yes. The reason you don't find answers to questions like "will this pushrod length be right" is that most will say you need to measure to get them right. And if you're insane like me you'll measure them all.

 

I'm also doing a build with 5315 Morels so thought I'd post my question here instead of a new thread. I also did two methods to check length but initially thought the EOIC method resulted in an unusual value but after reading this thread I'm not sure. With my comp cams length checker I got 6 5/8 turns for 0 lash. I planned on adding .06 preload which I calculated as a total of 7.825 turns on the checker (I rounded down to 7 3/4 turns on the checker). I hand tightened down the checker/rocker and got 3/4 turn to 22ft/lb. So does that seam reasonable?

Two other comments on what I'm confused about. First overall calculated length is 7.19 with the preload. This seams short. Adding to this, the wipe pattern is on the inside edge of the valve and it looks like the rockers need to be shimmed. Test done with piston 1 at TDC- I stuck the checker in the intake and turned the crank and it started rising so was on the intake stroke (6 and 12 oclock). Therefore test was done on piston 6 and should be on power stroke.

second thing I noticed is that once I tightened down the pushrod checker with preload I moved the rocker around to check movement and the lifter clicked down further. I figured this was due to the new lifter collapsing (lack of oil).

Does everything seem kosher? more details if needed tick street heat stg2 cam, LS1, AI ported high comp heads, .04 gasket.

Just to check I pushed on a couple other lifters and got the same result. Pushed on lifter until it fell out of tray onto cam. Continued to push slightly and the lifter clicked in futher.

 

It would help to know your setup. That seems abnormally short IMO.

 

Start here https://ls1tech.com/forums/generatio...od-length.html

I don't like counting the rotation of the length checker. Get a caliper. Measure the lengths you get. When you order, specify "as measured with a caliper"

Make sure your pushrod is in the lifter cup. That can result in unusually short pushrods.

You need to get the wipe pattern first. You want to shim to get the pattern centered and narrow. There are two schools. One is centered is best even if pattern is wide. Other is narrow is best even if off center. I'm sort of in the middle - narrower than centered and slightly off center, but not where it is narrowest.

Your shins will likely be in 0.120" territory, which puts your pushrods near 7.3x.

 

This engine is going into a midengine superlite build. It's an LS1 from 2004 corvette. Stock short block. Stock rockers with trunion Upgrade. Tick street heat 2 cam for ls1. Brian tooley spring kit installed by advanced induction who did the cnc porting on 241 heads (High compression head they reshape chamber). Note on AI invoice said milled to 60 cc. They did the valve job with stock valves. I assume this is what's causing my wipe issues and why I need shims. Seems like with shims I'm back closer to normal territory of pushrod length. The heads were supposed to leave stock ptv clearance which is why I'm using .04 gasket also.

So regarding the "click" when I push on the lifters when on the cam. Assuming I should not do this before measuring. Please clarify. I did plan on measuring with calipers but wanted to make sure I had an accurate measurement first and wasn't doing something wrong.

This all has me worrying about ptv also.

 

You're right where you should be. I have the same AI heads cut an extra bit (58cc), and 7.200 pushrods in mine with a factory .051 mls gasket. The HCR port on AIs begets a short pushrod due to the way they change its shape vs the final deck cut.

 

Do recommend the 11/32 big wall restricted pushrods from manton if its a road race deal. Stiff, strong, keep your oil from pooling in the top end .

 

Thanks for the info...I feel a little better. Did you have to shim rockers too? How much PTV did you have with your setup?

I was either going to do 11/32 or 3/8 taper.

 

Didn't measure PTV with the new pistons. They have more clearance then the old ones, which had over .1 - I don't have a huge cam. No shims on the rockers.

 

So after reading Svede's and Darth's post, I decided to go back through and measure each valve on the driver side. Sure enough #5 is coming in around .030 preload. So I bought 2 7.350 pushrods and my suspect noise went away. . Cylinder 1 shows .60 preload, 3- .054, 5- .030, and 7- .048. After adding .025 to #5 I am right around .055. I take it this is normal for heads that have been worked over?

