ek02
Well-Known Member
- Joined
- Jan 31, 2008
I broke the bearing webs on #2 and 3 mains. This is a NA 4.1 with a steel stroker crank and ARP studs, GN1 heads, Comp roller, etc. Maybe 325 HP without the nos. It had a 175 shot of nitrous on the last run. I usually run a 125 shot. It also shows a lot of cap walk on the block and caps. The pistons look perfect and the plugs were clean. There were no signs of detonation. The timing retards with a MSD Digital 6 ignition when the nitrous hits and there is a fuel pressure safety switch to turn off the nitrous if the fuel pressure drops on the dedicated fuel system. The only reason I can figure it broke and has cap walk is that the Buick 4.1 block is not strong enough to take the sudden hit of power from the nitrous. I have another block ready and a RJC girdle on the way. I'm hoping the girdle will solve the problem, but I will probably go back to the 125 shot. Any experience with NA's on nitrous on this site? I know there are a lot of boosted 4.1's out there that live with just a set of billet caps and studs.