Correct pushrod length? - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

Kbell99 · 05-10-2021, 07:48 PM

When i checked for 0 lash, my pushrod length was 7.525 (7.5+ a half turn). I talked to the tech guy at Johnson, and he advised me to go to about .050 preload instead of the advertised .035, due to engine expansion. I ordered 7.575” pushrods from trend performance. When I put the rockers on none of them sat on the pedestal, but after i torqued them down they were fine, a little side to side just like they were supposed to. 1 of the rockers canted to the side a hair, its still on top of the valve, but not perfectly in line with the pedestal. I have to dyno this Friday 5/14, and am wondering if i should just bite the bullet and order a slightly smaller set.. any advice would be appreciated

Clarkstar · 05-10-2021, 08:18 PM

Which lifters? Stock rockers?

Kbell99 · 05-10-2021, 09:31 PM

Quote:

Originally Posted by Clarkstar

Which lifters? Stock rockers?

I have johnson 2116LSR lifters and yeah kept stock rockers and went with the TSP trunnion upgrade.

Clarkstar · 05-11-2021, 05:53 AM

Well, I measured every one and ordered the lengths I needed for .035 preload. I think I ended up with 6 different lengths total. Maybe overkill for a streetcar but I wanted it right...

Your probably ok with the length you have, and it should be quiet. If you want to be 100% sure you have to measure them all.

Bildo · 05-11-2021, 06:10 AM

Quote:

Originally Posted by Clarkstar

Well, I measured every one and ordered the lengths I needed for .035 preload. I think I ended up with 6 different lengths total. Maybe overkill for a streetcar but I wanted it right...

Your probably ok with the length you have, and it should be quiet. If you want to be 100% sure you have to measure them all.

Absolute correct way to do it!

Kbell99 · 05-11-2021, 06:25 AM

Quote:

Originally Posted by Clarkstar

Well, I measured every one and ordered the lengths I needed for .035 preload. I think I ended up with 6 different lengths total. Maybe overkill for a streetcar but I wanted it right...

Your probably ok with the length you have, and it should be quiet. If you want to be 100% sure you have to measure them all.

Okay, i dont have the tools to measure my final length, as i am doing this in a frickin apartment. But thats what i kinda figured the one rocker sitting slightly crooked is just a concern, i read that sometimes the rods are a hair longer or shorter so i think thats what I’ll chock it up to, and just pray when i start it that my valves dont falcon punch my pistons.

Clarkstar · 05-11-2021, 08:33 AM

Quote:

Originally Posted by Kbell99

Okay, i dont have the tools to measure my final length, as i am doing this in a frickin apartment. But thats what i kinda figured the one rocker sitting slightly crooked is just a concern, i read that sometimes the rods are a hair longer or shorter so i think thats what I’ll chock it up to, and just pray when i start it that my valves dont falcon punch my pistons.

How did you get your length? You have an adjustable push rod? That's really all you need... I used a caliper to measure mine to be sure... but I think just going off the adjustable push rod will be good enough.

zz430camaro · 05-11-2021, 01:14 PM

When i checked for 0 lash, my pushrod length was 7.525 (7.5+ a half turn). What does the 1/2 turn mean? Zero lash is when all play is taken up and no pre load. If 7.525 was truly zero lash then a 7.575 push rod will be just fine, that lifter has 0.100" plunger travel so it will be in the middle when cold and you have plenty of room on either side. Did you start it? Is it really noisy?

1LEsteiny · 05-11-2021, 05:03 PM

Did you tighten them down when each cylinder was on base circle?

Kbell99 · 05-11-2021, 05:54 PM

Quote:

Originally Posted by Clarkstar

How did you get your length? You have an adjustable push rod? That's really all you need... I used a caliper to measure mine to be sure... but I think just going off the adjustable push rod will be good enough.

I just measured for length at 0 lash with the adjustable, then added my preload to that, is it a problem that the rocker isn’t perfectly square with the pedestal? It only took 3/4 after hand tight to get to torque value so it should be right, but the rocker is a little cattywompus

Clarkstar · 05-11-2021, 07:15 PM

Quote:

Originally Posted by Kbell99

I just measured for length at 0 lash with the adjustable, then added my preload to that, is it a problem that the rocker isn’t perfectly square with the pedestal? It only took 3/4 after hand tight to get to torque value so it should be right, but the rocker is a little cattywompus

3/4 turn is fine...

I'd take that rocker off and make sure your on the base circle then try again

05-10-2021, 07:48 PM	#1
Kbell99 Drives: 2011 Camaro 2ss Join Date: Apr 2021 Location: Newport News Virginia Posts: 9	Correct pushrod length? When i checked for 0 lash, my pushrod length was 7.525 (7.5+ a half turn). I talked to the tech guy at Johnson, and he advised me to go to about .050 preload instead of the advertised .035, due to engine expansion. I ordered 7.575” pushrods from trend performance. When I put the rockers on none of them sat on the pedestal, but after i torqued them down they were fine, a little side to side just like they were supposed to. 1 of the rockers canted to the side a hair, its still on top of the valve, but not perfectly in line with the pedestal. I have to dyno this Friday 5/14, and am wondering if i should just bite the bullet and order a slightly smaller set.. any advice would be appreciated

05-10-2021, 08:18 PM	#2
Clarkstar Drives: 2013 1SS 1LE Join Date: Jun 2016 Location: Ixonia wi Posts: 1,456	Which lifters? Stock rockers? __________________ 2013 1le- Katech 416 short block, TSP custom grind cam, LOD intake, cnc heads by F.ED., Nick William's 102mm T.B., CORN fed, Pedders coilovers. Performance street alingnment by Justin at Lake Country Alignment and dyno tune by Late Model Throttle. 603 h.p. 495 ft lbs tq.

05-11-2021, 05:53 AM	#4
Clarkstar Drives: 2013 1SS 1LE Join Date: Jun 2016 Location: Ixonia wi Posts: 1,456	Well, I measured every one and ordered the lengths I needed for .035 preload. I think I ended up with 6 different lengths total. Maybe overkill for a streetcar but I wanted it right... Your probably ok with the length you have, and it should be quiet. If you want to be 100% sure you have to measure them all. __________________ 2013 1le- Katech 416 short block, TSP custom grind cam, LOD intake, cnc heads by F.ED., Nick William's 102mm T.B., CORN fed, Pedders coilovers. Performance street alingnment by Justin at Lake Country Alignment and dyno tune by Late Model Throttle. 603 h.p. 495 ft lbs tq.

05-11-2021, 01:14 PM	#8
zz430camaro Drives: 2015 1LE Join Date: Oct 2015 Location: Cleveland, OH Posts: 1,485	When i checked for 0 lash, my pushrod length was 7.525 (7.5+ a half turn). What does the 1/2 turn mean? Zero lash is when all play is taken up and no pre load. If 7.525 was truly zero lash then a 7.575 push rod will be just fine, that lifter has 0.100" plunger travel so it will be in the middle when cold and you have plenty of room on either side. Did you start it? Is it really noisy? __________________ 2015 1LE, TSP 225/236 113+3, VMAX Throttle Body, CAI with race scoop, GPI Ported Intake, Land Speed Stage 2 Heads, 1-7/8 headers, NPP exhaust, 25% Fluidampr, LT1-S Monster Clutch, 485 RWHP & 444 TQ

05-11-2021, 05:03 PM	#9
1LEsteiny Drives: 2015 1le Join Date: Feb 2021 Location: Ohio Posts: 26	Did you tighten them down when each cylinder was on base circle?