Compression results

M

Marv 49

Member
So after finally concurring carburetor issues, I moved onto general maintenance and some base line readings for reference in the future. First on the list was a compression test which was taken after about a 10 mile drive.

Cylinder/Dry/Wet. Cylinder/Dry/Wet
5/110/110. 1/75/75
6/110/115. 2/85/90
7/105/115. 3/90/95
8/105/120. 4/105/110

I added 2 squirts of MMO to each cylinder for the wet test before having one of the kids crank it over 5 compression strokes. Cylinders 1/2/3 were a suprise for me since the car runs good and really doesn’t smoke out the exhaust. From what I have read those low numbers could be valve related since the numbers didn’t come up with the wet test. There is some valve train chatter that I’m assuming is related. Other than a leak down test, is there anything else I should try? I did add MMO to the oil before I ran the car and gonna try and drive it a bit more before bad weather to try and hopefully loosen up things. Thanks again guys for all you knowledge.
 
How long did this engine sit idle in storage? Stored indoors or out? There is a lot of difference between being worn out and being gummed up. I dragged a vehicle out of the damp and soggy NW Washington woods last year that had made a few short runs over the past 20 years. Not a ford it was an OHV six. I added mmo and seafoam to the fresh oil and also to the new gas. I also added these chemicals down the carb throat at fast idle, which gave some instant improvements. Drove it hard for the summer and the compression increased dramatically. The vacuum guage went from 16 and bumpy to a solid 20 and steady. Front to rear, the compression was increased by these numbers. 23,19,23,35,33,26 over the course of 3 months and about 1200 miles. I was very happy with the results. Worth a try.
 
My ‘36 Phaeton is a level 90 (dry) on all cylinders; consistency reassures in the absence of higher numbers
 
On my engine that had been in long storage, adding MMM to the oil did not help the sticky valve problem. But adding MMM to the gas eliminated the problem immediately.
 
The car has not had many miles on it for several years. Grandpa would get it out occasionally but I would say less than 20 miles each year. This year I have put about 50 miles on the car do to lots of overtime, chasing kids all over and issues with the carburetor. I put a vacuum gauge on it and had about 20”, the needle would flutter less than 1”. I have seen where guys were putting MMO in the fuel, will look into that. Is that gonna foul the plugs?
 
GB SISSON said:
How long did this engine sit idle in storage? Stored indoors or out? There is a lot of difference between being worn out and being gummed up. I dragged a vehicle out of the damp and soggy NW Washington woods last year that had made a few short runs over the past 20 years. Not a ford it was an OHV six. I added mmo and seafoam to the fresh oil and also to the new gas. I also added these chemicals down the carb throat at fast idle, which gave some instant improvements. Drove it hard for the summer and the compression increased dramatically. The vacuum guage went from 16 and bumpy to a solid 20 and steady. Front to rear, the compression was increased by these numbers. 23,19,23,35,33,26 over the course of 3 months and about 1200 miles. I was very happy with the results. Worth a try.
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This is encouraging as my '49 EAB engine has sat who knows how long, and will still be a year or more before being driven and I too was worried about my compression and vacuum numbers. Compression is about 90-100 and vacuum is about 16-18, mostly steady. I have run it in the shop but not driven with any load. Hoping a good run next summer will fix the issues.

Good luck with yours!
 
Marv 49 said:
The car has not had many miles on it for several years. Grandpa would get it out occasionally but I would say less than 20 miles each year. This year I have put about 50 miles on the car do to lots of overtime, chasing kids all over and issues with the carburetor. I put a vacuum gauge on it and had about 20”, the needle would flutter less than 1”. I have seen where guys were putting MMO in the fuel, will look into that. Is that gonna foul the plugs?
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I believe due to few miles on for several years the compressions are ok.
The vacuum gauge with 20" at idle is good and if it were me I would continue to drive as is and attend to whatever comes along. If idles ok, carb and condenser and coil ok and it starts ans stops ok on the brakes thats good for me. Possible carb gaskets may have dried out with sitting.
All the best.
Phil NZ
 
Kilohertz said:
This is encouraging as my '49 EAB engine has sat who knows how long, and will still be a year or more before being driven and I too was worried about my compression and vacuum numbers. Compression is about 90-100 and vacuum is about 16-18, mostly steady. I have run it in the shop but not driven with any load. Hoping a good run next summer will fix the issues.

Good luck with yours!
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Sounds like a good candidate for a 'snake oil overhaul'. Really, with all that stuff in the fuel I still never fouled a plug. I really did drive it pretty hard all summer. On purpose. I'm sure Grandpa didn't 'burn the carbon out' on his short trips. Mind your thermostats and drive it at 180 degrees plus. Those numbers sound good considering all the 'sittin' it has seen!
 
B75EA8D1-7961-4996-B1A7-108248A7CA45.jpg
GB SISSON said:
Sounds like a good candidate for a 'snake oil overhaul'. Really, with all that stuff in the fuel I still never fouled a plug. I really did drive it pretty hard all summer. On purpose. I'm sure Grandpa didn't 'burn the carbon out' on his short trips. Mind your thermostats and drive it at 180 degrees plus. Those numbers sound good considering all the 'sittin' it has seen!
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So the thermostat comment brings me to another issue. The car seems to run very warm. At the the third mark and slightly higher. The only thing I have done to the cooling system was make sure it was full and put a 7lb cap on it as the one grandpa had on it would not actually latch down. I attached the picture of the gauge. Does that look close to right? Sorry, don’t know why I can’t rotate the picture to its correct orientation
 
That does seem a little high, although you can't really be sure with 70 plus year old original gauges. If it doesn't boil over, I wouldn't panic. It might be a good idea to get an infra-red remote thermometer and check out what's really happening. They are pretty cheap these days ($20-$30) and can be quite useful for many purposes. I determined that our oven was 35 degrees less than the set temperature, which had caused a few problems.
 
Your cylinder compression is 100-110. Probably okay, haha. Guess you have good cylinder compression and high compression heads.



Get a infra-red remote thermometer as mentioned. Know what condition your condition is in.
 
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