I Have been trying to figure out the 90° reference for 4 hours, this video finally made me understand it and made it seem so easy! This was the only one I could find on the internet. Thank you so much 🤘🤘

I talked to Scott over the phone about this process to determine pushrod length. I checked all the corner cylinders of my build and I can say that this process worked flawlessly as it delivered the most lift and least amount of rocker sweep across my valve stems, each and every time I checked and double checked. Great video! Thanks Scott.

Thank you for an excellent video and explanation. I watched a half dozen tonight, and this was the clearest and easiest to understand. Thanks!

I’m literally just down to determining the pushrod length for my TT 383 build and someone on a different video told me about this one and man am I glad I watched it because it made the process so much easier

So I spoke with Scott on the phone and he took the time to explain to me in more depth the problem I was having with this method. Basically I was off a bit measuring my 90 degree angle. You have to understand the importance of being precise as possible on this step cause the slightest miscalculation is magnified because of the angles and ratios. Once I got it right the pattern on the valve was very narrow and just barely off center, which tells me my valve is being pushed straight down with very little sweep from side to side. This is the correct way to set up valve train.

Awesome vid! And Id like to take a moment to add you’re hands down the most helpful fella Ive run across. Ive never seen anyone say throw out call me if you need help/have questions as you. Hats off to you sir. 👍🏻👍🏻👊🏻

Scott, hands down this is the best explanation/demonstration about. Thank you.

This is absolutely THE BEST description of how to find your proper push rod length.

Thanks for the detailed explanation. Nearly every other video on this topic leaves out the specifics.

Best video I have seen yet on how to properly set up rocker geometry. I just watched a different video that was like you said, full of misinformation. Thank you for teaching proper techniques. Awesome video!

Great video, I’ve been racking my brain trying to figure out pushrod length without swapping springs or using solid lifters like almost every other video says you have to do. Thank you.

Here it is I was pondering how to figure it out, knew the info was somewhere, It’s HERE!! Now I can do my Pontiac heads like this with an entire different set up and get the correct PR pieces .. Thank you Very much for this valuable wisdom teaching!!

Man I cannot thank you guys enough for this video. This is the absolute best I have ever seen this process explained and it made measuring my pushrods so much easier. I can't like a video harder. :D

This is the very best info to make the adjustments and push rod length selection I have ever seen!

Thank you. Just exactly what I needed to learn. Hope you do more instructionals. Very well done

So happy to have found this vid. This has been the most logical explanation of doing this. It all makes sense this way. Hands down. I can't wait to apply this. Thx.

Thanks for sharing I was taking notes as you are teaching because I will be performing this method this weekend on my 468 BBC Hyd Roller Cam . I commend Howard Cams wouldn’t sell me push rods when I ordered the cam now I know the reason. More performance and longer life!!!!

Would just like to say big Thank you for your Talent. At 7:30 in the video your comment, You just established proper pushrod geometry. I then marked the top of my valve stem with a marker and held my rocker up and moved it back and forth over the valve stem. You now can actually see exactly where the rocker roller is located at half lift. Thanks again Scott for the video.

This tutorial just changed the game for me. Very good information!

I've watched a variety of videos read a lot about setting this up. Everything was all guess work. You're the first to introduce math and when dealing with precision measurements, you can't guess, you must measure. But... HOW? Well you clearly cleared that up. I've been stressing for days about doing this and if I'd get it right. Tons of second guessing and re-watching yours and other videos but your's is the only one that made the most sense. Sure enough, I did everything you said and with the first turns of the cam, I am 100% in spec with the rocker roller on the top of the cam. I'd like to offer you a virtual hug cuz you're amazing :)

Valvetrain Geometry is something most other engine building videos glaze over; this is by far the best video I've seen on how to properly do this.

I was reading "Rocker Geometry" by Jim Miller from Engine Professional, Apr.-Jun. 2010 issue, and trying to wrap my head around it. It's not the easiest article to understand the first time around, and after a couple read overs I looked to see if anyone had done a video on it. This one here made it click right away, and makes it easy. For anyone who watches this, I suggest checking that article out for some more background on why this method works, why measuring "swipe pattern" is tedious, and no way to measure for proper pushrod length, and why a good narrow swipe pattern is simply a by product of using the mid-lift geometry method. Thank you Scott for the easy to understand demonstration.

For those of you that are being sidetract about the rocker ratio and thinking the ratio affects how many turns of the adjusting nut....this doesn't matter.The rocker ratio could be 1.2:1 or 1.9:1........ you still want to have the centreline of the trunions at 90 degrees to the valve at mid lift.....and then when that is established, measure for pushrod length.

This video was amazing! Explains and shows everything so clearly! Thanks!

Thank you, my friend! My first engine rebuild a success thanks to your video.

Great video Scott . Thanks for the information!! Well done 👏🏻🏁😎

Thanks a lot for sharing this video. Very professionally explained.

This is the best video. Very nice explanation, and the camera got in there up close when it needed to

scott , just wanted to say thanks for the video . really helped me out . God bless .

Great video. You're good at explaining.

Excellent presentation! Three thumbs up!

