Good info, Richard. I've always heard that a tighter LSA will reduce P to V clearance. Say, a 110° LSA will have less clearance than a 114° LSA. After watching your video, I can see that would be correct.
Fantastic video and idea, Richard. Next up you should demonstrate techniques for actually testing PtV clearance. Perhaps do the "clay" technique and rolling the engine all the way over, and then also the dial indicator approach only in the danger zone. Then you can discuss the pros/cons to each approach.
@@richardholdener1727 would really be helpful to show how to test VVT and or lobe separation angles/LSA with a bigger/aftermarket parts and how limiting the phaser, change's-different's and for others the importance of it plus showing valve floating and deflection's-all-parts and why's it's okay and in some cases it's extremely a bad idea/thing to have. having a pushrod that's collapsible/expandable aka something like a hydraulic cylinder ( and or figuring a way of pressurising the lifter's in the cut-away, basically how my engine now works with a jerk-pumps and pipes/liquid-rods and slave-cylinder's and software/ECU instead of fixed steel-rod's+rocker's ) and a hand/porta-power ram-pump can showcase differences 😉 👍 , also a different but related idea is having a extra sloppy/stretchy piston or piston-pin can show were/high-mileage's/lacklustre-maintenance and also higher loading/RPM and how it can change P/V clearances and timing ect something i kinda/think 🤔i know how just not 100% testing processes/setup/efi-ect-tunes yet on my modified 1960's-540~ci hemi 4.3X4.5" stroke as i add a 60*lsx twin phasers ( yes i need the limiting blocks/software-lock's but not fully sure on maximum setting's yet 💯 ) to change VVT&LSA timing's ect plus VVL/multi-air system and variable valve-spring-rate like a f1/race-engine car ect
Use the cut off pieces to cast a clear acrylic part, slap that on the engine and run smoke through the chamber to see how the air flows. Love the cutaway engines, Chrysler had them as a motorized display.
Very cool cutaway. This is one of those things that's so hard to explain to people, and a great visual goes a longs ways. It would be neat to talk a bit about acceptable piston to valve clearance in different configurations, what impact cylinder head milling and gasket thickness changes have, and maybe demonstrate how some flycuts or aftermarket piston with reliefs can add meaningful clearance. It would also be interesting to explain some common failures that result in unwanted PTV contact (valve float, lifter pump-up, broken spring, loss of cam to crank sync via some loose cam bolts, etc) and what can be done to mitigate those scenarios. Great visualization, should be a lot of ways to use this to demonstrate all kinds of things.
When I was a punk kid in the 70's, the local lawn mower shop had a cut-a-way briggs flat head engine on the parts counter. I would stare at it in amazement! I learned so much fixing minibikes and lawn mowers, the basics still apply to modern cars.
Funny you asked how it looks in the cylinder when you advance and restart the cam. I was actually searching it so the I can learn to make 1.7 work safely on my sbf with n41 cam
Great demonstration Richard! Instead of trying to visualize it in my head I can actually see what is really happening. And yes I'd love to see the changes when advancing and retarding the cam when it comes to piston to valve clearance! Keep up the great work Richard!❤
Nice display and explanation. Just FYI: Dipping your carbide burr in ATF occasionally will make the cutting go quicker and keep the aluminum from sticking to the burr.
Great visual, I've seen animation and drawings - but this was way better. I asked a question on the live feed a few nights ago. You said LSA affects this. I'd love to see a bunch of 230 & 230+ intake duration cams at various LSAs and how tight they are, or if they even work at all. And maybe a method of getting in the ballpark of what will fit when selecting a camshaft.
Maybe find a cam with super fast ramp rate and big overlap. Something that needs valve relief in the pistons. Be cool to see then when it actually hits and where that corresponds on a degree wheel and dial indicator setup on ya demo.. Cool demo. 👍
Possibly demonstrate the maximum possible duration for a 4.8/5.3 or 6.0L Flat top pistons, Dished pistons. Would be awesome to see. I've learned alot from your channel 🏁
Fantastic, if I could subscribe again, I would! Suggest future tests to include 1) how does changes in LSA affect PV? 2) how does rod length affect PV? Thanks for sharing your insights with the community.