 

Added the .125 shims and things look much better. Will look at wipe pattern tomorrow. Honestly looks like it could go a little higher though.



With the added shim I retested length and made sure I was on base circle...now getting 13 turns...lol. That calculates to 7.5" with .05 preload. I had a hell of a time with the PTV testing too. Some of the issue is with the dial indicator moving on me and some is that I don't think the lifter holds up to the check spring for very long. I'd run a test then screw with aligning the dial and check the same degree and get a different number. meh

Anyway. Starting fresh with the other head tomorrow and see what I get....practice makes perfect. And I'm removing the timing cover so I KNOW where I'm at every time. Yesterday COULD have been on wrong circle or I didn't push in lifter enough since the jump with the shims was very high...dunno. I'm going to get this ish eventually though.

 

It's not that unusual to end up with a bastard pushrod length or two. I don't really know why, but I know it happens. My gut is that it's in the pedestal or rocker cradle, but I don't know for sure.

Glad that worked to quiet the motor down. You'll probably notice a bit better tgrottle response. Engines make the most power at equal preloads across all valves.

 

On stock rockers you're not going to get a good tight wipe pattern like you do with roller tips. However, getting yours centered like that has to be good. Also on wipe pattern you don't have to check each one. Check both sides of cylinders 1,2. Once you get a number, use it for all of them.

 

Kinda bummed...tested two cylinders today and intake ptv seems to be at .06 exhaust is fine at .12

I read someone claimed check springs are weak and you can add .015 to the calc but I'm not so sure. I realize the intake side of things is less risky though.

 

So I guess I took a risk going with the .04 cometic gasket with my setup and shouldn't have fully installed things until checked. Because my block was not machined just surface prepped by myself and because I was using cometics I used copper spray on the gaskets. How much of a pain is it to remove that stuff? How many would run the current setup potentially with .06 (+ maybe .015 cause of checker springs) on the intake side? Does it matter that I'm using fairly stiff pushrods (3/8 taper) and springs (BTR)?

 

run it

 

To update...even though my rocker looked better placed with the shims, it was not. Heed some of the other thread warnings about shimming stock rockers. My wipe pattern was much worse especially because the lift is slightly above .600. I wish I didn't buy the trunion upgrade now and had just done rollers but we'll play these out. So back to square one on the measuring. One question because the two preload methods don't seem to a line for me. If I set my checker tool to zero lash then add one full turn (.05 preload) if I then tighten it to 22ft/lb how far around should I expect to go? I thought one full turn but I had to add another half turn on the tool (.025 more preload) to get to one full turn. That's .075 preload for a turn not .049 or whatever it's supposed to be. So I'm either looking at the methodology wrong or overtightening to zero lash or something.

 

Don't forget that the 22 lbs of torque you add after the bolt rocker, bolt ect has seated is not adding to preload. Only the rotation you get up to the point of actually starting to torque is preload. The rest is just stretching the bolt itself. So about 3/4 turn is what I was getting at full preload before the bolt started to tighten and apply torque.

 

Correct. Darth explained this on page 1. Are you reading the instructions provided on how to do this? I know it took me a few tries, but you're just going to need to forget whatever you're doing and follow the steps. The checker turn method is going to keep you confused and inconsistent. Spend $20 on calipers at Harbor Freight. Write down all the measurements if you're not, it helps to visualize everything.

 

I understand that the last roughly 1/3 of the turn is "stretch" but I thought that was all taken into consideration in the 1 turn is .047 preload and shooting for 1.5 turns (for ls7 lifters - .07pl). I took zero lash on the pushrod then added .05 preload into the checker and I should have got 1 full turn (2/3 of which was preloading) but I got more like slightly less then 3/4 turn.

Okay I may just skip all that 22lb then. I measured 9 turns on the tool for zero lash and caliper reading on it was 7.263 overall so adding .05, I'm going to order 7.313". Shouldn't that be all I need?

Edit: Thanks Darth...read after post. Yes had calipers already was just trying to double check. Done. Man there's a lot of conflicting info on some threads. I got it now.