8ba 275 carb options

cadillac512 said:
Pretty good chance it'll be fine with the 325 heads. Without actually checking the cc's of the chambers you can't know exactly how they compare with stock heads, but it's VERY difficult to get even moderately high compression on a flathead without a lot of work and modification.


UPDATE! I found the chart listing the heads. VERY small chambers that may well do just as you said...too much compression for pump gas. I apologize for the misinformation...I didn't know those heads existed.
Hopefully Pete may offer an opinion...he is a good source of info on this type of situation.


Terry
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lol its probably the chart that i tried posting but it was a screenshot from my phone that didn't work apparently, is there a benefit to running heads with a chamber this small on this engine? not knowing yet what cam is in it
https://offenhauser.co/wp-content/uploads/2018/04/Offenhauser-Catalog-1987.pdf
 
The first thing you should do with the heads is check the clearance over the piston dome and the valves. A lot of used aluminum heads have been milled and may not even clear. Used heads sometimes have severe corrosion problems.

You will be well served finding out exactly where you are and what you have before making any big decisions. Some (most?) cams are marked on the nose which can help identify them. Pull the front cover and see what you can see. It would also be informative to determine if it has an aluminum or fiber timing gear.
 
tubman said:
The first thing you should do with the heads is check the clearance over the piston dome and the valves. A lot of used aluminum heads have been milled and may not even clear. Used heads sometimes have severe corrosion problems.

You will be well served finding out exactly where you are and what you have before making any big decisions. Some (most?) cams are marked on the nose which can help identify them. Pull the front cover and see what you can see. It would also be informative to determine if it has an aluminum or fiber timing gear.
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As far as I know these heads haven’t been ran from looking at them, EAB-A stamped on the end of the cam so I’m guessing it’s a stock cam?
Also, are the old valves ok to use? How long to the old ones typically last?
 

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If you're planning on running this engine in a '50 Ford Fordor, that's a pretty good cam for your application. I don't think it would be worth the time, money and effort to upgrade to an aftermarket cam.

From what I can see from the pictures supplied, that looks like a fresh engine. I don't think the valves will be much of a problem. I still think you should check the heads. Put pea-sized aluminum foil balls on the valves and crown of the pistons. Bolt the heads on without gaskets (4-6 bolts will do), and try to turn the engine over. If it stops, don't force it and try again with a set of gaskets (used will do). When you get it to turn a couple times, pull the heads and measure the foil balls with a caliper. You will be looking for .045-.050" over the piston crowns and .060" over the valves. Remember that a compressed head gasket is about .055", so be sure to take that into consideration.

Let us know what you find. Second-hand knowledge and published specs are not always reliable. I had a set of used Edmunds heads that had to have .025" milled off of them to bring the quench to optimum.
 
tubman said:
If you're planning on running this engine in a '50 Ford Fordor, that's a pretty good cam for your application. I don't think it would be worth the time, money and effort to upgrade to an aftermarket cam.

From what I can see from the pictures supplied, that looks like a fresh engine. I don't think the valves will be much of a problem. I still think you should check the heads. Put pea-sized aluminum foil balls on the valves and crown of the pistons. Bolt the heads on without gaskets (4-6 bolts will do), and try to turn the engine over. If it stops, don't force it and try again with a set of gaskets (used will do). When you get it to turn a couple times, pull the heads and measure the foil balls with a caliper. You will be looking for .045-.050" over the piston crowns and .060" over the valves. Remember that a compressed head gasket is about .055", so be sure to take that into consideration.

Let us know what you find. Second-hand knowledge and published specs are not always reliable. I had a set of used Edmunds heads that had to have .025" milled off of them to bring the quench to optimum.
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for now i might put ford heads on, should i check for clearance with those too? should i change out the fiber timing gear? shouldn't there also be locks on the bolt heads?
 
Alberta50fordor said:
for now i might put ford heads on, should i check for clearance with those too? should i change out the fiber timing gear? shouldn't there also be locks on the bolt heads?
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I would check the Ford heads only if I were to plan on reworking them and running them permanently. Reworking iron heads is a lot more work than aluminum ones. I prefer aluminum timing gears, but that being said, your gear looks good and should work well. I have never seen a stripped original Ford cam gear on a flathead, though I have seen them on SBC's. The aftermarket gears are another thing entirely.

