push rod length?

[montyd]

i bought a set of edelbrock performer heads with 1.6 roller rockers and i am have a f cam to go with it. i have been told be a buddy that i need different length push rods to run this set up. doesnt make sense to me but i figured i would ask. also what is the torque spec for the head bolts on an aluminum head? i got these used so i didnt get anything with them. thanks for the help

 

[Foxfan88]

are the rockers stud mount?? if they are and seeing how you got the heads used, they could be milled on the deck. i'd borrow/get a pushrod length checker, and adjust it to the length where to roller tip on the rocker sits in the middle of the valve stem tip. maybe even a little offset to the intake side. then buy those pushrods.

as for the torque specs, if you dont have some headbolts. i'd buy set of ARP bolts or studs and it will give you specs

 

[montyd]

the heads havent been touched as far as milling they are completely stock from edelbrock.

 

[Foxfan88]

are they pedestal mount our stud mount rockers?

 

[347HO]

It is always best to check your rocker tip to valve stem pattern to get the right pushrod length for your setup.
Noone can guarantee what length pushrod you need without doing this check.

 

[mustangfan1990]

I was told the same thing but I have AFR 185 with 1.6 and a trickflow stage 2 cam and I am running the STOCK pushrods for 2 years now NO PROBLEMS AT ALL....just my input though

 

[302RollinHard]

Any time you change heads, cam, and pretty much any valve train component, you should measure for PR length.
http://www.compcams.com/information/Products/Pushrods/
Read up on this and ask questions if you have any.
Anyone who tells you that "mine worked with the stock pushrods so yours should too." is wrong. Unless they got lucky and MEASURED and the stock PR just happened to be the right length.
Every motor is different. Deck thickness of heads can vary. Base circles of camshafts can vary even on the same grind of camshaft. There are tolerances built into any machining process.
That is why measuring and finding out what is right for your engine is important.
Use a sharpie to color the clean valve stem and when you turn the engine over by hand you will see the run-out pattern.

 

[302RollinHard]

ahhhhhhh just right.
With that said I would rather the witness mark be A LITTLE off center and narrow than dead center and wide.
Those images were courtesy of Joel5.0

 

[NKau]

As some stated, you really need to check to be sure. For what it's worth, with lightly milled Edelbrock heads, stud mount 1.6 ratio roller rockers and Comp's XE 266 cam the stock pushrods worked perfectly. To properly check, bolt down a head, and use a magic marker to color the tops of your valves. Install a stock pushrod, then turn the motor over by hand. Disassemble and see where the wear mark is. It should be centered on top of the valvestem as shown in the pic by 302RollinHard. You do need to have a 'solid' lifter to check this. When I did it, I disassmbled an old roller rocker I had laying around, flipped the plunger over, and effectively created a solid lifter for the test.

If you are not getting marks in the center of the valvestem, you will want to buy an 'adjustable pushrod length checker' and figure out what length you need. Also, keep in mind that even if the stock pushrod works, you will need hardened pushrods if you are running guideplates on those eddy heads like I did.
​

 

[PJC Racing]

It is best to check the length, but the performer 5.0/5.8 (only) heads are pedistal mount and are designed to be used with the stock pushrods.

 

[El_CUCUY]

I had mine checked as well. Very good thing to do
I have world windsor jr heads with 1.6 roller rockers and that added up stock length after i check the length.

 

[irish]

I also run windsor juniors and 1.6 roller on an uncut block, my pushrod length worked out to be longer than stock. Just goes to show you HAVE to measure because you need to know your geometry is right.

Matt