This is by far the best explanation of measuring proper pushrod length and rocker arm geometry. Thank You for this video.

THANK YOU FOR THIS VIDEO!!!😊 Very informative and helpful 👍. Can't make everyone happy. Just some miserable people out there. I got EXACTLY what i was searching for and understood the material exactly. This is not a 72 hour highly detailed engine build, instructional video. So obviously and naturally, some things are going to be assumed. It's a great video about a specific step. No one is perfect. I appreciate the time you took to make this great video. Helped me tremendously in my journey!! My project and i thank you sir. 😊🙏

Great video! Thanks for the excellent explanation. I spent a full day of my life trying to figure out push rod length for my 498 stroker BBC. I used 3 different measurement techniques and got consistently different length estimates. Your technique resulted in the longest measurements by about 0.10 - 0.15 over the other methods I used. I decided to rely on your method rather than collapsing lifters, looking at marker patterns, etc. Hope it works properly for me!

I wish you could do a video on shafted rockers. This video was fantastic! I am trying to apply what you taught me to find proper shafted rocker arm alignment. Thank you

Best explanation on rocker arm geometry .. A+A+A+..

Man on man this is an excellent video. A grade schooler can understand this. Thank you.

Great video. Excellent explanation.

couldn't be explained any better. good job

Loved the video. Well done my friend. Easily understandable and well versed and it tought me a thing or two that for sure.thanks. you just made a subscriber out of me.

I’m dyslexic AH. The whole geometry and pushrod length calculations voodoo have always been scary to me. This! I understand. This I can do and repeat over and over and check it and feel good about it. This gives us dyslexics a simple “visual” way to see it, understand it and accomplish it without the hoping and praying it correct and that we haven’t made a mistake. Thank you sir. Wish I’d seen this years ago!

Thanks...This made more sense than anyone here on KZfaq.

Excellent! Clear and concise!

Thankyou Scott excellent video.

Scott, excellent video! You explain the process so that it's very easy to understand and you're very well spoken. Thank you for taking the time to help us all out. I had a quick question though. Do you measure for both intake and exhaust lengths if you have a split pattern cam? Would you use a different push rod length for both if the gross valve lift is different for the intake and exhaust?

Thanks for sharing that, very good video skills.

Thanks for this excellent tutorial

That was a new way of doing it very enjoyable but still will be measuring both ways just 2 make sure of everything.

Great video. Exactly what I needed.

Great video. Very clear. Thank you!

Using this method I found out the pushrods I originally bought were dangerously short, .25” too short. Damn I’m glad I took the time to do this. I haven’t put too many miles on it yet so I hope the damage to the valve heads is minimal, it was good on the #1 exh valve I used to check this although my wear pattern was obvious, about 3/32” wide but centered over the top. So centering the roll pattern is obviously not the right way to determine PR length.

Great video, crystal clear, thank you, thank you!

I know this vid is like 7 yrs old and contains stellar info I was wondering why no-one has done a video when it comes to shaft mounted roller rockers as setting the pushrod length is quite a different process..I know you said its ok to call I still believe in being courteous and let you ultilize your time in the manner you need to utilize it in instead of me calling at an inopportune time.

Yea. That was pretty clean!! Larry

Waaayyy more informative and detailed than summits video.

This is an outstanding video.

Thank you for this video. Greenhorns like myself need the help. Much appreciated.

Top notch Sir, much obliged for the insight

Fantastic, thank you!!! Thumbs up for this video.

Scott, I read through all the comments and appreciate all the advice you willingly give. I had another question. I may be confused on where a hydraulic lifter sits when pumped up and in a running engine. I think I understand all the measurements and rationale however, here is the question. If I set up the geometry as you say, how is the lifter collapsing due to the 3/4 to 1 turn of the rocker arm nut and the resulting lifter collapsing and or where the push rod seat/lifter top cup (where the push rod sits) affect the measurement that we are calculating. In other words, it seems that the collapsing of the hydraulic lifter (versus solid lifter) would change our measurement (and the 90 degrees and so forth). Thanks in advance for your reply.

expertly explained. thank you!

First off, I'd like to thank you for this video (even though it is many years old now). It makes perfect sense. I was all revved up to go out and do this on my motor. However I ran into a problem. I marked my rocker arm as you did here, but when setting it up on the head, I actually have to RAISE the push rod side of it to try and create the 90 degree relationship. The problem comes in that I run out of threads long before I hit that perpendicular angle. Any insights?

Thank you for the tutorial.

Very nice video.. Thanks for sharing.

Thanks for sharing some of your intelligence. Wonderful detail!

Should edit the video to add a note about stock rocker studs sometimes needing to be swapped out for longer to get this method to work. I’m in the middle of trying to figure this out now. Thanks for the vid!

Great video, thank you for sharing. I was wondering, is there a way to apply this to stock BBC rocker arms? Thanks

This is what a video should be, I clicked he told me what he was meant to....I didn't hear about his wife, weather, or saw wrist and tired....made my day, Thank you.

Great video! .... one question though not directly related to the discussion. Any ideas on the best possible way to combat valve float ??...... all comments will be much appreciated!

