Zoom zoom BoOm x2.

[BlkZoomZoom]

cyl2. 3. 4. 1.

 

[ddogg777]

Looks like there was too much clearance, the rings were consequently not seated far in the grooves, they then bound with the cylinder walls and snap! Broken piston lips. Dang, I feel sorry for you man, that was an expensive build.


I used to read Encyclopedia Brown books when I was a kid...

 

[Focus]

Well you do see signs of detonation. Especially on Cylinder 1.

 

[BlkZoomZoom]

Heres the plug and a chunk of piston that came out of cylinder one.

ddogg7- There is very little scoring on the cylinder walls, very little. Even on cylinder one. I believe the block can be used if I were to give it a good hone job.

 

[Focus]

Looks like there was too much clearance, the rings were consequently not seated far in the grooves, they then bound with the cylinder walls and snap! Broken piston lips. Dang, I feel sorry for you man, that was an expensive build.

Not sure on that. It's only on 1/2 the piston lip.

 

[Focus]

Is that the plugs electrode and tip fused together ?

Heres the plug and a chunk of piston that came out of cylinder one.

ddogg7- There is very little scoring on the cylinder walls, very little. Even on cylinder one. I believe the block can be used if I were to give it a good hone job.

 

[BlkZoomZoom]

yes. Well at least bent over. The camera makes everything look like detonation marks. I didn't use a lint free cloth when cleaning the oil and fuel off.

However on cyl.1 I have no idea. I do know that you could hear pieces flopping around inside when I drove it off the dyno.

 

[Focus]

Still want you to send me your Map from the MPI

 

[ddogg777]

Not sure on that. It's only on 1/2 the piston lip.

Well sure, it wouldn't bind everywhere, just in one spot. Especially if the clearance was too much, the piston would be against the wall on one side (impossible to bind since the ring would be seated furthest in the groove here) and the extra looseness on the other wall would cause the ring to fail and bind, thus breaking the lip in that area... (rockon)

@blkzoom- If you overbore your cylinders (mine are all .02 overbored, it helped since cylinder #3 was out of line) you should be okay. Just make sure you have the block checked for hairs...

 

[BlkZoomZoom]

Easier said than done. I had been trying to load the datalog but everytime I try the laptop freezes.

 

[BlkZoomZoom]

I can't afford re-building again. I have a spare motor and turbo that are going on when I can look at it again without getting sick to my stomach....

 

[BlkZoomZoom]

Anybody know what the spec. for piston to wall clearance is with these pistons?

 

[ddogg777]

I don't remember off hand but I'm sure Beau remembers. I might have it written down in my CP box at home...

 

[MazdaT]

Anybody know what the spec. for piston to wall clearance is with these pistons?

CP claims .003 for the drop-in's. However, my #3 bore was tighter, and only yeilded .0025 clearance.

 

[ddogg777]

Blkzoom, do you see any fine vertical scoring on the walls? If so, where do you see them at? My guess is that they are at the top of the stroke going down. They don't have to be deep; kinda like scuff marks.

 

[BlkZoomZoom]

Never seen an engine that didn't have any scuff/ scoring marks. Yes there is some, pretty much the whole length of the bores.

 

[mp5jeff]

one reason my p5 won't ever see a dyno, i don't trust the operators, i've seen to many cars blow up on dynos because of operator error to dyno my car. If that was the case in this im not positive, but it sounds to be a little bit.

 

[terbow]

that was the first dyno ive been too where u cant drive the car.

 

[BlkZoomZoom]

I'll find out soon what the piston to wall clearances were, It may be all in my head, who knows. I'm sure its rpm climb to the moon did not help anything.

 

[terbow]

Not if it was a sustained trip to the moon either. Did u ever find out how long it was there? I thought i heard 6 secs but i could be imagineing it cause no dyno person in theyre right mind would leave a car at above redline for more than a second.