I'm thinking about approaching ARP to get some TR3/4 head studs made. I know
Greg Solow has studs that have some of the features I'll describe below, but
not all. And he already has the relationship with ARP, if you're willing
Greg maybe this would make a decent product for your company.
The stock studs are not generally much of a problem, but all you need is
threads to pull out once, or a long stud to snap off way down in the block
to wish they were a lot better. And there's a couple of things I'd like to
do different.
First is, for the studs at the ends of the block, get them a little longer
and put a couple more threads on the lower end so the hole can be drilled a
little deeper and a bottoming tap run in. Actually, all the short studs
would benefit from this to one degree or another. They tend to have slightly
raised metal at the head surface--a sure indication that they are not really
deep enough. But the worst actors are the ones in the outer corner that tend
to have a crack where the block is thin. That's what's sparking this
thought--I looked at all my spare blocks last night and all of them are
cracked from the inside of the hole to the edge of the thread boss.
Second, stock studs have a liquid relief slot for oil to run out of when you
bottom them. Rolled threads don't need this to start with, and in a race car
you'd clean out the hole anyway. The slot is where the crack starts if the
bolt breaks. Eliminate it.
Third, I'd put either a recessed Allen socket or a hex head smaller than the
thread diameter on the top of the studs so they can be zipped in and out
without double nutting or using a stud socket. When you pull the heads as
often as racers do you want to be able to get those studs out so you can
install your head gasket without damaging it. Makes it much easier to pull
the head also.
Fourth, if you break an ARP stud I don't want to arm wrestle you (or have
you torque anything on my car).
Anyway, Greg if you don't want to do this I'll check with ARP. Step one
though is to see how many people would like these improved studs. I have no
idea what they'd cost in quantity--probably a couple hundred bucks (that's a
wild guess).
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