Look at my pitted piston top (pic inside)
11-23-2010, 10:36 AM
#1
Teching In
Thread Starter
Join Date: Jan 2009
Posts: 39
Likes: 0
Received 0 Likes
on
0 Posts
Look at my pitted piston top (pic inside) Has anyone ever seen such a pitted surface on top of a forged piston, you can see it better on piston # 4?? Strange is all pistons look alike, always on the intake side of the piston. I think it could be detonation marks.
I had all season long a very high oil consumption due to LE porting my AFR heads. Could it be that the unburned oil made such marks?? After engine shut down I always had oil puddles on closed intake valves.
I’m using 93 octane gas, CR is 11.3:1, DR is 9.0
I had all season long a very high oil consumption due to LE porting my AFR heads. Could it be that the unburned oil made such marks?? After engine shut down I always had oil puddles on closed intake valves.
I’m using 93 octane gas, CR is 11.3:1, DR is 9.0
11-23-2010, 11:25 AM
#6
Teching In
Thread Starter
Join Date: Jan 2009
Posts: 39
Likes: 0
Received 0 Likes
on
0 Posts
Heads are back on, so no better pictures. Above the # 4555 you see imperfections of the surface, like small pinholes. When you go over it with your fingernail you can certainly feel it. On cyl. #4 you can see it even better, the picture taken is from cyl. #2. Look at the left piston...
Here is a link if you want to know where VERY high oil consumption can come from:
http://forums.corvetteforum.com/c4-t...100-miles.html
Here is a link if you want to know where VERY high oil consumption can come from:
http://forums.corvetteforum.com/c4-t...100-miles.html
Trending Topics
11-23-2010, 12:04 PM
#10
Maybe if you raise you CR a few more points, the extra pressure will blast the oil past the rings and back down into the pan. Dont forget that the pits will actually lower CR. Watch out for detonation and windage.
And you always pull your intake to inspect the intake valves?
Wow.
11-23-2010, 02:31 PM
#12
So how is it LE's fault for for this?
Maybe if you raise you CR a few more points, the extra pressure will blast the oil past the rings and back down into the pan. Dont forget that the pits will actually lower CR. Watch out for detonation and windage.
And you always pull your intake to inspect the intake valves?
Wow.
Maybe if you raise you CR a few more points, the extra pressure will blast the oil past the rings and back down into the pan. Dont forget that the pits will actually lower CR. Watch out for detonation and windage.
And you always pull your intake to inspect the intake valves?
Wow.
It's pretty obvious he doesn't vacuum check his heads after porting since mine were broken through in quite a few places too. 
11-23-2010, 03:57 PM
#14
Teching In
Thread Starter
Join Date: Jan 2009
Posts: 39
Likes: 0
Received 0 Likes
on
0 Posts
Okay fellows I'll explain it again. The picture in my first post shows piston # 2 and partially # 4. Like I said before, it's on the intake side and above the embossed # 4555. The piston # 4 shows it a lot better than looking at piston # 2. There are thousands of small pinholes which are seen on all pistons, but only in this area.
Here is the same picture red underlined is the area of the pinholes.
Here is the same picture red underlined is the area of the pinholes.
11-23-2010, 04:22 PM
#18
TECH Apprentice
iTrader: (8)
Join Date: Apr 2009
Location: Texas.
Posts: 320
Likes: 0
Received 0 Likes
on
0 Posts
You don't think that would be a problem, having two differnt companies port the heads...I don't know why he would have them ported, twice since flow #'s don't mean jack..it's even on his sig heavily ported 210cc LT4 AFR heads..that's a lot of material being removed. I don't see how this is anyone's fault but his own.
11-23-2010, 04:26 PM
#20
"AFR heads were done first by AI 286/216 then from Lloyd Elliot 314/236."
You don't think that would be a problem, having two differnt companies port the heads...I don't why he would have them ported twice since flow #'s don't mean jack..it's even on his sig heavily ported 210cc LT4 AFR heads..that's a lot of material being removed. I don't see how this is anyone's fault but his own.
You don't think that would be a problem, having two differnt companies port the heads...I don't why he would have them ported twice since flow #'s don't mean jack..it's even on his sig heavily ported 210cc LT4 AFR heads..that's a lot of material being removed. I don't see how this is anyone's fault but his own.