offy intake manifolds

Alaska Jim

Alaska Jim

Well-known member
I posted this over on the Y blocks forever forum, thought I would post it here as well

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
 
Thanks miker98038. I have read most of this in the past, but will review it again, as I don,t remember all of it, although I do remember the offy as being the worst performer. I do not remember if he tested a small port and a large port , or what. I will have to read the articles again. Thanks.
 
Jim,

I do not believe the manifolds got ID NOS. Most of what you read says no nos and then again, I have seen photos with a PN on the bottom..

You would need to find old OFFY cataloging or a period magazine ad I would guess. If you take EDEL for example, they had three intakes - 1954 - 1955/56 and big port 1957.

If a possible vacuum leak, have you tried using propane on the intake gaskets to see if they leak? The 1954 required different gaskets.
 
Kultulz, The car is in storage for the winter, and I probably will not be working on it for a month or 2. What brought this subject up is, my brother was looking at the car the throttle linkage other day, and noticed what seems to a ga between the podt in the head and the manifold port. Seems that this would cause a serious vac. leak. strange thing is, I have only about 1000miles on the eng, and it seems to run fine , idles down fine and runs good. I did check the eng vac. last summer and the idle vac. , if I remember correctly was close to 18". when I get back into town where the car is stored I will check it out a little better. I may have to look for a different manifold, but they are non-existent up here in Alaska, and I do not see them for sale very often, especially without carbs. seems they all have some carbs on them ,some junk, some good, all seem overpriced. Price depends on what some one is willing to pay.
 
Thanks Kultulz , I have read that before. I guess I will start looking for a different manifold. can anyone tell me if the ECZ-C head is considered a small or large port head. I have heard that is the next best if ECZ-G heads are not available. I have a set of these , but I have not really checked them out yet, but I am sure the need a complete rebuild.
 
Head ID number ECZ-C is a '56 part and would be the larger intake manif port size with 1.78 intake valves. They were even used on the 312's in that year.

The '58/'59 5752-113 head is also a good one. The chamber volume in the head is very close to the ECZ-G and they have the larger 1.92 intake valves also.

Specs at these links...
http://www.ford-y-block.com/cylinderheadchart.htm
http://www.yblockguy.com/head_casting_numbers.htm

Photo... small and large port intake gaskets.
The intake openings in the 'smaller' gasket are 1 & 1/16 high by 1 & 5/8 wide.
 

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dmsfrr, Thank you for that information, and thanks for the photo of the gaskets. I do not have a set of both here to compare, so this helps me visualize things a lot better. I have the car in storage 50 miles away, and do not have any extra gaskets laying around. Thanks again , I appreciate it.---Jim
 
Here's a pic of the problem. I can stick a wire in so I know its a air leak. You can see it right in the corner. Both upper ports on the drivers side are leaking.
 

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Alaska Jim said:
... can anyone tell me if the ECZ-C head is considered a small or large port head. I have heard that is the next best if ECZ-G heads are not available
Click to expand...

Smaller ports (medium) and intake valves -
 

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Something else to be aware of when swapping heads... the '54 to '56 heads use a larger internal thread size Temp sensor bushing at the left rear than the '57 and newer heads.
Since the engine has '61+ heads on it now and assuming you have a functional oem style Temp gauge on the dash, stay with '57+ heads & Temp sensor, or you can change the pressed-in bushing in an older head to the smaller internal thread size.
 

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Also, the '57 ECZ-G heads and heads after that had slightly larger intake ports than the 56 ECZ-C heads, but no mis-match of ports and will work with manifolds made for '55 or '56. Alaska Jim's Offenhauser intake must be for a '54 Y-Block. Bottom line is there were 3 intake port sizes over all the years.




Sal
 
I have an aftermarket mechanical temp gauge, so no problem for me there. The eng was a fresh rebuild when I bought the car. my brother and I would never had made the mistake of mis-matching the intake to the head. these are things that are always checked, but I can see how it might happen. I am a retired mechanic by trade and have built more engines than I can count, and my brother is a retired machinist. who has also built countless engines. the person I bought the car from said the eng was built by a reputable machine shop in Georgia. must not have been familiar with ford engines
 
According to a 1981 Offy catalog there was only one 3x2 intake offered and it is for 1954 239 with 3 bolt carbs. However I looked at another offy 3x2 intake and it appears to have bigger ports just looking at it. Certainly doesn't have as much gasket hanging out as the pic I showed. It has G heads on it.
 
I have an offy 3 x 2 on my 57. As far as I know there was only one offered. I hear 3 x 2 intakes for Y-blocks are no longer made by Edelbrock.
 
That is true. Edelbrock no longer makes an intake for the Y block. I bought a good used one. I have yet to install it, The car is in storage 50 miles away. between the virus crap, and the fact that my back has been giving me much grief, I have not been able to work on the car for the last month. soon though , very soon
 
Thanks Sal, it is getting better just slow. My brother called today and said he pulled the intake for me. It was a definitely a mismatch with the heads. He said he could not believe that the eng ran as well as it did. He measured the ports on the Offy manifold and the ports on the Edelbrock manifold, and the ports on the Edelbrock are just under 1/2" larger than the Offy manifold. He checked the bottom side of the Offy manifold for any markings or numbers and found none. Others have said that Offy manifolds they had , have had a number on the bottom side. no markings anywhere on the one I have. Now all I need is to get well enough to get into town and install all the new stuff on the car. will have the Edelbrock manifold , 3 different carbs than the ones I had before, and will now be running progressive linkage. I am expecting this thing to really wake up, once we get it tuned correctly. I have always thought this thing was a slug compared to what it should be.
 
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