So had some leaks at the valve covers and asked here for the best gasket. Mancini Racing delivered the new gaskets but appears some of my bolts are not long enough for the aluminum heads. Is it Better to use studs? What do you use? :dunno:
Quote from: Spikedog08 on August 31, 2023, 07:06:10 PM
So had some leaks at the valve covers and asked here for the best gasket. Mancini Racing delivered the new gaskets but appears some of my bolts are not long enough for the aluminum heads. Is it Better to use studs? What do you use? :dunno:
I went to Ace and bought some stainless steel bolts that were 1/4" longer. Been a few years so I might be off on length. Get a bolt and check.
I have bolts on mine stock heads. No leaks.... but to be fair my car hasn't ran in 30 years :smile: But I just purchased a new set from ARP and I noticed there are standard sizes and I thought I recall longer ones for aluminum valve covers. Do aluminum heads would need longer bolts, or did you mean aluminum valve covers?
My 383 has the MP cast aluminum covers, stock heads and the thicker gaskets.
I have studs in the bottom corners and bolts for the rest.
Well used factory cast iron heads tend to have the first few threads too worn to grab on.
For the bolts and studs:
I measured the stack up of gasket and cover, then measured the thread depth of the bolt holes.
Note full threads do not go all the way to the bottom of a blind hole.
Studs. They are bottomed, so you can see if the nuts are loose.
I vote for studs....work better for me.
So how tight? Wrench them down?
Most people overtighten valve cover bolts which causes more problems so take it easy when snugging them.
I suspect somewhere between 40 to 50 INCH pounds (4 ft-lbs) would be in the right range. Heat cycle the engine and retorque them after it cools off. Cast aluminum covers are less susceptible to being damaged or warped when snugging them down. Sheet metal covers are very easy to warp and that leads to leaks that gaskets may not fix.
Why studs, especially on stock valve covers? I watched something somewhere that talked about the benefit of studs to change the load from the shoulder of the bolt to the threads, or something like that. This makes sense for Heads and probably Exhaust manifolds. But currious why some believe they are better for valve covers since there isn't that much torque on them (hopefully :D). Is it an appearance thing, better seating? easier to keep the gaskets aligned, something else?
Just curious. I picked up new bolts and wondering what I'm missing.
Tom
Like Skdmark, I like a few studs. Not sure if I use them for the same reason as he does, but I like being able to hold the gasket and VC in place while I move things to line up better.
I use studs with the taller t-bar style nuts on the on my race engines that require regular removal for valve lash adjustments. On my street cars I just use regular bolts or cap head socket screws.
With studs, you will need to add a washer and then the nut. If you don't get the studs all installed to equal depth, then you will have differing thread heights sticking out past the nut. IMO, this looks less finished than a simple bolt and it provides greater area to accumulate dirt.
studs are nice and easy to use