Russian Motor in a 31 Cabriolet

[quickchange]

leaky head gasket , check torque on head nuts , pos a bit late , think you need a new gasket , copper with copper coat .

[SSsssteamer]

Originally Posted by 29Phaeton

....? It idles well but continues to backfire out the carb when trying to rev over about 2200rpm and acts like it's runnning lean unless I really open the GAV a few turns. ....Thanks for your help!

These are also the same symptoms of when a cam shaft gear is out of time with the crankshaft gear by one tooth.

[BILL WILLIAMSON]

"OILY" lookin' stuff is a mixture of water & unburned fuel.
Bill W.

[Bob C]

Do you belong to the Pomona Valley Model A Ford Club?
http://www.pomonavalleymafc.com/

Bob

[29Phaeton]

I bought a clear distributor cap so I can see what's going on at higher rpms and it looks fine to me. I checked this after dark and noticed for the first time that my exhaust manifold and muffler pipe started to glow red hot after about 5-10 minutes of a medium idle. I've followed the timing video and online instructions and think that's set correctly but now I'm questioning if maybe the muffler is clogged since the car was sitting for 30 years. I can feel exhaust coming out the pipe but given the red manifold, lack of power and carb backfiring at higher rpms....could it be a rats nest in my pipe?? Any way to tell for sure before paying for a new muffler?

[40 Deluxe]

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Originally Posted by 29Phaeton

I checked this after dark and noticed for the first time that my exhaust manifold and muffler pipe started to glow red hot after about 5-10 minutes of a medium idle. I've followed the timing video and online instructions and think that's set correctly

Where are you setting the spark lever after the engine starts? If you leave it clear up, the timing will be severely retarded which will quickly turn the exhaust manifold and pipe red hot.
The timing instructions you refer to are only for base timing, to get the engine started without kicking back. Once the engine starts, you use the spark lever to set the timing.

[29Phaeton]

When starting the spark lever is all the way up. Once started, I bring the lever down about half way while it's warming up. The idle level is about one quarter of the way down.

[Mike V. Florida]

GAZ engine start,

http://www.fordgarage.com/pages/gaz67enginestart.htm

Search http://www.fordgarage.com/ for GAZ for more info on the Russian use of Ford technology.

[Capt Quahog]

Just think . . . when old KGB guy uncle Vladimir comes to visit from mother Russia, you can give him a ride in the Soviet GAZ military powered Model A Ford. He'll no doubt feel right at home.

[Brad in Germany]

Here maybe this will help explain things if it is a timing issue :





Brad in Maryland

[1crosscut]

I admit I have not read all of the posts on here word for word so perhaps this has already been suggested and tried.
Have you sprayed starting fluid around the intake manifold while the engine is running to see if the engine speed changes? If it does you have a leak at the intake manifold.

Glowing red hot as in the most recent post is troubling. Something looks to be off in the timing.

Keep after it. You can win this one. If you can get another Model A person(s) to help the fresh set of eyes might find the trouble right away.

[29Phaeton]

Today I pulled the head and glad I did! Two of the studs were so thin at the base from rust they were ready to snap. And some of the water jackets had so much rust I can't imagine the back of the engine would have much circulation. The dremel is my best friend...it's all clear now.

Here's a before and after.

[lee in bend]

I'm actually in the process right now of re-ringing and new valves on my GAZ engine. I'm sure it's Russian as the crankshaft has GAZ on it as well as the Main Bearing caps and the pistons too. Guess it's a real Ruski. My engine came from that batch that was brought into Long Beach oh so many years ago. The engine runs like a top except for burning oil, rings and valves will help that. It turning out to be a regular "B" engine but with some hardware is metric...drives me nuts.

[Charlie Stephens]

Originally Posted by lee in bend

I'm actually in the process right now of re-ringing and new valves on my GAZ engine. I'm sure it's Russian as the crankshaft has GAZ on it as well as the Main Bearing caps and the pistons too. Guess it's a real Ruski. My engine came from that batch that was brought into Long Beach oh so many years ago. The engine runs like a top except for burning oil, rings and valves will help that. It turning out to be a regular "B" engine but with some hardware is metric...drives me nuts.

I have one of these engines. What hardware was metric so I can be on the watch for it?

Charlie Stephens

[rocket1]

If it has "b" timing cover it could be out of time,get number 1 piston up in the firing position and see if the timing pin is close to the hole in the gear.then check the rotor for correct position.

[FRANK PKNY]

May be as simple as dirt in the main jet. Backfire generally caused by too lean a mixture. try a known good carb. Make sure your fuel flow freely. Clean out the fuel sediment before puting on a different carb. JMHO

[Drive Shaft Dave]

You say a new style distributor is in place, are there modern point's as well?

[tinkirk]

two things come to to my pea size brain
1- bad intake valve if it's popping back thru the carb.
2- week valve springs

had the same issue 2 years ago installed all new valves and springs problem is gone

good luck
Tinkirk/Terry

[29Phaeton]

Thanks for all the great suggestions. Still has the same backfire. But, two clues are leading me back to the carburetor. If I run it with the choke partially closed the backfire is almost gone. Also, if I open the GAV a few turns (3) the backfire also gets better even though you can smell how rich it's running. I have cleaned this carb three times including a new kit so I am getting a rebuilt. If this doesn't do it I'm going to check the valve springs but the symptoms seem to point to a lean mixture.

[Tom Wesenberg]

A leak down test should let you know if you have a leaking valve, and a vacuum gauge should let you know if you have weak springs causing valve float.