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difference in heads


Jonpro03

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Ok, heres the story, it kinda embarasing so don't flame me too bad :twisted:

 

1996 Gp SE 3100 with rollers

 

Last time i went to the track, I did 2 runs and noticed a ticking. I thought it was the guy infront of me so I thought... Poor bastard went and f#cked up his motor. :lol: Get back to the pit and HOLY SH!T, Its me!! I got scared and of course cut it off right away. Let it cool for an hour and fired it back up. Still ticking. Cr@p. Went to cut it off, and noticed the low oil light was on. :eek: GODD@MN IT, HOW COULD I BE SO STUPID. CHECK THE OIL!! I says to myself. Added a quart. Drove it home.

 

So I originally thought I bent a pushrod or messed up a lifter. The sound definately comes from the topend under the rear valvecover. So I disassembled the top end and inspected everything. It all looks fine. pushrods are straight as an arrow and there's no play in the rockers. WTF? So now I think I messed up the heads or a valve. So Im changing the heads.

 

Here's the question

 

Ive got a donor motor chillin in the garage. Its out of a 94 gp. Before I go and swap heads, is there any differences between the two years?

Are my roller rockers gonna bolt right in? Any difference in pushrods? Ports or otherwise?

 

Thanks

Jon

 

 

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My car was ticking and I replaced all the hydraulic lifters with all new units and soaked all pushrods and rockers in chemdip (to dissolve all deposits). Put it back together and the motor is super quiet now.

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lifters are the same. they are all hydraulic roller

 

The heads are differnt in that 96 has fulcrum roller rockers, and the 94 has the stamped steel. if you want to use the fulcrum roller you need to swap heads.

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Post to keep track of what you find out, mine does this too.

 

Mine too...It lets me know when the oil needs changed.

 

Oil is perfectly fine, it even does it when it is fresh and full. Some days it's louder than others though.

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Post to keep track of what you find out, mine does this too.

 

Mine too...It lets me know when the oil needs changed.

 

Oil is perfectly fine, it even does it when it is fresh and full. Some days it's louder than others though.

 

Well, there are a couple reasons why it does it..

 

1- Piston slap, all 3x00s have it in some form or another. It even sounds valvetrain related, but its actually piston slap. Perfectly safe

 

2- Harmonic noise through the lifter valley actaully echos a bit and sounds louder than it actaully is, especially apparent on those with the hollowcamshafts

 

3- GM released a different torque procedure and specs for our rockers. Its adds a bit more torque (those of us with roller valvetrain) and this will typically shut our valvetrains up quite a bit, but there will still be some noise from the 2 reasons above.

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Post to keep track of what you find out, mine does this too.

 

Mine too...It lets me know when the oil needs changed.

 

Oil is perfectly fine, it even does it when it is fresh and full. Some days it's louder than others though.

 

Well, there are a couple reasons why it does it..

 

1- Piston slap, all 3x00s have it in some form or another. It even sounds valvetrain related, but its actually piston slap. Perfectly safe

 

2- Harmonic noise through the lifter valley actaully echos a bit and sounds louder than it actaully is, especially apparent on those with the hollowcamshafts

 

3- GM released a different torque procedure and specs for our rockers. Its adds a bit more torque (those of us with roller valvetrain) and this will typically shut our valvetrains up quite a bit, but there will still be some noise from the 2 reasons above.

 

I'd like to hear some more about the different torque procedures. Not a big problem any way I see it, runs great. It is just very loud on some days. I can hear it on some days with my windows up :exclaim:

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Mine too...It goes away after a couple of seconds usually and then I'll hear a light tap (piston slap) for awhile and some days it's gone too...

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Well damn. The heads aren't interchangeable. The roller rockers wont fit on the 94 heads as noted earlier.

lifters are the same. they are all hydraulic roller

 

The heads are differnt in that 96 has fulcrum roller rockers, and the 94 has the stamped steel. if you want to use the fulcrum roller you need to swap heads.

 

This sucks for me. I know what piston slap sounds like, thats not what I got. Its a LOUD ticking. Like you could hear it from a block away. It honestly sounds like a rocker is hitting the valve cover. So now Im just trying to diagnose the noise. Im going to reassemble the motor and try to get a vid up on youtube so you guys can see it.

Honestly, I wouldn't be surprised if I put it back together and the noise was gone. Where can I get the new torque specs and procedure at?

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