MCXPRESS 270 NYTRO HEADSHIM ???

[NYTRO270]

What would cause the headshim to fail?? Talked to a few people and they said at 17lbs you need to run 1/2 prem and half c12? Is this just under a certain elevation? Also Im going to turn the boost down to 14lbs. Is anyone else having headshim issues with the 270 kit?

 

[M5-]

I just blew up a headshim on my 240 kit. It went between cylinders 2 and 3, dealer said it was mileage and that he has only seen 1 other go. They fixed it for free, I hope it holds. I'm only making like 12 13 lbs which is nothing IMO. I think I'll probably do rods an pistons in the summer.

M5

 

[robb]

What would cause the headshim to fail?? Talked to a few people and they said at 17lbs you need to run 1/2 prem and half c12? Is this just under a certain elevation? Also Im going to turn the boost down to 14lbs. Is anyone else having headshim issues with the 270 kit?

What kind of miles do you have on it.

 

[NYTRO270]

1000

 

[M5-]

I think if your failure was fuel related you would see signs of detonation on the pistons. My pistons looked fine but the shim just melted away like when you over heat a piece of aluminum welding it. Dealer claims the material just basically vaporizes once the first crack happens. I think I'm becoming a believer in rods and pistons for compression drops.

M5

 

[robb]

1000

where do you ride it. I have the same kit on my 09 nitro and just pump gas from petro can. I only have 500 miles on mine. I also wonder about fuel my self. But they say you dont need race fuel and mine is ok. Mine will build 16lbs of boost at 1800ft in sask.

 

[Washy]

Robb, turn it down to 12-13 psi in Saskatchewan or you will be replacing not only the head gasket/shim but probably the motor. You can only run 17 psi on pump gas if you are at 7000 feet. 12-13 maybe 14 at 1800 feet.

 

[jehay]

where do you ride it. I have the same kit on my 09 nitro and just pump gas from petro can. I only have 500 miles on mine. I also wonder about fuel my self. But they say you dont need race fuel and mine is ok. Mine will build 16lbs of boost at 1800ft in sask.

Don't do that for very long

 

[robb]

so you say add race fuel or turn down the boost on a stock nitro motor

 

[NYTRO270]

so you say add race fuel or turn down the boost on a stock nitro motor

At the elevation you are riding 18lbs on premium is too much IMO.

 

[jehay]

50/50 c12

 

[robb]

At the elevation you are riding 18lbs on premium is too much IMO.

I never said 18 lbs i said 16. They will run 15 to 16 here and 18 to 19 in the mountians. Thanks guys the more info we have on here the better.

 

[M5-]

I never said 18 lbs i said 16. They will run 15 to 16 here and 18 to 19 in the mountians. Thanks guys the more info we have on here the better.

IMO that's too much for pump gas. At 18 - 19 at any elevation with the 3 holer I'd be thinking rods and pistons myself. JMO

M5

 

[RACINSTATION]

As stated above, that is too much boost for your elevation on pump gas. When I have seen a head gasket or shim fail it has been from too much boost. Boost is pressure. Even if you are not getting detonation you still have massive cylinder pressure fighting that spacer or even the head gasket. If you are tearing it down get the head o-ringed, put some low compression pistons in it and rods. If you are going to run 15-16lbs or less, you will be fine with the stock pistons and rods. They seem to fail around 18lbs.