How to Measure LS Engine Pushrod Length (In 7 Minutes)

[@travismcalister5241]

This is by far the best explanation on push rod measurement on the internet.

[@MapesTom]

Hey Jacob, love the videos, but I have a serious piece to this that everyone seems to miss. THE "GAUGE LENGTH." Hope this all makes sense, here goes- Basically, if you measure 7.350 with your adjustable, and order 7.400 for .050 preload, you'll actually end up with approx .067 preload, because the 7.400 is a nominal measurement. You'll see this if you recheck preload with a dial indicator when installing your new pushrods that you measured/calc'd. The pushrod companies add about .016-.018 because of the cups/oil holes/etc. YOU NEED TO SUBTRACT .017 FROM YOUR MEASURED LENGTH, then add lash, and order that length. .017 might not seem like that much, but when you're already fudging one way or the other to get to .025 steps of available sizes, it can throw your preload waaayy off. If you have over .200 of preload to play with, it's probably fine. But not all lifters have such a large range, and adding almost 20 thou of preload could hang valves open. Most people probably don't notice, but I learned the hard way after my measurements didn't add up, testing with a dial indicator for preload during installation. I called Trend pushrods to get this figured out during my troubleshooting.

[@nickferguson9418]

Thanks for this comment. I am measuring for new pushrods and noticed that my old pushrods measure at 7.4155" even though they have 7.400" etched on the side. I was having a hard time finding any info online about it but haven't called a pushrod company yet.

[@frankdatank7751]

Awesome information Thankyou

[@gustavosanchez8158]

Thank you I measured exactly like this and ended up with my valves open no compression....pushrods too long....I'm assuming because my johnson lifters have less margin of error than the other lifters

[@MapesTom]

@gustavosanchez8158 when you say you measured "like this" do you mean you compensated like I described? Or did it like the video and found that to be the problem?

[@gustavosanchez8158]

​@MapesTom by doing it like the video and not subtracting the .017. I found out last night going from no compression to 150 just by cracking the rocker bolts. If using ls7 lifters or sum with a wider range of preload might be ok but with the Johnsons I think that's the issue.

[@gkft]

Explained very clearly and concisely, great video.

[@daryltaylor659]

You have really helped me on my LS1 build, thank you

[@evcass69]

Exactly how I did my st2126lsr's. I had oem ls3 heads, new oem valves, fresh vj, still unhappy with variance. New rocker stand helped. Still had 3 that seemed to hang a valve open, Manton got them to me the next day and we were good.

[@NoMercyGTCS]

Will manton make a custom set with different lengths in it? If say i measure all 16? I have ST2116LSR lifters

[@evcass69]

@@NoMercyGTCS They sure will. Give them qty x overall length.

[@NoMercyGTCS]

@@evcass69 What would you advise if the lengths vary per valve? do an avg of some sort?

[@evcass69]

@@NoMercyGTCS hmm, I suppose I'd error slightly longer if I stayed within the lifter preload range.

[@NoMercyGTCS]

@@evcass69 i’m trying to be certain i dont hang a valve open! Didnt know if that meant sticking on the shorter side of my doubts lol.

[@GrandPitoVic]

WOW brother!!!! That's way easier. You def give useful information. Thank you

[@JacobVillemain]

No problem 👍

[@russcole5685]

Are thete a type of adjustable rockers available so you dont need to get push rids of different lengths

[@illnock1]

Where did you get those calipers??

[@chandlerlofton6536]

Good info! I’m trying to get my Yella Terra rockers/ LS7 lifters to shut up. I’m going to use this when I change to a different cam I got. What preload works best on LS7 lifters? I’ve been told they have .200 plunger travel. Should I go .100 on my preload? I just want a motor that doesn’t sound like a sewing machine.

[@bwill03z76]

You can run up to .100 preload on the LS7 lifters but I personally feel Iike .070 to .080 is the sweet spot

[@6xcchamber971]

Are Factory LS engines the same as this, I thought they were the same length??? Thank you!!!

[@papergatorzfedducca7998]

So the exhaust and intake will have different measurements throughout the engine? Thanks for the video.

[@NoMercyGTCS]

Awesome video bud! Thanks for going into detail on this subject, you tha man!

[@timweb1510]

Thanks for the content, always trying to learn more

[@JacobVillemain]

You're welcome!

[@toddgreim9254]

Another great detailed video, thanks.

[@peterphan8990]

Jason, do you recommend soaking the lifters in oil before doing this measurement?

