull the engine. The next week I asked him what he did with it. He put it back in. iron block 360 sprint cars.
That was an aspect that I never considered. So here's another question. My coolant temp runs 180, my oil temp is 215. How much will that change things? I'm not really looking for an answer, just something to think about.
Glad I made my clearance on the tighter side,with an iron block lol,,So I wonder with alum blocks,the cam tunnel would also grow,losing some oil pressure to the mains,unless it's a priority mains block,,Great work Daniel
When doing this little demonstration of thermo-expansion, don't forget that the shaft running inside that housing is expanding also.... Aluminum expands 13.1/5.8 times as far as cast iron (2.25 x)...so don't be surprised if your Alum, Twin turbo, 4 cyl, has a short life when pressed hard...
As a fellow machinist of 20 years my next question would be what alloy is the aluminum block made from? I assume it would have been heat treated when initially manufactured. On a side note. Is it safe to assume that bearing clearances as defined by say a factory service manual are measured when cold, because the engineers have factored in the thermal expansion when designed? So if a manual calls for say .002" clearance on the mains after machining, then when at operating temp the main bearing clearances are ACTUALLY more like .004" when in use and up to temp?
I’d expect the crank to grow about the same as the cast block if you are doing a cast crank. Be interesting to see a cast crank and a forged crank. Put them in the washer together so everyone knows they got the same heat soak.
There is a thing that can happen with aluminum blocks with a solid camshaft. If you lash them hot they can scorch the valves when you start them up, the blocks shrink more than anything, including the pushrods, and it ends up hanging the valves. A cast crank should be almost the same expansion rate as the cast block, a steel crank should be a little more. An iron block with a steel crank might actually have tighter clearances when hot.
Aluminum has a fairly high thernal expansion coefficient of around .000013 / inch / deg. If you think the bore grew more than you thought, imagine the legth of the block itself how much that also grew.
interesting, I fitted alloy heads to a Ford sb and solid lifter cam, instructions only directed me to the cam card for the valve clearance, .22 thou, noisy so I reduced the clearance to .18 which sounded about right, most European pushrod engines use solid lifters which is what I’m used to, no science in this just a guesstimate I’m afraid read that alloy expands at a far greater rate than steel, up to (5 times) and was expecting your findings to show a greater difference but the alloy block likely has steel liners, don’t know but always learn something watching your work 👍
G'day Dan . Iron expandes .008 per foot when molten Aluminium. 014 . On my fifth machine shop, one court case and one pending . When are you moving Down Under ? Kit
Fascinating test, i always wondered about the aluminum block vs the iron block metal growth factor, you answered that question.. since the main caps are steel and the block is aluminum in your test i have always wanted to know what the cam bore does under hot temperatures since it is a solid aluminum bore vs a iron block cam bore.. and a crankshaft temperature test would be very interesting as well, i suspect that an iron block with an iron crankshaft that the clearance will not really be different under most temperatures cold/ hot , i would suspect that the clearance from an aluminum bearing would grow and take up a very small amount of clearance.. thanks for the comparison.. another fascinating bore dia. Vs hot temperatures test would be an aluminum cam bearing installed in an aluminum block vs an aluminum cam bearing in an iron block?? That would really be quiet the test.. your story video was quite inspirational, much respect to you and your wife 🪽
@@powellmachineinc WOW, thats going to be awesome .. stumbled across your videos by accident and have been impressed with the level of expertise and the striving for quality and innovation.. I have learned much from you, im working on my ls2 swap and needed help thank you very much for the educational videos .. Peace
That's something that I never considered. I have a question. I have a rig with a Chrysler Magnum V8 in it, and I want to rebuild the engine. It will be a mild, low rpm torque engine for a truck. It will not be driven often, but when it is, it will get a workout as a snow plow truck. So lots of cold weather starts (below 0° F). Given that information, should I set the clearance a bit loose due to dry starts and then getting hot because the plow blocks airflow, but the back and forth of plowing really heats things up? The truck sits too far away from the main house to plug in a block heater.
