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.

[gt350hr]

    Mine liked 8,200 for a shift point but it was a 5.315 rod 331. Now with the VicJr heads that replaced the TPs , it likes 8,000. (same short block). I think the stories ( from the day) of the tattle tale tachs reading 9,000+ were from downshifts because the engines didn't have enough valve spring to rev that high under power.

[frnkeore]

Although expensive, I think you best bet for a intake, would be a sheet metal Weber 48 IDA or even a a 48 IDF, cheaper and closer spacing.

[gt350hr]

Although expensive, I think you best bet for a intake, would be a sheet metal Weber 48 IDA or even a a 48 IDF, cheaper and closer spacing.

     Frank  ,
       Webers , in an IR situation are too small to feed a 302. The best manifold I tested was the single plane , dual four using two 720 cfm carbs made specifically for the tunnel port 302. There  were some more exotic "bathtub" dual four intakes but the giant plenum really lost bottom end torque. A friend has one of these that backfired and "expanded" the top cover. Luckily it didn't explode!
      BTW , Scott (pbf777) has one of the ultra rare 3-2bbl tunnelport  manifolds. Few know it exists and "I" only know of the one Scott has. I owned one of the single four TP intakes but it had fuel distribution issues because of carburetor placement. Ford was really desperate to make the engine work and it didn't.
    Randy

[frnkeore]

I don't know, for sure, Randy but, based on Jay's intake book I get the following:

427 peaks at 6400 rpm, with 584 hp, pulling 793 cfm

492 peaks at 6100 rpm, with 606 hp, pulling 868 cfm

370 would pull 856 cfm @ 8000 rpm

It would be close to the limit but, they should be able to produce at least 600 hp, with a lot more mid range torque and average tq and hp than any other manifold and carb combo and would excel in a road racer. Might tame those heads, too.

Other than that, I'd go with IR FI, even a constant flow system.

[gt350hr]

    Frank ,
      IR (individual runner) doesn't follow the same guide lines as a "common plenum" situation as far as cfm required.. For example the 255ci "pushrod" and DOHC indy engines used 58mm Webers. The '69 Boss 302 T/A race engines used TWO 1100cfm dominators. A "modern" 410 sprint car engine uses fuel injection with 3 inch diameter butterflies . All of these are IR applications . These would obviously be FAR too much if used on a "plenum" style intake manifold.
   Randy

[pbf777]

BTW , Scott (pbf777) has one of the ultra rare 3-2bbl tunnelport  manifolds. Few know it exists and "I" only know of the one Scott has.   

     Yep, 

     Scott.

[jayb]

       Webers , in an IR situation are too small to feed a 302.

Gotta say I strongly disagree with that statement.  I ran 48 IDA Webers on the 446" 390 stroker that I tested for my book.  This was about a 500 HP/500 lb-ft engine.  The Weber intake setup SLAUGHTERED every other intake in peak torque and average torque, and average HP, and was only 10 HP behind the top manifold (tunnel ram with 660s) in peak HP.  I tested over 30 intakes on that engine, all the good ones included, and the Weber intake was the class of the field.  In fact, it's performance was so impressive that I put it on the cover of my book.

Now if that setup can work that well on a 446" engine, I don't see any reason why it won't work beautifully on a 302.

[gt350hr]

    No argument on what you found Jay but you might have made more with 58's like Ford did in the day. Now on a 289-302 a Victor Jr and 750HP are usually 30 better than Webers. I've done it more than once.

[jayb]

I think the 58s would have helped on the higher HP engines.  Here's some data:

390 stroker, 445":
   - Weber Average HP 432  (1st place out of 49 intakes)
   - Tunnel Ram Average HP 424 (2nd place out of 49 intakes)

  - Tunnel Ram Peak HP 525 (1st place out of 49 intakes)
  - Weber Peak HP 515 (6th place out of 49 intakes)

  - Weber Average Torque 431 (1st place out of 49 intakes)
  - Tunnel Ram Average Torque 425 (2nd place out of 49 intakes)

  - Weber Peak Torque 538 (1st place out of 49 intakes)
  - Tunnel Ram Peak Torque 519 (2nd place out of 49 intakes)

