You are amazing! Fantastic presenter, entertainer and teacher! Your passion and personality work well with your diligent research and the extra effort you put into your editing. Thank you! :)
The problem with the varying ways in which cam duration is advertised has long been known. The best way to compare camshafts is with a graph which shows lift VS degrees so you can see everything at a glance, especially how quickly the cam profile opens and closes the valve which can greatly affect valve spring selection and wear on the valve train. If a manufacturer refuses to provide a graph, I won't buy their camshaft.
yea the profile is very important too. in germany we say a camshaft is "Scharf" if its not so pointy like stock but has a steep ramp and flat top which increases airflow because of more time open at nearly full lift
AusPhil Adventures from your name I assume your Australian, if so the duration is similar to the solid cam in the falcon GTHO, not so tame, keep in mind the rocker arm ratio in these types of engines makes things different to the OHC engines, you can’t transfer the duration numbers over between them.
This video got my Sub. Great job. I hope you can make a video about different types of cams (na, supercharger, turbo, nitrous), cam degreeing, cam break in, cam tuning. There is so much to talk about with cams.
True, you could write a book, probably two or three books actually. There will definitely be more content on cams. Thanks for watching and for your support
I have a 4age smallport on a corolla ae100. Its sitting for 3 years outside. i tried starting it last week and to my surprise it did start. All your videos are very helpful to me so keep em coming. Im planning on carbureting it. Shoutout from your new subscriber here in the philippines! Stay safe
Important note for those curious about advertised duration vs duration at .050"/1.00mm lift and why both exist: Duration at .050"/1.00mm is a relatively reliable method of measuring camshaft duration for a *hydraulic* lifter style setup (the lifter/bucket/finger follower has some sort of fluid plunger that utilizes pressurized engine oil to make up for valve-train lash/gaps. The reason for this is that on average, there's about .050"/1.00mm of 'squish' or compression of the lifter (not the hydraulic fluid) that occurs before the lifter starts following the profile of the cam lobe. Hydraulic lifters tend to be a piston and cylinder with a spring inside, where the pressurized oil from the oil pump feeds into the chamber above the piston, and then the piston pushes some of the oil out as the forces from both the cam lobe and the valve-spring push against each other. The lifter pushes out a certain amount of excess oil before effectively becoming solid, at which point it follows the cam profile throughout it's duration. Advertised duration is important for engines with a *solid* lifter setup (think NB VVT miata engines for example) which use either shims in OHC setups or poly-locks in OHV style engines. Since the lifter is completely solid, and therefore doesn't have any squish or compression, it's going to follow the ENTIRE cam lobe profile, not just a certain portion. The final point to make about this is that even with a solid lifter setup, the reason why there's still a duration at .050"/1.00mm is that the amount of airflow occurring past the valve (intake or exhaust; doesn't matter) is negligible prior to this point. It's important to know what type of lifter style your engine is before choosing a performance cam, because you want to know which number is pertinent to your engine build. A lot of different performance aspects hinge on the camshaft design, ranging from intake runner length to exhaust header primary length, ignition timing, block deck clearance tolerances, and many more.
One of the best channels to learn stuff from. All others talk talk and talk but never get to the gold. Here you get to know the core information which I think is very very much sacred if you want to be good at building engines.
Now I know why it never made physical sense to me that an engine could operate at all when a valve is still open when the piston is near the top of it's compression stroke. That's because I always thought duration was in reference to camshaft duration. I see now I had it wrong this whole time. I'm grabbing the dunce hat now.
The kelford cam has MORE duration ...@ 0.3mm / 0.012" it is 266 deg so I suspect @ 0.1mm / 0.004 " it would be 270 + odd deg , where as the Cat cam is @ 0.1 mm 262 deg .....but the ramp on the Kelford cam is softer on acceleration to 1 mm/ 0.040 " which may make the cam lobe wear less ? The only true test is dyno runs
Finally a real Motorhead on UA-cam. Wish your channel much success!!!Very happy I subscribed. Would love to see some cylinder head porting using a flowbench.
Valve lash also factors into play as well for non self adjusting lifters. You can theoretically squeeze out a slight duration advantage by running solid valvetrain at the tight end of the clearance spec range, unless that's already the lash spec they are measuring duration with. Not sure how much difference an extra .05 mm added on to how much more cam duration is used up to actually get the 0.05" valve lift point for most cams. .05 mm is the allowable range for valve lash on both Honda engines I have which all use solid valvetrain.
Raps are iconic engines only :) ppl often ask about them and seem to expect me to rap all the time. I can only get that embarrassed once or twice a month :)
This is good, but I think you may have made a slight terminology error. Duration isn't measured at the "valve lifter seat", it's measured at the valve seat...whether advertised or "@0.050" (1.2mm)". Normally the cam manufacturer specs the rocker ratio (if applicable) the measurement was made at and it can also change based on hydraulic vs solid lifters. For example a wild sounding solid lifter cam will measure out much more tame compared to a similar duration hydraulic cam...the reason this happens is due to the solid lifter requiring mechanical lash vs the hydraulic lifter effectively eliminating any notable lash. But that minor issue aside, this is a great video for the new crew looking to build a hotrod.
