Flathead intake manifold recomendations

hb32

hb32

Well-known member
In the process of having a 39-41 Merc flattie overhauled for a 32 pickup. Specs as follows;
Cylinders have been opened to 3 5/16 with 3 rings pistons, 4 inch crank, Edmunds custom heads, Isky 77B cam, new valves, bearings etc. My plan is for a dual intake as well as Stromberg 97`s.
Thoughts on a intake manifold?​
 
If You use an Offenhauser Regular intake for 2 97's, a generator with a pulley mount fan will fit without much 'fart'n' around.
OL' RON is right, IMO a Max 1 is a good street cam. There will be a thousand opinions about this.
 
Ol' Ron said:
I think the 77B cam is a major wast of money, as it's not much better than a stock cam.
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What would you recomend cam wise for the specs I gave Ron?
I realize that there will be a thousand opinions but from your posts that I have read, respect your advise.
Not needing a race motor and really had no intent of balancing at this point but that could change as well.
 
With your bore and stroke, an L100 sounds like a good option. And the guy that grinds them is here on the Barn.
 
Not sure on the 1932-1948 Offy regular dual manifold but on the 1949-1953 Offy regular dual manifold the generator mount is offset to the left 3/4" to help the generator clear the carb. Might be worth looking into before buying a manifold.

3/4" may not be anything on a F1 truck but in a 32 Ford with a 17" wide radiator, it can be a big deal, as it was with mine.

A 17" wide radiator with a fabricated fan shroud along with the largest diameter fan I can fit just wasnt going to work with a 3/4" offset to the left.

My solution was to re engineer the generator mount to the center of the manifold. It was a lot of work to fabricate.

Bill
 

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justpassinthru said:
Not sure on the 1932-1948 Offy regular dual manifold but on the 1949-1953 Offy regular dual manifold the generator mount is offset to the left 3/4" to help the generator clear the carb. Might be worth looking into before buying a manifold.
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Don't think that carburetor clearance has anything to do with it.
I am running an Offy 4 bbl. manifold and it has the same? 7/8" offset which caused interference with my fan/shroud.
I fabricated an offset pulley/fan mount to compensate.



 
I had a whole thread a couple of weeks ago about cam selection on a 258" (for a light car) and a 276" for a heavier car. Other than the guy who grinds the "Kiwi L100's", nobody had any suggestions on a good street cam for a close to stock motor on the street. Looks to me like a Merc cam, (If you can find one), is the best choice for a street motor. If you don't already have it, buy "JWL"'s book and look at the torque figures he got from an Isky Max-1 (oh yeah, I already own one.). Looks like a waste of money to me; and if "Ol' Ron" says a "77B" is worse, I'd run real fast from that one.

Antybody want to enter into this discussion?
 
Stock cam, one carb. Nice and smooth, nice power and never did an engine idle like that. If you want to go really fast, drive your wife's camry. :D
 
tubman said:
I had a whole thread a couple of weeks ago about cam selection on a 258" (for a light car) and a 276" for a heavier car. Other than the guy who grinds the "Kiwi L100's", nobody had any suggestions on a good street cam for a close to stock motor on the street. Looks to me like a Merc cam, (If you can find one), is the best choice for a street motor. If you don't already have it, buy "JWL"'s book and look at the torque figures he got from an Isky Max-1 (oh yeah, I already own one.). Looks like a waste of money to me; and if "Ol' Ron" says a "77B" is worse, I'd run real fast from that one.

Antybody want to enter into this discussion?
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For this build I would also recommend The KiWi-L100 cam I can also grind you a Merc grind if that is what you choose. You would need to be sure you had enough valve to head clearance with your Edmunds Custom heads . For an intake so as to keep your stock genny & fan I would suggest a Thickstun or a tall manifold with the setback like a Thickstun .
I would recomand that you also balance your rotating assembly .
Have fun !
Cheers
Tony
 
Since I started this thread, I researched the death out of the 39-41 Merc and have switched blocks to a C69A 46 Ford. It will be opened up to 3 5/16 with a 4" Merc crank. Pistons will be Ross 3 ring and Manley stainless valves. Cam will be the L-100 which I have read lots of good reviews about. Rotating assembly will be balanced as well. A long way off my original intent which I have digressed from. I appreciate the help to date and still looking for thoughts on a manifold for the change in engine.
 
I am real happy with my new Edelbrock "Super" dual manifold. The design of this one puts the carbs directly over the ports. You will need an offset bracket for the generator. Cost about $250 ?
 
HB32, why would you use Ross racing pistons in a street engine? Granted, their probably the best racing piston available. However they require excessive piston to wall clearance. Egge, makes a light weight piston that can be fir tight and has a modern ring stack. Back to alittle more research.
 
Ol' Ron said:
HB32, why would you use Ross racing pistons in a street engine? Granted, their probably the best racing piston available. However they require excessive piston to wall clearance. Egge, makes a light weight piston that can be fir tight and has a modern ring stack. Back to alittle more research.
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Ross makes a street piston.
 
51Merc-Ct; Nice job on fixing that fan pulley offset problem. I would like to know more about how you modified the stock fan carrier bracket. If possible, could could explain further with a sketch or photos. Did you cut and reweld the bracket? Did you use nickel welding rod? Any additional info. is appreciated. Thanks, JIM
 
19Fordy said:
51Merc-Ct; Nice job on fixing that fan pulley offset problem. I would like to know more about how you modified the stock fan carrier bracket. If possible, could could explain further with a sketch or photos. Did you cut and reweld the bracket? Did you use nickel welding rod? Any additional info. is appreciated. Thanks, JIM
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I did not modify the stock carrier, I fabricated a new carrier out of 3/4" flat stock, a piece of round bar and material for a small gusset.
After cutting the basic shape using a bandsaw and drill press the round bar and gusset were welded to it and then normalized.
Then it went to a machinist to bore the press fit hole for the pulley shaft.
 

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Pete, I didn't know that. Will have to check. We run .004/.005 clearance and 180 stats to tighten up the race pistons for street. I assume their street pistons are high on silicon? How tight can you run them I run the Egge pistons at.oo2
 
Ol' Ron said:
Pete, I didn't know that. Will have to check. We run .004/.005 clearance and 180 stats to tighten up the race pistons for street. I assume their street pistons are high on silicon? How tight can you run them I run the Egge pistons at.oo2
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I don't recall but a call to them will get you all the info.
I have never used the street type.
 
Pete said:
I don't recall but a call to them will get you all the info.
I have never used the street type.
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Correct. I forgot what my machinist said, but it wasn't that "big" with Ross. Call their customer service/tech. line. Great company to deal with.

If I recall, using a torque plate during honing tightened up some of the clearance.
 
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