What compression numbers can one expect for a '76 300D engine (617.910) in good shape? Thanks!

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quoting 240DieselDog: "...the 115/240D is a better car than any that have since been built - that's *any* car from any automobile manufacturer."

according to my MOTOR repair manual from 1980 it is 313 to 331 with a minimum of 213. presumably tested cold.

tom w

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Heh only a few people know it seems... thanks a lot!

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quoting 240DieselDog: "...the 115/240D is a better car than any that have since been built - that's *any* car from any automobile manufacturer."

it's me again. A seller just sent me the numbers of his 300D and they are:

Cylinder 1= 209
Cylinder 2= 211
Cylinder 3= 210
Cylinder 4= 211
Cylinder 5= 207

He added a new engine has about 220, and everything above 200 is considered "good".

Tom, could it be that your numbers are for a different engine? Otherwise the seller would lie to me flatout....

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quoting 240DieselDog: "...the 115/240D is a better car than any that have since been built - that's *any* car from any automobile manufacturer."

Although the variation between your figures is minimal which is good, those #'s look quite low overall and good compression is critical to a diesel. A recent test of a family members 240D was 275 PSI on one cylinder and 350 PSI on the other three.

Are the numbers you are providing PSI values?

In theory and not taking into account wear, leakage, and gauge inaccuracy:
one atmosphere = 14.7 PSI X the compression ratio (approx 21:1) = the approx. compression value in PSI. This also concurs with t walgamuth's MOTOR manual #'s.

Try posting your question in the Diesel Forum, some of the experts may offer you some valuable info.

unless he is using another measure, the statement is simply wrong. i cant say if he is just misinformed or deliberately lying. if the numbers are psi, they are very low for a diesel. just above the minimum. so if i decide a person is lying i usually would simply move on and find a car that is honest and an owner who is too.

i would assume that the minimum from the book represents a figure below which it becomes difficult to start the engine reliably. so if you buy that car there is not a lot of life left in it, but it might start and drive pretty well. if you live in a warm climate it might be ok for you. on a diesel, when they get worn they become hard to start but often run fine once started. it is less critical if in a warm climate.

good luck.

tom w

__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.