I purchased this 300SD not really knowing what is wrong with it for $400 - not a bad deal at all. COLD compression test came out as follows:

1-300
2-270
3-240
4-260
5-260

What do you think?

For $400. you got a good deal there.

Four of them are a bit low, #3 being the worst, but it will probably do an acceptable job for you. What's the situation with the blowby? It will be interesting to see how it does in 20°F. weather.......or below.

400 bucks WAS cheap. The body is very straight and has minor rust on the left fender in front of the tire.

The original first aid kit is still installed!

Im wondering how the compression is going to change once the engine warms up. Do you think the car will run well as-is?

The compression will almost always be higher when warm. But, the test is defined as a cold test at crank speed. If you tested it at idle speed, you would have significantly more compression. So, the engine will probably run just fine.

The only caveat is starting it when cold. Now that you have the compression numbers, PLEASE DO report back, on this thread, with it's cold starting capabilities. It's valuable info to have for an engine with slightly less than desirable compression.

You'll start to get into trouble starting it, for sure. Now, whether this occurs at 25°F. or at 10°F. or somewhere in between these two extremes, is the question.

Not that I know much but those numbers seem good for a cold engine from what I've read. Have you done a valve adjustment? Correct me if I'm wrong but that can improve compression numbers if they're maladjusted, right? Or do they have to be really off?

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Seth

1984 300D 225K
1985 300D Donor body
1985 300D Turbo 165K. Totaled. Donor Engine. It runs!!!
1980 300SD 311K My New Baby.
1979 BMW 633csi 62K+++? Dead odo

300 is a good number. But, there is only one of those.

And, yes, if the valves are really off and are not closing, then the numbers will drop. Or, if the seats are in bad shape and they leak, the numbers will also drop.

I wouldn't worry about the numbers unless the performance of the engine is not what you require.

where is your location? anywhere near az?

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have no worries.....President Obama swears "If you like your gun, you can keep it

If you call WA close to AZ, yes.

Where in WA close to AZ are ya?

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1979 240D- 316K miles - VGT Turbo, Intercooler, Stick Shift, Many Other Mods - Daily Driver

1982 300SD - 232K miles - Wife's Daily Driver

1986 560SL - Wife's red speed machine

300 numbers will come if the engine is tested hot.

my chilton numbers were for testing 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.

spokane

Just a quick update - I adjusted all of the valves and the IP timing. This thing runs great. It sounded like it had a miss, but the idle just needed to be turned up a small amount. It smokes a bit on cold starts, but runs clean when warm thanks to my bosio nozzles!

good for you!

they will run a long time with marginal compression, especially if you live somewhere it doesnt get too cold.

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.