Russian Motor in a 31 Cabriolet

[29Phaeton]

I bought a 31 Cabriolet 68-B and have been having a tough time curing a carb backfire problem. I discovered this engine looks slightly different from other As as the oil return line is missing and it has a fuel pump port with a cover plate on the block. Looking through some old hand written records that came with the car I see the note "Russian motor from Long Beach". The block has no engine number stamped on it, the plate completely is blank. The head says USA and has standard size 7/8 spark plug holes, not metric like the GAZ head.

How do I confirm my suspicion of having a GAZ B Motor? If someone later installed a standard "A" head on it would that work? 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. I've verified free flowing fuel, timing is spot on and spark is good. It also has a Zenith 1 carb and I read the Zenith carb for a B engine is bigger so if I have a B block can it run with A parts (head/carb/Dist)? Here's a pic (ignore the large plug in the vacuum port). Is a GAZ B more valuable since it's so rare?

Thanks for your help!

[jw hash]

it looks like a B motor with a A manifold and head.

[Cornishman]

My car has a Model B block with a Model A head, Zenith carb, distributor and water pump. It runs perfectly. Like yours it has no engine number on the block.

[Synchro909]

B motors had no number on the block. It was on a boss on the flywheel cover just above the starter motor. The flywheel cover is discarded when coupling it to an A gearbox and replaced with a standard A flywheel housing, hence the original engine number is lost.

[Mitch//pa]

''''Spark is good'''''

Did you run it with a spark tester inline while its breaking up at 2200 rpm's to see if its erratic?
Try inducing a richer fuel mixture

One or the other should lead you in a certain direction

Could it be an exhaust leak and not actuallly breaking up

[1931 flamingo]

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Valves sticking?? Run some MMoil thru it. Nothing to lose. Is it an A or B distributor?? Front cover an A or B??
Paul in CT

[ronn]

the note most likely was someone's past opinion and not valid.

if the engine doesnt run right, could it be communist?

[jm29henry]

Try carb on a good running A and see if it is good?

[Bob C]

In the mid 1960's Ford Obsolete in Long Beach CA imported a bunch of the GAZ
engines. Some were complete engines and they also assembled some short blocks
from parts. I have one assembled from parts.

Bob

[Jim Brierley]

GAZ blocks were quite crude (rough) castings. They also had big lettering on the left side, center, and the left front and rear corners were more square. This could have been ground off and smoothed.

[29Phaeton]

Thanks to all who responded. I did hand crank the engine while inspecting the valves through the plug holes and they all seemed to move as they should, not sure about needing adjustment. I have replaced every ignition part from the coil to the spark plugs including an new style distributor so I'm not sure what more could be causing this. My gaps are at spec so how to I test for a breakdown at higher rpms?

If it's a B block is that a plus? Balanced crank?

[Mitch//pa]

Originally Posted by 29Phaeton

Thanks to all who responded. I did hand crank the engine while inspecting the valves through the plug holes and they all seemed to move as they should, not sure about needing adjustment. I have replaced every ignition part from the coil to the spark plugs including an new style distributor so I'm not sure what more could be causing this. My gaps are at spec so how to I test for a breakdown at higher rpms?

If it's a B block is that a plus? Balanced crank?

Read post #5.

[29Phaeton]

Sorry, I don't know what a spark tester is. I'll do some searching here in the forum. As I posted, if I open the GAV a few turns to give it more gas it gets much better but you can smell it's running too rich.

[briphaeton]

GAZ engines I saw had distinctive markings on the side of the block.

[quickchange]

G28T engines have welch plugs in block front & back , alloy sump, down draft intake, plus many other differences , some of which can be replaced with A-B parts , but not the block or sump .

[29Phaeton]

I'm so frustrated with this car I'm thinking about setting her free on Craigslist. I've spent the last four weekends solid trying to fix it with no luck. Very frustrating to say the least. I'm going to go see if I can find a spark tester today at my local parts store.

[29Phaeton]

Yup, my block has those markings on the left side "M-6015"

[BILL WILLIAMSON]

I'm AMAZED at how much info can be acquired, in a few minutes, when folks care enough to contribute what they know.
This is what we're ALL ABOUT, NOT just a "contest" about who's the SMARTEST--LOL
Bill W.

[Art Newland]

Just because the valves appear to open and close properly, at speed they may be sticking slightly and not closing all the way before combustion takes place thus producing the back-fire. The valve(s) may not be seating properly either and need lapped (or replacement). Did you try some MMO as mentioned earlier? A compression and leak-down test might be helpful in this instance. A bad distributor cap can cause a "cross-fire" situation, but since you mentioned trying a modern distributor you can rule that out. The Zenith has a filter screen inside that could be plugged, maybe just crud partially blocking something in the carb. Do you belong to an A club? Borrowing a known good carb would be nice to try. Looks loke a nice car, don't give up on her!