The question is, do you size Main tunnel Under the minimum size, .0005"or .001" under minimum, but how much can you go before it affects the bearing shell when fitted... But also best if you want .003" hot, you start with .0015" cold, then you a smidge over what you were chasing....
My shop is at my house. Don't know how many times one of the cats spoked me coming up and rubbing on my leg. My kids also like to walk up as quiet as they can when I'm under the lift and man, those lift arms don't move when you hit them with your head, lol. If the tolerance changes, does that justify running a different weight oil? I'm trying to decide what weight oil is best for different applications. I wonder what lubrication changes happen when taking an oem block past it's oem specs. If an oem iron block has alum heads, does the cams/valves change geometry and hurt the performance when hot? If an iron block and alum heads changes specs at different rates, how are you supposed to know what you need to do for the best build? I'm sure I'm over thinking it and it prob doesn't matter much on a low hp build. If you had a 10k hp engine, it prob does make a difference enough to build accordingly.
5 місяців тому+1
Yearsago I used to do a good deal of aluminum pipe welding forthe aerospace industry and we had to be very careful of the amount of heat expansion the aluminum pipe would grow. A 3 diameter pipe 100 foot long would grow 11" in 100 feet after a heat cycle f the system it serviced .
OT question : in an older video, I believe you were driving some valve guides into or out of a head and it looked like you were using some sort of hammer drill. Can you tell me exactly what that was ? I've googled all kinds of terms but can't find it.
I have read from variuos sorces that aluminum 283 s used in sscorvette in late 50s or early 60s had to be so tight cold they would barely crank so they waould oil pressure when hot. metallugacy has improved a lot. excuse my spelling
6:36 Aluminum rods have dowels for this reason...correct? Don't you have to drill bearing to match steel dowel in aluminum rod. Have you ever seen a spun main bearing in aluminum block?
You have great vids, I love when speak about the CNC work. The BEST vid was when you fired ebay and the USPS. Right now I have package that is riding around the state, pitiful....
Coefficient of thermal expansion..........a person who is really good with numbers could figure that out for both materials, also the crank, and the clearances. That person hasn't been me for a while now.
Looking forward to seeing how much the crank grows, interesting to see if the actual clearance changes much. Thanks for sharing the info
You bet
I am so glad there are still people like you that believe in quality and treating customers how you would like to be treated. I have tried hiring some people to do some work and they either do not show up or they half ass the work or they charge a fortune. Keep doing what you do!
Tyvm
I may be reading your comment wrong but it sounds like you're expecting top tier work for mediocre prices. Of course the lowest bidder is going to do shoddy work... if they show up at all.
@@aaadamt964It’s more nuanced than that. There are tradesmen who don’t charge top dollar, yet still do quality work. While these folks typically won’t be the LOWEST bidder, they will do a quality job at a reasonable price. The lowest bidder will occasionally be a (misguided) new guy trying to build a business. That guy might also do a good job at a below-market price. The rest of the lowest bidders are usually just hacks looking for a quick buck. They’ll promise the moon and deliver a shiny pile of steaming dog shit.
@@alantrimble2881 below market value. Lol
@@alantrimble2881 so I did read that right.
This is the 1st time I've seen anyone actually measure and show the results of this, and I'm surprised as well! 🤯 well done! 👌🏻
Ty
Well, in either case, aluminum block or Cast iron, the bore grows .002 to .0025. So your oil clearance will increase by .001 to .00125. But since the crank diameter will grow the same amount for a cast iron crank, and even a little more for a steel crank, the net change in oil clearance will be pretty much nil, maybe .0001 up or down. So I don't think you should change your line hone dimensions at all. Just my opinion as a retired engineer and metallurgist.
