ClassicCar

rogerwmitreorg

I drive my '53 Hudson Hornet convertible in a local parade each August and have had problems with engine stalling and not restarting. The engine will not restart until it cools for about 20-30 mins. Last year I replaced the ignition coil on the advice of a stranger and did not have the problem in the parade last year. This year, the engine stalled again (car had to be pushed to the end of the parade) and would not restart for about 15 mins. A local mechanic who maintains the car talks about vapor lock which might be solved by installing a fan for the dual carburators. The problem restarting has happened in other situations in the past but much less now with the new coil.

Any suggestions out there for what to do next to alleviate this issue??

TOM-WA-

You might want to check the HEAT RISER and make sure it's working..If it's stuck it can cause a problem much like vapor lock in that it will cause the fuel to percolate in the carbs...

Marconi

ALSO, DO YOU HAVE THE HEAT SHIELDS UNDER THE CARBS?

ski4life65

I have a back-up electric fuel pump mounted near the gas tank. I only turn it on when vapor lock sets in

Tallent R

Well if you suspect vapor lock just pour some cool water on the fuel pump. That is ususaly where the the issue occurs . If the car will then restart you know you have found your problem.
And with todays gas there is going to be that type of problem. You can ad a return line as Walt describes in his book . Or instal a electric fuel pump as a back up in the fuel line back near the tank.
There are some reasons it can happen like no spacers or heat sheild under carb. Or improper routing of the fuel line too close to manifold or exhaust pipes. Even the big spacer behind the fuel pump aides in keeping it cool ,
Roger

lostmind

I had a 54 Hornet that I installed an inline fuel filter near the gas line.It was a metal canister and when it got hot the car quit untill it cooled down.
I relocated it and the problem was solved.
I think the best solution is to do away with the mechanical pump altogether and use an
electric with a regulator.Not for show cars , but if you are going to drive in the summer
with todays gas , it might be the solution.

Jon B

The electric pump will stop the problem, and it's not hard to install, but there are other solutions that are less involved and might help. (I for example have a mechanical pump only, yet have not experienced vapor lock in my '37 for several years.) You can use it as a backup and just switch it on when you experience vapor lock, or you can do away with the mechanical pump entirely.

Some have already outlined these alternate 'fixes' above: make sure the heat riser valve is working freely (and not sending hot exhaust gasses under your carburetor). Be sure you have one of those metal heat shields under the carb. And, use plenty of spacers under the carb. I have above 4 of them above, and 4 below, the metal heat shield. Another fix would be to wrap the fuel line with an insulating material, between the fuel pump and the carb (we used to use asbestos but there are alternative wraps now). And, you might also wrap the exhaust pipe with an insulator, where it passes near the carburetor.

Has the carb been rebuilt within the last few years? If not, you might consider investing some money in having a first rate rebuild. I had mine re-done by a company in Florida for about $250 which is way more than the normal replace-the-gaskets job, but it looks and acts brand new and I have had none of the starting problems I used to have. When you have a Hudson for 41 years as I've had, it's an indication that it's probably a "keeper" and is thus worth investing a little money in!

I once heard someone say that adding Marvel Mystery Oil to the fuel, would keep the modern gasoline from vaporizing quite as quickly. Anyone want to comment on that?

lostmind

Kerosene does the same thing, it's the vapor rating of the gas with ethanol that causes the problems.

35terraplane

In the summer, I add a small amount of 2 cycle oil to each tank of gas. No vapor lock. works for my 35 Terraplane.
Ed

Park_W

Roger, I had this problem with my '51 C8. It was not classic vapor lock, but fuel boiling in the carburetor bowl. All was well as far as heat riser operation, gaskets under the carb,eat shield, etc. So thought I'd start by lowering the temp under the hood by loweruing themp of the engine, which ran a bit warm. Had the radiator re-cored with modern-type core and the problem disappeared, never to return.

