What is the shot put record for a Marvel carburetor?

[Dwight Romberger]

The U.S. record would be fine. If someone knows the World record, that would be even better!

Hi All,

Here is the deal: While running at idle a few weeks ago (testing overheating problem) the engine slowed down gradually (over 10 sec?) and then stopped. As I wanted to set the timing (one possible cause for overheating I had not ruled out) I pushed it into the garage.

Discovered there was no spark. Changed coil, points and condensor. Now spark.

Timed engine. #1 spark plug now fires when flywheel is exactly at the 15 degree advance mark.

[Note:The firing order was correct, but #1 spark plug wire was connected on the distributer cap where the #2 spark plug wire should be connected. The others followed in the proper order. I corrected that, and according to the manual, now the wires are in the proper order on the distributor and on the plugs.]

I tried to start the car yesterday. There were a couple backfires in the muffler then nothing. With additional cranking, gas ran out of the air intake of the carburetor. Left it sit overnight. Blood pressure went back to normal. This A.M., I sprayed starter fluid in air intake. Loud backfire out of carb but no starting sounds.

It seems to me like it has to be a carb problem?

A few weeks ago (prior to this slow down and stop/starting problem) I disassembled the carb. Cleaned it. Replaced float. Car ran nicely (but overheated) There is clean gas running in new tubing from a nurse tank to the fuel pump.

I would really appreciate any suggestions:).

Thanks,

Dwight

Edited June 28, 2013 by Dwight Romberger (see edit history)

[60FlatTop]

That's a lot of changes.

If that car came into my garage this afternoon the valve cover would come off and I would rotate the engine by hand in the proper direction. I would watch the timing mark, the valve action, and the distributor rotor position. I might even talk to myself kinda low; something like: " Intake valve is opening, exhaust is closed, intake closing, closed, wiggle both, no pressure, where's that rotor, it's coming around, almost there, both valves still closed, there, just a couple degrees before, nice." Take it through a couple of revolutions, verify, and away we go. If it didn't do what I expect dig a little deeper. Questions like: why are both valves closed, the piston at TDC and the rotor pointing at the other terminal? That's the mechanical one, the the electric question, then the fuel one. Get the first two covered and you'll marvel at the third.

Bernie

[michaelod]

My first guess would be something other than a carburetor problem. As you sprayed starter fluid through the carb intake that would seem to indicate that fuel (starter fluid) is reaching the cylinders yet it still won't fire up even briefly.

Bernie's plan of action seems like a good one.

Just my 2 cents worth...

[Dwight Romberger]

Bernie (and Michael),

I took the valve cover off and watched the valves open and close in relation to the timing mark. I took pics of the valve, rotor and timing mark positions when spark plug #1 fires. As you can see, (maybe)the intake valve is closing on cylinder #1 but not quite closed. The timing mark is on 15 degrees advance. The rotor is in the #1 distributor position. The intake valve closes completely when the flywheel moves another 3" and reaches a mark labled UDC 1-6. The exhaust valve then begins to open as I rotate farther.

Edited June 28, 2013 by Dwight Romberger
I get further and farther mixed up (see edit history)

[Dwight Romberger]

Based on this little animation, Animated Engines - Four stroke my spark plug is firing too soon. I wonder if what I think is #1 on the distributor is not #1?

[michaelod]

[Note:The firing order was correct, but #1 spark plug wire was connected on the distributer cap where the #2 spark plug wire should be connected. The others followed in the proper order. I corrected that, and according to the manual, now the wires are in the proper order on the distributor and on the plugs.]

Thanks,

Dwight

Sounds like you previously had the wires connected correctly on the cap prior to swapping them around as you mentioned the car was running reasonably well prior to the recent changes. If they were wrong on the cap in the past it would seem that the car would run very poorly if at all. Worth taking a second look at.

[Dwight Romberger]

In the manual, it shows the distributor primary terminal pointing straight forward. In pic#3, it is counterclockwise of that position. I wonder if that is the problem?

[michaelod]

I will take a look at mine for you later today.

On second thought I just realized there are no plug wires on my car at all since I rebuilt the distributor before going to the paint shop about year ago.

Edited June 28, 2013 by michaelod
Memory lapse... (see edit history)

[Dwight Romberger]

I am going to rotate it it to the proper position and then reset the point gap and timing. If I am right (that would be a switch) it will correct the problem.

[Dwight Romberger]

A few bangs out the carb. Done for today. I will try your suggestion Michael and put it back the way it was.

Edited June 28, 2013 by Dwight Romberger (see edit history)

[Dwight Romberger]

I was too frustrated. I couldn't wait until tomorrow. I put it back the way it was. vaarrrooooom!

I still overheats, but at least it runs again.

Thanks Michael and Bernie.

