VC Bolts backing out
 

Over the winter, I swapped on a set of those PRW fabbed aluminum valve covers that Butler and Tin Indian sell. For the money, they appear to be well made. They use the 3” long bolts with the 1/4” Hex Heads that drop through the valve covers. I found that with regular valve cover gaskets, the bolts would bottom out in the head (D-Port E-Heads) before getting a decent compression on the gasket. So I am using the nice 5/16” cork gaskets from Butler.

My issue is that they loosen up after literally every drive. I discovered this after finding a decent puddle Of oil on the floor under the passenger side of the car and quickly tracked it to the rear lower corner of the valve cover. I removed them - wiped everything down - and replaced them. All is dry and clean, but those hex bolts do back out after every drive - I am snugging them before each drive.

I read on another forum about using the lowest strength Loctite (222) on the VC bolts - but then they could not be snugged (if necessary) without breaking the grip of the Loctite. Another forum suggested RTV because it remainS pliable and would continue to ‘grab’ the threads even if you had to snug it down a quarter turn or so.

Any thoughts about keeping these bolts from backing out?

Thank you.

Not sure if you could use threaded rod, or studs Loctited to the heads, then use locking nuts to prevent the loosening. Just a thought, not sure if you would have clearance issues installing, and removing the covers lifting them off of the studs, as each engine has different issues as far as valve cover clearance.

If you have to keep the bolts, you could try locking washers of either the conventional split lock washers, or the star type lock washers.

My thoughts.......:2cents:

Do you have the small lock washers installed under the head of the valve cover bolts? I have the same ones and zero issues

You've found the root cause of the issue with the hold down bolts bottoming out in the bolt hole, so the cure is running thicker VC gaskets by whatever means you choose.

I have used the longer Hex Head Allen Screws for 50 years.

I installed them in the heads with "thread locker" but this was a long time before I knew about Loctite and the different other brands.

I measured the height the heads were drilled, the uncompressed gasket thickness, the thickness of the Mickey Thompson "Ribbed Valve Cover" flange, the nuts & washers I wanted to use and installed the parts. I plan on doing the exact same thing with the E-Heads for the 455 engine when the heads are installed on the engine.

Never was a need to remove the set screws and they worked well with the cut off top valve covers (when I was setting the running lash on the solid lifter cams).
Finish the lash settings and the M/T covers went back on the engine.

I "double nutted" the fasteners holding the covers in the old days but today I will use the chrome Nylock nuts from the hardware store. They are cheap and rarely do the covers need to come off as the Valve Lash always stayed set.
It will be even easier with the Rhoads Pro Lifters.

Tom V.

When I've had that problem, it wasn't the bolts loosening up. It was the gasket continuing to compress. I had to keep tightening the bolts for quite awhile.

Yup - as indicated in my original post, the bolts bottomed out when using the standard thin gaskets. I swapped in a set of the thick 5/16" gaskets and I am definitely not bottoming out any more, but they just don't stay tight.

I'm considering what Mr. Taylor said and I'm wondering if the firmer composite gaskets in the thicker 5/16" are going to be the answer. I have squished a noticeable groove-indentation in the head side of the current 5/16" cork gaskets.

I'd be glad to use a lock washer, but these are the style with the small allen key headed bolts that slip into round recesses in the valve cover that do not allow any room whatsoever for a washer of any kind.

Over the decades I have noticed that the extra heat on the Exh port side of the head makes for a constantly shrinking valve cover gasket.
The best way to deal with this is to run the thinnest gasket you can and if it's Cork seal both sides with forma gasket.

If you need a spacer due to not running a thick gasket then make one.

Hint, a old Aluminum valve cover is perfect for this!

If you need a spacer due to not running a thick gasket then make one.

I’ve got plenty of clearance for my rockers and poly-locks. I had grabbed a set of the 5/16” cork only because the bolts they supplied with the valve covers bottomed out just as I began to get contact on the thinner gasket. But ... I may just lop 2 threads off the bottom of each bolt on a band saw and clean the ends up nice. That should allow me to go back to the 1/8” composite gaskets (that don’t compress as much as the cork ones) and get a nice compression all the way around without bottoming out.

My main concern with feeling the need to snug the current set up back down after every drive is the fear of stripping one of the VC cover bolt holes in these aluminum heads. That would be turning a relatively small problem into a relatively bigger one!

Just ran into this directly from the pdf. of the installation instructions for Edelbrock D-Ports:

VALVE COVERS: Due to the valve cover bolt holes piercing the top of the intake port, valve cover studs have been supplied. Use thread sealer when installing these studs to prevent oil leakdown.

Any recommendations on the correct thread sealant first this application?

Permatex vs ARP?

‘Regular’ or High-Temp?

Thank you.