A very interesting experiment, thank you for doing it. It got my brain working.🤔
the linear thermal expansion rates are not the same per degree.
Thanks for checking this.
I've measured several LC9 blocks at 200* and they were .0017-.0018" larger than at 80*.
So I make sure main clearance is .0015" at 80* and it makes high oil pressure cold.
But when oil and coolant temps are at 200* oil pressure is in the mid 40s at 800rpms and 95-100 at 7500 rpms.
I measured a few stock cranks but don't remember their expansion numbers :(
Ive heard of free-range chickens before but a engine machine shop free-range is on another level lol,love your videos
Lol, thank you
Yes sir Mr.Daniel thank goodness there’s still quality people that do quality work instead of only worrying about quantity. Thanks for all these videos and sharing your knowledge with us.
Tyvm, we really try hard to do the best job we can!
Bearing clearance and chicken chasing. Love it.
Always!
It's nice that you take the time to make these kinds of educational videos. Also that you don't know in advance what the results of your experiments are going to be.
Absolutely, we are glad to do it!
Makes sense. Aluminum expands more and faster than cast iron. The whole reason we need MLS head gaskets when swapping iron heads for aluminum. Good video to illustrate this. Thanks for bringing attention to it. As always, great and very useful content man.
Right on
You know Daniel, there is a formula to calculate the growth of each one, right?
well theres also the steel maincap on aluminum block so differnt expansion rates to consider and then there how much thicked to the bearings get when they heat up
soo many factors to think of with engines alot of people dont even know about
Definitely
That is a very interesting and surprising result. I re-torqued cylinder head bolts cold, then set valve lash. Cold being room temp and one head bolt at a time. This 4 cylinder import was alum. on cast iron and never had a customer loose a head gasket. They also didn’t have torque to yield bolts either. 300k miles was not uncommon for life.
Very interesting! Thanks.
Very welcome 🙏
@@powellmachineinc To give a thinking man a new thought, is the best gift he can receive!
Thank you kindly Sir.
Very much appreciate this channel.
Our pleasure!
very interesting. i will be looking forward to see how much the crank grows. great video as always
Thank you!
Thanks for taking the time to give us this great info. Would be interesting to see how much the lifter bores expand also.
Looking forward to seeing how much the crankshaft expands 👍
Good info. Thanks for taking us along for the ride!
You bet!
Respect for doing these experiments so that you know, first hand, what the facts are.
Definitely! Ty
This is stuff we all need to know. Thanks Brother.
TY!
Yes it was interesting, one of those things I never got around to doing, I was surprised aluminum grew that much. Thanks to you now I know.
Thanks again I thought it would increase clearance just how much I didn't know Thanks
Interesting on aluminum expansion, remind me of my air compressor with aluminum rods I had to hone the rod a little bit bigger because when it heated up it would end up with not enough clearance.
Thanks. Love this type of content
More to come!
I would never think that a roughly 100 degree temperature change would make it grow that much. I figured at most it would grow 0.0005". Thanks for doing this.
Thanks for watching
Only 5 tenths? Lol.
@@ShortArmOfGod What's funny about that?
Thernal expansion coefficient of aluminum is about .000013/inch/deg. Its actually one of the more aggressive materials for temperature changes.
Love these clips, very informative. Oh, i like the new employee.
Glad you like them!
This temperature expansion is actually a major issue in the manufacturing of cams. Even just from room temperature on a normal day to a hot day (~70-115) can add a few tenths on the journal size on a larger cam. So after grind you'd have to wait for the part to normalize to QA area.
Did a big project at a company that made cams for the OEMs and we had to add a temperature scale at the automated gauging to prevent making u/s parts in hot days after they cooled down.
Good stuff man!
As soon as I saw the results of the aluminum block, I was asking myself how much the crank would expand... Great question producing video.
Thank you!
In the past I’ve seen value lashes grow.004 on aluminum and.002 on cast iron heads at the Dyno from cold setting to warm average.
