Cyl Wall Thickness

[stoner]

I had a 1986 3.2 rebuilt to a 3.8 stroker. Inside Cyl diameters are 102mm with cyl walls thickness 1.5mm. After 1200 miles, cyls split. What is minimum acceptable cyl wall thickness. A standard 3.2 cyl thickness is over 4mm.
Thanks

[tom1394racing]

Is that a 95 mm bored to 102 mm?

Seems like a real stretch.

[BURN-BROS]

Sorry for your Loss.

I would only attempt a 102 on a 3.2/3.0 with a set of Nickies from Charles @ LN Engineering...... Is that a steel linered cylinder? What size was the case spiggots machined to?

[88-diamondblue]

+1 Burn-Bros on the Nickies

95mm stock cylinder can be bored to 98 and the Mahle 100 need the spigot bored to fit so the casting is larger than the 95 casting. EBS confirmed the 95 & 98 are the same external dimension allowing the boring to 98. Who did the boring/rebuild?

BTW Welcome to the board. We all like to see pictures of your car. Hint, hint

[stoner]

Hi Guys, I was out of town. Sorry for not getting back to you. The cylinders are iron sleeved. The cyls appear to be Koblesmidt ??? which have been modified & bored out so the liner could be installed. This did not leave much to support the liner as the alum cyl is also extremely thin. I asked the company that did the rebuild to send me the specs on their big bore kit but they won't because (they said) it is a trade secret and don't want the competition to know what they are doing. At this point I would rather not say who the company is that did the rebuild, but I'm sure you all can guess who it was.
I have checked with other more reputable builders and the response has been for "big bore rebuilds" that the cyl wall thickness ran as thin as 2.5mm but down from the top they had a "thick" section at the top for greater hoop strength at the peak cyl pressures. So, my 1.5mm thick walls was a "time bomb" ticking.

[snbush67]

I am guessing Motor Shiester? Trade Secret.... If it was you who paid for the rebuild you should get a refund.

Good Luck,

Shane