Sorry to hear about this Justin.

You better start working out your hands. Things that get touched by Majorecho suddenly develop an ability to tear the fingers off the handlebars of the rider.

What size injectors are you running now? Are you running gas or methanol now?

 

Having spent many years in the engine business I have to say that I have seen very few wrist pins fail, even in high performance engines. Typically one will fail when there is a detonation or preignition problem (two different things), mega amounts of boost or nitrous or of it drops a valve, but then the wrist pin just gets beat up by the valve and piston fragments. Did you have water in the cylinder? Got any photos of the piston, wrist pin and cylinder? If so that may explain the problem, water doesn't compress well (at all really) and if you get enough water in there... well, something has to give, in this case it may have been the wrist pin.

Just my 2 cents.

 

No pictures yet. the wrist pin was sent with the nitrous piston (when I ordered it) so it should be built to withstand a little extra although it was definitely thinner walled than the stocker. There was no water in the cylinder that I know of and No signs of detonation. Overall there was alot more carbon build up than normal, like it was a bit rich.

I am running the 96lb injectors now. Huge difference. Way more power. I was definitely running a little lean with the 63's.

 

 

here are some pics of the cylinder and pistonclick

 

I have to agree with MR HP. The last time I saw a one of our drag motors with a broken wristpin was from detonation. In the one picture it even looks like the ring land is pinched. I think it was the last pic.

 

I have never had a RW's piston pin problem. I have turned the ring land up ( from heat ) on there old style piston but nothing with either of the new ones. I dynoed 95 hp with them on a 650cc. I did jerk the the bottom wrist pin skirt off one of MrHP's pistons just running motor on a stage 2 and folded up the rod.

In the racing world you will have parts failures.

 

was the ring end gap set by installer of piston? if there wasn't enough end gap, you could get the vertical scoring on the cylinder wall?

the piston doesn't look like a typical 8:1. the compression may be higher than 8:1 unless the piston stops before the top of the cylinder by a significant amount.

 

It was installed by the local bomb mechanic. I am not sure what he gapped it to and he doesn't remember exactly.

 

Scooby, this was a nitrous piston that had been milled down by RWR to about 10.5-11:1- we are on the hunt for an 8:1