1937 model 74 blowing the blues

[Dameon Hubbard]

Hey guys,

Short story, the car I bought has gone from a 10 a day smoker to a couple of packs a day smoker. The last run was for around 100 miles and burnt over a quart of oil. There isn't any real obvious smoke on start up, its when you hit the road there is a fair whack of blue smoke coming out the exhaust. Enough to piss of other drivers and the police.

I did a compression test today and got 6 cylinders at 60 psi and 2 cylinders at 85/90 psi. I did realise after putting everything back together that I hadn't held the throttle wide open.

Car runs like a top otherwise. EVERYTHING has been reconditioned on this car asides the engine.

In my opinion it's pointing to rings. Am I right?

Totally new to old cars.

[jimTN]

you do not say which engine you have, 60,21 std 85 or 24 std 100hp. If its the 85 with sleeves, may be rings. 100, wore out bore and rings. 60 stuck rings.

[19Fordy]

Time for an engine rebuild as it's not going to get better.

[Seth Swoboda]

This summer I put 1200 miles on a '37 tudor with the same issue you have described. Same cylinder psi. That engine started up and ran great. Burnt oil and was low on power. I just replaced it with a fresh 221, 21 stud and wow, what a difference.

Yes, It's time for a rebuild. It will be worth the cost in fun alone. In fact I not only installed a fresh engine, I rebuilt the transmission and 3rd Gen Automotive built me a 3.25 rear end. I did 75 mph recently.

[Bill OH]

I purchased a 221 in 1950 - burned oil as you describe. I ran detergent oil and it cleared the problem. I also cleaned 3/4 inch of sludge out of the pan. I could always depend on 86 mph and even hit 92 once. Never replaced rings or bearings.

[Kurt in NJ]

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Model 74 is 60 hp, about 74 mph should be top speed
It could have tin sleeves, steel pistons, the sleeves could have worn through the surface hardening

[Dameon Hubbard]

JimTN, It's the 60hp 21 stud.

[Dameon Hubbard]

19Fordy, Yeah, I'm totally with you. I've rebuilt everything else, so it makes sense to finish the car and do this engine.

[Dameon Hubbard]

Seth Swoboda, yip. Rip off the band aid.

[GB SISSON]

If it has been sitting, sometings the rings get stuck in the lands of the piston. You could try the Bill OH suggestion before you give up on the engine. I would go one step further than Bill and add a quart of marvel mystery oil to the new non detergent oil and a healthy slug of it into the gas in your tank. Then run it hard, but keep your eye on the oil pressure. What has it been showing so far on the oil pressure gauge?

[BobR35]

Originally Posted by Dameon Hubbard

Hey guys,

Short story, the car I bought has gone from a 10 a day smoker to a couple of packs a day smoker. The last run was for around 100 miles and burnt over a quart of oil. There isn't any real obvious smoke on start up, its when you hit the road there is a fair whack of blue smoke coming out the exhaust. Enough to piss of other drivers and the police.

I did a compression test today and got 6 cylinders at 60 psi and 2 cylinders at 85/90 psi. I did realise after putting everything back together that I hadn't held the throttle wide open.

Car runs like a top otherwise. EVERYTHING has been reconditioned on this car asides the engine.

In my opinion it's pointing to rings. Am I right?

Totally new to old cars.

I would suggest changing the oil, I use Castrol 20/50 in FL heat, add MMO, 6 oz, and run it a couple hundred miles and do it again. Add MMO (Marvel Mystery Oil), to the gas tank as well, same amount on 10 gals. I did this when I purchased my '35 after sitting for many years and it did clear up. It will and should consume a little oil but not smoke. Good Luck!

[dean333]

I stand by Kroil oil in the gas and crankcase to loosen rings and stuck valves.

[tubman]

Originally Posted by Dameon Hubbard

JimTN, It's the 60hp 21 stud.

Uhhh, which is it? V8-60's have 17 studs; '37 21 stud engines are 85 HP.

The car may be a Model 74, but that's not to say the engine hasn't been changed some time in the last 84 years.

[Dameon Hubbard]

Originally Posted by tubman

Uhhh, which is it? V8-60's have 17 studs; '37 21 stud engines are 85 HP.

The car may be a Model 74, but that's not to say the engine hasn't been changed some time in the last 84 years.

Hey,

What a goose I am. Its a 17 stud.

[GB SISSON]

Originally Posted by BobR35

I would suggest changing the oil, I use Castrol 20/50 in FL heat, add MMO, 6 oz, and run it a couple hundred miles and do it again. Add MMO (Marvel Mystery Oil), to the gas tank as well, same amount on 10 gals. I did this when I purchased my '35 after sitting for many years and it did clear up. It will and should consume a little oil but not smoke. Good Luck!

Gosh there Bob, were were a minute apart but on the same wave length even though we are about as far away as you can get in the lower 48! Good advice btw. And back to the subject at hand, the last two long sitting engines I brought out of hibernation took a surprisingly long time to reach where they are today. The H flathead six also had a valve that hung up. One thing that made an immediate improvement was running PB Blaster, WD 40, Liquid Wrench brand spray oil or whatever was around down the carb while at a fast idle. The perfect smoothness (along with the high and steady reading on my vacuum gauge) continued for about 5-10 seconds after I stopped spraying. I continued the MMO treatments and finally the hung valve was sealing and the compression climbed by an average of 20 psi across the cylinders as the rings found the cylinder walls. Of course if your engine is worn out your results will vary, and not in a good way..

[GB SISSON]

Originally Posted by dean333

I stand by Kroil oil in the gas and crankcase to loosen rings and stuck valves.

I have heard nothing but good things about kroil, so I can only imagine it gets where it's needed when taken internally by an engine.

[Dameon Hubbard]

Originally Posted by GB SISSON

Gosh there Bob, were were a minute apart but on the same wave length even though we are about as far away as you can get in the lower 48! Good advice btw. And back to the subject at hand, the last two long sitting engines I brought out of hibernation took a surprisingly long time to reach where they are today. The H flathead six also had a valve that hung up. One thing that made an immediate improvement was running PB Blaster, WD 40, Liquid Wrench brand spray oil or whatever was around down the carb while at a fast idle. The perfect smoothness (along with the high and steady reading on my vacuum gauge) continued for about 5-10 seconds after I stopped spraying. I continued the MMO treatments and finally the hung valve was sealing and the compression climbed by an average of 20 psi across the cylinders as the rings found the cylinder walls. Of course if your engine is worn out your results will vary, and not in a good way..

I'm new to engines but if it was the valves wouldn't there be a tonne of smoke on start up? and wet spark-plugs? Theres no smoke on start up, and dry plugs.
When the manifold was taken off we checked for stuck valves and got them all looking good (there were two stuck).

[Dameon Hubbard]

Originally Posted by GB SISSON

If it has been sitting, sometings the rings get stuck in the lands of the piston. You could try the Bill OH suggestion before you give up on the engine. I would go one step further than Bill and add a quart of marvel mystery oil to the new non detergent oil and a healthy slug of it into the gas in your tank. Then run it hard, but keep your eye on the oil pressure. What has it been showing so far on the oil pressure gauge?

Ive stuffed up and bent one of the exhaust valves slightly when doing the compression test. Will I be able to do the above with that? Or get that fixed first?

[Dameon Hubbard]

Originally Posted by Dameon Hubbard

Ive stuffed up and bent one of the exhaust valves slightly when doing the compression test. Will I be able to do the above with that? Or get that fixed first?

Actually, after a bit of research, me buggering that valve has just confirmed that the head and intake are coming off now regardless.

[dean333]

How did you bend a valve doing a compression test??