I have a 1950 ford with a Flatty in it and am having some issues with it. For one it overheats in about 5 min after starting. Second is it ideals great revs great but about 3/4 down on the pedal going down the road it misses like no other. I just replaced the head gaskets, Radiator has been gone thru. Has new plugs, wires, cap, rotor, points and is timed almost perfect. I am running a electric fuel pump. The carb has been rebuilt. Also i am running open headers cuz i dont wanna put money into mufflers till i get it all running good. If it goes bad i will just pull it out. Please help im getting very frustraited with it.
What carby are you runnning ? it could be a jet size problem , running to rich or lean , have a look at the plugs , or maybe the powervalve?
I have a holley 94, Jet size is a 50. I was having power valve problem before but replaced it. Carb has been rebuilt 3 times till i found out the vacuum advance was completely gone. Was thinking maybe i have to much fuel pressure with the electric pump im not running a pressure regulator.
Don't let it get you down. Flatties are awful sensitive to timing (and, hence, your overheating problem) issues and the stock Loadamatic dizzy was never worth a hoot really. Check out fellow HAMBer GMC Bubba's site: http://www.lindertech.com/bhrs/ He turns a stock SBC dizzy into one heck of unit that works great for flatheads and he's got lots of good info there. Do a search on flathead timing and I'm sure his name will come up in one of the threads. I don't think the fuel pressure is the issue as I believe it would run crappy or not at all if fuel was pushing its way past the seat. BTW, flatties only like about 2-4 lbs pressure using a Holley 94. My old timey mechanic showed me a timing trick, but am not sure you'll want to use it. Bring #1 cylinder up to TDC (if your TDC is off, your timing will be as well, obviously). Loosen the dizzy and put a piece of cigarette pack foil between the points and pull on it a bit under the pressure of the points. Start to turn the dizzy until the cigarette foil pulls out. Tighten down dizzy and fire it up. See if it makes a difference. It's always worked for me, but...
I'd run a regulator for sure it could just be pouring raw fuel into your engine maybe why its running bad till you get to higher revs when that extra fuel is getting used just an idea good luck and don't give up just yet
the regulator is a good thing to have.. those small carbs like that cant handle much needle valve seat pressure. and the electric fuel pumps, regardless of what they advertised psi is, they pump more. get a regulator. sounds like you may have fuel puddling up in the intake. been there done that.
good point--i think that 94 only needs around 3 lbs. of fuel pressure and most electric pumps run at 7 or so.
Re over heating ??? Do you have thermostats installed ? If so test them for opening in a pan of hot water. If no stats it should not heat up that fast. In any case do a combustion gas into the cooling system test ,commonly called a "Block-Chek" . Flatheads are FAMIOUS for cracking and all the other repairs and head gaskets won't do a thing for it if cracked.
Food for thought. Missing underload & overheating: Timing is off, retarded condition will over heat a flathead. (is the vacuum hooked up) Hey you can mess with it, but RodGuyinCO suggestion is a good one. Ask for some hot sauce too. Missing underload: Coil and condenser bad, even happens right out of the box. Missing underload: Lean condition or air leak in carb. Regulator: Not a bad idea, but wouldn't the carb be spilling out gas? if the pump is over running the needle? The engine wouldn't be able to keep up, so gas would be spilling/shooting out. Plugs: How do they look?
Overheating First question: Is it overheating on the gauge, or is it actually spitting water out and boiling the radiator? The stock gauges are notorious for being inaccurate and H may not be anywhere near too hot. If that's good and you really are overheating in 5 minutes, that's seriously bad. That's no water in the block kind of overheating. So, first check that you don't have air pockets in the heads. Do you have thermostats? If so, drill a small hole in the flange so water can get through - a 3/16" or even 1/8" hole will work. Then fill your system slowly so the water can burp out through the hole. If you're not running thermostats and/or you have confirmed your heads are completely full of water with no air pockets some other way (like filling nearly full with the hoses and stats off, re-assembling and finish filling) - overheating in 5 minutes is cracked block kind of territory. Check your coolant for combustion gasses with one of the various testers. If it's positive, and you've replaced the head gaskets, you may have a bad block. If you're exaggerating, and it's more than 5 minutes before truly overheating, based on your running crappy and missing comment, I'd start looking at the ignition system. If the timing is retarded at all, it will overheat. If you are using the stock 8BA load-a-matic distributor, the very first thing you need to do is throw it in the trash and replace it with anything else. Anything. But best would be one of GMC Bubba's converted SBC distributors. But anything will work better than the stock distributor. Seriously. It was a bad idea from the get-go. If you're restoring for shows, then drive it to the show with the SBC distributor and swap to the load-a-crapic distributor at the show. And what are you doing on a hot rodding website? Once you get that taken care of, if you still have high-end miss issues, I'd be looking at the condensor (which will get fixed with GMC Bubba's conversion) and the coil. Coils and condensors don't do well when hot either, so there is a chance that if you fix the overheating, you'll fix your ignition too, but better to put known good pieces in there. Good luck.
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