Mr. Foxwell, lots of mixed info out there about finding true TDC, how to degree the cam, check it’s specs and measure piston to valve clearance, too. Would love to see what you have to say on these matters. Thanks

fantastic video mate , the real reason the internet is here , knowledge sharing.

Awesome information!

Great video!

Great video and explanation. I'm going to give your method a try. Question. Using hydraulic roller lifters. Do I need checking springs? It appears I wouldn't since I'm going to just add for lifter preload. What do you think? Thank you

Good video very informational !

Fantastic video

Hi Scott, I am curious, how would you apply this to BBC shaft rockers like T&D or Jesel? I can see, how it would be easy to roll the engine to half lift and check the 90 degrees, is that the only way with that style rocker? Do you have anything posted I can look at on this? I love this video itself, it made the visualization quite easy, thanks!

Now THAT was impressive and best of all, you made it EASY to understand, So I gather if my MAX intake lift is .499 is the number to use divided by 2 or the .510 exhaust??Also, if you use a marker on the valve stem tip, is it going to look different than the typical method (center it, rotate, check the mark? ) Part of why I understand this so well is that LP records and tonearms work the same. The angle of the arm outside is very different tha n the inside . So when aligning a tonearm cartridge (using tools) what you are trying to achieve is a balance in the middle because alignment centering at either extreme will cause a flaw at the other end (sorry I digress) hope you can answer my questions and again...AMAZING video

This video is great but could you explain how this method is going to work when you have a shaft rocker like on a mopar small block early LA engine with comp adjustable roller rockers.I dont know the thread pitch on the adjusters . plus how does this relate to the use of lash caps ,which I often do to create a wider wipe area on the valve stem for the roller tip.. hmmm

Seriously awesome video, 👌

I have one question: Previously for piston to valve clearance checking purposes I converted two of the existing hydraulic lifters my engine uses into solid ones. I did this by using washers to locate the top internal moving part of the lifter (sorry not sure what it's called exactly) against the bottom of the retainer wire/clip piece. Should I use the lifters in this condition for the geometry check/set-up or change them back to original first?

Great video! Thanks!

Awesome Video thanks

Could you please make a similar video using shaft mounted roller rockers - showing shimming under pedestal mounts etc. for centerlines?

Awesome explanation!!! With a flat tappet hydraulic cam and lifters. Do I need to use a special modified lifter or would a normal lifter be fine for this check? And I assume the lifter would be sitting at max lift on the cam? Correct?

Question: What is more important - the 90* relationship between rocker and valvestem @ 1/2 lift - OR - a centered swipe of the rocker on the tip of the valvestem? I'm setting up a garden variety healthy 355 sbc. Using 1.6 roller rockers and Flotek 180cc heads. I used this technique to determine PR length. However, with this "correct" length PR, my contact patch between rocker tip and valvestem tip is a bit outboard of the valve centerline. I could "correct" that by shortening the pushrod - but then I wouldn't have the 90* angle anymore. Is one more important than the other?

Now i get it. thank you very much. Now does rocker arm degree change any of these dimensions such as going from a 1.6 to a 1.7 degree rocker arm?

Great video, thanks for the schooling. Paisano

Many thanks, great vid very clear....

would i install head gasket , with a couple bolts with a tad bit of torque to get accurate length also ?

Never have installed a roller cam or rockers before, using the half lift method make sense to me theoretically, just wanted your input and see if my thinking was right on this. Averaging the lift between intake .515 and exhaust .530 on the Lunati 20510711 roller cam .5225 half that .26125/.050 is equal to 5.225 turns past 90 degree point with the valve. So if I stop at 4.5 turns + 1 flat of the adjusting nut to measure for the pushrod, then when it’s installed it would be 5 turns + 1 flat or half turn past zero lash and that should center the roller on the valve stem and set the preload on the lifter?? Will this keep the pushrods all the same length or do you need to do one length for intake and another length for exhaust?

If your mocking up the engine, it's best to use a used (previously compressed) head gasket. This will save wasting a new one to get the head in the location it will be on the finished engine.

Thank you excellent video

I am building a 540 bbc with dart pro 1s. The question I have is to get proper rocker geometry do u need to torque the head down with the gasket? I also need to check my piston to valve clearance. I would hate crush a brand new gasket in order to set the geometry right. What I am really saying I want the proper pushrod for when I check my piston to valve clearance. Any advice would be greatly appreciated. Thanks

If you are in the center of measurement for the available pushrod length, should you go over or short on the length? Great vid!

Should you use the cam card for lift figures or actually measure the overall lift with your rockers. I ask this because rockers are rarely exactly what it is stamped (1.5,1.6 Etc..). great video!

i checked mine on my 383 sbc with a retrofit hydraulic roller cam & lifters using this video & i got that it needs a 7.650" push rod. how much more do i need to add for the lifter preload? the lifters i'm using is Street Performance Hydraulic Roller Lifters, i'm not sure how much preload they require. the sweep pattern is on the exhaust side just about 3/4 of the way across the valve tip, but the sweep pattern is only about .040" wide.

what an awesome video thanks for that mate :)

Wish I saw this sooner lol. Great explanation!

Thanks for sharing