DeTomaso Mailing List: October 99, Message #12

Cal,

I've previously posted the data for you to answer your own 
question.  I'll post them again here.  A Dart II flows nearly
as well on the intake but not as well on the exhaust as a 
*stock* 2V.  Porting yields similar gains for both heads.  Note 
that the N351 head is the "Sportsman" head, not the Dart II.
It is a special head that is not a 1-for-1 replacement for
a Windsor head.  It was produced as a low cost circle track
part.  Edelbrock produces a special intake for Ford that 
matches it.  It also has non-standard exhaust header flange.  
The A3 *kills* a Sportsman.  Not in the same league.  The 
Windsor heads that retain true Windsor layout (GT40, Dart II, 
Edelbrock Performer, etc.) have a hard time out flowing a 2V 
Cleveland head.  The good "race" Windsor heads typically have
non-standard port locations (exhaust), valve locations, etc.  
It's mostly not a big deal but you *must* know the details 
before bolting them on.  The Twisted Wedge heads require 
matching piston reliefs and specific rockers/pushrods to 
retain geometry for instance.  Many off-the-shelf headers 
won't fit.  The Edelbrock Victor require a rockershaft system.  
Etc. Etc.  The devil is in the details.

The canted valve SVO heads have evolved into pure race parts.
The best of the lot Yates C3H, Brodix/Neal, and the new Blue 
Thunder are claiming ported max intake flow in the 380 CFM 
range.
 
Dan Jones

Air flow taking @ 28 in. H2O.  
 
   Heads    I/E .100  .200    .300     .400    .500     .600    .700

Stock 2V    I   59    114     177      202     204      210     N/A
            E   45    83      117      150     170      179     N/A
  
2V with 4V  I   70    139     197      216     216      218     216
valves      E   54    102     142      166     178      181     181

Stock 4V    I   65    107     162      208     245      267     N/A
            E   50    85      122      145     160      167     N/A

SVO GT40X   I   56    107     159      197     217      227     234
            E   53    110     144      150     150      149     149

Dart II     I   58    111     154      188     207      217
            E   47     89     114      135     145      149

SVO N351    I   64    127     173      210     232      248     255
            E   49    100     132      148     155      167     174

SVO A3      I   68    142     218      274     311      330     N/A
            E   52     97     126      154     184      206     224


> ----------
> From: 	Eustaquio, Cal J[SMTP:cal.j.eustaquio@lmco.com]
> Reply To: 	Eustaquio, Cal J
> Sent: 	Friday, October 01, 1999 9:50 AM
> To: 	Multiple recipients of list
> Subject: 	RE: 351W Dart Heads
> 
> Hi Steve and Company:
> 
> What is the equivalent head for the 351C that we can use to compare
> against
> the 351W Dart heads? Some of us don't have 351W's in our cars (at least
> yet)
> but would like some comparable performance head to put on our Clevelands.
> The only one I suspect this will do are the Ford Motorsport A3 heads. I
> thought about the Yates all out racing versions but I don't think they
> will
> fair well in the low end environment. Cal. #2428r. 
> 
> > -----Original Message-----
> > From:	Steve Donegan [SMTP:donegan@quick.net]
> > Sent:	Thursday, September 30, 1999 4:16 PM
> > To:	Multiple recipients of list
> > Subject:	Re: 351W Dart Heads
> > 
> > 
> > 
> > On Thu, 30 Sep 1999, Dave & Carol Aument wrote:
> > 
> > > >
> > > >Reverse those numbers - Sportsman heads are (up to) 2.02 intake,
> > > >1.7something exhaust :-) 800$ fully assembled is a very good price.
> (my
> > > >set has 2.02/1.75 and a nasty porting job on the flowbench for weeks
> -
> > > >flows WAY better than 4V Cleveland heads :-) 
> > > 
> > > 
> > >  But not nearly as well as the SVO or Neal/Yates heads or thats what
> > > everybody would run in that "stockcar" series. 
> > > 
> > > 					Dave 
> > > 
> > > 
> > >
> > 
> > Well, it's simple - you can beat 'old' technology senseless with 'cheap'
> > new hardware - ie Dart, TFS, Edlebrock etc heads - all in <1200$ trim.
> > They beat 4V Cleveland heads hands down in over all flow and definitely
> in
> > driveability - their low end flow velocity is much better. Pure race
> heads
> > - now you are talking Yates, TFS R models, etc. Totally different animal
> -
> > and they still do better at bottom end than 4V heads and a whole lot
> > better at top end. But they cost a bunch more. My point has been, and
> > always will be, put a modern, cheap, aluminum set of heads on your
> > Cleveland (or better yet SVO 351) and you'll see a bunch more HP/TQ, gas
> > mileage, and drivability improvements. As always - your mileage may vary
> > :-) If you're a purist for 351C great! If you want real HP/TQ in a
> modern
> > platform that fits your exotic then you have other, cheaper,
> alternatives.
> > 
> > 
>