Pushrod question - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

scottm078 · 03-14-2024, 02:44 PM

Hi guys. I’m putting a cam in my car and had a question about measuring the pushrods. I measured 7.3. (6.8 for tool and 10 turns at .05 each). I also verified with a set of calipers. The pushrods I ordered are 7.35 to account for preload based on everything I’ve read. Basically looking for assurance that I did it right and I’m not an idiot (I am). It’s a sum-8715r1 cam and I’m using the stock lifters (ls3). Thanks.

scottm078 · 03-14-2024, 04:29 PM

So I found this video and did the turn method. With 7.4 pushrods I got 1 1/4 on the intake and 1 1/2 on the exhaust. With a 7.35 I got a 1/2 turn on the intake and a 3/4 turn on the exhaust. I have both lengths coming in the mail. I think I may use the 7.4 for the intake and the 7.35 for the exhaust.

https://m.youtube.com/watch?v=0prKu4292EQ

morepowerjoe · 03-14-2024, 05:06 PM

I'm not sure about all that turning stuff, but this is how I do it. Get to zero lash on the base circle of the cam by rotating the engine until the cam is not on the lobe. Put the rocker arm on and hand tighten the rocker arm bolt all the way down and you should be able to just spin the pushrod checker. If it's too loose remove the checker and unscrew the checker until there is no play in the pushrod length checker and you can just spin the checker. If it's too tight then screw in the checker until you can again just spin the checker. Then measure the checker with a large caliper and add however much preload you want to run. I shoot .060-.080

So if you have measured out a 7.3 inch pushrod with your checker and add say .060 for preload then you would need a 7.36 pushrod

I bought this caliper to measure the pushrod checker
https://www.amazon.com/VINCA-DCLA-12..._ba_s_3_t&th=1

morepowerjoe · 03-21-2024, 05:13 AM

I revised my post above. Sorry I was so vague.

03-14-2024, 02:44 PM	#1
scottm078 Drives: 2013 Camaro ss 1le Join Date: Jun 2022 Location: New Hampshire Posts: 20	Pushrod question Hi guys. I’m putting a cam in my car and had a question about measuring the pushrods. I measured 7.3. (6.8 for tool and 10 turns at .05 each). I also verified with a set of calipers. The pushrods I ordered are 7.35 to account for preload based on everything I’ve read. Basically looking for assurance that I did it right and I’m not an idiot (I am). It’s a sum-8715r1 cam and I’m using the stock lifters (ls3). Thanks.

03-14-2024, 04:29 PM	#2
scottm078 Drives: 2013 Camaro ss 1le Join Date: Jun 2022 Location: New Hampshire Posts: 20	So I found this video and did the turn method. With 7.4 pushrods I got 1 1/4 on the intake and 1 1/2 on the exhaust. With a 7.35 I got a 1/2 turn on the intake and a 3/4 turn on the exhaust. I have both lengths coming in the mail. I think I may use the 7.4 for the intake and the 7.35 for the exhaust. https://m.youtube.com/watch?v=0prKu4292EQ Last edited by scottm078; 03-14-2024 at 04:29 PM. Reason: Adding link

03-14-2024, 05:06 PM	#3
morepowerjoe Drives: 2012 Chevrolet Camaro l99 Join Date: Aug 2020 Location: Austin, TX Posts: 2,232	I'm not sure about all that turning stuff, but this is how I do it. Get to zero lash on the base circle of the cam by rotating the engine until the cam is not on the lobe. Put the rocker arm on and hand tighten the rocker arm bolt all the way down and you should be able to just spin the pushrod checker. If it's too loose remove the checker and unscrew the checker until there is no play in the pushrod length checker and you can just spin the checker. If it's too tight then screw in the checker until you can again just spin the checker. Then measure the checker with a large caliper and add however much preload you want to run. I shoot .060-.080 So if you have measured out a 7.3 inch pushrod with your checker and add say .060 for preload then you would need a 7.36 pushrod I bought this caliper to measure the pushrod checker https://www.amazon.com/VINCA-DCLA-12..._ba_s_3_t&th=1 __________________ DSS Pistons, Eagle ESP L19 Rods, ARP Head and Main Studs, TSP PRC CNC Ported Heads milled .030, Cometic .040 Head Gaskets, GPI SS3 VVT Camshaft, GM Racing Lifters, CHE Trunnions, Melling 10355HV Oil Pump, Cold Air Inductions CAI, Fast LSXR Intake Manifold, Nick Williams 103 TB, TSP Longtubes, ZL1 Fuel Pump, Mishimoto Radiator and Oil Cooler, 3600 Circle D Converter, Tru Cool 40k Tranny Cooler, Fluid Dynamics Balancer, EBC 3GD Rotors with EBC Bluestuff NDX Pads, Bilstein B6 Shocks / Struts with Eibach ZL1 Drop Springs Build Thread https://www.camaro5.com/forums/showthread.php?t=609817 Last edited by morepowerjoe; 03-21-2024 at 05:11 AM.

03-21-2024, 05:13 AM	#4
morepowerjoe Drives: 2012 Chevrolet Camaro l99 Join Date: Aug 2020 Location: Austin, TX Posts: 2,232	I revised my post above. Sorry I was so vague. __________________ DSS Pistons, Eagle ESP L19 Rods, ARP Head and Main Studs, TSP PRC CNC Ported Heads milled .030, Cometic .040 Head Gaskets, GPI SS3 VVT Camshaft, GM Racing Lifters, CHE Trunnions, Melling 10355HV Oil Pump, Cold Air Inductions CAI, Fast LSXR Intake Manifold, Nick Williams 103 TB, TSP Longtubes, ZL1 Fuel Pump, Mishimoto Radiator and Oil Cooler, 3600 Circle D Converter, Tru Cool 40k Tranny Cooler, Fluid Dynamics Balancer, EBC 3GD Rotors with EBC Bluestuff NDX Pads, Bilstein B6 Shocks / Struts with Eibach ZL1 Drop Springs Build Thread https://www.camaro5.com/forums/showthread.php?t=609817