That was a alsome video very cool to be able to see inside the combustion chamber.That deffenly explains a lot so many be you can show what advancing really does come into play
Great video! I'd like to understand the limits of the clearance and not specifically a number but methodology to the number. Why is it anything greater than zero clearance? What factors contribute to it being greater than zero? Does RPM play a factor? Can valve float cause an issue?
Great demonstration! That engine is gonna have some serious blow-by issues though. 🤣. Seriously though, thanks for hacking up some parts to make this video!
GREAT VIDEO!! Install a cam designed for supercharger use with 0 to negative overlap verses a NA cam with lots of overlap which gives that old school lopy muscle car sound. And explain why no to negative over lap (explain negative over lap too) is best in a blower application verses a NA cam with lots of over lap. And how wide overlap can get dangerous with piston to valve clearance. And add to this how a improperly timed cam can cause piston to valve strikes. And why degreeing a cam is very important bro know it’s timed correctly before starting up.
Great job on this video! I just bought the low buck truck. On my LS1 which has flat tops with no valve releafs, I had to deck the block .005" and over time the heads were milled .015" I an anxious to get the parts back and pre-assemble to see if I am going to have to go with a thicker head gasket and have to figure out the best way to check P-V clearence.
Absolutely the most lift the rocker geometry will allow like 1” lift and play with LSA and timing events to make it work without piston modifications. Basically the most ridiculous cam ever that will probably not idle and definitely not make power. But it would be a nail in the coffin about the “how much lift can I run” question!
I would like to see PTV based upon head milling. So if you over mill the head you can then simulate different head millings with gasket thicknesses. Bias cause I had my head milled .020 and would like to see the change to PTV it caused.
Piston chases the exhaust valve so always use .110 min on exhaust side, youll be safe intake 0.080 min with 0.031 radius in piston pockets ! Save for lots of street strip motors
Great job! That cam is a good duration and fairly typical LCA. Maybe you could go through an example where you measure the clearance with a dial indicator and then advance and retard the cam to show how PV changed.
Now the question is, will my 241 heads milled 40-thou work with a BTR stage 3 na Ls1 cam without cutting valve reliefs 🤔 haha. Thanks as always, Richard!
In machining, clearance is clearance. As long as your parts dont hit each other while everything cold or when everything's warm, thats it. A gap is a gap.
It would be great to know how much deviation there is in a static clearance measurement compared to an actual dynamic amount when factoring in deflection of parts under load with a full valvetrain. I would guess this must equate to quite a bit but no clue how this could be measured
A good video on how to know what cam will fit without pulling the heads. Is there an equation or something to use with your current p2v clearance to find out if another cam will fit before installing it?
Question: you didn’t share with us what MINIMUM clearances we need on the exh/int sides? .070” ?? 🤷🏻♂️. Also does ratio rockers affect piston to valve clearance and how? Thank you 😊
I have seen some people fly cut their pistons because the piston to valve clearance is not enough. I am curious is fly cutting an acceptable procedure, or it's not recommended.
so was that a good aluminum block? OMG. anyway lets see what changing LSA does. I remember a test that was done when you changed the lsa and kept the duration the same. that should be redone with this display block and head.
I’m curious in understanding how lsa/icl affects how you install a camshaft. Greater lsa = more pv clearance, but usually pushes peak hp/torque higher in the rev range. Should (or can) you advance that camshaft to lower peak hp/torque, or should you retard the camshaft to take advantage of the high range of the camshaft? Or is it specific to the rest of the build? How about all of this with a tighter lsa/icl? Do you need to take into account a certain amount of wrist pin slop at the top of the stroke when installing the cam? How do you know when the pv is too tight?
You can put a zero overlap cam in and show how much real overlap there actually is. The Red Hot would have only had 6 odd degrees of overlap at 50 thou tappet lift but there was plenty of valve opening for both valves at TDC.
I sorta understand the duration argument. But wouldn't cam timing be a bigger factor? I could have less duration but still induce a collision by adv/ret? (I am not the smartest tool in the drawer)
I am building a NA 5.3 for a very light car. Sub 2k pounds. After reading and watching alot of your videos I plan to run flat top pistons, 317 heads milled .030, and a an ls9 cam wit lh 7k redline. I am not chasing max power. I am wanting to change the character of the engine from low end grunty truck engine to rev happy sports car. Also running a 4 speed manual transmission. Being the car is so light and I am only able to fit a max for 185 section tire its an advantage for me to have more power higher in the rpms than down low where I have little traction to work with. What do you think of this combo? Go or no go? PTV is a concern which is why I ask on this video. Not a cobra btw.
