This is exactly why professional engine builders "Blueprint" An engine to exacting specs. And the fact that aftermarket parts vary from factory standards and the fact that valve stems are different lengths after seating is why they set up EVERY valve to an exact geometry. Correct me if I'm wrong, but i believe they would remove that valve and grind the tip to be exactly the same so geometry is same or pay closer attention to valve seating heights. My knowledge ends here. This attention to detail is what enables the engine to live. your video is perfect for people like me. 25 lifetime engine builds. Or to be more specific....... 15 engine assemblies.... And about 10 engine builds. Ive come to the point that I would want to correct that un-equal valve length. People should pay attention to every detail thru out the engine. .......Pay close attention to this video, and save untold money in destroyed engines. Very well done.
I'm not aware of any competent machinist that will grind the ends of the valves anymore, except for MAYBE a stock application. With more modern tooling, a QUALITY machinist will set valve heights via the valve job, which is the CORRECT way to set it. This also helps to equalize chamber volume since the valves will all sit at the same depth. Also, correct rocker geometry should be set BEFORE determining pushrod length. Pushrod length is a result of correct geometry. Geometry is NOT the result of the correct pushrod length. This is not the ideal way to find pushrod length....
One of the very BIGGEST NAME builders sent us a 383 Chevy complete after Dyno runs. 2800 miles later: 2 sets of chinesium roller rockers. 2 sets of "their name" plug wires Another set of plugs. Now a complete distributor... Chinesium HEI.🙄 On the THIRD Sniper injection set up. First one wouldn't work out after hours with Holley. Sent for exchange. Then a bad injector. Now on the third. What a piece of crap for $12,000 plus labor. Owner is having a fit.
This is a old video..Proform makes a pushrod checker tool that makes it a whole lot easier to find what length pushrod you need..Great job on the build!
Thanks man! They have made that tool for a long time, seriously don’t use it - Iv seen that mess so many people up because you have to make some assumptions. You are looking for the smallest pattern possible - a good adjustable pushrod, and light spring will set you straight 👍
Hey bud quick question, figured id ask here vs creating post on the facebook group, checked my lenght using comp cam tool and soft checking springs, i hand tightened the nut till it snugged up while at base lobe, got a great pattern and centered with the adjustable pushrod extended to 6.35, do i add .025 to that measurement for preloaded as you mentioned at mark 5:43?
I think I understand it now. My head is already torqued down so I won’t need to add in head gasket thickness. I’ll be using the light checking springs as well. So basically instead of using a mock up solid lifter just use the hydraulic lifters I’ll be using for the actual build and just don’t put any preload on them for measurement purposes correct? Let’s say I’m happy with my wear pattern with my pushrod measuring tool at 6.300, to get my final pushrod length I’d need to add .025 to .030 (or half turn) to account for lifter preload, correct? That’s the part that gets me every time
If I need 7.600" pushrods but I have 7.625" ones, is the pushrod length as important if I have adjustable rocker arms? Or does it not matter since I can just adjust the rocker arm to make up for the 0.025" difference?
Roller rockers aren't adjustable. If they were adjustable, 1 push rod, let's say 6", would be all that's made, for every engine ever made. Lol That doesn't work either, because some engines are bigger than others, or valve length is different from one head to another. So you measure like he says, with the wear marks. Then, pick the closest match to the length "you think", you need. Either you picked one to short, perfect, or to long. Rockers aren't adjustable. But, maybe if you picked a rod that was too long, you might get away with just adding a "lash cap", to the top of each valve, depending on sizes available. Unless you have premo, shaft mounted rockers, rockers aren't adjustable.
Question. I checked pushrod length on my sbc using your method with light springs. Accounted for .020 preload and .015 for head gasket. I checked number valves. Now that I have my actual pushrods, actual valve springs, and heads installed with gasket, the rockers seem to be too long. I haven’t primed the oil pump yet. Will they line up correctly once engine runs? Just wondering why they seem long now. I’m 99% positive I checked the pushrod length correctly.
