whats your idea of good compression/mods with motor out

[kevin2m4]

im thinknig about buying a motor with 200,000 kilometers on it and they test the compression where they pull the motors but they dont label the compression to it. they say they dont pull anything with less than 125psi

now is that good compression or will it burn oil and blow smoke?
i keep reading here with people having 150-170 compression.

also can i just pull the oil pan off and look at the bearings to see if they are good?

and what mods should i do while the engine is out, on a budget and with used parts.

its going in a 4500lb 1986 lincoln towncar and the motor is from an 89 mustang

 

[TheUser]

from what I understand, it's not really the numbers that matter as much as how close they are to one another. They should all be within 10% or so of each other. The motor in my GT has like 70 psi on #5, 110 in another and the others are 125-150; I know it's not good and I know it needs to be fixed, but I don't have the money. It has fresh head gaskets and doesn't blow any smoke, so we'll see how long I can beat on it I have the lower intake off now to fix an oil leak, but it was running. Whether you buy the motor or not is up to you, i'm just giving you the info I have.

As far as doing anything, if you have plans to do anything to it, the best time to do it is while it's out - you obviously realize this. The typical mods, though can be done w/ it in the car (K&N, etc).

 

[kevin2m4]

whats the compression of a car that has blow by. at what compression does blow by and oil burning start?

 

[Fastime331]

whats the compression of a car that has blow by. at what compression does blow by and oil burning start?

That's a good question. My old engine had blow-by into the crank case that would push oil out the front and rear main seals and it had compression between 164-187 psi.

My only explanation would be that the ring gap was obvioulsy incorrect and that my old engine builder sucks.

 

[Blue Thunder]

I wouldnt buy a used motor unless they're willing to put the motor's mileage in writing.
If you buy a small block with under 75,000 miles on it, unless a fool owned it before you, it will run nicely.