I'll chime in...Fantastic job Ted! You are truly an asset to Y-Block lovers everywhere.

Which model Strombergs were used? Stock jets?

The compression ratio (9.2) on that dyno engine seems pretty low for the cam being used. It would seem that 10.0 or more might be optimal. What octane fuel was used?

Now I'm glad I traded my Offy 3-2 manifold for a pair of posted G heads!

Thanks!

FIGHT CONFORMITY! 

The Stromberg carbs being used simply say ‘97’ on their side.  They are big numbered on the end carbs and have a small number imprint on the center carb if that helps with the model identification.  The Strombergs are all jetted with #48’s for the test.  Originally started out with 45’s in the ends and 48’s in the center but the engine was running just a tad on the lean side and rejetting the end carbs fixed that.  A big Thank You goes to AussieBill again for the extra jets to get those carbs ‘on the money’.

91 octane pump gas is being used for all Y-Block testing at this point with the stock heads in place.  Total ignition timing is 38° BTDC using a MSD distributor.  Engine has 13” vacuum at 850 rpms for what its worth.  Performing a cranking compression check is on the list before changing the heads out for some heavily milled heads in the near future.  Engine sounds strong at idle even with 9.2:1cr.  118 pulls on the engine thus far and just now starting to pick up traces of some oil leakage from around the rear main seal area.

Lorena, Texas (South of Waco)

The aluminum 4V intake being referred to is the new Mummert offering.  I have tested the Mummert intake against the Blue Thunder piece on two different engine combinations and the Mummert intake came out on top in both instances.  Because the exhaust system being used on the 312 dyno mule has been found to be too restrictive during the single 4V intake testing, some of the tests will be repeated in the near future using the same exhaust system that was used for the 3X2 testing.  The Mummert and Blue Thunder intakes were also tested on the EMC engine in back to back testing and the Mummert intake really shined on that combination peaking out at 464 HP on pump gas.  That engine still idled nicely at 950 rpms with a 254°/258° @ 0.050" camshaft and the Mummert intake.

Lorena, Texas (South of Waco)

Awesome test Ted. That took an hour or two! Where would the "B" intake with the original 4 BBl fit into this?

   I suspect all the aftermarket three-two intakes were developed before the '57's came out. Meaning that the only factory intakes available would have been the 2bbl's, or an A intake with a teapot. I'm not counting the dual quad intakes because those were really rare, I don't ever remember seeing one on the street.

Frank/Rebop

Bristol, In ( by Elkhart) 

pegleg.. I think the edelbrock 573 came out in '57 and the 553 in '55, at least that's what i read somewhere.. the rest of them i don't know.. that could be the reason it outperforms the rest

Dustin

Southern Oregon Y's Guy

http://www.facebook.com/?ref=home#/profile.php?ref=profile&id=1441322018

Good job Ted. The only other manifold I would have liked to have seen tested would have been a Fenton. Anyway, the tests confirm the negatives about the Offenhauser that were in an article by Doug Thrasher in YBM #55, Mar-April 2003. At -29 H.P. & -25 Ft. LB. behind the Edelbrock 573, the Offy intake would make a good garage ornament...

Paul

Hi Ted,  Great article and nice to have one's judgement about the Offie's confirmed.  Of course the old Popular Hot Rod article result compared to the '56 HRM/Edelbrock tests made it a pretty easy guess.  BTW The HRM/Edelbrock test finally took the '56 Ford carbs they used and machined the venturi's out from 1.06" to 1.187" dia. The 97's are 0.97" venturi dia. which is a severe reduction.  It would be interesting to know what the venturi area of your test 4bbl is. But it seems like the 753 is a pretty good manifold.

  

Doug T

The Highlands, Louisville, Ky.

1.250” on the primaries and 1.312” on the secondaries are the venturi diameters on the L1850 Holley being used on the Mummert 4V intake at the tail end of the 3X2 test session.  Total agreement on the ‘573’ being a good manifold.  It had already previously been dynoed on a souped up Y that was making 340 hp with #50 jets all the way around and was a good indicator that the Edelbrock ‘573’ with Strombergs has some great potential.  It was on the rich side on that particular engine and with the leaner jets that are in it now, it would have undoubtedly made some even bigger numbers.

Lorena, Texas (South of Waco)

Great Job Ted!

Couple questions while you still have the intakes on hand, It is funny to note that the small port Edmunds DM-424D had the best torque numbers. What is the difference in the 2 Edmunds 424's? The one I sent you are calling the FORD 424. I did notice before I shipped it, it had been repaired in one runner which could have added a small restriction to that runner. I also noticed it had plenty of meat for hogging out, if you want to do an experiment by porting it out to a large port etc while you have the setup, have at it, I don't see myself needing it in the near future. You could then compare a ported 3x2 to a mummerts etc.

2nd, Do you have any low end torque numbers you could post? Most people don't get to hold their cars at the peak horse rpms very often, but they like the off the line tire fryer capabilities at the low end torque scale.

55 Vicky & customline

58 Rack Dump, 55 F350 yard truck, 57 F100

59 & 61 P 400's, 58 F100 custom cab, 69 F100, 79 F150, 82 F600 ramp truck, 90 mustang conv 7 up, 94 Mustang, Should I continue?

Billy.  Here are the lowend torque numbers and are rounded off for easier viewing.  The new scoring order is in the bottom row if simply basing the performance of each intake on its lowend torque values.  The Edmunds DM-424D in this format would be the best from a daily driver point of view but all the Edmunds 3X2 intakes still look good.  No matter how you look at the Offenhauser intake though, it just comes up short.

rpm	Edel 573	Edmunds DM-425	Edel 553	Edmunds DM-424D	Weiand	Edmunds Ford 424	Offy
2500	292	303	296	309	293	294	277
2600	305	314	308	320	306	306	287
2700	313	323	316	328	316	314	294
2800	321	329	322	334	322	319	300
2900	325	332	327	336	327	323	305
3000	328	333	330	337	330	326	308
3100	330	334	332	338	331	327	310
3200	333	335	333	338	332	328	311
3300	334	336	334	339	332	330	311
3400	335	336	334	338	332	330	311
3500	336	336	333	337	332	330	312
Avg	322.9	328.3	324.1	332.2	323.0	320.6	302.4
Order tested	1&8	7	3	6	4	5	2
Overall scoring order	1	2	3	4	5	6	7
Revised scoring order	5	2	3	1	4	6	7

The two Edmunds 424 intakes are different in appearance at the backs of the manifolds and obviously came from different molds.  One has 'Ford 424' on it and the other 'DM-424'.  The DM-425 and DM-424 manifolds each have ‘425’ and ‘424’ cast also on their insides in a couple of places but the ‘Ford 424’ manifold does not have those same identifiers on the inside of the manifold.  Both the 424 intakes are small port versions though whereas the 425 is a large port intake.  Looking at your Edmunds 3X2 intake, I can see where it has been repaired on the inside but the repair doesn’t look to be a problem.

Lorena, Texas (South of Waco)