What happens if you have a very short, duration, low overlap, but extremely high lift cam shaft? Does the cylinder get more air? simply opening the valve more, but not necessarily for longer. Normally LS engines really like a 600 lift but what if there was say a 7 1/4 lift or even more than that?
Actually, that is a good question to answer. Have you tested enough cams to actually run into this effect and if so, what lift-to -duration numbers bring about the instability you mention and at what rpm? For instance, say you are building an engine and want the cam lift to be .525". How short of a duration would cause the effect? Then give duration thresholds for different lifts as well, for example .550", .575", .600" etc... so the trend can be graphed and or visualized. I expect that you would see why the old small block HP cams had such low lift to high duration numbers. The trend today is to go for mega lift while trying to keep duration short which starts to infringe on the laws of physics with drastically increased stress on the valvetrain. Would Comp Cams already have such a graph showing which lobe designs are prohibited by the lift-to-duration relationship? @@richardholdener1727
We like it when the P is close to the V
Well, this P to V is cheaper than eighteen years of child support.
😂
I love when my P is destroying the V😂
Suck squeeze bang blow!
Good info, Richard. I've always heard that a tighter LSA will reduce P to V clearance. Say, a 110° LSA will have less clearance than a 114° LSA. After watching your video, I can see that would be correct.
Now you need to show us how cam duration and lobe separation effect P to V clearance.
Fantastic video and idea, Richard. Next up you should demonstrate techniques for actually testing PtV clearance. Perhaps do the "clay" technique and rolling the engine all the way over, and then also the dial indicator approach only in the danger zone. Then you can discuss the pros/cons to each approach.
I want to show where the valve hits on the piston and why LS dish pistons might not improve p-v
@@richardholdener1727 would really be helpful to show how to test VVT and or lobe separation angles/LSA with a bigger/aftermarket parts and how limiting the phaser, change's-different's and for others the importance of it plus showing valve floating and deflection's-all-parts and why's it's okay and in some cases it's extremely a bad idea/thing to have. having a pushrod that's collapsible/expandable aka something like a hydraulic cylinder ( and or figuring a way of pressurising the lifter's in the cut-away, basically how my engine now works with a jerk-pumps and pipes/liquid-rods and slave-cylinder's and software/ECU instead of fixed steel-rod's+rocker's ) and a hand/porta-power ram-pump can showcase differences 😉 👍 , also a different but related idea is having a extra sloppy/stretchy piston or piston-pin can show were/high-mileage's/lacklustre-maintenance and also higher loading/RPM and how it can change P/V clearances and timing ect
something i kinda/think 🤔i know how just not 100% testing processes/setup/efi-ect-tunes yet on my modified 1960's-540~ci hemi 4.3X4.5" stroke as i add a 60*lsx twin phasers ( yes i need the limiting blocks/software-lock's but not fully sure on maximum setting's yet 💯 ) to change VVT&LSA timing's ect plus VVL/multi-air system and variable valve-spring-rate like a f1/race-engine car ect
Use the cut off pieces to cast a clear acrylic part, slap that on the engine and run smoke through the chamber to see how the air flows. Love the cutaway engines, Chrysler had them as a motorized display.
Very cool cutaway. This is one of those things that's so hard to explain to people, and a great visual goes a longs ways. It would be neat to talk a bit about acceptable piston to valve clearance in different configurations, what impact cylinder head milling and gasket thickness changes have, and maybe demonstrate how some flycuts or aftermarket piston with reliefs can add meaningful clearance. It would also be interesting to explain some common failures that result in unwanted PTV contact (valve float, lifter pump-up, broken spring, loss of cam to crank sync via some loose cam bolts, etc) and what can be done to mitigate those scenarios. Great visualization, should be a lot of ways to use this to demonstrate all kinds of things.
Love this video! I would be very curious to see how increasing the rocker arm ratio effects clearance.
When I was a punk kid in the 70's, the local lawn mower shop had a cut-a-way briggs flat head engine on the parts counter. I would stare at it in amazement! I learned so much fixing minibikes and lawn mowers, the basics still apply to modern cars.
