[DeTomaso] Another Grenade Job - (sorry long)

[JDeRyke at aol.com]

In a message dated 12/27/09 12:25:39 PM, wkooiman at earthlink.net writes:

> So, what happened?
> a)       Did the cylinder split?
> b)       Did I over-rev the engine?
> 

On quite a few 351C blocks, boring it 0.030-over leaves a cylinder wall 
thickness of less than 0.070" which allows the weakest spot to flex in and out. 
Cast iron doesn't flex long before cracking, so it can simply blow a piece 
of wall into the water jacket. Continuing to run the damaged cylinder may 
soon crack the piston. Paper-thin describes the basic problem and is the 
reason most knowlegable engine builders will not sell you a 351C without first 
sonic-testing the block before boring, and if its to go into a Pantera, making 
sure you have a baffled 10-quart oil pan before the engine loses a rod 
bearing. The slight overheating might have affected headbolt tightness, but 
cylinders split from lower-end damage or over-pressure such as detonation etc. 
Note that such a block with one thin cylinder (or a max of one per side) 
can be successfully sleeved for less than the cost of digging a junk block out 
of the wrecking yards and produces a block thats actually a little stronger 
than it was pre-blowup. We raced a sleeved block for years in a 450-bhp 
Pantera and I believe the repaired engine is still running 20+ years later. 
Since you "sonic-tested" this block the hard way, don't throw the block away 
before checking around for sleeving prices. And don't junk it in any case 
before stripping EVERYTHING removeable off the broken block- most of the 
removeable bits are no longer available new. Better luck in '010, Will- J Deryke