necessary to change pushrods with cam change?
- Thread starter Modular2v
- Start date
You need to buy hardened pushrods if you have guideplates. Are you using the afr's?
You also need to check the pushrods length geometry. Color the valve tip with black marker and then set that rocker and rotate the engine at least twice and check the wear mark. I believe you want it in the center and less than .080".
You also need to check the pushrods length geometry. Color the valve tip with black marker and then set that rocker and rotate the engine at least twice and check the wear mark. I believe you want it in the center and less than .080".
Still using stock heads? Just check the geometry like I said. Then you'll have to do it again once you do the afr's and you'll need hardend pushrods since (assuming you're doing it right) you'll be using a stud mount head.
Modular2v said:
You won't know until you measure. Just b/c piston to valve clearance is fine doesn't mean the pushrod length is fine. Check the way I said by coloring the valve tip with a black marker, set that rocker and rotate the engine at least twice, then look at the contact patch. I believe it should be close to centered and less than .080" travel. I believe the shorter the wear mark, the better.
NKau
Founding Member
You won't know what length you need until you get your new heads on and check with an adjustable pushrod length checker. Too many variables to consider (head gasket thickness, deck height, if heads are milled, etc.)
I learned from the best, Rick 
By the way, Rick, do you know what size pushrods afr 185's usually take since i know you've dealt with them a lot? I checked on my friends 306 and stock size seems about right. Also, how do you tell a hardened pushrod from a non hardened pushrod? Trying to get this 306 finished up so we can run it before the snow comes.
By the way, Rick, do you know what size pushrods afr 185's usually take since i know you've dealt with them a lot? I checked on my friends 306 and stock size seems about right. Also, how do you tell a hardened pushrod from a non hardened pushrod? Trying to get this 306 finished up so we can run it before the snow comes.
rd
Founding Member
If the pushrods you have otherwise fit, and are hardened if needed, you can reuse the pushrods.
I have done both, changed them to make sure I had all new stuff, and also put a random group of used ones in, both approaches have worked fine. My 82, with used stock pushrods on a leftover group of stock stamped rockers works fine with my Rhoads Lifters from 1987, and my Comp Camps valvesprings from 2003. None of that stuff was from the same engine.
I have done both, changed them to make sure I had all new stuff, and also put a random group of used ones in, both approaches have worked fine. My 82, with used stock pushrods on a leftover group of stock stamped rockers works fine with my Rhoads Lifters from 1987, and my Comp Camps valvesprings from 2003. None of that stuff was from the same engine.
Mod, hehehe...just ship me the motor
Mike on most "0" deck blocks, with a .040 gasket, on a AFR I find a 6.25" works, but do the marker trick anyway to check it out. Just make sure the roller on the rockers goes out towards the header, first then rolls back towards the intake.
What brand/model pushrod is it? [email protected]
Mike on most "0" deck blocks, with a .040 gasket, on a AFR I find a 6.25" works, but do the marker trick anyway to check it out. Just make sure the roller on the rockers goes out towards the header, first then rolls back towards the intake.
What brand/model pushrod is it? [email protected]
hell if i wasnt a broke college student i would have u just do the whole set up lol.... at least this way i will learn how to do everything myself. hope your still around here in a couple years (when im out of college and not broke) because i plan to go with a 393 or 408 later down the roadRick 91GT said:Mod, hehehe...just ship me the motor
Mike on most "0" deck blocks, with a .040 gasket, on a AFR I find a 6.25" works, but do the marker trick anyway to check it out. Just make sure the roller on the rockers goes out towards the header, first then rolls back towards the intake.
What brand/model pushrod is it? [email protected]
I don't plan on going anywhere RNH Performance is here to stay. If things keep up this could turn into my day job. I live and breathe this stuff 24/7....45-50 hours a week as a design engineer during the day, then another 40-60 as RNH Performance at night/weekend.
Thanks for all the continued support...
Thanks for all the continued support...
WOW my hat is off to you with much respect rick, i wish i could do something like that, cars are the only real passion i have in life as far as working goes! Keep up the good work and if all goes right consider me a customer as soon as im out of collegeRick 91GT said:
