here's one for the LS gurus

[sread]

I'm getting the LS1 ready for install in the hot rod and have run into a question re: the install of the balancer /crank pulley set up. I am using the March Pro Track pulley and bracket system which requires a billet hub adapter to be installed on top of the oem balancer to which the crank drive pulley is than installed. The issue is that the oem torque for the balancer uses a torque to yield fastener which calls for a specified torque (don't recall exactly what it is) and then add 140 degrees of rotation. I read where somebody actually measured it and it was north of 300 ft lbs. There are various aftermarket replacement fasteners, ARP for one, which just call for 220 to 240 ft lbs. Long story short - they want that SOB tight!
So here is the problem...the new hub from March requires removing the oem bolt, placing the hub on top of the balancer and then using a new longer (supplied) bolt but they only specify a torque of 75 ftlbs. That is a huge difference. The balancer is a press fit only with no key way so it is pretty important to keep it secure. Anybody ever run into this before? I am kind of concerned about the discrepancy. I have tried to call March tech support but they aren't answering right now.

[HerculezJT]

Hey sread, try checking the inner diameter of the March and the outer diameter of the crank snout. The March might be tighter compared to OEM, ATI or Fluid that are keyed and could be why it only need 75 ft lbs. But, in all honesty, that number is low to me after having built a few LS1/6 a 3 and an LSA. I wouldnt be worried about the pully falling off, but more about slip and damaging the snout. I would wait to see what March has to say. If they say that is correct, you can use a small amount of high temp epoxy to hold it, forewarn though, this will make it a PITA to get off in the future.

[Mike N]

I would use something like this with the lower torque. https://lsxinnovations.com/product/ls-crank-pin-kit/ This is very common with boosted LS motors that drive the blower off the crank.

[sread]

Finally got hold of March and to be honest they weren't much help. After I explained the issue to the guy , there was some mumbling, some back and forth conversation with somebody else in the room, and then he comes back and says just torque it to 180 ft lbs. I say" okay, but where did that come from" - " from Bill" - " who is Bill? "he is the manager, been here for 20 years".
I say " well, don't you think it might be a good idea to update and correct the instructions?" him ," we're working on stuff like that".
BTW, the March piece doesn't replace the oem balancer, it just sits on top of it and then their pulley bolts to the hub adapter. I think I will just buy the ARP bolt , torque it to 220 and call it good, although the drill and pin kit is probably a good idea also.
This is my first time going into an LS and I have to admit it is easy to see why it is such a popular powerplant - love the gasket system they use - all aluminum shim with embossed rubber - really makes it easy to work on.

[HerculezJT]

Well at least they gave you a better number, never dealt with March before. ARP is always the way to go! That pin kit may work, you might have to do one pin with the harmonic and snout and then the March to the Harmonic.

[HVACMAN]

I'm getting the LS1 ready for install in the hot rod and have run into a question re: the install of the balancer /crank pulley set up. I am using the March Pro Track pulley and bracket system which requires a billet hub adapter to be installed on top of the oem balancer to which the crank drive pulley is than installed. The issue is that the oem torque for the balancer uses a torque to yield fastener which calls for a specified torque (don't recall exactly what it is) and then add 140 degrees of rotation. I read where somebody actually measured it and it was north of 300 ft lbs. There are various aftermarket replacement fasteners, ARP for one, which just call for 220 to 240 ft lbs. Long story short - they want that SOB tight!
So here is the problem...the new hub from March requires removing the oem bolt, placing the hub on top of the balancer and then using a new longer (supplied) bolt but they only specify a torque of 75 ftlbs. That is a huge difference. The balancer is a press fit only with no key way so it is pretty important to keep it secure. Anybody ever run into this before? I am kind of concerned about the discrepancy. I have tried to call March tech support but they aren't answering right now.

I'm using a CVF Racing drive system on a LS3 376/480. It uses a longer bolt torqued to 250 lb/ft.