Thread depth/holding power

[shawnlee28]

Poly locks on the rockers......are 5 1/2 turns enuff to hold them down?
Stock studs and roller rockers ,460 ish lift and mild springs.
There soo long ,it just seems like 20 turns would hold better,...but the studs would need to be real long.I guess the extra length on the locks are so you can install a girdle ?

[cffisher]

If the stud dosen't come through the top of the nut it won't hold.

[shawnlee28]

Thats for the factory nuts,I have poly locks with the little allen head locker that goes down the center of the nut/poly lock.

[cffisher]

OK those are what I use. You should have atleast the dia. of the stud inside the nut.

[halftanked]

It's a threads-per inch thing, 5 turns on 10 per inch,great,5 turns on 20 per inch,probably pull threads off. Hank

[brianrupnow]

The generally accepted engineering theory is that the minimum thread engagement should be at least 1 1/2 times the threaded fastener diameter.

[kitz]

The 1-1/2 rule is particularly valid when using bolts up to their full clamping potential. You always want the bolt to fail in tension rather than risk pulling out the female threads. Usually 1 diameter engagement will insure this with a big safety factor.

Rockers are not stressing the studs to that degree (90% proof load) so you could definitely get by with a lot less than 1 1/2 engagement.

For 1/2 - 20 UNF studs 5 turns is 1/4 inch engagement. That represents 50% engagement which should be adequate IMO. After all, the clamp load for a 1/2-20 UNF G8 bolt is 13,000 Lbf.

Kitz

[shawnlee28]

I hope they work!!!!!!
Whats the worst case......it pops off and I shut it down or....it blowes a head gaskett?

[cffisher]

When it gets right down to it You have no choice you have to adjust them to the proper setting where ever that is. The only way to change that would be longer studs. Then even higher rocker covers. Then your locks wouldn't be able to lock. I think werre chasing our tails here.

[dizzle]

what engine is this for? are you sure you have the right length studs, a friend of mine had a set that were too short and sheared off a stud.

[kitz]

Shawn you are an optimist!

The worst thing that can happen of course is death. Say you're up at 100 mph and it pops off, goes through the valve cover causing a fire and you lose control and hit a tree.

OK, probably not .......

[pat mccarthy]

if you get them down to 1/2-7/16 on the threaded stud thats good .more you may be better not for any thing than it may center up the rocker fulcrum lower on the stud and get part of the rocker off the threaded part of the stud have used longer studs all the time arp sell them in all dimension