DeTomaso Mailing List: March 2000, Message #95

With the 2V heads, you don't have much of a choice for dual 
plane intakes.  The Edelbrock Performer/F351 2V is it, unless 
you port match to a 4V intake.  With my Aussie 2V heads, 
I've been quite happy with the Weiand Xcelerator 2V single 
plane and a Holley 735.  It will pull smoothly from 1000 rpm in 
5th gear and knock down 20 mpg on the highway.  The Weiand 
ports are larger than a 2V head port, so it must be port matched.
With my engine combination, the only driveability problem is 
a little low rpm surge when the engine is cold.  Within a couple 
of blocks that goes away and the response becomes very smooth. 

The Edelbrock Performer 4V with its smaller than 4V but larger 
than 2V ports might be a good choice for 2V heads.   The best 
approach would be to open the intake ports of the 2V heads so 
that either the Performer 4V or the Xcelerator 2V will match 
and then test both (with and without carb spacers).  I'll probably 
do this when I swap the Pantera's engine into the '56 F100 project 
truck.  

Jack Butler just finished dyno testing his 377 stroker.  There was 
a big difference going from a 650 DP to a new HP series Holley.
30 to 50 hp increase across the board, not just at high rpm.  Jack, 
which HP series carb did you use?

Dan Jones
 
> I note you don't mention your intended manifold selection.  I highly
> recommend a dual-plane for street use.  The Pantera gear ratios put you in
> the low RPM range a lot on the street.
> 
> I had a 10:1 with American 4V heads and a single plane Weiand manifold and
> a
> similar cam.  A 650 double pumper had crisper throttle response on the low
> end, a 750 double pumper had more torque on the mid and upper end.   I
> attribute the bottom-end "sleepiness" of the 750 to poor atomization of
> fuel
> due to the single plane and low velocities in the big ports.  The dual
> plane
> manifold cuts the plenum averaging effect in half, the Aussie heads will
> have higher port velocities, so this will likely off-set the bottom end
> effects I saw, so I would heavily lean toward the 750.  I have always much
> preferred mechanical secondaries over the vacuum type.
> 
> I would never put a 600 on a 351 Cleveland.
> 
> 
> ----- Original Message -----
> From: <Cars5244@aol.com>
> To: Multiple recipients of list <detomaso@realbig.com>
> Sent: Thursday, March 02, 2000 3:50 PM
> Subject: 600 or 750?
> 
> 
> > Sorry for all the questions, but you guys have been through this before.
> I
> > really do appreciate you input.
> >
> > Engine will be 20 over  KB #148 pistons, approx. 10 to 1 using Aussie
> heads,
> > Crane cam 524421( 226/230 @ .050, 528/536 110 LC. Will be for street
> use.
> > Should I use the 600, would that be the 80457S or 750 80508S or is there
> > another model for each?
> > Thanks,
> >
> > Skip
> >
> 
>