PISTON BREAKS

[stroking]

i installed a hotrod 4mil kit with stock head,and i used the spacer plates that go on top

 

we ran it up and down the street about 6 times than we hit the track and made one pass and this happen!!

 

after looking at the head and piston it looks like the piston may have been hitting the head...JUST ALITTLE on the edge because the head was not cut to fit the bigger bore piston,so im thinking that maybe it was the cause.......what do you think......can alittle tap on the head with the piston cause this ??

 

 

[flyhighprerunner]

i installed a hotrod 4mil kit with stock head,and i used the spacer plates that go on top

 

 

Did you put it on top of the end or the bottom side of the jugs? got any pictures?

[stroking]

 

the plates go on top,there between the head gaskets that comes with the kit.

 

i have sense had a head cut to run without the plates.

[flyhighprerunner]

can someone translate?

 

*EDIT*-it all makes sense now!

[SAVAGE420]

Sorry dude but that ONLY thing that goes between the head and the deck of the cyl is a gasket.

 

No plate goes there man. :ohmy:

[slopoke]

hummmmmm Are you sure it was hitting? Did you ck anything like squish before cranking it or did you just hope it worked? Kinda looks like detonation maybe. Don't see any really good evidence . Need to do some clearance cks

[slopoke]

What piston is that? Is it cast or forged? Aint no 795 I don't think. Or I don't see the number anyway.

[Rodneya]

cylinders not ported for a 4mm run the plate under the jugs. If you are ported for a 4mm then there is a plate that goes between the stock head and jugs.

 

Those look like el-cheapo Namura junk

[yamahaman244]

What piston is that? Is it cast or forged? Aint no 795 I don't think. Or I don't see the number anyway.

 

 

whatr kind of piston dont look like a wisco does it slopok

[slopoke]

kinda what I thought. elchepo If thats the case a little predetonation will do just that!!!!! there are some short cuts u just dont take and this is one of them,,,,,,cheap pistons

[yamahaman244]

kinda what I thought. elchepo If thats the case a little predetonation will do just that!!!!! there are some short cuts u just dont take and this is one of them,,,,,,cheap pistons

 

 

hey slopok im sorry to ask this put what is detonation or predontation

[slopoke]

pre-ignition low octane +high compression =knock knock break

[stroking]

this is a FULL HOTROD STROKER KIT that comes from motosport.....the $799 kit 4mil/5mmlongrod crank...pistons gaskets all included

 

clearance was good as far as squish go's,but it looks like the edge of the piston was hitting the head,you can't see it in the pic though

 

this motor is run on alcohol....those marksontop of the piston are from the metal getting in between the piston and head after it cracked...not det or pre det.

[stroking]

Sorry dude but that ONLY thing that goes between the head and the deck of the cyl is a gasket.

 

No plate goes there man. :ohmy:

guess you never seen a spacerplate that go's on top

 

i get you a pic if you like to see one

[XxMeltIcexX]

That's a stupid way to set up a motor IMO. Who's the builder? If you had adequate squish then you wouldn't be hitting the head. Although it really doesn't look like it was to me in those pics.