[@saschan.6070]

New to this. Working on my first LSA. What is the point of lifting the rocker back off the valve stem towards the push rod? I see some people do it and some don't.

[@l77scmaro2]

You can feel the lash close up so you feel when to stop and it helps keep the pushrod seated on the lifter while turning it.

[@Trikekid84]

Awesome video!

[@jameslahee3658]

That's really doing your homework awesome

[@joshC6GS]

Do you just have to measure both intake and exhaust. Or measuring the intake enough .

[@privatedata665]

great content as usual . Thanks !

[@JacobVillemain]

Glad you liked it!

[@tristenoberlender9685]

The head is fully tightened on right?

[@jamesb5010]

Another great and informative video. Do you know when you guys will get the Gaterman link bar lifters back in stock? Looking to pickup a set for my Ls build.

[@JacobVillemain]

They are on the way to the shop. We have several sets already backordered though.

[@NoMercyGTCS]

Tried this tonight, after torquing the bolt down, i tried to spin my checker to extend it, and the entire pushrod checker spins on the lifter bucket. Any tips to get just the top portion to spin so it will extend up to the rocker arm?

[@93vertz42]

Same here, very annoying. Ended up using a different method

[@darryn3791]

Mine did the same. I found I could wind it in though. So started bigger and wound down till I found the sweet spot

[@chaasayadsawapah]

I went through 3 days of foolishness with this tool. It kept spinning when I removed it to measure. It spins the entire tool. I ended up using tape to hold it in place. Next time, I will order multiple sized pushrods.

[@caymccarp34]

This is exactly what I need to see. I'd like to build my first LS 6.0 LQ4 for my first motor. Can you do a series on start to finish ? Short block to long block. I wanted to do a 1000 hp 6.0 with a roots blower. I love your videos, you make the videos easy to understand, thanks

[@BucketList22]

Ok so do you subtract the width of the bulkhead from the total measurement? I would know that if the person said the measurement.

[@Six_ftdeep32]

Would lapping the valves cause a significant enough change in pushrod length to re-measure?

[@JacobVillemain]

No it would not...unless you lapped one valve for hours haha

[@Six_ftdeep32]

@@JacobVillemain ok cool thx man. Great video btw

[@flexmasterscx1056]

How much preload on a stock lifter

[@JayThomp04]

So basically you just add your desired preload length to the measurement of the adjustable pushrod at zero lash ?

[@phild6509]

Is it important to check all of them or just a pair on each bank?

[@JacobVillemain]

I check one cylinder on 90% of our builds. If everything is machined square & parallel there should not be more than 0.005-0.010” difference across the 8 intakes & 8 exhausts. (It is normal to run two different lengths on I vs E)

[@Robert-uc5pb]

I'm doing a head gasket job on an 07 Yukon Denali. I got the heads back on an now I'm installing new Rocker arms. I notice when I'm torquing the arms to 22 ft lbs the tip of the arms are sliding from the center of the valve stems the tighter they get. Also the springs are compressing as I torque them. I'm quite sure the #1piston is top dead center and the pushrods are seated properly. What can possibly be the problem? I live in Minnesota and I'm trying to get the truck up and running before winter hits. I would greatly appreciate your help

[@44special9]

When the # 1 piston was at top dead center were you trying to tighten them all down at once or just the valves at the # 1 piston ?

[@Robert-uc5pb]

@44special9 I was tightening down the valves on the #1 piston. The intake rocker was sliding off the center of the spring while torquing and the exhaust rocker compressed the spring quite a bit once it was torqued to 22 ft lbs. I'm doing this job for my nephew. He ordered some rocker arms that were supposed to be for either a 4.8, 5.3, and 6.0l engine but he has a 6.2l would that make a difference?

[@44special9]

I checked the specs. on the On ALL Cylinders website and it appears that the 6.2 l. has rocker offset on the intake rocker and the smaller engines have no rocker offset which might explain it sliding off and why the 6.2 l. wasn't listed on the box , just my guess . As for the exhaust rocker compressing the valve spring , you may have had the #1 piston at top dead center on the exhaust stroke (lifters not on base circle) and not TDC on the compression stroke . It's best to have the lifters on the base circle so you're not fighting the valve spring and the torque wrench doesn't want to click off before the rocker is seated . If you're sure you did then the exhaust rocker may be different on the 6.2 also . To be sure you can turn the crank clockwise (viewed from front) and feel the intake pushrod rise and as soon as it falls the whole way start watching for the TDC mark because it will be at the pointer soon and line them up or some other method of getting the lifters on the base circle because there's plenty out there . Hope this helps . @@Robert-uc5pb

[@44special9]

I believe lining the timing marks up to get TDC only works on pistons 1 and 6 but when one is on the compression stroke the other is on the exhaust stroke .

