416, sleeve hit crank,why?

[chad400]

416 with about 30 hours on it, my motor just locked up.i took it apart to find what looks like......the sleeve dropped e-nuf that the rings caught the top of it and pulled it into the crank, shattering it, needless to say the motor is in a ba-zillion pieces so now its time for a new sleeve and a 440 kit. can somebody tell me why this may have happened?

[chad400]

going to order the 440 kit.....11;1 or 12.5;1 help??

[hotex]

The only way for the sleeve to migrate down is if the top of the cylinder was machined too deep and allowed it to do that.

Tony

[mojoe2878]

is the top part of the sleeve still flush with the jug? the sleeve can only go one way and that is upward, unless like hotex said and the lip in the jug was machined too deep to let it slide downward, and the top piston ring would not have cought the top of the sleeve without smacking the head in the process.
you need to check the crank and rod bearings real good fod excessive play.
if you go 440 i would get the 11:1 ratio kit so you can still run premium pump gas and use the stock rod if you want to if it isnt damaged.

[K_Fulk]

Originally posted by chad400
going to order the 440 kit.....11;1 or 12.5;1 help??

Your gonna have to tear it down that far you might as well upgrade the rod. If you dont mind running race gas get the 12.5:1 piston.

[440exnacsracer]

yea, i would say go with the 12.5-1. i had an 11-1 440 motor in my ex, and bought a 12.5-1 comp. piston. believe it or not, i got about as much power from the new piston as the bore

[400hondaex]

I had the same thing happen to my 300ex. I think the stock sleeves just let go. Mine was bored out i think .30 over on the stock sleeve. It let go and hit the crank. Beware lol Good luck on the rebuild!

[400exrider707]

Originally posted by 440exnacsracer
yea, i would say go with the 12.5-1. i had an 11-1 440 motor in my ex, and bought a 12.5-1 comp. piston. believe it or not, i got about as much power from the new piston as the bore

Yeah thats because a bore really doesn't give all that much power. The compression is where the power is at.

[MIKE400EX]

Check the piston and see if it seized in the bore temporarily. Maybe it broke the top lip off and pulled the rest of the liner down.
Was the liner ever replaced before?

[440exnacsracer]

Originally posted by 400exrider707
Yeah thats because a bore really doesn't give all that much power. The compression is where the power is at.

yes and no, boring to a 440 isnt really that big of a difference to tell much power. this increase in displacement only gains power due to the increased fuel and air consumption. if used with a good lightweight piston, this provides a better top end motor, but with greater compression, this brings the powerband back to the lower rpm's also allowing more torque

[400exrider707]

Originally posted by 440exnacsracer
yes and no, boring to a 440 isnt really that big of a difference to tell much power. this increase in displacement only gains power due to the increased fuel and air consumption. if used with a good lightweight piston, this provides a better top end motor, but with greater compression, this brings the powerband back to the lower rpm's also allowing more torque

agreed