[1931 flamingo]

Give us the town you live in, maybe there's someone around the block that can help you??
Paul in CT

[hardtimes]

Originally Posted by 29Phaeton

Yup, my block has those markings on the left side "M-6015"

Hey Phaeton,
I've got one of the original imported GAZ complete B engines...(covered in cosmoline), that Joe imported. One of maybe 50 or so.
It has been running in my '30 roadster for over 10 yrs, with only 2500 mi on it now. I stripped it down and used the nos block with all high end parts to build a rock solid powerful B, with tooo much $ sunk into it ! Strong reliable runner that I built for long distance running, but never did.

You didn't answer the question of....which front timing cover do you have on this block, i.e.- A or B ? Makes a big difference in exactly what you are saying about TIMING, eh ! After reading all of your remarks about all the A stuff that someone put on this block, I'm thinking that just maybe 'they' put an A timing cover on also. Most likely stripping the A block that they were replacing with this B and adding A stuff on.

I'm also in Socal. If you have any questions and think that I can help, PM me

[Marshall V. Daut]

Has this been a problem since you bought the car, or did this problem just start? The way you phrased your first sentence, I would assume the car came with this problem. That means the previous owner couldn't find the source, either, and simply sold the car.
He probably had tried all the things you have, likewise without success.
While reading the list of symptoms and what you did to correct the misfiring and backfiring, like post #8, I suspected the carburetor. Possibly a passageway inside the carburetor is plugged. That would still allow a nice idle, but when more demand for fuel is needed, the plugged passageway will not flow enough fuel = misfire. I know some guys have had success just blowing out passageways with compressed air, but I have also encountered Zenith carbs (and most Tillotsons) that needed the lower passageway to be drilled out because of accumulated crud. No amount of compressed air or soaking in carb cleaner will get rid of this crud. The brass plugs must be drilled out and a wire, drill bit or small brush inserted into the passageways to "scrub" them clean. It has already been suggested to try a known good carb. If you have a local Model A guy with a carb he'll loan you for a temporary swap, go that route. If no improvement, then at least you can rule out the carburetor and concentrate on other areas.
Does the car have an auxiliary water temperature gauge or oil pressure gauge, perhaps anchored at the bottom of the instrument panel? A strange question, I admit. But one with a reason for asking. I restored a 1930 Coupe for a doctor friend in Phoenix 20 years ago. After I moved away, the doctor died and the family sold the car. It showed up here in Iowa - but with a constant misfire/backfire that wasn't there when I gave the good doctor his finished car. The place that now owned the car asked me to find the misfire. I spent a great deal of time trying to track down the source of the misfire. Of course, the usual suspects were checked out, but nothing helped. Like you, I was really becoming frustrated. Then I noticed something that I had not installed when restoring the car. The doctor had put in an accessory water temperature gauge mounted at the bottom of the instrument panel. There was an electrical wire running to the terminal box for power to operate the gauge's light. While re-installing the instrument panel for umpteenth time in an effort to find the source of the misfire, I neglected to hook this wire back up. Upon starting the engine and driving the car, NO misfire, NO backfiring! Hurray, I thought. I noticed the wire's connection dangling, so I re-connected it. Guess what!? Yup - the engine started misfiring again. Aha! Disconnecting the wire again resulted in no misfire. For some reason that only an electrical guru could probably explain, connecting that water temperature light wire was causing a misfire in the ignition system. Everything happens to me.
I am not saying this is your problem, but if you truly have tried everything and the misfire remains, before dumping the car on Craig's List, disconnect any auxiliary wires to accessory electrical items. Don't give up! There IS a reason why this is happening and it is probably a very simple thing. Once you find it, you'll kick yourself for not thinking of that right away. But you will also come away with one heck of a feeling of satisfaction that you stuck it out and solved the problem. That is priceless.
Marshall

[29Phaeton]

Thanks again guys. I'm in Pomona California. I noticed this morning I now have motor oil on my block coming from the seem in the front under the water outlet...guess I need a head gasket as well! This car has sat since 1990 so all of this shouldn't be a surprise. Pulling the head may also give me a chance to really see the valves. I run MMO in my gas at all times per posts I read from here.

[Henry's Lady's Man]

Originally Posted by ronn

the note most likely was someone's past opinion and not valid.

if the engine doesnt run right, could it be communist?

Maybe, but if it is a GAZ, it would be "Stalin", not backfiring!

[Tom Wesenberg]

There isn't any oil running in the area of the front head gasket seam.

What color are the spark plugs?

Guess I wouldn't have been so quick to pull the head, but can you post pictures of what you see, such as pistons and combustion chambers, and spark plug color?

[Mitch//pa]

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Could it be grease from the water pump

[Marshall V. Daut]

"Maybe, but if it is a GAZ, it would be "Stalin", not backfiring"

OOOO!! Ouch!!! I LOVE it!!! But you really shouldn't be "Russian" to such conclusions!
Marshall, who always goes for the obvious

[29Phaeton]

Okay Marshall! It must be backfiring because I can hear it PUTIN through the carburetor! HAR HAR

I didn't pull the head yet, if there's no oil in the front I have no clue unless it's waterpump grease. Beyond frustrating for a newbie. I'm convinced it's electrical but then I quesation why it will rev higher if I open the GAV a few turns. If it we're electrical it should breakdown regardless.

