Hey all,
I'm a newbie here, but I have a noise after my GT40 head swap I thought I'd run by you all to get your thoughts. Details of my setup below. The noise only shows up when the engine gets at/near operating temp, and is definitely is coming from the top end. It sounds like a dull hollow noise, almost like the rockers lightly tapping the valve covers. It is clearly not a harsh tapping or knocking noise. I've tried the double stacked valve cover gasket trick and it still seems to be there, but loudest near the baffled area. The engine seems to run nice and smooth, but only had it on the road for a few miles before I noticed the noise and decided to bring her back home.
It doesn't really sound THAT ominous, but I just want to make sure it's not causing any wear/tear on the newly freshened up heads or the rest of the engine. It definitely sounds different than most other videos of valvetrain noise I've found, so I really am in the dark here.
My thoughts/possibilities:
1. Rockers tapping valve covers, but the double gaskets should have eliminated it
2. Stock stamped rockers sweeping the top of the valve stem accentuated by the stiffer springs
- Maybe it would go away after the rockers and valve stems get used to each other?
3. Preload / pushrod length issue? (hoping not, this stuff is a nightmare to me)
4. Open to suggestions here!
Details of the car:
85 Mustang LX Vert 5.0 5 Speed - ~50k miles
96 Explorer heads
- Milled either .020 or .030, double checking
- Upgraded springs, not sure of the specs
Stock stamped rockers
- Shimmed .040 (preload between 1/2 and 3/4 turn)
Stock pushrods and lifters
Weiand stealth intake manifold, new during head swap
Holley 4160
Link to a video - Shot with the single valve cover gaskets installed, just after a good drive.
https://goo.gl/photos/CyHkUSNeGwBZ3iZ98
I appreciate your time!
Lucas
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