But even with the disclosed valve lift figures be it 0.1mm or 0.5mm or 1mm, that is still not the full picture. e.g. 262" at 0.5mm is still leaving out 240" at 2mm and 10" at 5mm and xxx" at max lift etc etc. The only proper way for full disclosure is actually a graph with a curve no?
Actually, the lift can be confusing as well. I was involved in a race series where the regs specified a maximum VALVE lift. The aim of this was to hopefully restrict the choice of camshaft. Unfortunately, the writer of the regs didn't realise that the lift quoted by the camshaft manufacturer didn't allow for the valve clearance. As a result, I found that I could use the next cam up the range because the actual VALVE lift still conformed to the regs (and I wasn't the only one). The actual lift was only about .5mm more than the lower spec camshaft, but it also came with more duration. For a while there was confusion as to why certain engine builder's engines were so much faster than the others. At the end of the season the regs were changed to specifically allow only one cam profile. Of course, none of this will apply if you have hydraulic lifters. Regarding duration, this is a bit similar to hi-fi amplifiers being quoted with a power output without specifying the measuring criteria or distortion levels used. I have a 1970s 50W RMS amplifier that is way more powerful than many others with the same claimed power outputs.
I wanna know more about lifters pushrods and rocker arms ..can u make a video on these?! Cuz i didnt got much informative vids around here on youtube been searching for awhile plus ur explanation is pretty good n easy to understand
This is a very timely video for me because I'm doing this exact same thing right now. Without saying what lift measurements are taken from, or giving a cam lift diagram, any camshaft advert is almost completely useless. Totally impossible to compare cams from different manufacturers.
For this video I understand why you did not mention LSA. LSA places the intake valve at the optimum opening and closing point and cubic inch and intake valve size have a huge influence on maximizing cylinder fill. Most cam grinders and engine builders get it wrong and that just adds to the confusion of understanding cam specs. Even Ford got it wrong on a line of replacement high perf cams from the dealer, I think it was for the Windsor engines. Lobe separation angle is very important and grinder use wide LSA to reclaim vacuum at idle instead of adjusting duration.
Great video. Can you do a video of how to determine the specs on a camshaft if you don't know its duration and lift? How that can be measured with the head assembled but not on the block. Also to do it with the engine fully assembled. Also, is there a way to measure the cam specs outside the head. So 3 methods.
got a question for u my brother....i got 1990 k5 blazer 5.7 just got the enging rebuild still have the swirl port heads on it and its pretty mush stock i have high perfomace intake im eliminating the computing trying to make my mine up if im going to go with a carb or some efi sniper..i have 700r4 trans and 4.10 gears and up graded my torque convert to a 2000 to 2400 stall ..it has a up grade cam in it howard cams ratter 188005-09 lift .525/530 and duration .050 ; 227/235 centerline 103 i want to no is that a good cam to go with them swirl port heads and would i be able to hear the cam..i dont no to mush about cams..i no the vortec or aluminum heads would have been better but the engine was already build already..i do have headers 3 inche pipes all the way back
All the aftermarket manufacturer habits of how they express cam specifications began with single cam engines and it was much easier because valve timing, eg. 30/70, 35/75, 36/72, etc. was directly proportionate to duration and the main reason you wanted to know the difference between advertised duration and duration at 0.050" was to give an indication of ramp speed, which tells you whether you can use solid lifters or not. So, for example if you buy a 30/70 cam and it gives the duration as 290 degrees you know damn sure that's crack to close on that timing and you'll ask the manufacturer what the duration is at 0.050" or, if he can't tell you then whether or not it's a hydraulic camshaft (breaks things in a solid setup) or a solid lifter one (can be used on both). If you know what the 0.050" duration is, the advertised duration and the valve timing however, you know which type of camshaft it is with a little think about it, combined with knowing the lift and rocker ratio (if used) all this info gives you a very good indication of exactly what valve gear setup to use with it, down to the spring rates so you don't have to attempt trial by fire with a wild guess or some bad information from an aftermarket parts salesman, which happens since the guy on the counter usually isn't the guy who makes them and probably used to work in a bank. Otherwise the way everybody talked about their camshaft specification was simply by using valve timing as a general, but very loose indicator, eg. 22/62 is a street cam, 35/75 is a track cam, whilst 30/70 sits in the middle, heavy street or mild track. It's not strictly true but most people didn't know any more than that, in fact in street cars most people used to just call 30/70 "full race cam" and 22/62 "mild street cam" and pretty much thought those were the only two options. Now you have all this twin cam doody dah and I don't know anything about that, I suppose you can dial in your own valve timing between the cams yourself so it's a different ball game?
hi Driving 4 answers! one question! talking about cameShaft swap for better performance, alright! but why forget to mention the need to re-map the injection times. I doubt that a different cameshaft with the same (original) programmation of the fuel injection timing will work! what is your opinion bro? Farid :-)
Not sure why he said that the SAE standard (0.006" off seat) was not super common. It's the most common standard I know off. It's only in the last 10-15 years here in Australia that the Crane 50thou standard has become common place.
you have a gift for automotive component explanation dude... I honestly think all those high schools that have driving class type things should have to watch your videos of engine operating basics.. they prolly wouldn't get it at the time since most would be only thinking about driving and not motors but I know for a fact I would of been so much better off knowing a car inside and out while simultaneously learning how to operate one becuz it makes you realize what's actually going one from key turn and that knowledge would undoubtedly be priceless and would remove alot of ignorance that comes with just thinking your car is a magic wheeled box that eats money and oily fluids and in return provides freedom and self Independence.. keep up the good work homie your UA-cams automotive BillNye lol if that American TV show reference has you confused look him up and have a laugh lol
It's honestly a bit weird how that leaflet I showed in the vid is everywhere around the Internet and links to the actual cam card almost nowhere. I needed an example for the vid and the poncams came to mind as I remember struggling to find their actual cam specs. Maybe I should have looked in the most obvious place first.