On weird note...I reversed the coil wires thinking maybe it was on backwards and it made no difference at all in how it runs. Plugs are black.

The ghost of Henry Ford and Stalin are laughing at this car for sure.

[Henry's Lady's Man]

So vee it!

[29Phaeton]

How do you tell the difference between an A or B timing cover? I used a timing light and it sounds good but....still not running right.

[Art Newland]

pun-o-mainia! Love it!

[29Phaeton]

Okay, after searching for comparison photos it looks like I have a timing cover to an "A" engine on a Russian "b" motor. Would 19 degrees difference cause backfiring? Until I can swap a model B cover I need to figure out how to guesstimate the correct timing. What I don't know is if a US cam gear was also swapped with the timing cover.

Can I just eyeball the piston position for TDC through the sparkplug hole and use that for timing?

[1955cj5]

Originally Posted by 29Phaeton

How do you tell the difference between an A or B timing cover? I used a timing light and it sounds good but....still not running right.

From a previous thread..

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

[Charlie Stephens]

Originally Posted by 29Phaeton

Okay, after searching for comparison photos it looks like I have a timing cover to an "A" engine on a Russian "b" motor. Would 19 degrees difference cause backfiring? Until I can swap a model B cover I need to figure out how to guesstimate the correct timing. What I don't know is if a US cam gear was also swapped with the timing cover.

Can I just eyeball the piston position for TDC through the sparkplug hole and use that for timing?

From your picture of the distributer in the first post it looks like it is a Model A distributer and that means you should use the A timing cover. How about a few better shots of your distributer or do you know what it is? To the best of my knowledge all of the timing gears were the the same. Just the timing cover was different between the A and B.

Charlie Stephens

[Chippy Minton]

You need the timing mark to match the distributor you have. If it's an A distributor you need the timing pin to locate at TDC, if you have a B distributor the pin needs to be in the other position. It's very straightforward to check if your timing pin locates at TDC or BTDC, I used a plastic zip tag to feel the piston crown. Looking at photos convinced me that I had a B timing cover and an A distributor but the pin slotted in at TDC so the rest was straightforward.

[hardtimes]

Originally Posted by 29Phaeton

How do you tell the difference between an A or B timing cover? I used a timing light and it sounds good but....still not running right.

Yup, timing will be different if WRONG cover is used.
If you can not see the two covers to know difference, I have both A/B front covers that I can take side/side photo of and put it here for you. Let me know if wanted.

BTW... I use a timing light and crank marking system to time all engines that I've ever had.
I'm thinking that you will find out some valuable information....by locating TDC on piston #1. Then looking at where your current timing is set. Might startle you and might explain why /how timing is set wrong with wrong front cover.

[A31Woody]

Someone shared this page with me recently as I was attempting to identify my front timing cover. http://www.fordgarage.com/pages/timingcovers.htm

[29Phaeton]

I know I have both a model A distributor (new style I just installed) and I know I have an "A" style timing cover from the photos I've seen. So from what you've posted it would seem my timing is correct. Still no reason for it to backfire over 2200rpm.

[29Phaeton]

Update: I can see tiny bubbles coming from this seem while the engine is running. Have to believe it's time for a head gasket? What else could cause this?

[Tom Wesenberg]

Look at the holes in the side of you oil fill/breather cap. Most likely the oil fumes are blowing out the cap and onto the block.

Wipe the block clean, put a sock over the oil fill cap, and see if that helps.

[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.

[lee in bend]

I have a Russian engine in a '29 Roadster. The info that its from Obsolete Ford parts and sold from Long Beach, Calif. is accurate as I understand. I know mine is Russian because I had it apart recently for a valve job and rings. The crank was marked GAZ as well as the tops of the pistons and connecting rods. The head is a "B" head (three bolt water pump) and is marked "GAZ' as well as the valve cover. This car with the "Ruski" "B" engine was originally from Bakersfield, Calif. and restored in the early 60's. I did have to paint the head and valve cover bright RED so it would be identified as Russian. The lettering on the head and valve cover was also painted Yellow. I always wondered if someone just used a GAZ head and valve cover on a stock "B" engine. Now I know the internals are also Russian.

[lee in bend]

I have a Russian engine in a '29 Roadster. I know it's completely Russian as I had it apart for a valve job and rings recently. The crankshaft was marked "GAZ" as well as the tops of the pistons and connecting rods. It has a "GAZ" head and "GAZ' valve cover too. I always wondered if it was a plain "B" with a Russian head and valve cover. Found out it's a true "GAZ" engine throughout. The info on it being from Obsolete Ford parts and sold in Long Beach, Calif. is accurate as far as I can determine. The engine runs well and is just a bit different in the castings. This car was restored in Bakersfield, Calif. in the early to mid- 1960's. As far as I could tell the pistons and connecting rods had never been out before since the pistons were not marked in any way. I painted the head and valve cover BRIGHT RED and the "GAZ" markings YELLOW for distinction. Hope it keeps running.