XtraCajunSS

iTrader: (2)

Also, make sure the ball bearing is the same size as the stock pushrod tip. That bearing appears much too large. The ball end of the stock pushrod I'm using measures out at .3115". I've measured this 10 times and keep getting the same thing. FWIW, I am using a piece of stock GM pushrod .460" long with both lifters. I am getting overall lengths of 2.7650" and 2.7655"

Shane

Havoc40

correct, anything with a d-bar or trays.

XtraCajunSS

iTrader: (2)

I can appreciate your disdain for that term. What I can tell you is that I answer tech calls ALL DAY LONG from my own customers AND many other shop's customers some of them VERY well known in the LS1 community. My specific area of personal interest in performance engine building is focused on all things valvetrain related. Its just what I like to do. I have corrected countless customers mismatched combinations by diagnosis over the phone and most of these problems are caused by incorrect pushrod length and or improper rocker arm or spring choice or setup. I have had customers ask me how I could possibly know what was wrong with their car before I even saw pictures or before they even had the valve covers off. There are hundreds of members here who could attest to that fact. If you call here and ask what pushrod length you will need in almost every instance on an otherwise stock LS engine, I will give you the proper length the first time. Most customers appreciate that fact since they are trying to get the right parts the FIRST time. My experience is invaluable in this regard.

maybe a better term would be internet mis-information.

Shane

SweetS10V8

iTrader: (4)

I too alway tell everyone you have to measure no matter what anyone says, on PTV, pushrod lenth, or whatever.

We simply must have different lifters somehow. I dont think there would be a .045" tolerance stackup on a lifter.

XtraCajunSS

iTrader: (2)

That definitely must be the case. I only even went through this whole exercise because I have installed so many of the same cams with LS7 or LS1 lifters and time after time the preload is the same. I got so tired of hearing that the lifters were different I pulled a few and started checking. I have LS1 lifters from multiple engines and of course nearly an unlimited supply of new LS7 lifters to test.

We do check lifter preload on every install here. When we sell a cam package, we give the customer the pushrod that best fits their stated mods and most of the time we are right on. I can hardly remember the last time I used a pushrod shorter than 7.375". In almost every instance on a stock motor with a cam over .600" lift, the 7.425" pushrod is the proper choice.

Thanks for taking the time to setup your measurments perhaps I'll send you a few lifters to check out for yourself. Let me know if you are interested.

Thanks,
Shane

Havoc40

Being new here, I kind of feel obligated to keep contributing to this. I've been in engineering, manufacturing lifters, for about 11 years now. The dimensions that contribute to O.A.L. add up quickly. Things like axle hole locations, pushrod seat thickness, pushrod seat location, clip groove location, etc. etc. etc. Not saying I like what I'm seeing, these numbers are a little excessive IMO. All I was pointing out is that a +/- .025" (.050 total) extended length is common practice on mass production lifters. Aftermarket manufacturers, like myself, can and will hold tighter tolerances, but at a premium. From my observations, these are still intended to be dimensionally the SAME lifter as every other GM roller.

1989GTA

All I can say is Hmmmmmmm.

speedtigger

iTrader: (16)

I will throw another interest twist to the discussion. I just replaced the lifters in my LQ9. The lifters looked identical meaning they both looked like the LS7 style fully shrouded lifters. When I bolted it all back together, I measured with the Comp Cams 7702-1 checker and found that I now need a shorter pushrod. In fact your measured difference of .0425" looks about right for my situation too.

brian_rs/ss

i wonder if there is an unspoken difference in production runs....and if there's even anyway to find out. hmmmmmm.

not that it even matters to me, i am using morel link bar lifters, but this is still a question that needs a definative answer.

ShoddyHog

iTrader: (1)

If a picture is worth 1,000 words, how much is a video worth?

LS2 lifters in this video were removed from my cammed LS2 (25,000 miles cammed), and replaced with LS7 lifters when I installed my LS3 heads. They lasted about 45,000 miles before failing, and taking out the cam with it.

I replaced them with Lunati / Morel Street Hydraulic Link Bar lifters, and since I've seen everyone fussing about this, and don't trust anyone, I measured. Found these differences:

LS2 = shortest
LS7 = LS2 + 0.05"
Morel = LS2 + 0.06"

www.youtube.com/watch?v=GSnKcxx8GWE

speedtigger

iTrader: (16)

The question is: Does the ls7 lifter have a .050" larger plunger travel or not.

ShoddyHog

iTrader: (1)

If GM "techs" are dropping those in as a direct replacement, then they would have to have more travel. Unless you really think they actually check pushrod length.

speedtigger

iTrader: (16)

One would think so. I have just not heard of anyone actually checking.

ShoddyHog

iTrader: (1)

I hate to do this, but LOL.

My best friend has been is GM master tech, and has been working at a Pontiac (now Chevy) dealer for 30 years...I owe him a phone call.

I have the original FSMs for my GTO. I haven't looked, but I'll bet you a 12-pack, it doesn't explain anywhere in the book how to check preload.

95ONE

iTrader: (1)

Don't forget to line bore your rods after using ARP Rod bolts..

LT194CamaroZ

iTrader: (15)

So does this mean my raptr cam kit I ordered has 7.425 pushrods coming with it? Thanks for the time you've put in with all these measurements just to dispell a myth for the lsx community.

ShredSled

iTrader: (11)

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