Carbing a blown flathead?

Say you wanted to put a Eaton M90 blower from a mid 90's T-Bird on a Flattie. How much carb do you think it would need? 500cfm

 

That would work fine.

The challenge with the Eatons is that damn rear inlet. They're good blowers - relatively efficient too, but packaging is a bitch for a more traditional application...

 

Flat Ernie is right, I looked at an Eaton M90/M112 but knocked it back for the same reasons he mentioned even though they are good,efficient blowers.

I run 2 x Stromberg WWs - around 500-550 cfm and its works a treat. I did'nt feel comfortable with running 2 x97s or 2 x 94s as there wasnt enough cfm/fuel in the curve and did'nt want any lean outs at WOT.

I considered a 500-600cfm 4BBL, but dont like the way they look...too modern on a blown flathead for me, even though i can get em working real good.

Rat

 

I run my flaty with 2x 94, it works very good, But I run 6 PSI...more than that, you need more cfm for sure...

 

I have seen them done with two Holley 94s. Cool looking set up with a home made intake plenhem. Sorry no pics

Flatman

 

I agree the carb location/packaging is the biggest challange. I have a couple ideas for that.

 

Wish I had more information, but snapped this picture at the 2005 L.A. Roadster Show. I think it had a small Edelbrock 4brl on it. It look kind of strange with the carb against the firewall. Guy said it ran really good.

 

That one looks like the M62 - it's pretty short.

The other challenge is manifold. While not a huge deal to someone with some fab skills, you are definitely on your own when coming up with an intake.

Many folks run the Holley 390 - the Edelbrock 500 isn't as far off as the numbers imply - Holley flows their carbs wet, Edelbrock flows theirs dry.

 

I made this 2x2 carburettor adaptor for the M90 supercharger

 

Is that something you are going to produce and sell?

 

Yes. I have cast and nearly finished machining 20 of them.
As yet I have not set the price for them.

 

I did blown a few flathead, 4/71 and scot repro from HandH. the best results so far is using the big 97 carbs, 250cfm each. you also can go with the larger holley 94 from 1953-54, they flow 175 cfm each.

 

I super charged my 8BA with a M90. I noticed that Eaton at some time made one with a carb mounted on top. So I decided to try it. Just put a plate over the rear intake port. All so just happen to have a Q-Jet off of a supercharged 79 Buick V6. Only had to drill holes in the throttle plates for more idle air. The darn thing works GREAT. Been running for about eight years now with no problems. Starts easy, runs good and pulls HARD. I guess I'm really BAD for not putting those crappy vintage crabs on LOL.

 

Complements on that beautiful manifold. Hope it sells good for you. If it's successful perhaps you could design one that comes in from the side for those who have a clearance problem with carbs being to high.

 

Heres my thoughts on carbing a blown Flathead since thats something I have some knowledge about. Go with 600 CFM you could use a single four barrel the easiest way to do it but not as traditional as two deuces. If you decide two deuces is what you prefer then look for a pair of Holley 2110 carbs the same carb used on the Y block Ford engines.
The Ford type Holley carb has a 1- 1/16 venturi Holley also made them for multi carb applications with 1-5/32 venturi. These Holley carbs have the common Ford style three bolt bases. Holley 2110 carbs were also made with a four bolt base for use on Volkswagen tubular intakes this version of the 2110 is also know as the bug spray carb.
Ronnieroadster