Yes to all of the questions at the end.
Funny you asked how it looks in the cylinder when you advance and restart the cam. I was actually searching it so the I can learn to make 1.7 work safely on my sbf with n41 cam
Great demonstration Richard! Instead of trying to visualize it in my head I can actually see what is really happening. And yes I'd love to see the changes when advancing and retarding the cam when it comes to piston to valve clearance! Keep up the great work Richard!❤
Great demo, Richard - looking forward to your next educational session on piston to valve clearance - lots of good suggestions posted.
Nice display and explanation. Just FYI: Dipping your carbide burr in ATF occasionally will make the cutting go quicker and keep the aluminum from sticking to the burr.
I did that
Great visual, I've seen animation and drawings - but this was way better. I asked a question on the live feed a few nights ago. You said LSA affects this. I'd love to see a bunch of 230 & 230+ intake duration cams at various LSAs and how tight they are, or if they even work at all. And maybe a method of getting in the ballpark of what will fit when selecting a camshaft.
Maybe find a cam with super fast ramp rate and big overlap. Something that needs valve relief in the pistons. Be cool to see then when it actually hits and where that corresponds on a degree wheel and dial indicator setup on ya demo.. Cool demo. 👍
This sectioned display motor is really cool
Possibly demonstrate the maximum possible duration for a 4.8/5.3 or 6.0L Flat top pistons, Dished pistons. Would be awesome to see. I've learned alot from your channel 🏁
Fantastic, if I could subscribe again, I would! Suggest future tests to include 1) how does changes in LSA affect PV? 2) how does rod length affect PV? Thanks for sharing your insights with the community.
Can you please compare PTV on different LSAs on otherwise similar cams.
16👍's up thank you for sharing 😊
You did a awesome job explaining pistons to valves clearance, i really appreciate all your videos
Great visual aid, Use high compression domed piston with different over lap and valve float would be a good one. Awesome dude!😁
This is amazing, Richard! Thanks so much for showing us this. What a great concept to open up the engine and let us see the whole process.
thanks that was great! what changes does a higher lift rocker make at TDC? 1.7, 1.8.
That was a alsome video very cool to be able to see inside the combustion chamber.That deffenly explains a lot so many be you can show what advancing really does come into play
Yes that would be nice to see, at what degree of retartd and exhaust valve will contact a piston, and on what advance an intake.
would like to see the summit stage 4 8709 cam
I have the stage 3 and am curious too even though clay method showed adequate clearance
was your test method accurate
I always learn new things when I watch your vids, thank you! I would like to see turbo magnum! turbo magnum! turbo magnum!
Now that you mentioned it, It would be pretty cool too see what it looks like to advance a cam! Maybe a video about that wouldn’t be a bad idea 👀
Perfect video for explaining the need to P2V clearance!
Glad it was helpful!
Great video! I'd like to understand the limits of the clearance and not specifically a number but methodology to the number. Why is it anything greater than zero clearance? What factors contribute to it being greater than zero? Does RPM play a factor? Can valve float cause an issue?
Great graphic Richard. Thanks for the visual demo.
Holy crap! You go all the way.... GREAT WORK! You are the man.👌
Great demonstration! That engine is gonna have some serious blow-by issues though. 🤣. Seriously though, thanks for hacking up some parts to make this video!
This is how to teach! Great video!
Great tool to explain different cam specs and what they actually mean...
Great demonstration I’d like to see how a dome piston reacts with a big duration cam
dome pistons usually have valve reliefs, so p-v is increased
Adjustable cam sprocket measured at 1 deg intervals whilst measuring PtoV clearance accordingly
Great walk through for people that may not understand.
Fun Demo! Excellent!
On of cam company had "soft springs" you could compress by hand as you rotated engine.
Super cool to see it like this. Great video and I'll share this one with friends.
Excellent video. Can you discuss float, which I presume only matters on the exhaust valve.
Wow, I need to check ptv on this next motor and now I’m going to cut up a torched head and make a couple of these too! Great idea
Great video . A suggestion - putting in a cam that won’t work and the valves hit - too much duration .
Very well done👍
Very very well explained!!!
Hello I would like to see a narrow LSA, a 107° . A narrow LSA will raise cylinder pressure which will change dynamic compression
GREAT VIDEO!!
