LS2 dry sump issue, help

So I got the dry sump system from John at AVIAID and was half way through installing it on my LS2 install and I have an issue. The new crank shaft damper and dry sump drive pully has a 1.34" longer stack that the crankshaft bolt needs to pull down than the LS2. The LS2 bolt is 4.000" long, the LS6 bolt is 4.875" long, both are too short to make this work. I need a bolt 5.340" long. Does anyone have a source for this special bolt? I called Dave at AVIAID and he was no help. :((

So I got the dry sump system from John at AVIAID and was half way through installing it on my LS2 install and I have an issue. The new crank shaft damper and dry sump drive pully has a 1.34" longer stack that the crankshaft bolt needs to pull down than the LS2. The LS2 bolt is 4.000" long, the LS6 bolt is 4.875" long, both are too short to make this work. I need a bolt 5.340" long. Does anyone have a source for this special bolt? I called Dave at AVIAID and he was no help. :((

Paul, I have regularly faced this problem. What I do is measure up the stack to be clamped and the thread depth available in the crank snout. Then I purchase a cap screw of the correct dia and plain shank length (unthreaded portion) that also has sufficient threaded length so you can cut it to suit max threaded insertion into the crank snout.

I use a cap screw as these are made of high grade material (check spec prior to purchasing). The reason that I seek to have max threaded insertion into the crank snout is that it is not uncommon for these bolts to work loose (in fact this is the reason I was able to pick up my current 347 super cheap - the balancer flew off the engine after the damper bolt worked loose and fell out..........!!). Hence I have gone through this exact process with the 347.

If you are unable to get a cap screw of the correct dimensions, do not despair. Look for a reputable machine shop that manufactures bolts/cap screws and have them machine one up of the correct specs. A friend of mine had this done over here and got 2 bolts for approx NZ$30.

One watch out Paul is to absolutely ensure that the bolt does not bottom out in the crank snout as otherwise you will not achieve any stack torque load. Apologies if I am stressing the obvious but I have seen this happen to many times.

Kel.

Thanks for the info Kel, I am a gas turbine mechanical design engineer of 40 years, so i know where you are coming from on bolts. The LS2 is a metric engine and uses a torque to yield tie bolt, around 250lb-ft, so its a very strong bolt. I was hoping that because this dry sump system i got was off the shelf from a national supplier (AVIAID) that the bolt would also be an off the shelf item. But........., if I can find one i will follow your plan.

At lunch today I'm going over to the race engine shop here in West Palm Beach the builds the engines for the Mosler Race cars which run Ls motors with a dry sump and see if he can point me in the direction of an off the shelf bolt or as you said, a local machine shop that does work for him.
Thanks for the reply.

Say hi to Mike @ TEC for me! :-)

Paul, buy something from the man geesh....lol

I went by at lunch to see mIke and he was out to lunch also. :(
So I called ATI, and it turns out they make the ATI damper and the longer damper hub that comes in the dry sump kit and of course they have the required longer bolt for $20. So problem solved. I dont know why AVIAID didn't increase their dry sump kit price by $20 and include the longer bolt, but thats business.

Paul, call ARP they stock longer bolts for the ls motors... And they are reusable u like the TTY bolts that come stock. Thats what devil and I use.