Shimming the rockers???

[mercuryzephyrz7]

I have a set of '89 heads and I have a really loud tick. I just read that you are supposed to shim the rockers? I don't know what the pedestal mount rockers look lik,e but I think they came on the '89 heads I have.

Two questions, first did the pedestal mount rockers come on '89 302 heads (from a bronco)?

Second, if I have the type that need to be shimmed, how do I shim them? and how do I know how much to shim them? Do I just use washers from the hardware store or is there something more precise I need? This is crazy.

[jsam]

are you shure you have the correct length pushrod? i'd check that before i started shiming rockers

[mercuryzephyrz7]

are you shure you have the correct length pushrod? i'd check that before i started shiming rockers

The ones I put in matched the ones I took out, but just for good measure....what is the correct length rod that I need?

[jsam]

iirc 6.25" is stock 302 pushrods but that all can vary from deck height, heads being milled, cam size. you really need to measure to be honest.

[mercuryzephyrz7]

OK i'll measure them tomorrow, why not.

Heads have not been milled though, I do know that.

Thanks

[19COBRA93]

Rocker shims won't cure a tick. The shims are used when the pushrods are too long, like when you have heads milled. You'll need shims when you bolt down the rockers and it preloads the valve more then 3/4 of a turn (hanging the valves open).

If you've got a tick, you have too short of pushrods, or lifters not pumping up, or a rocker issue.

99% sure you don't need rocker shims.

[jsam]

Rocker shims won't cure a tick. The shims are used when the pushrods are too long, like when you have heads milled. You'll need shims when you bolt down the rockers and it preloads the valve more then 3/4 of a turn (hanging the valves open).

If you've got a tick, you have too short of pushrods, or lifters not pumping up, or a rocker issue.

99% sure you don't need rocker shims.

yep that is why i was saying to measure. then again it very well could be the lifters

[mercuryzephyrz7]

With the covers off the rockers are quiet, the tick seems to be the lifters because it sounds like it's below the intake manifold and I can feel it when I hold on to the distributor. Do new lifters normally tick for a while? I'm doing an oil change this weekend, maybe getting some clean stuff in there would help.

[jsam]

did you soak them in oil before installing?

a new lifter could be bad yes. back off your rocker nuts with the motor runing. if your sound does not change the cylinder you are adjusting on will be a good place to start looking for a bad lifter.

[mercuryzephyrz7]

Yes they sat in 20/50 overnight, and then after I installed them I primed the engine for about two minutes. I'll try backing them off one by one tonight, good idea

[NAVYCAT]

you might have a exhaust leak, that will sound like a tick tick.... i had one