compression

65f100

65f100

Member
what is a normal compression reading - im getting 50/55 across all 4 - engine smokes when it gets warm - im thinking of giving cylinders a few squirts of MMO and let it soak in for a couple days
thanks
 
For a stock engine, your compression readings are in the ball park.

What is the history of the engine. Has it not been run for a long time or?

If the engine has not been run for a long time, the smoking may subside after it is driven a while. Also some MMO is a good idea.

What color is the smoke? Black is rich mixture, gray or blue is usually oil smoke and white may be water vapor which may be a leaking head gasket.

What weight oil are you using?

Let us know more about the situation and we may be able to make some good suggestions.

Chris W.
 
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thank you for reply - engine has been sitting for god knows how long - its is oil smoke for sure bluish in color and plugs oil residue - im running a 15w/40 now - i belive the cylinder head is stock and looks like a copper head gasket - engine did have a stuck exhuast valve which i freed
 
65, assuming you have the standard 4.1 head and you are around sea level you are ok.

4.1*14.7=60.27 PSI.

Put in 4oz of MMO per 10 gal of fuel. Drive it, and see how she is.
 
I have had great luck with older long stored engines doing the following.

Marvel Mystery Oil in gas, four quarts of 20w-50 HD oil, STP Blue bottle as last 1/2 quart in oil pan. All this after good cleaning of oil pan and dipper tray.

I would think that you would want to slowly remove any built up sludge around rings, valves, and valve gallery.

Change oil after you run engine a coupe of hundred miles. Or when oil looks dirty on dip stick. Just take it slow, these are great old engines. They can take a lot of beating.

Enjoy.

If you drop oil pan, clean oil pump screen.
 
thanks for advice i will order some gaskets and drop the pan as the first oil change i did looked like mud the second not as bad - i will also try the 20/50 /stp formula next change and some MMO in gas - trucks not on the road yet just been running in the garage
 
It will probably run better after you get it on the road and run it for a while. Rings may seal up and it may be just fine.

Chris W.
 
I sure hope so and if I use old31's formula based on my aprx. altitude of 4400' my compression is good so seems I should be in godd shape in the mean time Ill fog my nieghborhood keep the bugs away
thanx for replies!
 
this pic is first start up after i freed the stuck valve but it does smoke quite a bit when warmed up
 

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Glad to hear the MMO amounts used. My 601 Ford tractor stuck a valve about a year ago, a pushrod popped out of place so it took some time and work to get it running again. I determined it was caused by the new gas being so dry, so started adding MMO to the gas, at a rate of about 1 oz. per gallon. It now runs good but smokes a little. I will now try 4 oz. per 10 gl. as suggested above. I'm adding it in my A's too. Thanks for the info!
 
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