[DeTomaso] A3 data

[Daniel C Jones]

> Anyone out there have the original specifications, flow data, port size etc
> on E2ZM6049-A3 heads?? I want to put this info into a cam sizing program.

As cast, the M-6049-A3 head had intake port volumes of 241 cc's and exhaust
port volumes of 134 cc's.  Ford published flow data showed the intake flows
280 cfm but that was at 25 in Hg pressure drop, not the usual 28" in Hg.
Nominal combustion chamber volume for the high port heads was usually
listed at 62 cc's, though Ford Motorsport sometimes lists 65 cc's.
Nominal valve sizes were 2.15" intake and 1.71" exhaust though 2.19"
intakes are often used.  Special versions of these heads were made for
certain race teams.  I have a set of narrow intake port A3's, for instance.
The data listed here is for the wide port version.  I flowed a set of my
A3's.  They had some cleanup work done in the bowls but no port work.
Results were:

 Valve  A3      A3
 Lift   Intake  Exhaust
 (inch) 2.19"   1.71"
 0.025   33     33
 0.050   48     45
 0.100   84     67
 0.150  119     86
 0.200  154    108
 0.250  187    128
 0.300  211    142
 0.400  257    169
 0.500  299    191
 0.600  327    214
 0.650  ---    ---
 0.700  309    226
 0.800  ---    234

The flow is in CFM and was tested at 28" pressure drop on a SuperFlow 600
flow bench at Stiegemeyer Racing Heads in St. Charles, Missouri.  A 4.155"
diameter tube was used to simulate the bore and the intake was flowed without
a manifold, using a piece of clay around the intake port.  No pipe was used
on the exhaust.  When Dave Williams had a pair of iron 4V Cleveland heads
tested on Jim Kuntz's bench, the operator mentioned that naked intake ports
usually flow 20-30 CFM less than a port with manifold.  I'm also told an
exhaust port with pipe picks up a similar amount.

I also have some flow data on some A3 heads that went through a shop that
Chip Barret-Smith worked at.  He said the bench they use posts numbers
that are a lttle more conservative than what a Superflow reads.  His results
were:

 Valve  A3      A3
 Lift   Intake  Exhaust
 (inch) 2.19"   1.71"
 0.050  32.10   23.90
 0.100  67.80   51.90
 0.150  105.4   80.30
 0.200  142.2   97.00
 0.300  217.5   125.5
 0.400  274.4   153.9
 0.500  311.2   184.0
 0.600  329.6   205.8
 0.700  ---     224.2
 0.800  ---     234.2

Dan Jones