[DeTomaso] port matching

[JDeRyke at aol.com]

In a message dated 10/23/10 12:46:03 PM, doug351c at gmail.com writes:

> Are there any tricks for determining intake to head port matching.  The 
> only way I've found so far is to bolt the intake down with .050" thick 
> cardboard in place of the gaskets to make a dual sided impression.  Is this the 
> best way?
> 
That works, but first, you should decide if cutting the ports is really in 
your best interest. Most often this is done to an aftermarket intake since 
most Panteras came with gigantic 4V heads, and a small intake port bolted to 
a big cylinder head will make the combination work as if BOTH were small.   
This   enhances low and midrange engine speeds (up to the low 5000-rpms). 
The mismatch between the parts acts as a reversion generator or port-plate 
with no extra parts needed. Max rpm running will be adversely affected but 
unless you only drive on long straightaways or at big racetracks, the average 
Pantera drives bettter with small ports. 
Port-matching the exhaust has much less effect on engine running; port 
matching at the bottom of the exhaust port does nothing since thats mostly a 
dead-flow area. The upper sides & top flow most of the exhaust. Exhaust 
restriction is further out the system, in the Ansa mufflers. Good luck- J Deryke