Ted,



Noticed that in the 3x2 testing you did a while back, the Edelbrock 573 (1. 336.0 Tq / 279.3 HP - Edelbrock ‘573’) came up with similar peak numbers as the 4bbl (G heads are 286.1 HP @ 5300 rpms and 336.4 lbft torque @ 3400 rpms) on this series of tests. Would your opinion be that the peak numbers from both of those tests are due to the restricting nature of the iron heads in both cases? I know you are quite busy, but any chance you cold run the 573 on the aluminum heads just to give us an idea what that combination is capable of?



You guys have done such an awesome job, I hope that the financial returns to you both will make this endeavor very worthwhile.

My name is Greg and I am addicted to Y's.

There are a multitude of combinations which will alter the torque band.  Carburetor and/or carb spacer changes are just one way to alter these curves but there are many others.  Advancing or retarding the camshaft is another just as changing the camshaft itself can give completely different results.  And don’t forget the exhaust system.  Too many times altering one component means changing up the rest of the combination to make it optimal again.  The combinations are endless and simply comes down to how the vehicle is being driven as to what is the most desired torque band.

Lorena, Texas (South of Waco)

The similarity in rpm torque bands between the single four and the three deuce intake testing was indeed related to the fact that the same heads were used for both but the camshaft also plays into this as well.  Had the camshaft been a different grind but remained the same for both the 3X2 and single four tests, the peaks would have changed from the camshaft that had previously been used.  But testing with some specially tailored four barrel carbs as well as some different exhausts on the iron heads has had some dramatic effects on low end torque production so it’s still the total combination that must be considered.

 

It was interesting to note that the peak horsepower of the dyno mule engine went from 5300 rpms with the iron heads to 6100 rpms with the aluminum heads.  Same camshaft, same intake manifold, same carb spacer, same rocker ratios, same exhausts, and same carburetor.  By switching only the heads, the differences in torque production as well as the usable rpm ranges could be definitively evaluated.

 

Time constraints has put any additional 3X2 testing on the back burner for the time being.

Lorena, Texas (South of Waco)

I'm interested in seeing how the 3x2 does, too. And also to see how they stack up against ported iron heads.


Lawrenceville, GA

The strong probability is that the 3x2 setup would fare  no better than the single 4 on the iron heads.

I do not recall the flow on those carbs but the three carbs combined is not as good as the single 4. The heads were the cork before but with the 3x2 the cork will definitely move to the carb/intake.

Guy's,

Ted is approaching testing these parts the right way. When evaluating parts you must have a base where each item is tried. This is the only way to check what characteristics each part will give. Some minor tuning with jetting and ignition timing is acceptable.

As a guideline you can use the percentage gained by the heads and use that percentage 56Hp(increase)/291hp(base)  19.243% to get your peak against what was tested before with the 3x2 shootout. This peak will change throughout the rev range and should be considered point to point. 

In evaluation part for an engine build you start with an understanding, a desirable outcome and try different parts in different configurations to obtain a desired result. This is something that only top engine builder can afford for one engine not for the entire range of parts available. Not even for Y block.

We are getting a lot of information from some guys who have taken a financial risk to produce a part for something they love. 

Grizzly (Aussie Mainline)

Air, like anything else, takes the path of least resistance. I found when testing a 3-2 intake on a flow bench that over 80% of the flow came from the carb closest to the port being tested. About 15% came from the center carb and the carb farthest away could be opened and closed with almost no noticeable gain or loss.

http://ford-y-block.com 

20 miles east of San Diego, 20 miles north of Mexico

Hi Ted, do you think the performance of the Cain manifold will improve with the alloy heads???

a couple of photos for those not familiar with this inlet.

Pete, one of the Aussie mob. Beechworth, Victoria60 F100 Panel Van, Y-block. 65 Galaxie Country Sedan 390

I don't know what size carbs Ted used on the 3-2 testing but when HRM did extensive testing of a 312 back in 1956 they eventually had to bore the carbs to make maximum power. As I recall they were using .94"s and could only make 271 uncorrected HP. When they bored the carbs they made slightly over 300.

They gave a formula for optimum venturi size related to engine size. I would have to find the formula, can't remember. It was somewhere in the 50 - 55 cubic inch of displacement per square inch of venturi range.

http://ford-y-block.com 

20 miles east of San Diego, 20 miles north of Mexico

In the 3x2 testing post, Ted said that an engine he dyno'd in the past made 340hp with a 573 and that it was rich and most likely would have made more. That's why I want to see how the 573 compares. If it's near the 4v's, it'll be 3x2's for me.


Lawrenceville, GA