View single post by Sylva
 Posted: 11-13-2006 02:35 am
PM Quote Reply Full Topic
Sylva

 

Joined: 09-14-2006
Location: Malaysia
Posts: 54
Status: 
Offline
 I run a 2.2 910 Block with all the mods. And JE Pistons +30. I had the engine rebuilt, (In Malaysia,) by a good machine shop, (But not the best Mechanics). I ran the car for 5 track days up to 6,000 Rpm. Then raced it, And the Pistons hit and broke down to the 1st ring, on 1,2 an 3.

When I stripped the engine I found that the dowels to locate the head gasket were not in place and thrfore the gasket and linner bores were no aligned. So the Pistons had hit the chrome ring of the gasket.911.25 CR Pistons).

So rebuilt the engine By some one else who I trust, using 10.5 CE Pistons from JHPS. Ran the car for 4 track days no trouble, then raced it at up to 7000 rpm and same thing, 1, 2 and 3 Pistons broke, but this time the gasket was aligned and the pistons have hit the head.

So my question is, does any one have any experience of this problem. MY thoughts are that the rods have streached (sould be 5.5 inches +001 between centres), and I'm pulling the rods out to check this weeknd.

Head has never been reground, and valves are not hitting. And head Gasket is the right one, I'd apprecate any advice, including where you guys buy your steel rods from.

My source at Lotus tell me that there should be no problem with rod stretch until at least 8,500 rpm and I didn't get near that.