Hey guys, I’m plugging away at my 49 mercury, I recently swapped to a ford style 3 bolt flange intake and picked up a nice used stromburg 97. I finally test drove the car today. It is an absolute dog, I can’t even get into 3rd gear in a half mile strip. Could I have picked a carb that was jetted for a multi carb setup? Or is the 97 just not enough carb for the 255 flathead merc that’s in the car?
There are several points raised in this thread: https://www.fordbarn.com/forum/showthread.php?t=252048 Some possibilities include the fact that the vacuum advance is designed for the teapot, so swapping carbs could mean the timing isn't advanced enough under load, which would perform like you describe. Also the basic stromberg 97 is a 155cfm output from my research, and your original Holley 885 FFG "teapot" is a 225-275cfm based on some math done by folks on this forum: https://forums.g503.com/viewtopic.php?t=310329 So technically you are operating with 56-68% decrease in flow, which also would cause a decrease in performance. Your engine is among the largest flatheads, so it needs either a 250+cfm single carb, or dual Stromberg 97s with 155ea and then jet them to proper fuel levels. Another option is ordering a BIG97: https://stromberg-97.com/product-index/stromberg-big97/
If you have the Holley backdraft that came on it originally, buy a kit & clean it. Despite looking stranger than other carbs, they're quite easy to clean & adjust.
I hope you didn't get rid of the original 4-bolt Mercury manifold. I have had very good results mounting a small base Rochester 2G on these manifolds. The carb will bolt right on to the manifold, although the throttle bores are smaller than the 2G and should be enlarged to 1 7/16" to gain full advantage. If you mount the carb backwards on the manifold, the gas line and throttle linkage are very close to lining up, and the Mercury automatic choke can also be used (if you have a carb with a matching coke mechanism "divorced" or "conventional"; the carburetor and the manifold some both ways). Because of the advance problems and size, a Stromberg 97 is the wrong choice for you car.
I run the Edmunds intake with two Rochester 2GC carbs. Expert carb rebuilder put in .054 jets. Runs so good I have not checked the spark plugs yet. Starts with a half turn of the starter. Wish I could find another intake like it.
I passed on one of those manifolds because I thought $400 was too much. Dumb move on my part. I have had one 2G on the '51 Merc in my car since 2016. I checked the plugs last summer and they looked perfect.
Im definitely sort of a pack rat, we’ve got about 5 of the teapots floating around. I’ve been told by a buddy here local that runs a rod shop that will not touch them. Says they never run right even after a professional rebuild. I was contemplating the 2g swap and I have one on the line but I fell into this set up so I ran with it.
There's a guy n "The Ford Barn" that is an expert on those Holley's. I believe his handle there is "Scicala". You might want to talk to him.
I’m personally gonna go to a 2 or 3 pot manifold on my Merc flathead eventually. Of course I’m not looking for performance as much as I am the look that goes with a flattie. 2 or 3 super 97’s ought to definitely get you down the road
I'd recommend avoiding the 9Super7 carbs, they're poorly made asian reproductions sold by Speedway. Tried running a pair on a 1950 Ford, never was happy with the performance and idle, as soon as I went to genuine Strombergs, it performed like a totally different car.
The very first carb I ever rebuilt, at age 13, was a haystack Holley (a.k.a. teapot) for my 1956 Ford 292. Ran absolutely trouble-free until the engine broke a ring and started using more oil than gasoline. By far, the most reliable Holley I have ever owned! Only Holley I ever owned that DIDN'T leak! How is it that a 13-year old can rebuild one that works great, and a professional cannot??? Maybe said professional above needs to consider a different profession. Since 1959, before I quit restoring carbs 12 years ago, I personally restored dozens of the haystack Holleys, and sent them out with our 1 year / 5 year warranty. Never had a call-back. Just for the record, the haystacks were used on several military vehicles, and I.H.C. used them on large engine trucks as original equipment through, I think, the 1979 model year. Interesting, at least to me, that it wasn't until the internet that I learned the carb that went about 150,000 miles on my 1956 Ford was junk??? Also, never heard them called teapots before the internet; we knew them as "haystacks". Perhaps it was the rural area. Jon
What I found interesting is that the very first teapot (or haystack, if you prefer) that was factory equipment on 1953 Lincolns is the only one I've seen that has mechanical secondaries.
I always thought that the teapot upside down carbs were called towering inferno. Had one on a 50 merc motor, no thought of rebuilding it as I wasn’t going to use it . Didn’t even try to start the motor as the carb was a gusher.
Have always called them Teapots. Ran 2 for 40 years on my T’bird never had trouble. Rebuilt them the first time at age 16. Given today’s ethanol fuels AVOID the rubber tipped float valves, look for kits with all metal float valves. Use the right vacuum source for you distributor choice- ported for Loadamatics and un-ported for vacuum advance distributor or you will have a real dog on your hands. MIKE
Well I don’t think anyone’s mentioned it yet but what have you got for an air cleaner? A lot of the small ones are very good at blocking air
This 97 I have is a genuine stromburg and I wasn’t running an air cleaner. I know exactly the air cleaner you’re talking about Tim and I wouldn’t trust those on my lawn mower . I had a Holley 94 laying around from the truck intake, I went through that carburetor and now it’s running like a Swiss watch. I honestly believe that if a had the funds currently for a twin carb intake and a second 97 it would have been fine. Quick back story, I lost my job in February and have been searching other peoples parts bins and junk piles to put this car together. As important as this car is, I’ve had to put it on the back burner
That’s FoMoCo’s famous loadamatic vacuum only advance. It’s the system that 90percent of flathead hot rodders choose to ignore! Why? I don’t know? I guess folks would rather have a cool carburetor regardless of how it runs. This is like the worst kept secret of flatheads. Without a LOM compatible carburetor there is no advance. The system does not work like you think it does. It has to be used with 1 compatible carburetor. The stock factory equipment carburetor and the stock factory equipped distributor were matched pairs. The Strpmberg is not compatible with the stock distributor! The only thing you can do with a 97 in this case with the stock distributor, is to unhook the vacuum advance, set the timing in the “middle” and hope for the best. It will be like a broken clock. A broken clock is correct 2 times a day. If you change carburetors, you have to change distributors on the last generation flathead.
On the carburetor front there is a simple math equation to figure out your maximum CFM requirement. All ford flatheads were almost perfectly carbureted when they were bone stock and the maximum rpm was what about 3500?. If you rev the engine up higher or you've increased the volume metric efficiency or bored or stroked the engine your carburetor will be undersized most hot rodders figured this out about 5 minutes after the engines were designed and dual carb intakes became a thing back in the 1930s and tri power for really healthy built flatheads in the late 1940s-50s. The formula for calculating how much CFM (cubic feet per minute) an engine requires is: Cubic Inch size of engine x maximum RPM x Volumetric Efficiency ÷ 3456. A stock flattie engine will have a volumetric efficiency of about 60-65%. A really healthy (built) Flathead that is naturally aspirated is probably around 75% volume metric efficiency. I am not an expert on Flathead building so don't quote me if I got my volume metric efficiencies wrong but I'm pretty good with engines generally speaking and flatheads are one of the worst designs from a volumetric efficiency standpoint especially Henry Ford's Siamesed exhaust cylinder ports but thats another story. But engine math doesn't lie and this math problem works on all engines of all sizes of all ages.
I ran a pair of them on the 55 that I raced in the late 60s. In the Pacific North West they were called Tea Pots back then. I heard bad things about them, but I pitted with a guy named Danny that said they were good carbs unless they were wore out. It helps to properly tune your car so that it does not back fire. LOL
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