Nice demo. I think many of us could have made an educated call on some increase happening but not able to put number to it. I expected a bigger difference between the cast iron and aluminum blocks, but either way, with a bore size having a range of 8 tenths or so it would be easy to go out of spec on a warm engine. It would be nice to see if the crankshaft journal expansion would take up the extra space, as well as how much variation in expansion there is block to block. Thanks.
Appreciate the detail and tech tip. Thankyou.
Glad it was helpful!
As a retired Mechanical Engineer and car nut, I would expect the crankshaft will grow at about the same rate being steel. Steel vs Aluminum block will be interesting, A 1/2 a thou is a half a thou. Good science, great content, love the chicken.
Thank you sir!
I scuffed a rear main on a 400 SBC dirt late model engine, so after that I started running .0035 to .004” at position 5, thrust and bearing always looked good on future builds. That was a gas engine running about 220-230 oil temp.
that was really cool...!..dont remember see'n/or hear'n from anyone who has ever done that..!..i now know why VW pined there main berrings in the the bugs..!..there were alumium cases..!..screw'd around with them since i was 6 yo..!..thanks Daniel...great topic...!..learn something new...every day...!
Right on
Vw cases arent Aluminum, theyre magnesium. The type4 cases are Al but the basically every type 1 case made by VW is Mg
@@timothybayliss6680 not all of them were magnesium...& i was try'n to keep the reply "generalized"...!..the break down of the "metals" in the "original" vw cases...has yet to be dupelacated by any aftermarket manufacture...to date...!...dont belive me...read Gean Berg's tech artical on type one cases..."if" u r a big vw expert..?..u should know who he was...!...i was just try'n to keep the reply generalized & simple....& also....the majority of the mteal in the type one case.....is "aluminum"...!...with the exception of the few years that were "magnesium"...!...& if u want to be so perfict...they werent "ALL" magnesium...the germans had metal experts design the formula of "metals" in the vw case...!..like i said...listen to Gean Berg...!..he knew better than "both" of us...!..!..& he had the tests done to "prove" it..!..
Aluminum ls 800 hp sprint car motor. .0017 clearance. Its 80 psi at 1000 rpm cold and 40 when hot. Always worried something was wrong. Thanks for doing this test. Makes me feel better
No problem!
I nearly pissed myself over the chicken bit. Fuking awesome
LOL! We like to keep it professional around here u know 😆
Lol
I have been keeping an aluminum Ford Can-Am 498 running for a while. When I opened it I could see the center main was just grabbing the crankshaft. The indicator measured .0005 runout on the journal which I see as normal for these heavy crankshafts. I knew it should be opened however I had no time. It had been running so I did what I could by adding .002 shim between the block and cap. Now I know that's not the right way to do it but we've got to go and the next time it's down we'll look at it. Besides I did gain clearance.
After the racing, we looked it over and it was still trying to grab the crankshaft. The crankshaft still had .0005 runout at the center.
Like you, I measured the mains cold and hot from the tank. Same .002" growth. -- I told the crew to preheat the engine before starting figuring that could do it.
The next time in, still the same. The cold clearance was .0025/7. The center bearing was still didn't look that great so the crank was ground 11 under and 12 on the center main. I really didn't care what clearance it was, I was looking at what it was telling me.
It's running fine and yet to come back. -- I fought the piston clearance as well as they were sticking when it came in. Two sets later and were at .0095". I know, but again. Everyone before me has been wrong with this piece. I'm just listening to what it's telling me.
I worked in a machine shop that repaired and ground mill rolls. I couldn't believe how much the size would change with temperature on some of the rolls. Also when doing a new bearing journal how much we could get the roll to grow with heat to shrink fit the journal.
will be interesting to see how much journal gets out of round on alu block with steel caps.
Very cool set up!
