My old buddy Mike has some interesting observation on studs vs. bolts if you go this way. I still have a preference btw of starting with the best block one can get, meaning spending the $ on a 390 block is much less preferable to getting a real 427 block, be it OEM or an aftermarket block. JMO!
To main cap or not? My lesson learned about friction.
December 30 2013, 6:13 AM
You will know when you NEED to do something with caps or clamp load WHEN you start to transfer block material onto the cap or vise-versa.
I did work for a street racer....yes we all know they exist. Anyway he was running a BBC 4 bolt main block using 200 HP NO2 on top of 650 HP engine. He did not have a lot of money but whatever he won he would try something else to go faster. One thing was always the same is the tune-up used.....
The blocks would get hurt very often while learning how to get on the tune-up. Melting across the deck melting one piston all else perfect you get the idea. I would take his ARP main studs out of the block and use them in the next block Now we would re-block mid-week many times. So finally I worked ahead and got a block ready to go with a new set of ARP studs so we could just swap the crank rods and add a piston of two LOL.
Well one night of racing maybe three allout pass's time to fix it.
Surprise I found that the caps are transferring metal WTF. Swapped studs in the next block and off it went.
Next time it came down the caps looked better, and the next time no metal transfer at all Hmmmm.
**** This is what I learned is that ARP uses a black type of paint to keep the studs looking great and from rusting. The problem is if you assemble used just OIL the friction is very HIGH in between the nut and stud threads causing the torque wrench to tell you you're done.
Now if you were tightening by TTY, TTA or BOLT stretch method this problem would never have happened.
This was many many years ago and now you know why they say use their ARP anti-seize and torque specs.
**** Point being is you can wire brush the black coating off and have no problem at all.
**** Just as reusing the studs wore the coating off more with each reuse so they clamped tighter.
The 390 caps with ARP studs and DO NOT DETONATE THE ENGINE as that will rattle the caps making them transfer metal when you really don't have a problem if tune-up is correct.
Mike Caruso
Do It Like You Mean It .....or Don't Bother!
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