[DeTomaso] Torque Plate

[JDeRyke at aol.com]

In a message dated 2/3/10 7:05:25 PM, detomasoregistry at gmail.com writes:

> If someone can 'splain dis better dan I please do!
> 
Just a couple of additions; ideally, a steel torque plate is used with iron 
heads and an aluminum one for alloy heads. If you're gonna use studs, add 
them before torque-plate-honing, or your results will change. 
And the very first torque plate was reportedly by Smokey Yunick who was 
trying to cope with the poor ring seal and thin decks on early 327-350 Chev 
V-8s. So he bored cylinder sized holes clear through a stock iron head, 
suitably torqued down, then did his boring & honing through the head-holes 
(swapping the destroyed stock casting from side to side). And he found the rings 
sealed better and lasted longer, and the engine made appreciably more power. 
After that. other engine shops picked up on the practice, except they used a 
3" thick slab of steel instead of a stock head casting.
 
The Cleveland block has thicker decks so it benefits a little less than a 
Chev. But when a Nor-Cal member's 351-C was measured before & after 
torque-plate honing, all the bores changed when the plate was torqued on. The 
variance wasn't much, but if you're using cast/hypereutectic pistons, the change 
was an appreciable fraction of the recommended piston clearance. FWIW- J 
DeRyke