I'd like to see the crank shaft numbers
Great videos!! You can calculate the change in dimensions for Aluminum and Cast Iron/Steel. Cast iron/steel will grow .000006" per degree F. Aluminum will grow .000012" per degree F. This is very handy when you are assembling Press fits. You can easily calculate how much to heat or cool parts to create slip fits and make assembly a breeze. I didn't pull this out of thin air.....it comes straight out of the AERA Machinist's text book.
@@turbodave231 Tycm!! but it's always good to test and verify,
Different oils fertilize different metals differently. You have to feed it the right mix if you want it to grow
I always wondered about this, very educational. Tnx sir.
💯
I run my spray wash at 90c.
I've measured blocks and cranks after.
I've seen bores grow 2thou.
Cranks grow thou to thou and a half.
Alloy blocks with alloy main caps main tunnel grow 3thou
If the crank grows (diameter wise) just like the block bore diameter does, then the clearances hypothetically will somewhat stay the same. I've never washed the crank and block to see how much they grow separately with heat in them! Enjoy your videos very much! thanks
Ye!
Very, interesting! Have, wandered about this before.
Glad it was helpful!
Just a question, but isnt the international standard for machine shops that they should be at 68 degrees f ambient temperature for measurements, not "normalized to the outside" temperature..?
You are confusing a specific measurement to a comparison measurement
The coefficient of thermal expansion for grey cast iron is about half that of aluminum. With that being said on the aluminum block half of the bore should grow twice as much as the iron block resulting in about 25% more overall growth. His experiment results make sense.
I thought that was interesting. Thanks for the post !
Yw
I am interested to see the effect on the crank (forged and cast?)
Coming soon
Not surprising at all and thank you for this. Different materials have different expansion/contraction rates. Not only to be considered for block clearances but also when determining valve lash and other tolerances. Cold and hot lash can vary greatly. For example, a ZL-1 all-aluminum Rat-motor valve lash should be different than that of an all cast-iron engine or one of a cast- iron block with aluminum heads given the exact same mechanical cam. I'm generally a Ford guy and have always taken this into consideration when building and tuning engines. Factory-installed Ford Boss 429 cast iron blocks topped by dry-deck aluminum heads have different valve lash specs than a 429 SCJ all-cast iron wedge engine using the exact same mechanical camshaft. Measure twice under different conditions.
💯, yw
First of your a wealth of info and lately iv'e been binge watching your video's.
I got to ask though, do you lift weights or are you huge from lifting iron blocks .all day!! and farming work?
I go to the gym 6 days a week, I use to be be 316lbs......
@@powellmachineinc Its sure working, your forearms are huge too!!
You look wicked tall so 316lbs wasn't all that bad..
Anyways keep up the great videos...
@@petereconomakis149 ty so much! I really appreciate that 🙏
Really surprised the aluminum block grew that much. Will be interesting to see how much a crank grows. If it grows anywhere that much, then the block growth is a non issue.
Definitely
great stuff ,,,thanks
Glad you enjoyed it
That’s good information I never knew about this.
Ty
Excellent video
Very interesting. They both grew. Now, how do you account when building a cold aluminum block yet allow for hot clearance and not be so tight the crank won’t turn until hot?
Very few good things about a iron block.. To me the best is they can take alot more heat... Ran a iron block at 280 degrees for 10 laps an never hurt it ( big race running 2nd )... Motor ran the rest of the season with 7 wins... Can never do that with aluminum...
Pulled in at 270° many times and even pitted next to a guy that pulled in at over 270 and he had his guys pull the engine. The next week I asked him what he did with it. He put it back in. iron block 360 sprint cars.
That was an aspect that I never considered. So here's another question. My coolant temp runs 180, my oil temp is 215. How much will that change things? I'm not really looking for an answer, just something to think about.
Absolutely
Glad I made my clearance on the tighter side,with an iron block lol,,So I wonder with alum blocks,the cam tunnel would also grow,losing some oil pressure to the mains,unless it's a priority mains block,,Great work Daniel
Good one.
