PopeyeTheSailorMan

Hi guys, im always on honda-tech, however i have never really gotten to around posting. So for you guys that know your stuff, ill give you a basic breakdown. I have a fully built motor, re-sleeved block, JE pistons, etc etc. I then blew a headgasket about 3 days ago. The motor has been dyno-tuned with the hondata 4b unit roughly 7 months ago. I pulled the head off on sunday and the headgasket was blown near one of the #1 piston water jackets, exactly where i thought it would be blown since that is where it was leaking coolant at. Upon further inspection i realized that the #1 piston is a little bit "pourous" feeling around the edges, however the cylinder walls are not scratched (i did the fingernail trick) and the car yeilded perfect compression before the head was taken off. Below is a picture of the #1 piston, it has me a bit concerned.





[Modified by Mike A, 12:03 AM 11/28/2002]


[Modified by Mike A, 1:25 AM 11/28/2002]

rjardy

it looks like it might have a little surface damage from running lean. but allso there is carbon build up on it, so just make sure your af is good and just run it till it gives, its not that bad though!


Rob

PopeyeTheSailorMan

The car was tuned on the RICH side, so the only possibility for running lean was the coolant mixing in with the fuel and combusting. I think the coolant/water seeped into the cylinder and was burned with the fuel. My guess is thats why it ran a bit lean in that one cylinder. Also, i believe the coolant/water helped to increase cylinder head combustion temperatures. Any other guys have an opinion? Thanks Rjardy.

rjardy

NP, hey is it rough like sticking up like build up or like little dents down in the top of the piston?

Rob

HybridKOOP

Looks fine to me. If you want to clean it up, use a medium grit sandpaper on it..

PopeyeTheSailorMan

The roughness does not protrude from the top of the piston or dip down. Its kind of like a coral rock, a spongy type appearance but a bit rough. Just for the extra sense of security im going to take it to the dyno to make sure everything is up to par.

PopeyeTheSailorMan

oh i forgot to mention, im talking about the edges of the piston between 9 and 12 oclock is where it feels a bit pourous and you can see it looks somewhat melted but not "melted-melted". the center of the piston is perfectly fine, just regular build up.


[Modified by Mike A, 1:26 AM 11/28/2002]

earl

Did you do a leak down? Could be lifting a ring land

earl

Definitely pull it for a look. How does the cyl wall look at that spot?

Jared

The carbon is definitely gone because of the coolant, but the pitting like earl said, is probably a ring land lifting.

TEAMGENDAI

sdfgsfg


[Modified by TEAMGENDAI, 4:50 AM 11/28/2002]

Adi Radoncic

Earl and Jared what do you guys mean when you say "the ring land is lifting?

Adi

earl

Basically what it says. The top of the piston in that area raises up where the heat is and makes the ring land area bigger in that area. Kills your ring seal. That's why I asked if you did a leak down. I'm not saying that's for sure what is happening as it is hard to tell from the pix.