I imagine your head gasket is more like .045-.055, not .015. So that’s something there. And you need to be sure that if you are checking with a hydraulic lifter, that the spring cup doesn’t collapse at all during the process
@@ThunderHead289 it’s a this .015 compressed thickness gasket. I didn’t have the deck resurfaced and the new pistons have. .010 shorter compression height. So I was trying to get my quench and compression on par. I was using light checking springs like you have in your video. To be sure those weren’t compressing the lifter.
I know this is an old video but just curious why you wouldnt go ahead and put the head on with gasket and torque, unless there is reason to remove them again.
With this method you must already have a good idea what push rod length you need. The much better way to do it is use the center line half lift method. That way your geometry is set to exactly the correct angle for every degree of lift in on your cam. Also you do not need to have any idea what size push rod to start with. With this method you need to know deck height and a whole lot of other info not being told here.
No, you don’t need all that. You get the length checker that is the same length & longer than your stock pushrod length. Simple as that. Retrofit roller lifters? Measure from valve stem height to lifter cup - order length checker. Pattern is everything. Bad pattern = accelerated wear. I learned the hard way
Scott Foxwell has a much more accurate method of measuring push rods. He uses the half lift method and math. Perfect pattern without guessing. Every time!
@@dannymccarty344 you dont really need to do it if youre not building a racing engine. im gonna use this method as it has worked forever. the math is cool and all but unless youre building a high dollar race engine or something that makes quite a bit of power, there no real point unless you just wanna say you did
Probably not - highly plausible that the base circle size, which plays the biggest role in dictating pushrod length, will be the same on intake and exhaust
+ThunderHead289 ok, I am using the stock springs on the heads and can't get consistent marks, like I'll be adjusting it longer 1/6 of a turn at a time and a fat line goes closer and closer to the middle and the then it just goes way off to the left of the post
I don’t understand , why you add some mystically imagined 0.25 , when you can just fully tighten the rocker arm to factory specs , and measure the actual length without any gessung and adding some 0.25 . I watched all u tube videos and no one explained how do I tighten the rocker . Do I just tighten to zero lash , or zero lash plus fully tightened ( 3/4 of a turn ) no one explained it . I don’t get it
There are multiple types is why - your explaining pedestal rockers. These are stud rockers which require a preload from zero lash on a hydraulic lifter. And now you know
ThunderHead I need some assistance on a 91 roller 302 with AFR 165 heads, so I ordered a extra trick flow roller lifter and modified it to be a solid lifter (welded the cup solid) anyhow I pretty much followed your video to get a good length on a pushrod 6.35 inch. I torqued down my heads with a gasket... do I add the preload to the length of the push rod I believe it was a quarter turn in your video?? ill wait for your input before I order my pushrods. thank you sir
thunder bolt hey, I add the 20-25 thousandths to the length so 6.35 would be 6.37 or so. That really doesn’t look like it’s going to effect you. I remade this video and explain in much better in my opinion. Here’s the link - ua-cam.com/video/76wbtu9l09A/v-deo.html
Yes indeed - if the rocker geometry is right, the contact pattern will work through the center of the valve stem. i actually just remade this video a few days ago - check my recent uploads - its a bit longer, but more straightforward.
If you don’t, your lifters collapse and you have an inaccurate reading. Unless you make a solid lifter the exact same geometry of a hydraulic, you in fact do
@@ThunderHead289 nope! It's simple, don't collapse them. That's more for those not paying attention. I've been doing this for over 20 years, I've checked lengths with and without. They give you no advantage except a lighter wallet.
I disagree with using light springs when checking for pushrod length... You should use the valve spring thats going in the overall build to determine it correctly.. My Opinion
You will get a bad measurement from deflection in your pushrod checking tool. As long as you account for your preload, you are fine. If you don’t use a solid lifter when using the actual spring, you will absolutely get a bad read. Does this make sense?