427 Sideoiler:

  - Weber Average HP 472  (1st place out of 27 intakes)
   - Tunnel Ram Average HP 472 (2nd place out of 27 intakes)

  - Tunnel Ram Peak HP 603 (1st place out of 27 intakes)
  - Weber Peak HP 584 (7th place out of 27 intakes)

  - Weber Average Torque 498 (1st place out of 27 intakes)
  - Tunnel Ram Average Torque 495 (2nd place out of 27 intakes)

  - Weber Peak Torque 547 (1st place out of 27 intakes)
  - Tunnel Ram Peak Torque 544 (2nd place out of 27 intakes)

427 Stroker (492"):

   - Tunnel Ram Average HP 535 (1st place out of 25 intakes)
   - Weber Average HP 513  (21st place out of 25 intakes)

  - Edelbrock Victor Peak HP 675 (1st place out of 25 intakes)
  - Weber Peak HP 584 (7th place out of 25 intakes)

  - Tunnel Ram Average Torque 564 (1st place out of 25 intakes)
  - Weber Average Torque 546 (12th place out of 25 intakes)

  - Tunnel Ram Peak Torque 624 (1st place out of 25 intakes)
  - Weber Peak Torque 600 (4th place out of 25 intakes)

As you can see the 48 IDA Webers fall off after around 550 HP, so I think the 58 IDAs would be better.  But based on my testing I have a hard time believing that a single 4 would beat them in a 550 HP or less engine.  Higher HP than that, it may make sense...

[gt350hr]

    I can't argue with what you found that is for sure! On the Boss 302 T/A IR dominator we LOST power going to two 750 dominators from two 1100s. Those manifolds had "communication passages" too! ( cross feeds). This could have something to do with our shorter strokes and attending reversion issues. I would hate to see someone going to the expense of making a one off manifold to lose power.

[frnkeore]

750 hp out of a 289?
Edit:
Sorry, I miss read that. I'm sure you were talking about the 750HP carb and not 750 actual horse power 

As for the 58mm throttle Webers (2.283), I don't believe that they are available, at least, I haven't seen them in the US. There is a 55mm DCO (2.165), still made but, I don't know the availability. I really don't think the 58's were needed on the 375 hp 255 Indy engine(it also had much larger ports than the 289 and we now that's not need either). If I could get my hands on a set of side draft, 58mm DCOE's, I'd try my hand at a sheet metal manifold for my adapter, on my 412 and 58 DCOE's would work well and produce more hp on this 370 ci engine. There were lots of 58 DCOE carbs and manifolds for the SBC in the '60's but, not so much SBF's.

Jay's book has been my bible on intakes, since I got it, about a year ago, I've learned a lot with it. Getting back to the 48mm carbs, I have complete confidence that they will develop 600 hp, because they have, above that, I can't say. But, in all cases, they produced more torque, over a wider band than all plenum manifolds and that is what is needed on a road race engine. I think it's especially important with these TP heads. BTW, the Boss 302 was also noted for it's high hp, low tq, narrow rpm band.

A 2 7/16 throttle, IR FI manifold, would work well (EFI or constant flow) if the rules will allow it. I put a Hilborn system on my avatar car and it produce, exactly the same hp & tq, as my 45mm DCOE Webers (similar size throttles) but, it was only checked at the same rpm as the Webers, for max tq and hp. It may have been off over the hp/tq curve. I didn't use it after the dyno test, the Webers are a much simpler setup and lighter, overall.

[blykins]

Just a few random points....take them for what they're worth.

The issue with the Boss 302 was the cam.  Lazy, straight up (or retarded) camshafts don't work with small displacement engines and big intake ports.  The issue with a lot of factory engines was the camshaft...

Webers don't work well on everything (neither does 8-stack EFI). 

It's nice to do multiple part tests on one engine, but all engines will not follow the same trends.   I did a lot of parts testing with the 352, but that doesn't mean that I could expect the same results out of any engine, especially across a different engine family, or completely different displacement.

Either way, the plan for this build has changed.  Customer wants me to build a stock stroke 302 for these "street" heads and finish the rest of the engine to suit.  It will be used in a street car.   This saves us from having to modify fairly rare pieces of Ford history.   I'll keep everyone abreast of the progress, both here and on my YouTube channel. 