@@d4a Hey man when I was doing my cam selection it took me a month to discover Tomei's cam spec page. :P Anyhow continue with the excellent work, you have for sure the best automotive content on youtube.
Can be a bit misleading still. Lobe shape and grind plays a ton into this, because of that, advertised duration is almost useless except for giving you maybe a 20% accurate picture of how aggressive the lobe is.
This one time, at engine boot camp, I stuck a... Whoa! What am I saying?! Children might be reading these comments! Another good video, the bit about Crane Cams was interesting to me. THX!
I ended up reading a bunch on Harvey Crane, amazing what he managed to achieve with an incredibly humble start. Lol at that first part of your comment :))
Isn't simpler to just use the normal measurement? What is the difference of the milimeters? It should be measured at the instant that the valve opens, or at 0.001mm lol.
my favorite type of poppets are well idk if their called that it would be rocker arms are very cool Uboat engines used them a lot for low rpm I believe but correct me if I'm wrong
You can raise compression and port the head, this will give some gains in power without a cam change. Also stuffing a bigger cam in with high lift also needs (on some cases) valve springs to stop binding and/or float. I have built many pinto 2.0 ohc motors and just going longer duration with same lift gets very good power gains , duration is the key not just lift, but both are best. I used to have a 320adv duration cam with 13.8mm lift , no power below 5k but all hell broke loose till about 9.6k rpms 😁
@@marty3469 People raise the compression ratio when they install a hotter cam. Because you talk about porting heads let me know you have been watching HP tv.
@@marty3469 You have never built an engine in your life. The stock 2.0 pinto cam is very weak. Adding nothing but duration on a small lift cam would be pointless.
@@blackericdenice yes I have built motors before, and I thought this might pull a nerve, cams in them are docile but there is still power available from them.... Not much I do admit. Also I don't claim to know it all about motors or I'd have some engine tune channel on the go . If you want me to visit your channel ask nicely please
is duration the degrees the valve has more than the specified lift on the opening as well as closing? or is it the specified lift until completely closed?
One of those RARE times when I'm glad I live in the U.S. - and only really Race with 5.7 and 6.0L Chevy, and 4.6 and 5.0L Ford V8s!! Cam selection, indeed ALL Engine parts selection, is vast, and easy to choose from.
Very informative video! I bought some cat cams for my 4age bigport. They're mild street cams at 238* overall and 212* @ 1mm lift (stock is 202* @1mm). Hopefully I see some slight improvements in the low-mid range.
I have two exhaust cams from the first catcams set in my 4age, definitely a nice chunky midrange, but not much drama at the top, works great in the real world tho
@@d4a exactly what I was going for! Should help a bit with my 3.73 final drive trans I'm running. If it ever goes I'm definetely swapping it for a fwd gts one with 4.13 final
Both advertised and 0.050" are important. Comparing the 2 for the same cam will allow you to gauge/calculate the lobe profile and ramp rate. The tighter the 2 are to each other the more aggressive the ramp rate is and the larger the area under the curve will be for the given duration, thus better performing better than a cam with relaxed adv vs 50 thou. For eg. a cam with 250º @ 50 thou and 300º adv will idle worse and make a little bit less torque throughout the rev range compared to the same 250º @50 but with 290º adv. This is because the very low lift areas of a high adv duration cam effectively lowering dynamic compression ratio and increasing overlap but does little in aiding air/exhaust flow. having the valves very slightly open for the amount of time is a compromise in performance for extending valve train life. The quicker you can get to max lift for your given 50 thou duration the better the overall performance. The obvious cost is valve train stability and longevity, the higher the ramp rate the stronger the valve train parts need to be and the stiffer the valve springs need to be to combat the aggressive acceleration of the valve train components. Would be worth mentioning this in a follow up video plus the following which would aid people in choosing a cam. Cam advance/retard (intake lobe centerline) LSA (lobe separation angle) Ramp rate (as explained above) For my own project I was looking at: 308º adv, 258º @ 0.050", 0.539" 104º intake center. This was the original race engine spec'd cam that was a flat tappet design. Spoke to the cam manufacture and got the updated specs for a roller lifter cam for the same race engine. 298º adv, 260º @0.050", 0.546" lift and 102 intake center. Because is it a roller profile they updated the profile to be more aggressive and in part helped explain why the later engines produced some 40hp more with everything else being virtually equal.
What if we know the measuring points of the two camshafts as well as their duration, but their measuring points are not the same. How can we know which one has more cam duration?
Let's say cam A has 250 duration @ 0.1mm and cam B has 250 duration @ 0.3 mm. In this case cam B has more duration. The higher the lift point at which you measure duration the lower the duration, so the cam that's measured at a higher lift point will likely be the one with more duration. But it can get tricky for example when cam A has 250 duration @ 0.1mm and cam B has 240 @ 0.3. In this case you would need more information before you could be sure which one has more duration.
