Best intake options for 50 sedan

[Alberta50fordor]

I’m getting a valve job done on the 8ba for my 50 fordor, I figured now is a good time to look into a better intake manifold and I’m most likely going to be putting on a set of offenhauser heads(the guy doing the work on it has them), anyway what are you guys running for intakes? I was considering the offenhauser super dual and the Eddie meyer slingshot from speedway but I’ve heard mixed reviews on that one, my thinking on the slingshot/high rise is better flow and not having to mess with the location of the generator but I’m not sure if the shoeboxes have the clearance under the hood

[tubman]

In my opinion, the best intake system for a mildly modified flathead in a relatively heavy car is a small base Rochester 2G series carburetor on a bored out 4-bolt Mercury manifold. Most of these carburetors came on 265/283 Chevrolet small blocks and flow just about twice as much as a stock Holley 94. This will give you the benefit of dual carbs without the complications of multiple carburetors. I have been running this combination on the 255 ci '51 Merc in my '51 club coupe for the last 4 years and am completely satisfied. I can provide further details if you are still interested.

Another thing to consider; a lot of people think that just bolting on a set of "High Compression" heads will automatically increase performance. This is not necessarily true, especially if the heads are used. The clearances over the valves and piston top are quite important; if they are too little, you can have interference problems. If too much, the combustion chamber will be inefficient and not provide optimum performance. If the guy doing the work has proper knowledge of this and will fit the heads specifically to your engine, it should work out fine; If not, it appears to me that he just wants to sell you a set of heads.

About 25 years ago, I had a 276 ci flathead built and just bolted on a set of Offenhauser heads and let it go at that. I was always disappointed with the performance of that engine. The last two engines I have built had the heads modified to provide .050" clearance over the piston crown and have been much more satisfied with the performance it provided. In my opinion, custom fitting the heads to provide the proper "quench" is the single most important factor in maximizing the performance of a normally aspirated flathead engine.

These factors are a bit too complicated to be completely addressed in a preliminary thread such as this. Do some searches on "quench" and possibly "squish" on this forum and read away. Some research into the theories of Sir Harry Ricardo may also be in order.

Sorry to complicate things for you, but if you are going to spend the time and money required to do this these days, you should do it an a way to reap the maximum benefits of your effort.

[Ol' Ron]

I go along with Tubman with one of Charles distributors. Have the heads angled milled to reduce the combustion chamber sizes. Thus LITTLE engine need compression
Gramps.

[tubman]

"Ol' Ron" is correct of course; any change away from a carburetor specifically designed to run with the stock distributor will require a distributor update. A "Charlie ny" SBC conversion is a good way to go; I prefer an original Mallory "flat-top" dual-point unit because I like old stuff.

[Ken Henry]

I think you would find ‘Flathead Facts’ an interesting read. Lots of dyno testing results for common upgrades. Ken

[Ol' Ron]

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The only good thing about my book is: The Chiloe recipe.
Gramps

[Ken Henry]

Ron’s book Nostalgia is great and another must read- my copy is full of greasy fingerprints but I have yet to find the chili recipe!

[mfirth]

Tubman & Ole Ron are 2 of the "masters" with real time & experience behind them. I am not, but from my experience multiple carbs & so called high comp heads are a waste of time & $$$ unless you have a cam, bore & stroke to work with them. My 1st 8ba had only a mild cam & stock dist. & carb and it ran as well or better than my 2nd engine with Offy heads etc. Keep it simple or go big......02 cents or nonsense. Just saying. mike

[tubman]

Mike is right; stock iron heads can be made to perform as well as fancy aftermarket finned items. I prefer the finned aluminum for two reasons : First, they look better, and second, aluminum is much easier to work on than cast iron.

I will stand by my opinion that heads modified to provide optimum "squish" will significantly improve the performance of any flathead. Certainly, properly modified stock iron heads will out-perform the fanciest aftermarket units that are just slapped on the engine with no more thought than if the gaskets are installed right side up.

[Charlie ny]

If multi carbs are a must I really like the Speedway version of the OFFY 2x2....
S'way pt # 910-15985. Carbs are CENTERED over the motor, not set back. Room
for an 8BA gen or an alternator...no offset bracket required. Per Ron Halloran and
Denny iron heads work good if prepped....EAB heads are the place to start.
OMHO,
Charlie ny

[tubman]

Charley, just to make things clear, do you also suggest running a straight linkage, smaller jets, and plugged power valves with this combination?

[slowforty]

Also on a fairly stock engine the stock cast iron manifolds work well, with dual exhaust.
I know headers are cool. but almost $300, buys a lot of Gas and Beer

[RalphM]

$300 doesn’t buy much gas anymore. $118.00 to fill my truck last night, and that was with a $.30 off a gallon Fred Meyer discount!

But on the subject of carburetors, I like this set up.
Of course this particular set up can also be run in aircraft

[Alberta50fordor]

I have headers on already and was also considering the benefits of better cooling with the aluminum heads, I have a bunch of extra stock carbs so that’s why I was leaning more toward the multiple carb set up vs a 4bbl, also the factory merc intake is a cool idea but tracking down one of those intakes and the carb to go with it is going to be difficult up here

[tubman]

One thing about Canada, they made Mercury manifolds cast from aluminum. An aluminum Canadian Merc manifold is a real upgrade as far as I am concerned. I have one on my '51 and really like it. Actually, it should be easier for you to find one than it was for me. I think I paid $150 four years ago.