Offy intake manifolds


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By 30 coupe - 5 Years Ago
Does anyone know, did offy make it's 3x2 intake in 2 different models, that is did they make a small port for the early heads and a larger port for the later heads?  If they did , do they have a way to tell them apart , other than actually looking at the ports in person. I have one on my 30' coupe, and I suspect that it is the small port manifold.  I also suspect that I have a vac. leak as it seems that the ports do not match.   The eng has C1TE  heads on it ( I know , not the best, but what I had at the time ) and a offy 3x2 intake. the intake has no markings other than Offenhauser on it. have any of you guys successfully used an offy manifold on later heads?  Thanks for any information anyone can provide.  I have a set of offy Valve covers on the eng. and like the look of having the same brand of intake on it.  The manifold and the intake are powder coated black with gold lettering.    Thanks for any help/ comments/ suggestions.-----Jim
By pintoplumber - 5 Years Ago
I had a small port offy on my 239. There was a 4 digit number stamped on the underside. I don't know if it was a serial number or a model number. I also have a big port offy on the shelf that has a number stamped on the underside. I remember the 2 numbers were different.
By PF Arcand - 5 Years Ago
When Ted @ Eaton Balancing,  tested 7 Tri- power intakes for Y-Blocks, there was no mention of more than one Offy model at the time or after by anyone. Assuming that is correct info, (published here & in Y-Block magazine) it was clear that the Offy intake was definately "last" in overall power. Its not worth installing.   An ECZ - B 4 Bbl intake is likely as good or better & less trouble prone. And can be altered as shown in Y-Block magazine to work better than stock..
N.B.- Historically of course, the name Offenhauser is famous.. however, the  3 carb intakes were apparently not designed or built by the shop of the original Fred Offenhauser, but later by a shop owned by his nephew of the same name. There was a law suite re the use of the name, but the results didn't really clarify the issues very well...            
By Ted - 5 Years Ago
All the Ford Y Offenhauser 3X2 intakes being used in dyno tests here at Eaton Balancing were the large port design.  A small port Offy intake has not been tested.
By 30 coupe - 5 Years Ago
Ted, thank you for clearing up the facts of there being a small, and a large port offy manifold, and which one was used in the testing.                                                          PF Arcand,   Thank you for the background info on the manifolds.
By DryLakesRacer - 5 Years Ago
I had one few years ago. With adapters and a lot of work installed 3 Rochester 2GC’s on it. I almost took a hole saw to the carb ports to open it all up because was not a good performer. Ran it once, another problem showed up and went to dual quads. Sold the unit for $1K.
There is a Buick guy online that makes changes to the Offy for the nail head with great results. I’m guessing he opens up the lower plenum so every doesn’t need to make a 180 at the end of the top plenum.
By 30 coupe - 5 Years Ago
Well, I have purchased a used Edelbrock  573 with carbs, linkage and air cleaners.  ( I know the stuff is not available new ) I am expecting it to arrive just before or after Christmas.  I will be getting rid of the Offenhauser manifold. I will get things set-up and swapped out over the winter. I am just wondering how much improvement I can expect and what I will actually feel in the "seat of the pants"   
By Joe-JDC - 5 Years Ago
Have you read the Intake Comparison Test of the Offenhauser 3 X 2 intake and Edelbrock in Y Block Magazine?  It is posted on Ted Eaton's site.  The Edelbrock 573 in stock configuration on a 400 hp engine was 46.8 Hp better than the stock Offenhauser, and ~30 hp better than the ported Offenhauser.  Check out Ted's web site for the complete read on the dyno tests if you have not done so.   Go to links above.   Joe-JDC 
By charliemccraney - 5 Years Ago
Maybe in the ballpark of 9% improvement overall, based on Ted's testing.  You're going from what is very likely the worst 3x2 to what is very likely the best 3x2.  It should be noticeable.

http://www.eatonbalancing.com/2013/12/18/y-block-ford-3x2-intake-testing/
By Ted - 5 Years Ago
Here’s the link to the 3X2 Offenhauser and Edelbrock testing performed by Joe Craine.
 
http://www.eatonbalancing.com/wp-content/uploads/2018/07/YBlock-146-Craine-3X2-Test.pdf
By 30 coupe - 5 Years Ago
Thanks Fellows, I have read Teds testing of the different manifolds, and was aware that the Offenhauser is the worst of the bunch.  I did not put the one I have on my car.  It was on the engine when I bought it, at the time I was not aware of the difference.   I had to find an Edelbrock on the web, as there is next to nothing up here for Y- Blocks.    I am sure it will be a noticeable difference, I will have to wait until at least late April before the roads are clear and any salt is washed off by the rain.  It may take until the 1st week of May
By Lanny White - 4 Years Ago
30 Coupe, I just finished reading this thread and wonder if the four numbers on the small port manifold are 2726?
By 30 coupe - 4 Years Ago
Lanny, I have not yet pulled the Offy intake off of my car.  The car is in winter storage, and is blocked in by another car being restored ( '65 Mustang ) that is making access to work on the eng difficult at best .  when I get the manifold off I will look and see if there are any markings on it. there are none on the top side.  I will post anything I find when I get the manifold off.----Jim
By Lanny White - 4 Years Ago
Thanks, Jim, I believe that the number is either raised or stamped on the underside.  If there is no number, would you let me know what the measurements are of the ports to the heads (when you get it off).  Also, what carbs are on it?
By 30 coupe - 4 Years Ago
I will check when I start working on the car, may be awhile.  It may be hard to see any #'s since the manifold has been powder coated black. carbs are Holley '94's I forget which ones, but they are going to be replaced with different '94's. the center one will be a  EGC 6  which has a larger throttle plate diameter. I will be headed to town this week end and will let you know which carbs are on the car now.
By 30 coupe - 4 Years Ago
Lanny, I have not taken the intake off yet, but the carbs on the engine now are all 3 marked 8BA.  the new intake will have 8BA carbs on the ends and a ECG-6 for a center carb. ( actually it will be the truck version of the ECG-6 without the automatic choke, and the air horn opening turned down to match the 8BA cab tops. )
By Lanny White - 4 Years Ago
Thanks, Jim, for the model numbers for the carbs.  Have they been rebuilt?
By 30 coupe - 4 Years Ago
Yes, carbs have been rebuilt by my brother and myself. the center carb was actually made from several core's it has larger throttle bores compared to the 8BA carbs and they have a 1 1/16 venture. some of the carbs are marked 1 1/16, but have the smaller throttle bores like the  8BA carbs.  next time I am in town where the car is I will take a couple of pictures.