General Chat
Q:
I had intended on doing a leak down test on the 260Z engine as per my previous post. But after talking with Tony it was decided that a leak down test would only further prove an already known problem. So I decided to just dig farther and take it apart after a hint from Tony at what the problem could be.
I guess that JeffP had had a similar problem with his car. The car detonated without making any noticeable noise. The detonation broke the ring lands on his pistons. In my engine 4 out of 6 had broken lands between either top and sec ring and or sec and oil rings. The cylinder walls showed ABSOLUTELY no indication of the failure. Just the comp drop.
The really scary part is that the car drove 150 miles like this with a noticeable decrease in power and only minor hiccups. It could have been even longer than that. Comp was 1-6 respectively 90,150,145,80,80,80. Turbo was set for 20psi and was only producing approx 15psi.
So I'm off to figure out whether to use new pistons or the relatively new Nissan Re-manufactured bottom end I have. We'll see.
Anyway Tony called it in an e-mail to me. Go figure. I've never seen a failure that didn't transfer to the cylinder walls. I guess I have now. As soon as I find my camera I'll post some pics of the pistons and the cylinder walls for your amazement.
Ray @ DMS
OH BTW:
To my surprise the skirts on all the pistons were perfect! Not a crack or break. I must be doing something right. Previous builds like this one have proved that the pistons skirts tend to fail first. Just another interesting point.
"I reject your reality and substitute my own"
Please check out Thanks!
"You can get anything you want at Alice's Restaurant, excepting Alice"
Post Edited (Oct 6, 6:55pm)
A:
I broke quite a few ringlands when I tried my 11.6:1 and 11.3:1 experiment a few years back. Never damaged the cylinder walls at all. High Nickel content in Datsun blocks keep damage at bay!
-----------------------------------------
12.804 @ 107.26 mph on crappy street tires with Dual SU Powered 2.9L Stroker!
ZCAR.COM member since Aug 1998
A:
"High Nickel content" agreed!
"I reject your reality and substitute my own"
Please check out Thanks!
"You can get anything you want at Alice's Restaurant, excepting Alice"
A:
To bad, you know, you could have driven that car for just about as long as you wanted, if you didnt mind adding oil every now and then LOL.
Well I sure hope this fix will be cheaper then my car 3800.00 to replace the pistons, rings, new bearings and have the (BRAND NEW GEROLOMY BIULT HEAD) checked out.
Total bummer, I think it happened on the dyno when everyone thought I was getting a misfire, WRONG the sucker was just out of fuel!
signed pseudotechnician view point, Sniper S^$ker, with girly arms : UCC 1-207
A:
I totally could have kept driving it! It was still fast enough to whip most 99% of the Hondas in town. The oil consumption wasn't to bad.
"I reject your reality and substitute my own"
Please check out Thanks!
"You can get anything you want at Alice's Restaurant, excepting Alice"