Go get the right head gasket torque all that shit down and start over .......Stop talking about how many turns on your adjustable pushrods and actually measure your pushrod
God you mid lift people I swear. The amount of times I see you all mess it up is uncanny. I'm thunderhead289 - respect the people that can dance circles around you with a blindfold on. This ungrateful bs is why I quit helping the automotive community this year.
@ThunderHead289 hey bud I just wanna say I value your content very much, this is all new to me and you informative videos have Given me the extra confidence to get the job done,
This is exactly why professional engine builders "Blueprint" An engine to exacting specs. And the fact that aftermarket parts vary from factory standards and the fact that valve stems are different lengths after seating is why they set up EVERY valve to an exact geometry. Correct me if I'm wrong, but i believe they would remove that valve and grind the tip to be exactly the same so geometry is same or pay closer attention to valve seating heights. My knowledge ends here. This attention to detail is what enables the engine to live. your video is perfect for people like me. 25 lifetime engine builds. Or to be more specific....... 15 engine assemblies.... And about 10 engine builds. Ive come to the point that I would want to correct that un-equal valve length. People should pay attention to every detail thru out the engine. .......Pay close attention to this video, and save untold money in destroyed engines. Very well done.
I'm not aware of any competent machinist that will grind the ends of the valves anymore, except for MAYBE a stock application. With more modern tooling, a QUALITY machinist will set valve heights via the valve job, which is the CORRECT way to set it. This also helps to equalize chamber volume since the valves will all sit at the same depth. Also, correct rocker geometry should be set BEFORE determining pushrod length. Pushrod length is a result of correct geometry. Geometry is NOT the result of the correct pushrod length. This is not the ideal way to find pushrod length....
One of the very BIGGEST NAME builders sent us a 383 Chevy complete after Dyno runs.
2800 miles later:
2 sets of chinesium roller rockers.
2 sets of "their name" plug wires
Another set of plugs.
Now a complete distributor... Chinesium HEI.🙄
On the THIRD Sniper injection set up. First one wouldn't work out after hours with Holley. Sent for exchange. Then a bad injector. Now on the third.
What a piece of crap for $12,000 plus labor.
Owner is having a fit.
This is a old video..Proform makes a pushrod checker tool that makes it a whole lot easier to find what length pushrod you need..Great job on the build!
Thanks man!
They have made that tool for a long time, seriously don’t use it - Iv seen that mess so many people up because you have to make some assumptions. You are looking for the smallest pattern possible - a good adjustable pushrod, and light spring will set you straight 👍
Still like your RIDE!!
Thanks for the upload. Great video.
Those afr heads have a lot of seat runout right out of the box. That's most likely why your getting different valve lenths. I've seen as much as .007
Like your advice, do measure/adjust to obtain a “perfect length” pattern.
Then go +.0.050 then, do a -0.050. to compare all three wear patterns.
thank you very helpful
Hey bud quick question, figured id ask here vs creating post on the facebook group, checked my lenght using comp cam tool and soft checking springs, i hand tightened the nut till it snugged up while at base lobe, got a great pattern and centered with the adjustable pushrod extended to 6.35, do i add .025 to that measurement for preloaded as you mentioned at mark 5:43?
I think I understand it now. My head is already torqued down so I won’t need to add in head gasket thickness. I’ll be using the light checking springs as well. So basically instead of using a mock up solid lifter just use the hydraulic lifters I’ll be using for the actual build and just don’t put any preload on them for measurement purposes correct? Let’s say I’m happy with my wear pattern with my pushrod measuring tool at 6.300, to get my final pushrod length I’d need to add .025 to .030 (or half turn) to account for lifter preload, correct? That’s the part that gets me every time
If I need 7.600" pushrods but I have 7.625" ones, is the pushrod length as important if I have adjustable rocker arms? Or does it not matter since I can just adjust the rocker arm to make up for the 0.025" difference?
Roller rockers aren't adjustable. If they were adjustable, 1 push rod, let's say 6", would be all that's made, for every engine ever made. Lol
That doesn't work either, because some engines are bigger than others, or valve length is different from one head to another.
