I tested out my 100 shot a couple of times. After pulling the plugs I saw that it was running way way too lean on fuel. I also discovered a miss on cylinder 6. I found a vacuum leak, and I'm thinking that added with not so high fuel pressure created the lean effect. I fixed the leak, and took off my mechanical fuel pump, added a holley blue electric pump, ran bigger fuel lines and added a fuel pressure gauge and regulator. I bought new $100 plug wires, new plugs, and a new cap and rotor. After much tinkering I still found a miss. After much debate I pulled the head on the side with the miss, thinking I had a bad intake valve seat because along with the miss I had air pumping back up into the carb. I discovered that it wasnt a valve, but a blown head gasket. I am also guessing this is what broke my ground strap off my #6 plug too( the gasket getting in the cylinder and hitting it off). The gap in the gasket is in between piston #4 and 6. I'm thinking that the compression from 4(since it fires before 6) is blowing over to 6 and blowing the air/fuel mixture away from the plug on 6 not allowing 6 to fire. I checked the head where the gasket blew and no metal was wore away, and neither on the block. Am I right thinking that running so lean blew this out? The motor only has prolly 3K on it so I'm sure it's not from long time wear. Should I slap another head gasket on it, bump up the fuel regulator to a higher pressure and try it out? Should I get a different head gasket? I know now that I'm not running lean on fuel now with the new fuel system. Are any of you guys running nitrous have different head gaskets? Thanks

 

be sure to check for hairline cracks on the block and head. same thing happened to my brother's motor, but the other bank (#7miss). hair cracks can be fixed.

 

That sucks that this happened. The #6 plug lost the ground strap due to detonation. Detonation (extremeley high cyl. pressures) is what blew that head gasket. It was not due to the #6 cyl. ground strap.

This is what happens when you run lean with a fair amount of HP. It can blow a head gasket that quick. Sometimes detonation will be bad enough and cause a spark plug to glow which then causes pre-ignition. This is worse than detonation and will take out a piston and/or head gasket in a matter of seconds.

Not sure what to tell you on the head gasket selection. Hopefully, the nitrous users will post there opinions/current setup. I would put new gaskets in both sides of the engine, just my opinion. The other gasket may not have been blow, but could have been weakened.

 

depending on the thickness you're running/need, I highly reccomend the MLS gaskets for N2O/forced induction. You won't blow them out.
- I agree, the lean condition took the gasket out, the moment you hit the button.

 

thanks guys, you have really eased my thoughts. I was hoping I was right in thinking the lean condition blew them out, and now I know. I'll look up those gaskets you suggested. I'll just do both like you said, better safe then sorry. Are they readily available at say my local machine shop? or should I just order them?

 

order is probably much cheaper. I don't think many machine shops have them yet. You can get Cortec or Felpro. MLS stands for Multi-Layer-Steal. They're awesome as long as your decks are true. I've seen them take 30psi from a 1471, no problems. - it's nice to finally have a gasket to take that w/o having to o-ring the block, etc....