Compression Test

[TrisK]

Can i compression test an engine with it out the car? or am i not going to be able to turn it over fast enough?

Maybe ill have to do a leak down test?

[StuDoc 72]

Not really as you should really test it on a warm engine.

Yes you also need quite a quick turn over.

You could easily bolt the gearbox onto it and the starter if you have them should be a canter since its not in the car.

[AdamB]

Having the engine warm makes little to no effect on the reading you get anyway, although ideally it should be tested when warm.

A leak down test would be far better as it is a lot more accurate than a compression test. Anything more than 5% leakage indicates a serious problem.

Edited June 24, 2013 by AdamB

[daniel_g]

Id expect leakage on an old FTE to be a bit more than 5% tbh.

[AdamB]

Id expect leakage on an old FTE to be a bit more than 5% tbh.

Depends what you want to use the car for tbh. A car to run to the shops and back will be fine with upto 20% leakage, but looking for a good performance motor 5% would be ideal.

[StuDoc 72]

Id have to agree with Daniel.

Also ofcourse temp matters. Metal expands when warm - engines are metal. Its simple physics.

[TrisK]

Basically, i have a engine with knackred big end bearings. im going to replace them with out stripping the whole thing (just sump off), but i want to confirm everything else is spot on before i put it in a car, and get a shock that a ring was gone too or something else etc

[daniel_g]

Well i can pretty much guarantee that a 15 year old + FTE will have a greater leakage than 5%.

Trisk, you could replace the bearings and do a leak test before you put it in the car or whatever. Providing you have / can get a loan of an air line obv.