Dwight

[Dwight Romberger]

I rechecked (I'm like a dog with a bone). The firing order on my 6 cyl is 1-4-2-6-3-5. The engine is running pretty well now with the #1 spark plug wire connected where the #6 wire should be on the distributor and so on around in order with the rest of the wires. (It did not run with the #1 wire connected where the #1 wire should be on the distributor)

From what I understand, this means my distributor is "180 degrees out." I searched the web and

some threads say "it makes no difference." You just put the wires in the new locations and forget about it.

Other threads say it "throws everything off." (Maybe on more modern/sophisticated engines?)

I am well beyond my pay grade here and would appreciate any advice.

Thanks,

Dwight

Edited June 29, 2013 by Dwight Romberger
The mud wasn't dark enough (see edit history)

[Bob Engle]

As long as the cam and crank are in the right relationship, When #1 cylinder valves are closed have #1 plug wire in the cap lined up with the rotor. Make sure all other wires are in the right sequence. You can then rotate the distributor to get the amount of advance for best performance. A vacuum gauge works best to get the optimum timing. Point gap gives the proper dwell for proper coil saturation. Changing point gap changes timing, so get the gap correct first. If you want the wires to match the manual, crank the engine to TDC for # 1 cylinder. If the rotor is not pointing at the correct position, pull the distributor and turn the shaft until you get it where you want it. Then rotate the distributor body to give the proper amount of advance.

Bob Engle

[JohnD1956]

...From what I understand, this means my distributor is "180 degrees out." I searched the web and some threads say "it makes no difference." You just put the wires in the new locations and forget about it...

Dwight, it should not make a difference where you have #1 on the distributor cap. The distributor is a switch that works exactly the same on each cylinder. There is only one advantage to correcting this, that is the wires would match the drawing in your manual. Otherwise there is no difference as to the location of the No# 1 cylinder. As you have already seen what is important is that the rest of the wires follow the #1 wire in the proper firing order.

If you want to match the manual you will need to ( I apologize if you already know all this) :

1- rotate the engine to the TDC mark on the flywheel.

2- Determine if your distributor cap clips are in the proper orientation.

If not remove the entire distributor and then rotate the unit till the clips are where you need them, and then turn the inside distributor shaft till your rotor is aligned with the #1 position. Obviously, if the clips are in the right position already, you will still need to pull the entire unit but just rotate the distributor shaft aligning the rotor with the #1 position.

3- you need to look at the gear on the bottom of the distributor. If the gear is cut on an angle you need to rotate the distributor shaft one tooth in the opposite direction of distributor rotation. When you put the distributor back in the engine this angle cut will engage the gear in the engine and automatically rotate the distributor shaft in the proper rotation to the spot where the #1 wire should be. You can be as exact on this as you desire however, if you are one or two degrees out of position it would still work.

4- Now here is the important point. Once you have the distributor aligned the way you want it, you should check the very bottom of the distributor shaft for the orientation of the slot what fits into and drives the oil pump. You'll need a big screwdriver to turn the pump in the direction of rotation of the distributor shaft so that these two parts will engage when you drop the distributor back into the engine. Otherwise the distributor will not fully seat.

Two things. I have never worked on one of these engines and I do not have a manual for them, but I assume the oil pump is driven by the distributor as in post war engines. Also, depending on the way things are built the gear on the bottom of the distributor shaft may hit the gear inside the engine before the distributor drops all the way in. In this case you'll want to align the oil pump with the final position of the distributor shaft so that when the shaft automatically rotates it can drop down onto the oil pump shaft. It is not a difficult task so if you have to experiment a few times to get it the way you want it, then go for it.

[Pete K.]

One thing I've not seen mentioned, are you making sure you have the steering wheel mounted spark advance lever fully in the "retard" position when timing?

[Dwight Romberger]

Thanks Bob, John and Pete for your help. I really appreciate it.

Since it makes no difference, I will let well enough alone with the orientation of the distributor. At some point it will probably bother me and I will change it. Thanks for the detailed explanation of how to rotate the distributor, John. Your description should go in a "how to" section.

Bob, I will pick up a vacuum gauge to fine tune the timing.

Pete, Thanks for reminding me about checking the lever position. I wonder if you meant to write fully 'advanced" rather than fully "retarded?" I don't have a clue, but my manual says "advanced."

Again, Thank you all for the helpful advice to get my Buick running again.

And, my apologies to the Marvel. It was merely an innocent bystander in this problem.

Dwight

Edited June 29, 2013 by Dwight Romberger (see edit history)

[Guest outlaw car man]

Dwight- Are you running fresh fuel in the system ? Sandy

[Dwight Romberger]

Sandy,

Yes, right from the pump last week. I have not hooked up the gas tank yet, so the fuel pump is drawing out of a one gallon motorcycle nurse tank.

I think I solved one problem I was having with the Marvel. I noticed that when I had the lid off the carb bowl, the car started better and the carb did not leak. I finally figured out that when I replaced the float, the end of the screw through float just barely touched the lid of the float bowl if I screwed it down real tight. I put a washer on the other end of the screw and now it doesn't flood so quickly and doesn't leak.

Dwight