@@d4a thanks. I get that but I wonder if there's a formula you could use to calculate the cam duration of cam B @ 0.1mm if you know its duration at 0.3mm. That way you could compare the durations of both cams as if they were measured at 0.1mm
My 4age 16v poncams came with a data sheet that tells you actual duration (264° in/ex), duration at 1mm lift (226° in/ex) and at 0,05" lift (222°) I am pretty sure you can find this spec card with googling also before buying a set of cams ;)
Amazing explanation. I've learn so much from your university that anyone else. Thank you. Does the service manuals or Haynes manual provide this camshaft info? If not where can i get factory cam specs that mention measured valve lift for the duration?
how did this "standard exists but yeah we gonna do our own" thing even started??? is it possible that standard is rigid somehow that it can't accurately reflect whatever stuff this index is representing??? (im new as f😂 might just asked a stupid q😂thanks in advance for any answers!)
In Europe its usually @ 1mm ( 0.040" as near as makes no difference) but here in UK its both 0.050" and 1mm , and advertised can be lash to lash point ( where the clearance is taken up ) or at a the SAE standard . When plotting the duration you then have a single figure to compare which is the area under the curve . When actually designing a cam there's a whole bunch of factors to take into account . Different valve trains have different rates of acceleration of opening and closing as the first is at the maximum amount of stress and the second relies upon spring rate to keep the lobe in contact with the mechanism that opens the valve . Now here you can have an asymmetrical or symmetrical lobe design for rate of closing . Bucket and shim is typical but rocker and tappet ( whether flat mushroom or roller ) are common too and there's a third without a spring ( well maybe just a tiny one) the ' Desmodromic' as designed by Ducati . I won't bother with the pneumatics or solenoid operated as they are not cam reliant . All I can say is thank God there is now software that makes can design easy as designing them empirically was a PITA !
VERY informative video. Thank you for sharing your expertise with all of us. Oh, by the way, you explain things very well ... clear and easy to understand. Thanks!
Love your videos, one thing; can you please equalize the audio for your voice so its even L/R, it being all over the place almost gives me a headache with my headphones. (easiest way is just set your voice to mono instead of stereo.)
It's so informative the videos you've been making. Keep it up. You should do something on the history of the Honda prelude. One of the rare Honda's you don't see many of anymore.
The point (minimum valve lift) at which you would start to measure your duration is dependant on many veritables of which I feel would only be determined by not just application but your human application. We can both make the same engine to perform the same way in a different configurations but the difference in our configurations will only show themselves apon application
COMP Cams 12-602-4 Big Mutha' Thumpr SBC: amzn.to/3fvDzi7
Kelford Cams Ultimate 4AGE Race Cam: amzn.to/3b9ZZlz
Cam and lifter lube: amzn.to/2zhfrPQ
Camshaft degree wheel: amzn.to/35SxfNv
D4A merch: teespring.com/en-GB/d4a-merch
Patreon: www.patreon.com/d4a
You should do a video on the different types of cam shaft.
You are amazing! Fantastic presenter, entertainer and teacher! Your passion and personality work well with your diligent research and the extra effort you put into your editing. Thank you! :)
These videos are so interesting to watch, keep up the good work always a joy when watching!
The problem with the varying ways in which cam duration is advertised has long been known. The best way to compare camshafts is with a graph which shows lift VS degrees so you can see everything at a glance, especially how quickly the cam profile opens and closes the valve which can greatly affect valve spring selection and wear on the valve train.
If a manufacturer refuses to provide a graph, I won't buy their camshaft.
True. 2 cams with the same lift and duration at 0.050 can have wildly different ramps and flanks leading to considerable differences in performance.
@@bobraby9089 Exactly. And also the difference between hyd. and mec.
yea the profile is very important too.
in germany we say a camshaft is "Scharf" if its not so pointy like stock but has a steep ramp and flat top which increases airflow because of more time open at nearly full lift
My numbers look realy tame but I am told they are not because it is a roller cam and the figures are different to hydraulic? 260 Advertised 240 @ .050
AusPhil Adventures from your name I assume your Australian, if so the duration is similar to the solid cam in the falcon GTHO, not so tame, keep in mind the rocker arm ratio in these types of engines makes things different to the OHC engines, you can’t transfer the duration numbers over between them.
I had wondered about this, but hadn't researched it. Nice info! Thanks. Nice shirt, too.
Glad it's useful. I remember this confusing me way back when I was browsing cams for the 4ag, so I thought it's probably confusing someone else too.
@@d4a Now I'm curious about the maximum duration that the stock ECU can handle for a 4AGE because of different advertised and final can be different.
Jayhachi Talk to a tuner
This video got my Sub. Great job. I hope you can make a video about different types of cams (na, supercharger, turbo, nitrous), cam degreeing, cam break in, cam tuning. There is so much to talk about with cams.
True, you could write a book, probably two or three books actually. There will definitely be more content on cams. Thanks for watching and for your support
@@d4a man if you put all of this engine boot camp content into a book I'd absolutely buy it
Koenisegge engineers laugh at cam shaft driven engines and they don’t use cam shaft in their engine since 3000 years ago.