Install a cam designed for supercharger use with 0 to negative overlap verses a NA cam with lots of overlap which gives that old school lopy muscle car sound. And explain why no to negative over lap (explain negative over lap too) is best in a blower application verses a NA cam with lots of over lap. And how wide overlap can get dangerous with piston to valve clearance. And add to this how a improperly timed cam can cause piston to valve strikes. And why degreeing a cam is very important bro know it’s timed correctly before starting up.
the cam that makes more na power will make more boosted power-stop with all this overlap talk
Great job on this video! I just bought the low buck truck. On my LS1 which has flat tops with no valve releafs, I had to deck the block .005" and over time the heads were milled .015" I an anxious to get the parts back and pre-assemble to see if I am going to have to go with a thicker head gasket and have to figure out the best way to check P-V clearence.
easy to check P-V but you won't have a problem-you have miles of P-V on that cam (even with you minimal milling)
Absolutely the most lift the rocker geometry will allow like 1” lift and play with LSA and timing events to make it work without piston modifications. Basically the most ridiculous cam ever that will probably not idle and definitely not make power. But it would be a nail in the coffin about the “how much lift can I run” question!
What happened when the valves overlap
overlap is common on after market cams
I would like to see PTV based upon head milling. So if you over mill the head you can then simulate different head millings with gasket thicknesses.
Bias cause I had my head milled .020 and would like to see the change to PTV it caused.
Same I milled my heads to 58cc and have a 232/242 .600 / .600 113+3 cam. Clay method showed plenty of clearance but would be cool to see in action.
I can remove the gasket
It would be good to share your experiences with how much is enough PV with various lifter types and RPM ranges
.035
In my gen Iv 6.0 im running a mast motorsports 625in -648ex 248in 260ex @.50 and had to cut the pistons .040 on intake to get .080 with .051 gasket
Piston chases the exhaust valve so always use .110 min on exhaust side, youll be safe intake 0.080 min with 0.031 radius in piston pockets ! Save for lots of street strip motors
Amazing video, thanks
Hey Richard what about engine quench test’s, also check truck Norris cam because of the bigger overlap it has
BIGGER OVERLAP?
I would like to see valve to wall clearance . include cathedral port and rec port . how bad is it ?
What's the minimum valve piston clearance you can run
I ran it as tight.037 find the intake and I wasn't even concerned with the exhaust was doing
LSA and overlap, intake centerline etc
Great job! That cam is a good duration and fairly typical LCA. Maybe you could go through an example where you measure the clearance with a dial indicator and then advance and retard the cam to show how PV changed.
thank you for this valuable l information
Stock cam vs big cam. What is the difference and why it make more power.
lots of cam tests up-but can show p-v difference
Thank you for the video.
I'd like to see the Brian tooley racing f35 cam p2v clearance tested
That would make a really great teaching tool. I have a block, I just need a busted head.
Now the question is, will my 241 heads milled 40-thou work with a BTR stage 3 na Ls1 cam without cutting valve reliefs 🤔 haha.
Thanks as always, Richard!
See I appreciate that you want to explain and demonstrate it. But on the other hand I want to cry cause that poor head... 😢
the head was a piece of junk to start with
What is considered "safe" piston ti valve clearance?
In machining, clearance is clearance. As long as your parts dont hit each other while everything cold or when everything's warm, thats it. A gap is a gap.
It would be great to know how much deviation there is in a static clearance measurement compared to an actual dynamic amount when factoring in deflection of parts under load with a full valvetrain. I would guess this must equate to quite a bit but no clue how this could be measured
might be measured on a spintron
Super interesting!
Would be nice to see diffrent LSA with similar duration.
I wanna see what the biggest cam I can use on a 5.3 with 4.8 pistons and 706 heads
How does valve float affect p to v clearance
What is the max intake and exhaust duration with a common Lsa and intake centerline can be ran in an L33 and maintain good ptv
A good video on how to know what cam will fit without pulling the heads. Is there an equation or something to use with your current p2v clearance to find out if another cam will fit before installing it?
if you already know existing cam (and specs and how it was installed) -then you can calculate
Question: you didn’t share with us what MINIMUM clearances we need on the exh/int sides? .070” ?? 🤷🏻♂️. Also does ratio rockers affect piston to valve clearance and how?
