sloppy rockers............

[stroked302]

ok...need some help guys....i'm at a loss.

i bought a 92 gt as a project car, i was told it has some porting on the stock heads and a cam(not sure what it is). There was some noise coming from the passenger side head area....pulled the valve covers off and found a rad. hose clamp in the rear bottom corner of the head. i figured that was the noise and after inspecting to make sure it hadn't caused any damage i buttoned it back up....well, the noise was still there, so i took it back apart. i found that the rockers on cylinder 2 and 3 intake and 2 exhaust were loose(in that order by looseness). there isn't any part defects as far as i or either of my auto instructors can tell. they are both gm guys soooo. when the cam lobe comes up on those cylinders comes up it douse take out the slack, but when the valves are closed the push rods and in-turn the rockers are loose.

first, i thought i had a few dead lifters, but now im thinking the push rods are too short or the cam is bad.....any ideas?!

Thx,
Kyle

 

[Gearbanger 101]

First off...what kind of rocker arms are they?

 

[stroked302]

stock

 

[1987stangman]

stock

I had the same issue. I rebuilt the stock block and had the heads ported and after about 3k miles on the setup I got a nasty lifter tick at cold start one day and then the back passenger side rockers started chattering. I ended up replacing the lifters (which were new, but it's hard to pinpoint which one on that side makes the noise!) and after I got it all back together the lifter noise was gone but the rockers on that side, in the back still make more noise than I would like. I originally intended on replacing the stock rockers with rollers but I ended up using the stocker so I am assuming that they are just worn and need replacing.

 

[stroked302]

well, on a side note it also has timing gears....if you have had them or heard them befor....well, ya i can easaliy hear the rockers slaping around over those and my mac dumps....so when i say loose....its bad....so dead lifters......hmmm.....when the rockers are torqued should there be any preload on the lifters? they aren't sticking they are fully extended.

 

[Maryland Stang]

Someone may have set them that way. If you go to the FTI website and read their instructions for setting rockers you'll see where they want them set with only 1/4 turn or less for race applications. You can actually set them with a little bit of clearance if you like. The reason for this is lifters tend to pump up as RPM increase. If you get the RPM high enough the lifters can actually pump up to the point where the valves aren't completely closing.

I'd try resetting them normally before spending any money on new parts.

 

[Mustang5L5]

Stock cam, rockers and pushrods as far as you know?


red hose in the valve cover? lol. Reminds me of the guy who found his wrench in the lifter valley after 3-4 years!

 

[stroked302]

Stock cam, rockers and pushrods as far as you know?


red hose in the valve cover? lol. Reminds me of the guy who found his wrench in the lifter valley after 3-4 years!

aftermarket cam.....and it was a hose clamp...close enuf

 

[stroked302]

Someone may have set them that way. If you go to the FTI website and read their instructions for setting rockers you'll see where they want them set with only 1/4 turn or less for race applications. You can actually set them with a little bit of clearance if you like. The reason for this is lifters tend to pump up as RPM increase. If you get the RPM high enough the lifters can actually pump up to the point where the valves aren't completely closing.

I'd try resetting them normally before spending any money on new parts.

i see what you are saying but i dont think that is the case or im sure they would all be set in that manner.....i'm only haveing this prob. w/ 3 out of 16...thx for the info though. there is no reseting really....i torque them down and the push rods and rockers are losse as ****....no shims either....never buy a car from a moron...lol
it was a one owner until 2002 and its a 1992...then i bought it in 08 in between it went through 3 or 4 owners and had less than 20k put on the clock.....it seems too many fingers have been in it.......any other ideas i dont wanna throw parts at it....im gunna thorw it together and see if i can compare lift of a known good cylinder....for now......

 

[Mustang5L5]

Pushrods are wrong lenght with aftermarket cam??

 

[stroked302]

w/ just 3 out of 16 being wrong....and those 3 having different degrees of looseness. this is driving me crazy....im tempted to start replacing lifters n see what happens.....

 

[ls1beater4eva]

after being worn so much you may have to get shims for it i have had to do this b4

 

[Mustang5L5]

Do you have accurate measuring calipers?

Pull the pushrods out and measure? Swap them around and see if the looseness follows the pushrods.

If it doesn't, id look at the lifters