So you measure like he says, with the wear marks.
Then, pick the closest match to the length "you think", you need.
Either you picked one to short, perfect, or to long.
Rockers aren't adjustable.
But, maybe if you picked a rod that was too long, you might get away with just adding a "lash cap", to the top of each valve, depending on sizes available.
Unless you have premo, shaft mounted rockers, rockers aren't adjustable.
So true. Math is great, but if it doesn’t pattern correctly, all it did was get you close, which you could have done with a stick. 😂
What scorpion rockers you buy,you said a budget build
Great vid
Question. I checked pushrod length on my sbc using your method with light springs. Accounted for .020 preload and .015 for head gasket. I checked number valves. Now that I have my actual pushrods, actual valve springs, and heads installed with gasket, the rockers seem to be too long. I haven’t primed the oil pump yet. Will they line up correctly once engine runs? Just wondering why they seem long now. I’m 99% positive I checked the pushrod length correctly.
I imagine your head gasket is more like .045-.055, not .015. So that’s something there.
And you need to be sure that if you are checking with a hydraulic lifter, that the spring cup doesn’t collapse at all during the process
@@ThunderHead289 it’s a this .015 compressed thickness gasket. I didn’t have the deck resurfaced and the new pistons have. .010 shorter compression height. So I was trying to get my quench and compression on par. I was using light checking springs like you have in your video. To be sure those weren’t compressing the lifter.
Thumbs Up!!!
I know this is an old video but just curious why you wouldnt go ahead and put the head on with gasket and torque, unless there is reason to remove them again.
Pressurize spark plug hole with compressed air to change valve springs
What if you can’t get a narrow pattern but it’s in the center?
can you check pushrod length with normal rockers ? or only with roller rockers.
You can with standard rockers, but it is much more difficult. I have never tried it
im guessing those lighter springs will help if you are using a new flat tappet cam that hasnt been broken in yet?
Who has light springs? Certainly not I in the video. But yes, flat tappet cams need light springs for break in. Another reason I have gone roller
Do I need to do this when I put after market heads and rocker arms and lifters?
+Larry Archey it’s definitely always a good idea, a lot of geometries can change requiring a longer pushrod
With this method you must already have a good idea what push rod length you need. The much better way to do it is use the center line half lift method. That way your geometry is set to exactly the correct angle for every degree of lift in on your cam. Also you do not need to have any idea what size push rod to start with. With this method you need to know deck height and a whole lot of other info not being told here.
No, you don’t need all that.
You get the length checker that is the same length & longer than your stock pushrod length. Simple as that. Retrofit roller lifters? Measure from valve stem height to lifter cup - order length checker.
Pattern is everything. Bad pattern = accelerated wear.
I learned the hard way
Scott Foxwell has a much more accurate method of measuring push rods. He uses the half lift method and math.
Perfect pattern without guessing. Every time!
This is literally the same geometry as half lift - you just don’t have to go through a bunch of things that you can easily screw up.
Thunderhead289.
@@ThunderHead289 right, math is puzzling to some. But, it's the most accurate...for those who comprehend it, anyways.
@@dannymccarty344 you dont really need to do it if youre not building a racing engine. im gonna use this method as it has worked forever.
the math is cool and all but unless youre building a high dollar race engine or something that makes quite a bit of power, there no real point unless you just wanna say you did
`where did you find that sweet timing cover. if I could find one that nice I wouldn't paint it looks sweet anyway. Thanks'
My intake lift is .19 larger than the exhaust lift do i need two different push rod lengths. .584/.565
Probably not - highly plausible that the base circle size, which plays the biggest role in dictating pushrod length, will be the same on intake and exhaust
@@ThunderHead289 Thank you so much I kind of figured it would be OK just wanted to be sure. I love your video's by the way .
so like you were saying with me on the other video, do I torque it down to 25ftlb instead of doing the 1/2 turn?
Yes, just be sure you are on the base circle of the cam lobe. Ie the opposing valve is fully open on that cylinder.
