Budget Rocker choice

[B3RE]

If you don't mind, I have a question for you. You may or may not have an answer that I can comprehend but here's my set up. Block was checked for square and the j heads were shaved to 62 cc to get 10.2 comp. Pocket ported and 2.02s installed. Intake was cut to align ports etc. The machinist is a well known old salt that built race motors for years. I stuck the racer brown ssh 44 .510 lift 108cl 292 dur. hydraulic cam in it with johnson lifters. Comp pro 1.5 rollers. So I didn't have to shim much left or right to center them on the tips as they aligned well. Kept the adjuster 1-2 threads showing under and got pushrods to fit. Installed them .015 preload and blackened the valve tips. Was towards the exhaust slightly. Installed .010 shims under the shafts and then they rolled at center after a few revolutions. The mark of the roller was spot on and about .025 was the thickness of the line that the roller left. It was no where near traveling from the intake to exhaust side. Centered and about .025 roll on the tip. This may not be corrected by the way you explained so what would be my goal to correct geometry? I imagine a large solid cam would be way worse but I don't actually think this part has to do with the correct geometry but I am going to build more like it and the knowledge is appreciated.

My pleasure MerlinsMopar!

This is a little odd that shimming the shafts moved the pattern back toward the intake manifold side of the valve tip. It should have been the opposite. I really can't say where things are, or where they are supposed to be, without having some numbers/specs from your combination.

I can say that if your Comp rockers are using the cup style adjusters, then you have the adjuster turned out way too far. There shouldn't be any threads showing, and should only be turned down 1 to 1-1/2 turns from seated in the rocker body.

Actually, geometry is usually worse with smaller cams than larger ones.

 

[B3RE]

They have Cheap Rockers at Lowes, or Home Depot.......

Sorry, your chiropractor will have to do those corrections.

 

[MerlinsMopar]

They were cups and turned in fully then the preload varied 1 maybe 2 turns at most. The machine shop ordered the valves so idk what length they are and he picked the springs also. Said the 1s i had were too much but the explanation I think is about like a titer totter and then look for balance between valve and shaft. Is that right?

 

[B3RE]

They were cups and turned in fully then the preload varied 1 maybe 2 turns at most. The machine shop ordered the valves so idk what length they are and he picked the springs also. Said the 1s i had were too much but the explanation I think is about like a titer totter and then look for balance between valve and shaft. Is that right?

It's possible, but it would take a considerably shorter valve. Not sure if you could get enough installed height.
Your welcome to email me, and I will give you the list of info I need to do the math. It's the only way I can know for sure.

 

[Krooser]

Sorry, your chiropractor will have to do those corrections.

I prefer the Cracker Barrel rockers... With a side of country ham and hash brown cassarole.

IMHO most street builds gain zero from those shiny roller tip rocker arms. No HP gains...no gains from less friction. Imagine going back to the way back machine in 1962 only to find the top running 413's at your local strip have stock rocker arms.

 

[rumblefish360]

Anybody make a 1.6 non roller rocker for the MoPars?

 

[Wyrmrider]

Maybe we ought to ask Isky to a make another run - his were the best with the hard pad etc
to answers Merlins question above
You CAN get more lift and more power by lowering the fulcrum -easy with a sbc and shorter pushrods
we did when running stock and when they check the cam lift at the lifter
but
with the springs mandated you quickly run into the valve float problem mentioned above
and those old stock springs would not make it through a weekend
so we quit doing it and started setting the cam 8 degrees retarded and revving the hell out of it
NOW you get the SAME bad result by going to a roller rocker as we did with stock rockers and lowering the fulcrum
get your extra lift and area with the cam or rocker ratio- not by screwing with the rocker geometry

 

[RogerRamRod]

Anybody make a 1.6 non roller rocker for the MoPars?

I remember someone drilling 273 iron rockers for larger adjusters, but offsetting the larger hole closer to the shaft to achieve a 1.6 or damn close to that. It was here on FABO, but a few years back.

 

[anitrowarrior9]

As the saying goes you can lead a horse to water, but you can't make him drink. Details like rocker arm geometry are why 2 people with identical engines have different results.

 

[Wyrmrider]

rocker arms unlimited can install 7/16- 20 cup adjusters or 5/16 or3/8 ball adjusters moved over for 1.6
I've heard of 1.65 but not seen one
we used to do 1.6 50 years ago for trans am style builds
but
it's easier to do as much as you can with the cam
an example is the FT Mike Jones cam I sponsored for Kroosers dirt car
we can't increase the duration due to the 7200 rpm limitation without loosing off the corner torque
Jones says more rocker will pick up the top end
W2 heads may get some high ratio rockers next year but a lot more $$$$ than a cam