Ford 302 Tunnel Port Flow Numbers

[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