[@jasonfoust2010]

How do you spin the adjustment without spinning the entire pushrod?? I tried this method and the entire pushrod spun in the lifter

[@dgc940]

So Ive did lots of old school SBC but only thing I know about a LS is one is in my truck well actually I have a 5th gen I guess 2017 lol. so unlike old school on a stock LS they would be no preload and zero lash? Not working on anything just curious and trying to understand.

[@l77scmaro2]

They should have some preload if everything is stock. Remember, in this video he's checking at zero lash then adding .050 preload to the measurement for his custom application. A stock engine should have preload built into the the stock parts.

[@slicksloth_416]

What brand caliper are those?

[@syndicatestunts]

Hell yeah! Way easier 🙏🏽🤘🏽

[@regsmith7604]

Can’t wait to see that RHS 427 on the dyno. Can you do some N/A pulls too, just for good measure

[@JacobVillemain]

It will be dyno tested N/A!

[@regsmith7604]

@@JacobVillemain 👏🏽

[@WizKidAbLe1]

Can you do a video on how to set lifter preload?

[@m.r.s.mobilerepairservices8895]

He did that already in the measurements by adding .050 to his overall measurement to account for lifter preload

[@AustinJC77]

@@m.r.s.mobilerepairservices8895is that the same for every lifter or does it vary like can .050 be use for all lifters?

[@OminousCamaro]

@@AustinJC77many lifters are preload specific. For instance Johnson 2116SLR’s require a .030 +-.005 preload. Each manufacturer will vary and usually list the recommended preload of their lifters for optimal performance.

[@DJsConstrictors]

Might be a dumb questions but will pushrod length change/vary with different cams? I’ve never built a motor before and I’m going to try to LS swap my 98k1500 so I’m trying to learn as much as I can before I start

[@JacobVillemain]

It is possible.

[@turbotysen]

You only gotta measure 1 hole unless…. you have johnson short travels😂😂

[@mastmec]

i check them all because i have to recheck everything i get, especially from the manufacturer and some machine shops

[@02agray14]

Off topic here, but do you know of any resources or can provide the process of programming fuel injectors? I am doing a stock rebuild on my 5.3L LC9 and want to replace all the injectors. GM mentions the replacement injectors need to be programmed and I'm not turning up much luck searching

[@Six_ftdeep32]

You will need to input the data that comes with the set of injectors that you buy, into the ECU. Not sure if that's what you're asking about.

[@coarsegrind]

Don’t you have to account for the oil hole in the measurement?

[@alexanderknight7793]

Definitely have to zero out your caliper first before you go taking measurements, most likely why your intake and exhaust where so far off. But I like your method I’ll give this a shot when putting my engine back together next week with a fresh set of Johnson’s

[@JacobVillemain]

Caliper is zero'd. The intake valves are titanium so they run lash caps. That's what there is a different length compared to the exhausts.

[@bat5917]

What happened with Ricky?

[@JacobVillemain]

Racing got expensive. He is currently in the garage waiting to go to the fab shop to get the twin turbo kit made.

[@akuengi]

This is great except my entire pushrod lenght checker rotates 💀

[@LilLouisTV]

Fucking same 😂🤦🏾‍♂️

[@BEANS-O-MATICtransmissions]

Don't use this method (checking just one) without billet stands, factory cast LS stands can vary quite a bit ! If using factory stands, measure every one. Also, an easy way to remember which valve to adjust is, Every=exhaust Oliver=opening Is====intake Cool==closing YW=you're welcome

[@kevinwest3689]

If you're new" let me do you a big favor. This is not correct. If you want to approach it in this manner, you have to use a light spring inplace of those heavy springs. I pinch it here with my finger and then measure.... seriously?! 🤯 For those of you watching this with no experience at all. Before you make a decision go watch richard holdner. Then make your choice 📌

[@michaelslack6891]

Wrong. He is not spinning the motor with the rocker arms torqued down. Thanks for the video man!

[@TimothyGambino9085]

Doesn’t tell you where the rocker tip is on the valve stem . Anyone could take up lash and the rocker tip could be to far inboard or out board of the tip

[@yafois988]

Important to KNOW the lifter has oil in it to get correct operating height to do measurement. If is empty or partial fill, will not be best measure length.