Thank you 😊
rocker ratio can alter p-v because (in addition to lift) they also alter duration slightly (by 2 degrees or so depending on ratio change)
@@richardholdener1727ok thank you much! 👌🏼
an you measure domed pistons with a big cam shaft how to determine the timing on the cam shaft and what not
a big dome piston usually improves p-v since it comes with a valve relief
Opposite ends of extreme LSA durations and how close is too close?
Cool video! Id like to see how to check p2v on a motor with a VVT limiter.
test ptv at the extremes of the VVT (full advance and full retard), many ECU systems don't use all that is available
Awesome video, now how do I measure this on my engine with my setup? Clay? With or without head gasket?
clay with gasket works
How can we know what is happening with P-V in a close engine so we will be able to make the best valve clearance?
you measure it-using a checker spring and dial indicator
This also illustrates valve-cylinder wall shrouding.
I’d love to see this test on a MS3
different type pistons test be cool
I have seen some people fly cut their pistons because the piston to valve clearance is not enough. I am curious is fly cutting an acceptable procedure, or it's not recommended.
it can be done as long as there is enough material in the piston and it is done correctly with the piston in the proper position
My school had a pink cadillac motor cut out like that
Brother, that was awsome
so was that a good aluminum block? OMG. anyway lets see what changing LSA does. I remember a test that was done when you changed the lsa and kept the duration the same. that should be redone with this display block and head.
Right on
I’m curious in understanding how lsa/icl affects how you install a camshaft. Greater lsa = more pv clearance, but usually pushes peak hp/torque higher in the rev range. Should (or can) you advance that camshaft to lower peak hp/torque, or should you retard the camshaft to take advantage of the high range of the camshaft? Or is it specific to the rest of the build? How about all of this with a tighter lsa/icl?
Do you need to take into account a certain amount of wrist pin slop at the top of the stroke when installing the cam? How do you know when the pv is too tight?
What does changing timing do?
You can put a zero overlap cam in and show how much real overlap there actually is. The Red Hot would have only had 6 odd degrees of overlap at 50 thou tappet lift but there was plenty of valve opening for both valves at TDC.
I sorta understand the duration argument. But wouldn't cam timing be a bigger factor? I could have less duration but still induce a collision by adv/ret? (I am not the smartest tool in the drawer)
advancing reduces p-v on the intake
I love it when valves chase the pistons and the pistons chase the valves gets me excited😅😮😂😅😅😅!!!!!!
I am building a NA 5.3 for a very light car. Sub 2k pounds. After reading and watching alot of your videos I plan to run flat top pistons, 317 heads milled .030, and a an ls9 cam wit lh 7k redline. I am not chasing max power. I am wanting to change the character of the engine from low end grunty truck engine to rev happy sports car. Also running a 4 speed manual transmission.
Being the car is so light and I am only able to fit a max for 185 section tire its an advantage for me to have more power higher in the rpms than down low where I have little traction to work with.
What do you think of this combo? Go or no go? PTV is a concern which is why I ask on this video. Not a cobra btw.
This is a great video! How much more clearance can You get with the piston notchers that look like a valve? On a junkyard 5.3.
a lot
What happens if you have a very short, duration, low overlap, but extremely high lift cam shaft? Does the cylinder get more air? simply opening the valve more, but not necessarily for longer. Normally LS engines really like a 600 lift but what if there was say a 7 1/4 lift or even more than that?
the cam lobe is very unstable with high lift and low duration
Actually, that is a good question to answer. Have you tested enough cams to actually run into this effect and if so, what lift-to -duration numbers bring about the instability you mention and at what rpm? For instance, say you are building an engine and want the cam lift to be .525". How short of a duration would cause the effect? Then give duration thresholds for different lifts as well, for example .550", .575", .600" etc... so the trend can be graphed and or visualized. I expect that you would see why the old small block HP cams had such low lift to high duration numbers. The trend today is to go for mega lift while trying to keep duration short which starts to infringe on the laws of physics with drastically increased stress on the valvetrain. Would Comp Cams already have such a graph showing which lobe designs are prohibited by the lift-to-duration relationship? @@richardholdener1727
Would piston to valve clearance be the same with a domed piston
a non-factory dome piston would likely have valve reliefs
If everyone was asking how much lift they can run, but lift isn’t a factor, why not get into how much duration can be run?