Compression Impression

[Woodie1]

We have a 1939 Ford with 85 hp engine. I did a compression test & got 75 lbs on all but 1 cylinder which was 60. This was all plugs out. It didn't crank very fast so I charged the battery & tested 1 cylinder again & got 85 lbs. This doesn't seem bad to me. The question though is I started the car up last week. It was about 30 degrees in the garage & after about 10 minutes of running I noticed steam or smoke along the driver side cylinder head next to the intake manifold. It seemed to run for several inches along the head. I don't see the steam or smoke on the other head. I thought maybe a blown head gasket but with the numbers so even it doesn't seem like the head gasket is blown. I tried to tighten the hose clamp but it wouldn't budge. I hate to pull the head & have the same problem after I put a new gasket on.
we bought the car early fall last year & didn't have a chance to put any miles on, maybe 30 or so. Wondering what the thoughts are from the barners.

[Ken/Alabama]

If it’s not mixing any water with the oil,I’d run it and see if it’s loosing any water. Pulling the head isn’t that big of a job.

[Woodie1]

As far as I could tell last fall it wasn't loosing water, but then it wasn't very warm outside anymore. I just don't want to be 50 miles from home with it when it decides to blow a gasket. It was a very nice restoration years ago but I don't think it was ever driven much. Maybe an occasional car show.

[bobH]

For whatever it's worth.... It's been running high 20's to 30's in my garage. I've been working on an engine, and I've started it several times. I've also noticed considerable water vapor coming from wherever the exhaust heat gets to first. It puzzles me because there are no obvious water sources nearby. So, I'd say don't worry about it. And, when the weather is warmer in a few months, look again. In my case, I'm betting the water vapor will not be present. But, I'm still wondering where that moisture is coming from. Got to be humidity in the air. Obviously, opinion...

[Woodie1]

I did not see the vapor last fall when I was working on it. I want to know it's good for the summer season. I have a number of items to deal with before I want to drive it this year.

[GB SISSON]

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None of us wants to be 50 miles (or a block) from home and have it quit. Compression seems kind of low for a totally restored car. Sitting is never good, but I am here to tell you that running them pretty hard with some seafoam in the the sump and some marvel mystery oil in the fuel has evened and increased compression (along with some spirited driving) in many of the long dead relics I have brought back to life. The steam? Warm it up and retorque the heads. Probably never got done with it's history. Also some of us like pictures of woodie wagons. Just sayin'

[Woodie1]

This one isn't a woody wagon. I agree with you though GB. The problems may be from sitting so long. I should check the torque.

[ssffnomad]

Yes we need , and like pictures.
Stretch

[Tinker]

The compression is low. Run-able, Might need to run a bit to see if the numbers go up before tearing it down. That's free anyways and the valves will love it.


Hard to believe you are getting those numbers on a recent rebuild. Check torques again. Easy enough to put in another head gasket.

[mfirth]

GB is right. I'd warm it good & retorque the heads. Won'y hurt a thing. When weather allows, drive it & don't putt putt with it either. Rings & internals need to be "driven".

[aussie merc]

my view for what its worth if it isn't making smoke out the back or road tube, doesn't miss or isn't loosing coolant or mixing it with oil then drive it retorque the heads drive and repeat still good GO FOR IT sitting is about the worst thing you can do to them they where made as daily drivers and they love it ! Lets face it even when we retire we still like to think that we are still useful

[Woodie1]

I believe the rebuild is at least 30 years old. I will run it come warmer weather. It seems nice & peppy on take off. Don't know what cruising speed will be. Hopefully at least 55 mph. Like to keep up with traffic better than out "A" does.

[GB SISSON]

Originally Posted by Woodie1

I believe the rebuild is at least 30 years old. I will run it come warmer weather. It seems nice & peppy on take off. Don't know what cruising speed will be. Hopefully at least 55 mph. Like to keep up with traffic better than out "A" does.

Keep in mind Bonnie and Clyde always stole a V8 if one was available. It wouldn't just keep up with 'traffic', it would outrun it. You will love this car!

[aussie merc]

me again just a thought a little bit of two stroke oil in the fuel wont hurt anything and may help to free things up add about what you would normally use to gallon to a tank

[Lanny]

Also, when doing a compression test, keep the throttle held 1/4 the
way open so it can suck some air in the cylinders. It has to get air in
the cylinders to make compression.




.

[GB SISSON]

I was always told a brick on the pedal..... Needs WOT for a comp test. Once and only once I started it up with the brick still there. You don't want to go there... Fortunately no damage.

[Frank Miller]

Just because the clamp is tight does not mean you do not have a problem. I had something weird happen to me last fall. I pulled the 49 out of the garage and noticed a water leak. It was pretty bad from the bottom of the radiator. Not a drop on the floor so it just started. Tightened the clamp with no success. It was an original type clamp and I replaced it with a worm drive clamp which fixed it up.
You may have a minimal leak due to corrosion on neck. A little water accumulated and you see steam. That is where I would start or as others said just drive it and see what happens.
You can also pressure check the system and see what happens.