Hickory

My latest toy is a valve grinder mounted on an old sun cabinet. Now I've got to get an old sun machine.

How about a coolant pressure tester

What does that mean, did the plugs change dramatically between two different checks or was that an assumption from pulling them a month ago. Ashy could be from fuel additives or oil that has got real hot lately ory though, could it be coolant. I would check into the coolant one since it does it more the warmer it gets. If you have a leak down tester use it to pressurize cylinders and check for bubbles in coolant. If not you can use compression gauge check cylinder pressure, you can also adapt compression gauge hose to shop air. You can pressurize the coolant and see if coolant gets into cylinders. Many way to do this. You can also use combustion gas kit on radiator. But all test should be done hot.

One of the most basic checks is check the plugs right after a miss has developed. Are they wet, are they crusty and oil/carboned, or are they a nice coco. Mark how they look and position then switch them around and recheck.

Float bowl being half full isn't real relevant, floats float so the fuel should never reach the top. I would empty the bowl and blow compressed air through all of the passages, check out the accelerator leak. Test drive and then adjust the points and retest. I hate doing multiple adjustments and then find out it's fixed but don't know what fixed it.

So I'm sorry my plugs are 386 not 389. 9footbox I do have a dash timing advance by cable. I only have mechanical on the distributor no vacuum.

What I used back in my penny punching days was a vinegar soak, thena 3" flap wheel for a quick run then a lot of rigid hone. And then I used a ball hone. Some don't like a ball hone I do like the cross pattern from one. But they don't even things up so use both. That's me but before making a plan really clean up the pistons and check the piston lands. If they have cracks or broken then a new plan should be made. These engines are very forgiving but you don't want to cause more damage.

It's your car. These cars will run with broken piston lands, leaking valves ect. If you don't mind some smoke or running a little loopy. Hone it ring it and drive it. Save some money and have a winter project.

My research came up with an agreement with sniper and hotter run cooler combustion temps but I also found that a longer plug can have .5 degrees timing advance figure compared to the shorter plug.

I feel it's poor fuel distribution or atomization. So the autolite 386 plugs have a resistance listed of 3000-12000. Maybe different plugs and wires may help. I thought maybe a hotter plug may keep the plug cleaner and less likely to flood under full throttle.

I guess to start this thread I will say that I'm not looking for personal opinions on the best plugs. I see that question asked with a lot of mixed answers and bashing done. So my 29 DeSoto had autolite 389 plugs in it. Not sure yet what belongs in it yet. I'm looking more fo facts from people who can tune with plugs. First is heat range. I have two cylinders running a little warmer than others and I know you can mix heat ranges to help even this out. So do hotter plugs lower or raise the temps in the cylinders. Next is resistance of the plugs. Which works better in our cars. And how about wires, I have solid core beldin edge wires. I'm not a fan of napa ignition parts but do these wires work ok on our cars. On my car (remember updraft carburetor) #1 and #2 are a little sooty, #3 and #4 are black and damp, #5 and 6 coco brown. #5 and #6 run hotter. #3 and 4 probably are rich with updraft carb. What could help even these out.

What about the 54&56 DeSoto frames they may be an upgrade and the engine tranny are right there

Engine cylinders, as in cylinder sleeves, wheel cylinders, master cylinders, you got to give us more.

Maybe but why take the chance. Also if an owner had 12v hooked to a 6v starter as in a 12v conversion it may. These engines are old and I would try to remove as much as possible for no questions later if a problem pops up. How many of use have seen broken ring lands. That would be my concern before rod issues.

Here is the fan. It's 18" round and 6 blades. Old fan was 15" and 4 blades.

And on Saturday I drove the car to fuel it up and then on to the Mopar show.

So I have have a 6 blade flex fan I had to modify and install. Using 1"painters tape I have cut 1" of from every blade so they wouldn't hit the belts. Then I made my own spacer out of 3/4" aluminum flat stock . Drilled out the center hole to an inch, drilled the other 4 holes. Then put it on a lathe and turned the outer edge round. Then thinned it down to 5/8" thick. Installed my modified fan in the tight sleeping quarters and have 3/8" clearance between the belts and between the blades and radiator.

So that is someone else design I used as an idea. Throttle plate would be at #4 or stock carburetor. Choke plate at #1 that way you can control the bubbling. Baffles at #3 to keep liquid out of airstream. Electric plate would work but I just feel safer using a coolant loop. I wouldn't use heater cores but just a pipe looped in the box. For safety reasons and performance I would like to use a belt driven mini roots supercharger at #4. This would also assist cold starts.

I would like to try it on my 29 but I don't have a water bypass system in the coolant. I could drill and tap the head but I would have to make a pipe with a "y" in the lower radiator hose for the coolant to circulate.

Bingo?

And how he had two hoses going into the fuel I would have had one in the fuel and a smaller one drawing in fresh air near the top of the fuel level. Then it's more vapor and less agitation. Then he could have opened the ball valve more.

Vehicles will run of the air bubbles method but it actually runs rich that's why he had to choke the air flow down to control the bubbling. That is a good way to start till you get some heat into the fuel. Then it would use less gass and it wouldn't look as discolored.

Draw air into the liquid fuel to cause bubbles. You can use a choke cable and plate to slowly switch between the two systems. That's why I feel a belt driven supercharger screw style would be an improvement.

In our design (my father and me) we did not use air from around the exhaust, cool air more power. I was only 15 at the time and not knowing then how backwoods my father was the vapor carb we built worked, the selection of materials did not. My father used moms vacuum cleaner hoses on it and the fuel are it away causing the small fire. Boy I miss that old farmer. I think I want another run at it with my modern skills.

I watched that to. Interesting but it seems like wot would suck without a acceleration pump. I would think it would fall on its face and then recover.