RonS

I used to have the same problem in AZ. But I did a few things at once. I added phonalic Ford gaskets(2 ea. + 2 paper ones) to each carb. Sent my mechanical fuel pump to Then & Now(psi = 5#). Put in Craig Valves for carb floats. Wrapped all lines with Mylar 24" before the mech pump and all the way to the AC glass filter at the carbs T. Placed a Mylar "blanket" between the exhaust manifold and the MPump. I always had a Solenoid type electric(EP) pump in line to maintain @5psi. When it failed I replaced it with another one ( AC - Delco EP-11). I tried using an EP alone> It put out 6-7 psi at the pump, but at the carbs it dropped to @ 3.5, not enough volume for the big 308 Twin H. Over 92f fuel starvation was an issue. Ok for a booster or primer. A Rotary vane is better for primary use. So far I haven't had an issue but in fairness I don't go to parades in Tucson( there aren't any in the summer). I was adding 2qts kerosene per 20 gal of gas( 10% ethanol). But didn't this year. One quirk... If I shut down the fully warmed engine, then come back in about 20 minutes, I usually need to hold the pedal to the floor to restart quickly. Probably cookoff in the carbs... Oh well. Other guys need to do that as well.

RonS

Park, Do you know of anyone who has installed a electric fan to move the air under the hood? Is it worth the cost for a 6 volt unit? Thought about cutting a 4" hole in the sheet metal behind the Passenger headlight area, in front of where the windshield washer jar is mounted ( 53s). Air could rush past the grille and cool the fuel lines. ??

TwinH

Prior to adding an electric booster pump to mine I was in the same boat. To verify vapor lock
take a small cooler of ice on your next drive. When it acts up or stalls,stop and fill a ziplock bag (or an old sock) with ice and lay over the fuel pump. If it is vapor lock in the pump the ice will 'cure' it in just a few minutes.

Park_W

Ron, I've not known anyone who tried that. Thought about running a flex duct on my '51 C8 from behind the grille to blow on the carburetor. But the radiator changeout fixed the problem, so never tried the duct. The big question to be answered is whether it's really vapor lock or fuel boiling in the carb ... that would dictate how best to try to remedy the problem. I certainly agree with those above who recommend an electric pump as backup. On any car, whenever I've had a hesitation that seemed like a fuel feed problem (vapor lock, etc.), I've just switched on the electric pump and the problem was gone.

Geoff C., N.Z.

One small matter often overlooked - there should be insulating sleeves around the bolts that hold the pump on the block, and fiber washers under the heads, as well as the thick spacers under the pump. . My Jet used to vapor-lock all the time until I fitted these. Stops heat transfer from the block to the pump.
Geoff

RonS

I agree, since I have not had an issue in over a year I never followed up on the "vent" idea. What did you mean by a modern core? Do you mean aluminum, or a new copper core one such as Brass Works sells and soldered to the original tanks? According to my inferred thermometer the radiator is steady at @ 170. It's the blasted heat on the top of the fuel pump at 157 that I need to be concerned with. That's why I put the Mylar pad between the Manifold and the pump. OH, I redirected the fuel line from the pump outlet to sweep toward the fender liner and turn sideways to the glass filter on a 90 degree. That way the closest the gas line ever comes to the exhaust manifold is 8 inchs. Geoff, I have those sleeves as Al Saffrahn advised.

Jon B

The coil was mentioned as a possible problem, and I did have that problem once (car would stop when coil got hot, would re-start 15-20 minutes later).

Question to the pro's here: if one suspects a bad coil, could one do the "ice trick" and cool the suspected coil down quickly, then attempt re-starting? If it re-started immediately, this would indicate replacement was in order.

Park_W

Yes.

Park_W

Ron, I meant the newer type core ... traditional copper core, but the fins have little louvres stamped in them. That catches more air and transfers about 50% more heat than the older types did.

RonS

Yeh, that would be like the Model A Ford "dimpled" fins. Did a local shop supply that style in SC? They are at least 50% more cost for 31 Fords vs the flat fins. Lee at Brassworks will make that style, total cost for the my 31 rad is @$750. The core alone is of course cheaper, but add labor to it. Has anyone found an aluminum radiator that appears like the McCord?

lostmind

You can get your tanks fitted with a staggered three row core like they use on tractors.
Sometimes it's hard to get the engine hot enough with one of these.
.About $100.00 more than a standard recore.
Well it was ,3-4 years ago ,not sure now.

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