+ThunderHead289 ok, I am using the stock springs on the heads and can't get consistent marks, like I'll be adjusting it longer 1/6 of a turn at a time and a fat line goes closer and closer to the middle and the then it just goes way off to the left of the post
+0fVolfAndMan it's very hard to do with flat style rockers. Is that what you have?
+ThunderHead289 well, theyre rounded but have a big surface area
+0fVolfAndMan gotcha, those are tough. Stock heads? What cam?
Same method 408w with link bar lifter ??
Yes
I am surprised that u used head bolts instead of studs.
I don’t understand , why you add some mystically imagined 0.25 , when you can just fully tighten the rocker arm to factory specs , and measure the actual length without any gessung and adding some 0.25 . I watched all u tube videos and no one explained how do I tighten the rocker . Do I just tighten to zero lash , or zero lash plus fully tightened ( 3/4 of a turn ) no one explained it . I don’t get it
There are multiple types is why - your explaining pedestal rockers. These are stud rockers which require a preload from zero lash on a hydraulic lifter.
And now you know
ThunderHead I need some assistance on a 91 roller 302 with AFR 165 heads, so I ordered a extra trick flow roller lifter and modified it to be a solid lifter (welded the cup solid) anyhow I pretty much followed your video to get a good length on a pushrod 6.35 inch. I torqued down my heads with a gasket... do I add the preload to the length of the push rod I believe it was a quarter turn in your video?? ill wait for your input before I order my pushrods. thank you sir
thunder bolt hey,
I add the 20-25 thousandths to the length so 6.35 would be 6.37 or so.
That really doesn’t look like it’s going to effect you.
I remade this video and explain in much better in my opinion. Here’s the link -
ua-cam.com/video/76wbtu9l09A/v-deo.html
So I'm not to sure I understand 100%. So the marker was used to see how much the rocker was riding on the valve stem?
Yes indeed - if the rocker geometry is right, the contact pattern will work through the center of the valve stem. i actually just remade this video a few days ago - check my recent uploads - its a bit longer, but more straightforward.
You definitely do not need those "special" springs.
If you don’t, your lifters collapse and you have an inaccurate reading. Unless you make a solid lifter the exact same geometry of a hydraulic, you in fact do
@@ThunderHead289 nope! It's simple, don't collapse them. That's more for those not paying attention.
I've been doing this for over 20 years, I've checked lengths with and without. They give you no advantage except a lighter wallet.
@@saltycrowgarage7215can you please post a video on how you find pushrod length?
@@saltycrowgarage7215also if you been doing this for 20 years then why are you watching this video?
@@chickenfoundation9323
😂 right
what did you do with this engine
Sold it unfortunately
damn
I want 7thawss RPM 😭
I disagree with using light springs when checking for pushrod length... You should use the valve spring thats going in the overall build to determine it correctly.. My Opinion
You will get a bad measurement from deflection in your pushrod checking tool.
As long as you account for your preload, you are fine.
If you don’t use a solid lifter when using the actual spring, you will absolutely get a bad read.
Does this make sense?
@@ThunderHead289 will a solid lifter bend the checking tool or is that when you only use checking springs?
Are you running a solid lift? you need to reply
David Gray hydraulic
Go get the right head gasket torque all that shit down and start over .......Stop talking about how many turns on your adjustable pushrods and actually measure your pushrod
I don’t think you have an accurate understanding of how to measure pushrod length. Maybe you need to watch this again.
Why not measure it and skip buying expensive garbage garbage or you're not a real engine builder just wanna be God-bless everyone
God you mid lift people I swear. The amount of times I see you all mess it up is uncanny.
I'm thunderhead289 - respect the people that can dance circles around you with a blindfold on.
This ungrateful bs is why I quit helping the automotive community this year.
@ThunderHead289 hey bud I just wanna say I value your content very much, this is all new to me and you informative videos have Given me the extra confidence to get the job done,
I understood nothing.
then you shouldn't cam your engine yourself.