And they make less power than engines designed in the 1950’s, big deal
I have a 4age smallport on a corolla ae100. Its sitting for 3 years outside. i tried starting it last week and to my surprise it did start. All your videos are very helpful to me so keep em coming. Im planning on carbureting it. Shoutout from your new subscriber here in the philippines! Stay safe
My smallports been laid up for 18m now while I fix some accident damage. I start it regularly (
If you carb it,
It will no longer be able to sit for years, while still starting
Thanks for the info, getting a pair of 360° cams, gonna be lit.
That Guy *gonna be lift
Important note for those curious about advertised duration vs duration at .050"/1.00mm lift and why both exist:
Duration at .050"/1.00mm is a relatively reliable method of measuring camshaft duration for a *hydraulic* lifter style setup (the lifter/bucket/finger follower has some sort of fluid plunger that utilizes pressurized engine oil to make up for valve-train lash/gaps. The reason for this is that on average, there's about .050"/1.00mm of 'squish' or compression of the lifter (not the hydraulic fluid) that occurs before the lifter starts following the profile of the cam lobe. Hydraulic lifters tend to be a piston and cylinder with a spring inside, where the pressurized oil from the oil pump feeds into the chamber above the piston, and then the piston pushes some of the oil out as the forces from both the cam lobe and the valve-spring push against each other. The lifter pushes out a certain amount of excess oil before effectively becoming solid, at which point it follows the cam profile throughout it's duration.
Advertised duration is important for engines with a *solid* lifter setup (think NB VVT miata engines for example) which use either shims in OHC setups or poly-locks in OHV style engines. Since the lifter is completely solid, and therefore doesn't have any squish or compression, it's going to follow the ENTIRE cam lobe profile, not just a certain portion.
The final point to make about this is that even with a solid lifter setup, the reason why there's still a duration at .050"/1.00mm is that the amount of airflow occurring past the valve (intake or exhaust; doesn't matter) is negligible prior to this point.
It's important to know what type of lifter style your engine is before choosing a performance cam, because you want to know which number is pertinent to your engine build. A lot of different performance aspects hinge on the camshaft design, ranging from intake runner length to exhaust header primary length, ignition timing, block deck clearance tolerances, and many more.
0:00 He said my head is an engine. Heh Heh. Someday It's not running on all 8 cylinders though.
Camshaft duration is deceiving. Also, seller is not 100 percent understand what is the meaning those number. Be more careful
One of the best channels to learn stuff from. All others talk talk and talk but never get to the gold. Here you get to know the core information which I think is very very much sacred if you want to be good at building engines.
Now I know why it never made physical sense to me that an engine could operate at all when a valve is still open when the piston is near the top of it's compression stroke. That's because I always thought duration was in reference to camshaft duration. I see now I had it wrong this whole time. I'm grabbing the dunce hat now.
Atkins cycle is where this process came from ircc
The kelford cam has MORE duration ...@ 0.3mm / 0.012" it is 266 deg so I suspect @ 0.1mm / 0.004 " it would be 270 + odd deg , where as the Cat cam is @ 0.1 mm 262 deg .....but the ramp on the Kelford cam is softer on acceleration to 1 mm/ 0.040 " which may make the cam lobe wear less ?
The only true test is dyno runs
I'm fairly new to mechanics, and seeing the price tags on these, are y'all rich or do you ruin your credit scores to tune your cars?😨
Finally a real Motorhead on UA-cam. Wish your channel much success!!!Very happy I subscribed. Would love to see some cylinder head porting using a flowbench.
Valve lash also factors into play as well for non self adjusting lifters. You can theoretically squeeze out a slight duration advantage by running solid valvetrain at the tight end of the clearance spec range, unless that's already the lash spec they are measuring duration with. Not sure how much difference an extra .05 mm added on to how much more cam duration is used up to actually get the 0.05" valve lift point for most cams. .05 mm is the allowable range for valve lash on both Honda engines I have which all use solid valvetrain.
Tomei finally put pdfs for the camshafts measurements. For stock vqs, they’re the best bang for your buck.
Thank you from Colorado! What happened to the raps? I was mumbling one at work and everyone was dying.
Raps are iconic engines only :) ppl often ask about them and seem to expect me to rap all the time. I can only get that embarrassed once or twice a month :)
I end the videos before the cringy raps! :P
Colorado! Best state out there!
This is good, but I think you may have made a slight terminology error.
Duration isn't measured at the "valve lifter seat", it's measured at the valve seat...whether advertised or "@0.050" (1.2mm)".
Normally the cam manufacturer specs the rocker ratio (if applicable) the measurement was made at and it can also change based on hydraulic vs solid lifters. For example a wild sounding solid lifter cam will measure out much more tame compared to a similar duration hydraulic cam...the reason this happens is due to the solid lifter requiring mechanical lash vs the hydraulic lifter effectively eliminating any notable lash.
But that minor issue aside, this is a great video for the new crew looking to build a hotrod.
interesting dude !! keep discussing topics like this .😍
But even with the disclosed valve lift figures be it 0.1mm or 0.5mm or 1mm, that is still not the full picture. e.g. 262" at 0.5mm is still leaving out 240" at 2mm and 10" at 5mm and xxx" at max lift etc etc. The only proper way for full disclosure is actually a graph with a curve no?
Amazing. I never understood these numbers let alone how potentially misleading they could be.
