Shimming Stock Rocker Arm Stands?

[Anonymous]

I'm trying to diagnose a noise and I want to swap in a stock set of non adjustable rocker arms and ball/ball pushrods.

Since the block has been decked .040 and the head has been milled .080 I'm assuming that the lifters wont be able to take up the differance

Can I cut up some pop cans or somthing to shim the stands?? I'm assuming a stock pop can measures around .040....

Thanks,

Doug

 

[lyonsy]

hey
you can buy shim metal for rocker stands etc. its also helpful to squize the last few hp out of a motor as well
mark

 

[addo]

Are your cans steel or aluminium (don't say porcelain )?

I think the alloy ones are more like 8 or 9 thou. You're maybe into ground steel plate territory and water or laser cutting to make 40 plus thou... There's a lot of cycling stresses on them and I worry that a soft metal may deform.

Would it be cheaper to go back to "first principles", setup and measure you requirements, then check that against pushrod length? Personally I have come to mistrust my calcs as it always seems I have underrated or forgotten some aspect. What I measure, I can trust!

 

[Falcon62]

Doug - you should be able to pick up some shim stock at a well stocked auto parts store or from any engine rebuilder or machine shop.

 

[wsa111]

Doug, go to a good hardware store & buy some fender washers large enough to cover the oil supply at the rear rocker arm stand. you may have to drill the I.D. for the 3/8 rocker stud bolts.
Can you locate the tap via a stethoscope or by pulling plug wires to see if the noise comes from the valve train or from the piston area.
I'm sure have readjusted the valves??
Since this a new camshaft in your engine might want to check total valve lift or do you have a lifter sticking?? Keep us informed Bill

 

[Anonymous]

Our pop cans are aluminum

I could buy some shim stock, but I just wanted somthing temporary to make sure that the noise is in my rocker arms. It is worse from 1200-2200 rpm's and goes away totally under acceleration/deacceleration.

The pushrods are actually rubbing on the bottom of the rocker arms closest to the rocker arm tube. I took a dremel and opened up the area where they were rubbing but the noise doesnt seem to want to go away now.

The cam card says .480 lift 274 duration....thats with a 1.5 ratio rocker arm....I dont know what it figures out to be with the 1.6 rocker arms I have....somewhere around .500 lift??

Being I'm a body tech, I have a rather large supply of fender washers on hand

If this is the problem, then I'm going to buy the 1.6 ratio stock adjustable style rocker arms that Mike has.

One thing....I adjusted the valves several times, but the pushrods can still be turned by hand after the engine sits for a few minutes. Is this normal?

Thanks for the help!

Doug

 

[wsa111]

Doug, the lifters bleed down after shutdown & thus will remove pressure from the plunger to pushrod, so that is normal.
With the higher lift the base circle of the camshaft is smaller. You need to see if the roller arm end of the rocker arm is at the center of the valve stem @ half the camshaft lift. You may need pushrods which are .060 longer to compensate for the smaller base circle of the camshaft.
Since you have the 1.6 adjustable rockers where is the adjuster screw with the valves adjusted?? Is the adjuster screwed all the way down or is it at the bottom of the adjuster travel being backed out as far as it will go??
At what point of lift did the pushrod hit the rocker arm??
Let me know. Bill

 

[80broncoman]

Crane part number 99170-1 "Rocker shim kit" includes .030 and .060 shims
These are hardened and are for fords

Part number 99179-1 are round same .030 and .060 rocker bridge shims (olds, amc, pont 151s ... )