Compression for new purchase

[TonyPsj]

Hi all, I’m a new member in Spain and I’m writing my first post as I’m in the process of buying a S2 SE DHC which I have just inspected and road tested. It’s all looking good but we have done a compression test and I’m not sure about the results. It has had some work done on the engine about 10 years ago but I have no further details on what was carried out.
Could you give me your opinion on the attached results? They seem a bit low to me, but I haven’t been able to find information on “standard” engines. People only seem to test big valves and I suppose the readings are higher (from 160 to 200 psi)

Many thanks!!
Tony.

[gjz30075]

Can it be improved with a small amount of oil in the cylinder? That might determine if it's rings
or valves. If the rest of the car is nice, this could be a negotiating point with the price.

And welcome to the forum!

[TonyPsj]

Thanks for the reply. It’s probably something should have done (I’m 400 miles away from the car now) but do you know what the original values should be?
To translate the readings from the compression test they are:
140 PSI
136 PSI
127 PSI
141 PSI

[StressCraxx]

Two questions.

Was the compression test performed when the engine was warmed up to operating temperature?

Was the throttle held wide open during the test?

If both answers are yes, the compression numbers appear to be low for a stock engine. 160 Psig is considered minimum for a good road engine.

[TonyPsj]

The answer is yes to both, engine warm and throttle wide open...
The test drive was quite good, the engine pulling cleanly and smoothly from low down, all the way to 5500rpm. Maybe I was expecting a bit more punch but my experience on this car is very limited.
What are the possible consequences of those low readings? Is the engine on its way out? Should I stay clear from that car? What would be the solution and the cost to right it back to health?
Sorry, they are many questions but it's basically what I'm waiting for to go with the purchase or not, the rest of the car I'm good to go with.

[gherlt]

Hello Tony,
welcome to the forum.
I would do a pressure loss test. Quite easy and cheap, even if you need to buy the equipment.
If there is a loss, you can hear where the air is going.
May I ask where you are located ?
Regards
Guillermo

[TonyPsj]

Hi Guillermo, thanks for the suggestion. I live in Madrid.