Brotatoe chip pls BMW m50-m54 family.... Your doing Gods work with these videos ...truly.
Actually, the lift can be confusing as well. I was involved in a race series where the regs specified a maximum VALVE lift. The aim of this was to hopefully restrict the choice of camshaft. Unfortunately, the writer of the regs didn't realise that the lift quoted by the camshaft manufacturer didn't allow for the valve clearance. As a result, I found that I could use the next cam up the range because the actual VALVE lift still conformed to the regs (and I wasn't the only one). The actual lift was only about .5mm more than the lower spec camshaft, but it also came with more duration. For a while there was confusion as to why certain engine builder's engines were so much faster than the others. At the end of the season the regs were changed to specifically allow only one cam profile. Of course, none of this will apply if you have hydraulic lifters. Regarding duration, this is a bit similar to hi-fi amplifiers being quoted with a power output without specifying the measuring criteria or distortion levels used. I have a 1970s 50W RMS amplifier that is way more powerful than many others with the same claimed power outputs.
I wanna know more about lifters pushrods and rocker arms ..can u make a video on these?! Cuz i didnt got much informative vids around here on youtube been searching for awhile plus ur explanation is pretty good n easy to understand
This is a very timely video for me because I'm doing this exact same thing right now. Without saying what lift measurements are taken from, or giving a cam lift diagram, any camshaft advert is almost completely useless. Totally impossible to compare cams from different manufacturers.
For this video I understand why you did not mention LSA. LSA places the intake valve at the optimum opening and closing point and cubic inch and intake valve size have a huge influence on maximizing cylinder fill. Most cam grinders and engine builders get it wrong and that just adds to the confusion of understanding cam specs. Even Ford got it wrong on a line of replacement high perf cams from the dealer, I think it was for the Windsor engines. Lobe separation angle is very important and grinder use wide LSA to reclaim vacuum at idle instead of adjusting duration.
keep it up dude i like the way u explain
Great video. Can you do a video of how to determine the specs on a camshaft if you don't know its duration and lift? How that can be measured with the head assembled but not on the block. Also to do it with the engine fully assembled. Also, is there a way to measure the cam specs outside the head. So 3 methods.
got a question for u my brother....i got 1990 k5 blazer 5.7 just got the enging rebuild still have the swirl port heads on it and its pretty mush stock i have high perfomace intake im eliminating the computing trying to make my mine up if im going to go with a carb or some efi sniper..i have 700r4 trans and 4.10 gears and up graded my torque convert to a 2000 to 2400 stall ..it has a up grade cam in it howard cams ratter 188005-09 lift .525/530 and duration .050 ; 227/235 centerline 103 i want to no is that a good cam to go with them swirl port heads and would i be able to hear the cam..i dont no to mush about cams..i no the vortec or aluminum heads would have been better but the engine was already build already..i do have headers 3 inche pipes all the way back
All the aftermarket manufacturer habits of how they express cam specifications began with single cam engines and it was much easier because valve timing, eg. 30/70, 35/75, 36/72, etc. was directly proportionate to duration and the main reason you wanted to know the difference between advertised duration and duration at 0.050" was to give an indication of ramp speed, which tells you whether you can use solid lifters or not. So, for example if you buy a 30/70 cam and it gives the duration as 290 degrees you know damn sure that's crack to close on that timing and you'll ask the manufacturer what the duration is at 0.050" or, if he can't tell you then whether or not it's a hydraulic camshaft (breaks things in a solid setup) or a solid lifter one (can be used on both). If you know what the 0.050" duration is, the advertised duration and the valve timing however, you know which type of camshaft it is with a little think about it, combined with knowing the lift and rocker ratio (if used) all this info gives you a very good indication of exactly what valve gear setup to use with it, down to the spring rates so you don't have to attempt trial by fire with a wild guess or some bad information from an aftermarket parts salesman, which happens since the guy on the counter usually isn't the guy who makes them and probably used to work in a bank.
Otherwise the way everybody talked about their camshaft specification was simply by using valve timing as a general, but very loose indicator, eg. 22/62 is a street cam, 35/75 is a track cam, whilst 30/70 sits in the middle, heavy street or mild track. It's not strictly true but most people didn't know any more than that, in fact in street cars most people used to just call 30/70 "full race cam" and 22/62 "mild street cam" and pretty much thought those were the only two options.
Now you have all this twin cam doody dah and I don't know anything about that, I suppose you can dial in your own valve timing between the cams yourself so it's a different ball game?
hi Driving 4 answers!
one question!
talking about cameShaft swap for better performance, alright!
but why forget to mention the need to re-map the injection times.
I doubt that a different cameshaft with the same (original) programmation of the fuel injection timing will work!
what is your opinion bro?
Farid
:-)
Not sure why he said that the SAE standard (0.006" off seat) was not super common. It's the most common standard I know off.
It's only in the last 10-15 years here in Australia that the Crane 50thou standard has become common place.
you have a gift for automotive component explanation dude... I honestly think all those high schools that have driving class type things should have to watch your videos of engine operating basics.. they prolly wouldn't get it at the time since most would be only thinking about driving and not motors but I know for a fact I would of been so much better off knowing a car inside and out while simultaneously learning how to operate one becuz it makes you realize what's actually going one from key turn and that knowledge would undoubtedly be priceless and would remove alot of ignorance that comes with just thinking your car is a magic wheeled box that eats money and oily fluids and in return provides freedom and self Independence.. keep up the good work homie your UA-cams automotive BillNye lol if that American TV show reference has you confused look him up and have a laugh lol
0:12 - 0: :22 But now don't let your wife bring Clean and Nice Smelling things into your garage. Especially if it's pink. Okay?
