DeTomaso Mailing List: June 98, Message #156

I punched one of my engines out to .040 over (without a sonic test) because
you can buy TRW pistons at plus .040, and ran it for years with Nitrous,
7000 rpm, etc.  Finally one day it started to blow blue smoke erratically.
Assuming it was the famous Cleveland valve seal/guide problem, I re-did the
heads and it didn't help.  Upon thinking (very hard sometimes), I remembered
that the cylinder walls looked kind of funny when I had the heads off, I
re-pulled the heads.  The walls looked like they had Leprosy; dark and shiny
areas.  Evidently the walls were "giving" under heat, and the rings would
seal/not seal.

Ted (Vader) Mitchell
http://home1.gte.net/tmitch/pe.htm
http://home1.gte.net/tmitch/chpie.htm
http://home1.gte.net/tmitch/index.htm

-----Original Message-----
From: JDeRyke@aol.com <JDeRyke@aol.com>
To: Multiple recipients of list <detomaso@realbig.com>
Date: Wednesday, June 03, 1998 4:42 PM
Subject: Re: How BIG is too BIG?


>In a message dated 6/3/98 10:49:51 AM, teampantera@yahoo.com wrote:
><>>
>Dennis is right again about the block weights! I got curious, so...
>A naked 1969 351W, std bore block, with 2-bolt main caps = 165 lbs.
>A naked 1972 351C, std bore block, with 4-bolt main caps = 165 lbs
>both done on my highly calibrated bathroom scales. Estimated 15+ lbs of
weight
>in a 351C cast iron timing-chain surround. 2 lbs of die-cast alloy in the
>351W. A 351W block is 1/2" taller ea. side; no estimate of weight in the
bore
>extensions.
>
>Biggest advantage of the 351C block: ideal sized main bearings for hi-rpms,
>compact block, powerful 351C heads & accessories bolt right on; the Pantera
&
>its accessories designed for this block.
>Biggest problem with 351C block: thin or core-shifted cylinder walls
common;
>the convoluted oiling system can cause mucho problems; parts getting
scarce.
>
>Biggest problem with the 351W block: 3" dia mains limit safe rpms due to
oil
>shearing to around 5500 rpm (hey, its a truck engine!); not sure if the
front
>bracketry fits the Pantera. Might need (extensive) reworking.
>Biggest advantage of the 351W block: stronger main supports (because it's a
>truck engine), better oiling system, thicker or less core-shifted cylinder
>walls, taller block so you can more easily run longer rods for higher
torque.
>Late blocks supposedly have taller tappet bosses so factory roller tappet
cams
>fit(?)
>
>Early '69-70 blocks (either 351C or 351W) were supposedly thicker-wall but
I'd
>still sonic any Ford block for core-shift before I spent much on it. A wall
>thickness of less than 0.100" on the thrust side of any cylinder is
disaster
>waiting to crack. Also keep in mind, a stroker doesn't make you faster,
only
>quicker unless you regear the ZF to utilize the extra torque @ lower
redline
>rpms like Dennis did for his Silver-State Pantera. I personally would use a
>351W block with main bearing spacers, a stroked SVO forged crank cut for
Chev
>rod bearings, 351C 4-V heads & alloy intake, aftermarket H-beam 6" Chev
rods
>and a roller cam. What would this be- a Windsor? A Cleveland? A powerful
>bastard?
> J DeRyke (with an aching back. Damn, I used to be able to do this s....
all
>day!)
>