[My427stang]

Big change!

I’d want to do those heads one of two ways, narrow range, steep curves and screaming with a single plane, or modern cam street, early cam timing, min reversion, good amount of split and lsa to pull hard on the port right at and after TDC but in that case curse of the Ford lower plenum turn is likely present. Going to want a little grinding but purists may cringe

I wouldn’t want to do anything in between with that honking big dual plane

Fun regardless!

I have only 1 IR build, but FWIW it made the same hp peak and 40 lb ft less than an absolutely identical RPM equipped build.

[gt350hr]

    Yes Frank , I was talking about a Holley carb , not 750 horsepower 289-302. A REALLY good 289 will make about 600. On an IR manifold , "runner length" make big differences. Side draft applications certainly have longer runner lengths an IMHO better all around power over downdraft applications.
      Please don't misunderstand MY opinion on Webers. It is "my experience" ONLY. I am NOT the "world's authority". I am "one" person relating "my " experience on small block Fords with various heads. Jay's experience is with an FE which I haven't done with Webers despite having owned a set up forty years ago. I can't explain why Jay had good results because of my inexperience with the FE version. Certainly a long stroke engine would have better "signal" to the carb than a short stroke small block and that could be a serious factor as to why it worked. To get a stronger signal on a small block the RPM has to increase and SO does valve action induced reversion , that is simple physics.
    Again,  "My" information / opinion is but "one" man's view and others are as or more successful than me , NO QUESTION.
    Randy

[cammerfe]

Some years ago I had a '72 2 liter Pinto. Over the years, I monkeyed with it and at one point I put a mechanical constant-flow FI system on it. Ultimately I ran into parts-replacement problems and found out the company was out of business. I, therefore, went to a pair of 45 DCOE Webers. That was an EXCELLENT system. Pulled great from idle to 6500. Gave the feeling of twice as much midrange power.

I quit using carburetors when we put a pair of the original Holley TBI units on Brother Lon's 427 '67 Mustang. Depending on manifold design, you may not make more total power with EFI, but there'll surely be more power under the curve, and tuning is a dream in comparison. I switched to a Holley TBI set-up on my '63 Effie ICB/PI 390 and haven't used a carb ever since.

I'm looking forward to, ultimately, seeing what the cross-over injection Jay's designed will do, when he finally has time to get it on a dyno.

KS

[Joey120373]

Would love to see more pics of those heads.

Pretty sure I remember seeing advertisements for those heads way back when I was in high school, old grainy black and white adds at the back of the magazine.

That was back when I knew everything of course, and the only engines I cared about were the 350 SBC ( cause it was something I could at least sort of afford to dream about building…. ) and the FE 427 and whatever head I could dream about putting on it if I were to win the lottery…
So to me the Windsor tunnel port was cute but it wasn’t a “real” tunnel port, so at the time I just wrote it off as a gimmick. These days I wish I had paid more attention to all the different oddball stuff.

[Barry_R]

I have run a few Weber/Weber lookalike EFI deals on engines.  I love the way they look and they put out some pretty impressive dyno numbers on most street oriented stuff.  At the same time I absolutely HATE the way they act on the street.  I have personally struggled with at least 3 or 4 installations that seemed perfectly fine on dyno but would not run worth a damn once installed.  You would get them to idle and WOT great, but they'd do all sorts of goofy stuff in transition and part throttle - surging, stuttering and farting at seemingly random throttle positions and loads.  After a couple days of tinkering and tuning you'd get it nearly perfect - and the next day it was back to being stupid again.

[pbf777]

........... they'd do all sorts of goofy stuff in transition and part throttle

     Yep, that's typical!   

     Scott.

[Joey120373]

playing catchup here, I just watched your video on these heads, those are not what i remember seeing advertised as a young man. The  add, as i remember it, said something like " The iconic Tunnel port is back! " and the grainy pic looked like a conventional Windsor port with a rather large pushrod tube going through it. But memory is a strange thing, and i don't really trust that one.

That round port sure looks big , but the throat looks rather small. I think your plan of filling the floor to get a better short turn might do a lot of good. The exhaust port on that head sure looked good compared to most factory units.

Neat build for sure.