Make it simpler: rpms of maximum torque, how many hundreds of torque's rpms it's gained, 500? 700rpm?
big thank you from Bulgaria
These videos are great. Keep them coming.
Hey man the tomei specs are in this link just find you engine.
www.tomei-p.co.jp/camspec/
It's honestly a bit weird how that leaflet I showed in the vid is everywhere around the Internet and links to the actual cam card almost nowhere. I needed an example for the vid and the poncams came to mind as I remember struggling to find their actual cam specs. Maybe I should have looked in the most obvious place first.
@@d4a Hey man when I was doing my cam selection it took me a month to discover Tomei's cam spec page. :P Anyhow continue with the excellent work, you have for sure the best automotive content on youtube.
Can be a bit misleading still. Lobe shape and grind plays a ton into this, because of that, advertised duration is almost useless except for giving you maybe a 20% accurate picture of how aggressive the lobe is.
Thanks alot for the info, would be great if you make a comparison video of different types of camshaft as well i.e. hot cams and the others.
Don't say "Zero point zero zero six inches".
Say "Six thou". Cams lift is measured at 50 thou.
ONe of the best engine related content on youtube. Keep the good work going!
nice SF shirt
Use calculus to integrate valve lift with respect to degrees. Then you would have a good idea of how much total air an engine can flow.
My wife don't let me bring dirty stinky parts inside anymore either. That's why I stay in the garage.....🤔🤣🤣
This one time, at engine boot camp, I stuck a... Whoa! What am I saying?! Children might be reading these comments!
Another good video, the bit about Crane Cams was interesting to me. THX!
I ended up reading a bunch on Harvey Crane, amazing what he managed to achieve with an incredibly humble start. Lol at that first part of your comment :))
Very useful!!
I just got a new salutation for my folks at the shop! "What is up engine heads" 🤣
Isn't simpler to just use the normal measurement? What is the difference of the milimeters? It should be measured at the instant that the valve opens, or at 0.001mm lol.
my favorite type of poppets are well idk if their called that it would be rocker arms are very cool Uboat engines used them a lot for low rpm I believe but correct me if I'm wrong
Have you tested some upgraded camshaft? If yes, what degree did you. Any dyno numbers?
Fascinating
Thanks 😊
Really good stuff man! Love the shirt.
I’ve been saying on my channel for years. If you want to increase hp on any naturally aspirated engine. You have to install a hotter cam.
You can raise compression and port the head, this will give some gains in power without a cam change.
Also stuffing a bigger cam in with high lift also needs (on some cases) valve springs to stop binding and/or float. I have built many pinto 2.0 ohc motors and just going longer duration with same lift gets very good power gains , duration is the key not just lift, but both are best. I used to have a 320adv duration cam with 13.8mm lift , no power below 5k but all hell broke loose till about 9.6k rpms 😁
@@marty3469 People raise the compression ratio when they install a hotter cam. Because you talk about porting heads let me know you have been watching HP tv.
@@marty3469 You have never built an engine in your life. The stock 2.0 pinto cam is very weak. Adding nothing but duration on a small lift cam would be pointless.
@@blackericdenice yes I have built motors before, and I thought this might pull a nerve, cams in them are docile but there is still power available from them.... Not much I do admit. Also I don't claim to know it all about motors or I'd have some engine tune channel on the go . If you want me to visit your channel ask nicely please
All I want from you is to stop lying.
Why not at 50% lift? Like the "width" of a gaussian curve.
Can you do a video on the difference in shim over bucket or bucket over shim valve adjustments?
Why dont the intake valve open like 10° btdc and close at exactly bdc? Why keep it open past bdc?
is duration the degrees the valve has more than the specified lift on the opening as well as closing? or is it the specified lift until completely closed?
Made all that maths simple, thanks dude!
Amazing Video thank you🙏🙏🙏
Next video- Step by step, how to degree cams
Technically complete and informative.
"It all depends from where you measure" said many a disappointed bride
Like video is it possible to use hauldrolick lifter cam on solid lift if not way.
The problem is is you’re not using COMP Cams
Thanks for the video and happy Ramadan!
Awesome and informative as always. Thank you
I like CAT cams. Marauw!
And people wonder why I only order custom grinds...
Thank you for theses infos ! Really appreciated !
One of those RARE times when I'm glad I live in the U.S. - and only really Race with 5.7 and 6.0L Chevy, and 4.6 and 5.0L Ford V8s!!
Cam selection, indeed ALL Engine parts selection, is vast, and easy to choose from.
Thanks very impormative
Very informative video! I bought some cat cams for my 4age bigport. They're mild street cams at 238* overall and 212* @ 1mm lift (stock is 202* @1mm). Hopefully I see some slight improvements in the low-mid range.
I have two exhaust cams from the first catcams set in my 4age, definitely a nice chunky midrange, but not much drama at the top, works great in the real world tho
@@d4a exactly what I was going for! Should help a bit with my 3.73 final drive trans I'm running. If it ever goes I'm definetely swapping it for a fwd gts one with 4.13 final
Loving this!! Need more info when it arrives!!
