Won't go 80

Frank Miller

Frank Miller

Well-known member
Engine has been rebuilt and starts and runs good. New points and condensor. Timing is right on. Completely stock. Carb has been rebuilt with float set at 1.5" per Ken Ct. Beyond 75 mph it feels like it just runs out of gas. Let off on pedal and car slows down and it runs fine at 70. All new valve springs so I am ruling out float. This is a bone stock 49 Ford 8BA with OD. I am shying away from ignition because there is no backfiring. Could the fuel pump be weak? Power valve is what Ken suggested. TIA Frank
 
Simple answer its not designed to go 80! You are correct the old lawnmower engine with a single carb runs out of fuel. If you want to try to go 80 add more fuel with another carb and also add a set of better brakes while you are at it because if you are complaining about not being able to go fast wait until you try to stop from 80..
 
Frank, how fast do you want to go with it? 70 sounds good to me. Maybe you should run it for a while and let it settle in. Are you in OD when your doing 70? Reason I ask is this, I'm planning on installing a '49 Merc ****** w/OD in our '53 F-100 Panel Truck, matted to a stock 8RT that we are installing. Prior to the original Flathead getting tired, the truck would do 65 to 70 mph on the highway without too much trouble but there's no way I'd want to go any faster with that suspension even if I could.
 
You might try a Columbia rear end:) Seriously, my '40 has a Columbia and a 4bbl carb, but in keeping with Dick Spadero's comments, I have no desire to drive it much over 70 with those skinny bias ply tires and original brakes. When these cars were built, 65 mph was considered pretty breathtaking. JMTCW.
 
How fast do you want to go Frank. I can send bigger jets if you want them.Also could raise float levela little [like 1 3/8] instead.But could be a weak FP.Could be almost anything at that speed. Slow it down a little youl live longer. ken ct.
 
True I do not need to but just want to make sure all is well. Highways around here can be brutal. My commute to work frequently has me being tailgated at 80 in my modern car. Yes it is in Overdrive. Just want to make sure it is running ok. Vic, the overdrive works good. I have 3:78 gears which is the standard transmission set. OD had 4:11. I am getting a true 30% overdrive.
 
With 3:78 gears and OD you should be able to go 100 mph. Put on dual carbs and headers, let it breath. I use to be able to go 100 when I was young, now I can only go 50, I can't breath as good. Walt
 
Don't overlook the vacuum advance unit! That's all that poor 8BA has! If the diaphragm is shot, you will have zero spark advance and be waaaay down on power. You do have the correct carb, the one with the external spark valve, right? Otherwise the vacuum unit will not advance when it should. Remember, there is no mechanical spark advance, vacuum only on this engine. Moving on, make sure the muffler is not partially plugged from a mouse house or internal collapse from rusted out baffles. Or a kinked tailpipe from backing into a curb, etc. How about the fuel line? Have you verified (not hoped nor assumed) that it is not plugged? Think how many times in the last 60 years the car may have sat long enough for the gas to evaporate out of the lines and tank. When it does, it leaves behind some nasty varnish-like residue that will restrict fuel flow. Or rust flakes from the tank trapped in a bend in the line. I'm sure when your car was new it had no trouble running 80+!
 
Put a mechanical advance dizzy in it, makes a hole new game of the old flatty.

I made my own from a sbc points core, but if your not able to do it Gmcbubba makes em ready to run.

My shoebox stock flatty (other than dizzy) with no overdrive will run 80+, yes, its plenty nerve racking.
 
Get some bigger back tires and buy that ol' super duper charger from Walt. Then put some big brakes on it or a parachute on the back. I had a stock 49 once and it wouldn't go 80 right out of the showroom. Speedometer lies like a rug in them old Fords.
 
I bought a stock 52 Mainline new, with the v8. I broke the speeometer three times every time it got to the 100 mark. At that time you could buy a new one for $15 0r $20 dollars. If it is set up right it will do 80 without dual carbs, or hi comp heads.
 
Straightpipes said:
Get some bigger back tires and buy that ol' super duper charger from Walt. Then put some big brakes on it or a parachute on the back. I had a stock 49 once and it wouldn't go 80 right out of the showroom. Speedometer lies like a rug in them old Fords.
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Passed Pops in his Studebaker and he was doing 75, my speedo was pointed north of stupid.
 
:eek:i am luckey if i can go 40:eek:
 

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Frank Miller said:
True I do not need to but just want to make sure all is well. Highways around here can be brutal. My commute to work frequently has me being tailgated at 80 in my modern car. Yes it is in Overdrive. Just want to make sure it is running ok. Vic, the overdrive works good. I have 3:78 gears which is the standard transmission set. OD had 4:11. I am getting a true 30% overdrive.
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My 40 Tonner is running 4.11's behind a 49 Merc O/D trans with a slightly warmed up 239 engine. It will run at 70MPH all day without breathing too hard. To get there I removed the bias-ply tires and installed Michelin LT Radials on radial rims. Like others have said stopping is the Trick!! That's where the rubber really meets the road. As you know in O/D you lose the braking assistance engine compression provides. Not a real good feeling when the kamikaze drivers are zinging into your braking zone.
 
I mostly drive my 51 coupe 60 to 70 on the hiway, it has a merc crank single 8ba carb and stock distirbutor. it will do 85 with no problem, I am sure it would go faster but I don't see the need. it is nice to have the power to pass someone if needed. do a complete tuneup on your car using the advice from the fordbarn guys and you should get some more power from your flathead.
 
I have driven several stock 49 to 53 Fords with overdrivce and they all easily ran 80+. I always made sure the engine was well tuned up and installed radial tires.
 
Frank Miller said:
Engine has been rebuilt and starts and runs good. New points and condensor. Timing is right on. Completely stock. Carb has been rebuilt with float set at 1.5" per Ken Ct. Beyond 75 mph it feels like it just runs out of gas. Let off on pedal and car slows down and it runs fine at 70. All new valve springs so I am ruling out float. This is a bone stock 49 Ford 8BA with OD. I am shying away from ignition because there is no backfiring. Could the fuel pump be weak? Power valve is what Ken suggested. TIA Frank
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That is a sign from the man upstairs telling you to slow down.
 
Frank Miller said:
I have 3:78 gears which is the standard transmission set. OD had 4:11. I am getting a true 30% overdrive.
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Don't underestimate wind resistance. As you go faster, the amount of power required to overcome wind resistance increases exponentially. You can't just gear yourself higher and higher to hit 200 MPH unless you increase power.

I think you're overgeared and exceeding the available torque to push the wind at high speed. Try running at 80 in second overdrive and I bet it'll work. I have the same ****** with 4:27 gears and have no trouble doing 80.
 
rear gears are too large, put in a set in the low 3's, wont accelerate as well but will have a higher top end, personally I think you are a bit insane for wanting to go 80 and battle all these commuter cars on the way to work.
 
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