[DeTomaso] Wrong cam with Webers....

[MikeLDrew at aol.com]

Hi guys,

Here's a great video by an engine outfit in England that built a motor for 
a race Pantera.   I *think* it was for the yellow factory Gr4 that was 
converted to Gr5 spec, although it might have been for the red Gr3 converted to 
Gr4 spec (#5855).   The latter car never really ran properly.

Anyway, the interesting thing about Webers is that they demand an unusually 
wide LSA (lobe seperation angle) of 112-115 degrees to work properly.   
This engine was probably fitted with a very radical narrow LSA cam engineered 
for a big single-plane intake, which has completely different requirements.

They got a ton of power out of the engine, yes (I suspect it's a big-time 
cheater stroker).   But, note the effect of the narrow LSA--ungodly amounts 
of reversion, and a potentially lethal cloud of fuel vapors hanging over the 
mouths of the carbs.  Years ago, I saw the Adler's Gr5 Pantera literally 
catch on fire in the pits at the POCA Fun Rally track event, because this fuel 
vapor soaked the air filters, and then it backfired on startup and set the 
filters on fire.   Webers have lots of fiddly brass jets that will melt at 
low temperature, and it doesn't take long for an air cleaner fire to lead to a 
Weber meltdown, and molten metal that runs down into the cylinders is never 
a good thing.

Anyway, check it out....

http://www.youtube.com/watch?v=JRdwWgSGqvc

With Webers, wide LSA is your friend.   It really smoothes the idle out and 
removes much of the radical nature of a powerful engine, making the car 
sound quiet and docile by comparison.   But boy, will it go!

Mike