Think of it as the camshaft being the brain of the motor
Both advertised and 0.050" are important. Comparing the 2 for the same cam will allow you to gauge/calculate the lobe profile and ramp rate. The tighter the 2 are to each other the more aggressive the ramp rate is and the larger the area under the curve will be for the given duration, thus better performing better than a cam with relaxed adv vs 50 thou. For eg. a cam with 250º @ 50 thou and 300º adv will idle worse and make a little bit less torque throughout the rev range compared to the same 250º @50 but with 290º adv. This is because the very low lift areas of a high adv duration cam effectively lowering dynamic compression ratio and increasing overlap but does little in aiding air/exhaust flow. having the valves very slightly open for the amount of time is a compromise in performance for extending valve train life.
The quicker you can get to max lift for your given 50 thou duration the better the overall performance.
The obvious cost is valve train stability and longevity, the higher the ramp rate the stronger the valve train parts need to be and the stiffer the valve springs need to be to combat the aggressive acceleration of the valve train components.
Would be worth mentioning this in a follow up video plus the following which would aid people in choosing a cam.
Cam advance/retard (intake lobe centerline)
LSA (lobe separation angle)
Ramp rate (as explained above)
For my own project I was looking at:
308º adv, 258º @ 0.050", 0.539" 104º intake center. This was the original race engine spec'd cam that was a flat tappet design.
Spoke to the cam manufacture and got the updated specs for a roller lifter cam for the same race engine.
298º adv, 260º @0.050", 0.546" lift and 102 intake center. Because is it a roller profile they updated the profile to be more aggressive and in part helped explain why the later engines produced some 40hp more with everything else being virtually equal.
What if we know the measuring points of the two camshafts as well as their duration, but their measuring points are not the same. How can we know which one has more cam duration?
Let's say cam A has 250 duration @ 0.1mm and cam B has 250 duration @ 0.3 mm. In this case cam B has more duration. The higher the lift point at which you measure duration the lower the duration, so the cam that's measured at a higher lift point will likely be the one with more duration. But it can get tricky for example when cam A has 250 duration @ 0.1mm and cam B has 240 @ 0.3. In this case you would need more information before you could be sure which one has more duration.
@@d4a thanks. I get that but I wonder if there's a formula you could use to calculate the cam duration of cam B @ 0.1mm if you know its duration at 0.3mm. That way you could compare the durations of both cams as if they were measured at 0.1mm
My 4age 16v poncams came with a data sheet that tells you actual duration (264° in/ex), duration at 1mm lift (226° in/ex) and at 0,05" lift (222°) I am pretty sure you can find this spec card with googling also before buying a set of cams ;)
Amazing explanation. I've learn so much from your university that anyone else. Thank you. Does the service manuals or Haynes manual provide this camshaft info? If not where can i get factory cam specs that mention measured valve lift for the duration?
What about lift profile, i.e. the shape of the lobe?
Good job man, keep it up.
how did this "standard exists but yeah we gonna do our own" thing even started???
is it possible that standard is rigid somehow that it can't accurately reflect whatever stuff this index is representing???
(im new as f😂 might just asked a stupid q😂thanks in advance for any answers!)
In Europe its usually @ 1mm ( 0.040" as near as makes no difference) but here in UK its both 0.050" and 1mm , and advertised can be lash to lash point ( where the clearance is taken up ) or at a the SAE standard . When plotting the duration you then have a single figure to compare which is the area under the curve . When actually designing a cam there's a whole bunch of factors to take into account . Different valve trains have different rates of acceleration of opening and closing as the first is at the maximum amount of stress and the second relies upon spring rate to keep the lobe in contact with the mechanism that opens the valve . Now here you can have an asymmetrical or symmetrical lobe design for rate of closing . Bucket and shim is typical but rocker and tappet ( whether flat mushroom or roller ) are common too and there's a third without a spring ( well maybe just a tiny one) the ' Desmodromic' as designed by Ducati . I won't bother with the pneumatics or solenoid operated as they are not cam reliant .
All I can say is thank God there is now software that makes can design easy as designing them empirically was a PITA !
I always thought it was a German sex toy
Gotta love the shirt. Such classic. ❤
Another excellent video
With all the limitations of can shafts, I am surprised that no one has developed a solenoid valve for engines. Variable timing would be a breeze.
Freevalve?
VERY informative video. Thank you for sharing your expertise with all of us. Oh, by the way, you explain things very well ... clear and easy to understand. Thanks!
Love your videos, one thing; can you please equalize the audio for your voice so its even L/R, it being all over the place almost gives me a headache with my headphones. (easiest way is just set your voice to mono instead of stereo.)
The answer is : FREEVALVE !
It's so informative the videos you've been making. Keep it up. You should do something on the history of the Honda prelude. One of the rare Honda's you don't see many of anymore.
Great information
Awesome info and knowledge.
The point (minimum valve lift) at which you would start to measure your duration is dependant on many veritables of which I feel would only be determined by not just application but your human application. We can both make the same engine to perform the same way in a different configurations but the difference in our configurations will only show themselves apon application
I love wqtching this guys video, so much knowledge, thank you mate, for sharing the knowledge.
You start at 1mm and end 1mm of lift