Thanks for the video.
You're welcome
Not gonna lie that hen through me off for a second.
LOL! Us too!!
When doing this little demonstration of thermo-expansion, don't forget that the shaft running inside that housing is expanding also.... Aluminum expands 13.1/5.8 times as far as cast iron (2.25 x)...so don't be surprised if your Alum, Twin turbo, 4 cyl, has a short life when pressed hard...
As a fellow machinist of 20 years my next question would be what alloy is the aluminum block made from? I assume it would have been heat treated when initially manufactured.
On a side note. Is it safe to assume that bearing clearances as defined by say a factory service manual are measured when cold, because the engineers have factored in the thermal expansion when designed? So if a manual calls for say .002" clearance on the mains after machining, then when at operating temp the main bearing clearances are ACTUALLY more like .004" when in use and up to temp?
Nice work, Wonder if a Chromoly Crank Grows more than a Cast Crank
Can't find your other youtube channel "Powell cams" that you mentioned ??
I’d expect the crank to grow about the same as the cast block if you are doing a cast crank. Be interesting to see a cast crank and a forged crank. Put them in the washer together so everyone knows they got the same heat soak.
There is a thing that can happen with aluminum blocks with a solid camshaft. If you lash them hot they can scorch the valves when you start them up, the blocks shrink more than anything, including the pushrods, and it ends up hanging the valves.
A cast crank should be almost the same expansion rate as the cast block, a steel crank should be a little more. An iron block with a steel crank might actually have tighter clearances when hot.
This why solid cams have lash
Aluminum has a fairly high thernal expansion coefficient of around .000013 / inch / deg.
If you think the bore grew more than you thought, imagine the legth of the block itself how much that also grew.
Great info brother
Thanks for watching
Freaking awesome chicken in the shop love it.
LOL!
interesting, I fitted alloy heads to a Ford sb and solid lifter cam, instructions only directed me to the cam card for the valve clearance, .22 thou, noisy so I reduced the clearance to .18 which sounded about right, most European pushrod engines use solid lifters which is what I’m used to, no science in this just a guesstimate I’m afraid read that alloy expands at a far greater rate than steel, up to (5 times) and was expecting your findings to show a greater difference but the alloy block likely has steel liners, don’t know but always learn something watching your work 👍
I understand expansion and contraction with temperatures, I was trying to get a laugh 😂
G'day Dan . Iron expandes .008 per foot when molten Aluminium. 014 . On my fifth machine shop, one court case and one pending . When are you moving Down Under ?
Kit
I'd like to visit for sure
Fascinating test, i always wondered about the aluminum block vs the iron block metal growth factor, you answered that question.. since the main caps are steel and the block is aluminum in your test i have always wanted to know what the cam bore does under hot temperatures since it is a solid aluminum bore vs a iron block cam bore.. and a crankshaft temperature test would be very interesting as well, i suspect that an iron block with an iron crankshaft that the clearance will not really be different under most temperatures cold/ hot , i would suspect that the clearance from an aluminum bearing would grow and take up a very small amount of clearance.. thanks for the comparison.. another fascinating bore dia. Vs hot temperatures test would be an aluminum cam bearing installed in an aluminum block vs an aluminum cam bearing in an iron block?? That would really be quiet the test.. your story video was quite inspirational, much respect to you and your wife 🪽
Tyvm, we really appreciate that!, I will do a cam bore test
@@powellmachineinc WOW, thats going to be awesome .. stumbled across your videos by accident and have been impressed with the level of expertise and the striving for quality and innovation.. I have learned much from you, im working on my ls2 swap and needed help thank you very much for the educational videos .. Peace
That's something that I never considered. I have a question. I have a rig with a Chrysler Magnum V8 in it, and I want to rebuild the engine. It will be a mild, low rpm torque engine for a truck. It will not be driven often, but when it is, it will get a workout as a snow plow truck. So lots of cold weather starts (below 0° F). Given that information, should I set the clearance a bit loose due to dry starts and then getting hot because the plow blocks airflow, but the back and forth of plowing really heats things up? The truck sits too far away from the main house to plug in a block heater.
