Ford 302 Tunnel Port Flow Numbers

[blykins]

I got a set of heads in for a road race build and I'm going over preliminary measurements.   You can barely find anything anywhere on the internet about these heads when it comes to chamber volume, intake port volume, or flow numbers.  So, here's all of it....

These are the "street" heads with stud mounted rockers.   Heads had 1.980" intake valves installed and 1.550" exhaust valves.

Chamber as measured was 56.8cc.

Intake port volume as measured was 209.4cc.

Flow numbers are as follows, with a pipe and a 4.155" bore on the plate:

.1  70   59
.2  125  92
.3  166  120
.4  200  135
.5  231  145
.6  250  150
.7  257  155

Now, for a 209cc port volume, that's pretty bad.  But, back in 1968, these numbers were about 60-70 cfm higher than a 289 or 302 head. 

We will make them better......

[machoneman]

Thanks for the info Brent! And yes, today little is known of these rare heads.

I did do some extensive research on them long ago from various magazines. Ford did not make many sets, for reasons I note below. Many Trans-Am race teams, running 302-305 CID Windsor headed engines did get the TP heads and ran them extensively in testing and some race conditions IIRC. But, they found the low(er) rpm's needed for tight cornering at some tracks showed a major weakness of these heads. Apparently they were low on torque as one hit the gas to accelerate out of those tight turns. With Cleveland heads just over the horizon (Boss 302's), most switched back to std. Windsor head until in 1969 the Boss 302 came to life. 

I always wondered though how a 351W would do with these heads or maybe today's stroker 302's (347 CID).

[blykins]

These are going on a 370ci engine.  Full road race, billet Bryant crankshaft, Dyers rods, dry sump, etc.

[frnkeore]

Great, Brent!

I'll be following this, for sure. I think the race heads had about 2.11 intakes. I think you could get some 2.15 x 7mm in there.

Who's going to port them?

[Katz427]

Interesting Brent! I remember when they came out, one local racer got his hands on a pair.  He already had a pair of the GT40 heads, or sometimes called 289 heavy duty, heads he managed to procure from a Cobra team.  His experience, was the Gt40 heads, were much better on the track, a much better power curve, than the tunnel ports. The GT40 heads had pretty large intake ports, with a 1.85 intake valve, and a 1.625 exhaust valve. This guy was running a 289 or 302 against 350 SBC and regularly beating them. Lot's of late days as there were lots of protests after the races, by the SBC drivers. Some credit should go to the driver, as he was a pretty damn good wheelman !

[Katz427]

Another quick tidbit! I read Smokey Yunik's Power Secrets from the late 70'. In there he said his best Nascar, heads were about 250 cfm on the intake and close to that for exhaust.  So we are a bit jaded today, by the flow that is available, "out of the box". Interesting to see what the porter gets.

[blykins]

This is a 2.090 and a 1.500 valve.   A valve job will sink the intake valve a bit, but there's a few things that will stand in our way of going much bigger than that.   If the CSA gets closed up quite a bit (not ported/opened up) then the valve size doesn't have to be that large.   An AFR 205cc head will hit almost 320 cfm with a 2.080" valve.

[machoneman]

Nice pic Brent.

Say, how do the exhaust port sizes line up with say a standard (run-of-the-mill) iron Windsor port? I thought from pics of long ago it looked like Ford left these ports the same size as any old iron W head.

[Eken1]

It will be interesting to see what they flow without the pushrod tubes.  Ease of access to all structures would seem ideal to study the effects of vane modifications and possible directional port floor vanes, that may have application to the FE.

[machoneman]

https://bangshift.com/bangshiftapex/ford-302-tunnel-port/

[cammerfe]

It will be interesting to see what they flow without the pushrod tubes.  Ease of access to all structures would seem ideal to study the effects of vane modifications and possible directional port floor vanes, that may have application to the FE.

We first put a TP 427 in Brother Lon's '67 Mustang when it was just a few months old. Several years later, those heads were damaged when he lost an intake valve, and he replaced them with a set of MR.

Jump ahead another several years and we decided to build a new engine and use TP heads from Jim Dove. Looking for the best possibilities, I called Mose Nowland and asked him to talk to me about the work that had been done in research of re-shaping the TP tubes. He referenced the small block TPs as the latest work done and assured me they'd not had ANY luck with finding a better shape than a round tube. Take it for what it's worth.

KS

[pbf777]

............................... it looked like Ford left these ports the same size as any old iron W head.

      It can only be said that the exhaust port "looks" somewhat similar in basic shape to the standard S.B.F., but it is actually quite different, the closer comparison would be to the C6FE casting; this is an observation in the eyes of one who ports heads and has work with all of these castings in the past.   

      Scott.

[Falcon67]

The intake flow numbers look like my ported 2V 351C heads with a 2.19 valve.  The exhaust numbers look like the 351W GT-40 exhaust ports on my 302. 

[gt350hr]

    Gentlemen,
        I am one of the few that have used the "street" head which has some significant differences from the race head. I also ran the race head in '69 when they were "given away" literally . The first is the smaller valves Brent noted and because of the guide spacing it is not possible to install the race valve which was 2.150 in final form , though they did do some at 2.11 according to my SK notes. The tunnel port head had over thirty  revisions during the '68 season on the "race" heads. The street heads had a poor exhaust port (compared to the race head) as it was made for smog tubes. My heads were plugged and ported but the flow was about that of a C6FE head. BTW I had one of the best pairs of C6FE heads and the intake flow was a stout 260.
     My engine was a 331 so an additional 40 inches like Brent is using will completely change things for the better. It would be over 540 HP from my experience without taking Brent's skill and ingenuity. Mine was about 480-490. The intake manifold is one area where big gains could be found. There was/is a rare single plane dual four that made an honest 20-25 MORE than the more common dual plane. The only other possibility is a "small port" dual plane dual four that was made or the ultra rare single four ( two known to exist).
   I am anxious to see how Brent does on this one.
  Randy

[cleandan]

These parts, while developed for the road race circuit, sound like they may be well suited on the drag strip.
Build a Windsor based lower end for really high RPM and bolt this stuff on top for a very fun, albeit hard to convince the techs, factory Ford intake and head combo.

Shift at 8,700 and through the traps at 9,200....but before you do place bets with your race buddies about how many other racers will lodge a formal complaint about your cheater engine.