As to locks on the bolts, I do not know, since my machinist always assembles my engines and installs the cams. He is set up for it, while I am not. I'm sure someone else here has your answer.
 
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Run an Aluminum gear and use locks on the cam bolts. I stripped a fiber gear in an 8ba!!! Return the oil from the filter to the top of the timing cover - it helps the longevity of the gear.
 
tubman said:
I would check the Ford heads only if I were to plan on reworking them and running them permanently. Reworking iron heads is a lot more work than aluminum ones. I prefer aluminum timing gears, but that being said, your gear looks good and should work well. I have never seen a stripped original Ford cam gear on a flathead, though I have seen them on SBC's. The aftermarket gears are another thing entirely.

As to locks on the bolts, I do not know, since my machinist always assembles my engines and installs the cams. He is set up for it, while I am not. I'm sure someone else here has your answer.
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So i have those aluminum canadian ford heads or several 8ba cast iron heads, i also have a set of "mercury" heads on another old locked up engine, would there be any benefit running truck(RT) heads on this engine?
 
Alberta50fordor said:
So i have those aluminum canadian ford heads or several 8ba cast iron heads, i also have a set of "mercury" heads on another old locked up engine, would there be any benefit running truck(RT) heads on this engine?
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None at all. Those are the lowest compression of all the production 8BA Ford heads.
 
tUBMAN HAS THE ANSWERS, THE 2gc IS THE BEST ANSWERE FOR THIS APPLICATION.
gRAMPS
Sorry about the caps
 
Alberta50fordor said:
has anyone adapted the ford intake manifold to fit that carb? those mercury manifolds seems to be few and far between up here
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There are 3 to 4 bolt adapters available, but the problem is the throttle bore size. I've never tried to bore a 3 bolt manifold, but I believe "Ol' Ron" on here has, and I believe that when you go to the full 1 7/16", it breaks through into the carb heat chamber. I think they got by that by boring it oversize and using thin sleeves.

EDIT : Here's a picture of a 3 to 4 adapter I got from Speedway Motors. I added a divide plate and it ran better than without it.
 

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Please correct me if I’m wrong...I just used the VanPelts table to calculate cubic inches on a stock ‘49 Merc engine with a 0.03 overbore and got 260.18 cu. so how did you come up with 275 cu?
 
Ideally, a 4bbl (small pattern 4GC or similar) and a mechanical advance distributor with a vacuum advance can using manifold vacuum is by far the simplest and most reliable setup. Parts are readily available for both.
The primaries are same size (15/16") as the Stromberg giving you bottom end throttle response (cruising) and an air valve controlled secondary for high RPM CFM.
Old skool 3 deuces give you 3x the headaches. I sold mine complete years ago for that very reason. Besides, if you are going that route you are going to have to use a mechanical advance distributor anyway.
Granted, a 4 bbl doesn't have the "kool factor" but how kool is it sitting in
the shop waiting on parts from less than reliable suppliers?
 
Fortunateson said:
Please correct me if I’m wrong...I just used the VanPelts table to calculate cubic inches on a stock ‘49 Merc engine with a 0.03 overbore and got 260.18 cu. so how did you come up with 275 cu?
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That's because it's been bored to 3 5/16" + .030". That makes the bore size 3.3425"





Terry
 
Gene1949 said:
Ideally, a 4bbl (small pattern 4GC or similar) and a mechanical advance distributor with a vacuum advance can using manifold vacuum is by far the simplest and most reliable setup. Parts are readily available for both....
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True to an extant. A 2G is a lot simpler than a 4G simply because it's a two barrel. One will flow twice what a 94 or 97 will, which is plenty. To me, the biggest factor is cost. Have you priced a small base 4G lately? (If you can even find one.) And Merc manifolds are a lot cheaper than aftermarket 4 BBL units. I had a 390 Holley on an Offenhauser manifold on my '36 and liked it a lot. However, that combination would cost between $1500 and $2000 these days unless you're a real good scrounger (and lucky).
 
Yes, boring out a stock Ford intake manufold will probably break into the exhaust passage. However, Bell mouthing the intake to match the 2GC may limit flow, this is a street engine and how often do you run at WOT. I too consider the cost of thes projects and unless your running at Bivell Mox Nix.
Gramps
 
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