Std clearance, light oil and a block heater for sure
@@powellmachineinc . . okie doke, I appreciate it.
Awesome vid!
Glad you enjoyed it
The question is, do you size Main tunnel Under the minimum size, .0005"or .001" under minimum, but how much can you go before it affects the bearing shell when fitted... But also best if you want .003" hot, you start with .0015" cold, then you a smidge over what you were chasing....
Thx again
No problem
Just wondering if anyone installs torque plates then warms up the block and plates together before final hone?
Yes, "hot honing " is a thing
My shop is at my house. Don't know how many times one of the cats spoked me coming up and rubbing on my leg. My kids also like to walk up as quiet as they can when I'm under the lift and man, those lift arms don't move when you hit them with your head, lol.
If the tolerance changes, does that justify running a different weight oil? I'm trying to decide what weight oil is best for different applications. I wonder what lubrication changes happen when taking an oem block past it's oem specs.
If an oem iron block has alum heads, does the cams/valves change geometry and hurt the performance when hot? If an iron block and alum heads changes specs at different rates, how are you supposed to know what you need to do for the best build?
I'm sure I'm over thinking it and it prob doesn't matter much on a low hp build. If you had a 10k hp engine, it prob does make a difference enough to build accordingly.
Yearsago I used to do a good deal of aluminum pipe welding forthe aerospace industry and we had to be very careful of the amount of heat expansion the aluminum pipe would grow. A 3 diameter pipe 100 foot long would grow 11" in 100 feet after a heat cycle f the system it serviced .
How much do the bores grow, affecting the ring end gap?
Mike
Very interesting.
Very!
Aluminum connecting rods grow substantially. Aluminum cylinder heads swell much more, requiring MLS gaskets. Add heat, and it opens up even more.
Awesome video. I have been told to run the aluminum blocks .001 tighter cold than iron. Guess there was some truth to that.
OT question : in an older video, I believe you were driving some valve guides into or out of a head and it looked like you were using some sort of hammer drill. Can you tell me exactly what that was ? I've googled all kinds of terms but can't find it.
It's a valve guid driver for a air hammer
@@powellmachineinc Thank you.
Good info
Glad you think so!
I have read from variuos sorces that aluminum 283 s used in sscorvette in late 50s or early 60s had to be so tight cold they would barely crank so they waould oil pressure when hot. metallugacy has improved a lot. excuse my spelling
Are the specs for bearing clearance between the two blocks any different?
No
Awesome!
Glad you think so!
Dude, whatre your favorite tricep exercises..?
Standing overhead cable extensions it's the best for thickness
waiting for the crank test...
Coming soon!
How does the heat effect the bearing when you put it in?
Is the Powell Cams channel separate from this channel.o can't find it on UA-cam
youtube.com/@powellcams?si=ZJvzkQ__NXQveTQd
6:36 Aluminum rods have dowels for this reason...correct? Don't you have to drill bearing to match steel dowel in aluminum rod.
Have you ever seen a spun main bearing in aluminum block?
Yes amd yes
So we are going to put the block in the washer "oh look a chicken"
The crank will grow some as well. I so clearance might not be .004. just observing not telling you your business. I enjoy your videos
Definitely gonna find out
He covered that in the video.
You have great vids, I love when speak about the CNC work. The BEST vid was when you fired ebay and the USPS. Right now I have package that is riding around the state, pitiful....
Ty! We try hard
Coefficient of thermal expansion..........a person who is really good with numbers could figure that out for both materials, also the crank, and the clearances. That person hasn't been me for a while now.
Wondering what that does to bearing crush?