Cylinder Compressions

[Iain]

Hi there,

just checked my stags cylinder compressions to see what variance there might be, range from 105psi to 120psi, anyone out there know what manufacturers specification is, am struggling to find any information.

:?

[V Mad]

imported post

Apparently there are no manufacturers figures. Your readings are about the same as I got on a good running car recently.

[Tdm]

imported post

About 12 years ago I had mine checked by a local mechanic (nr Conwy) who was also a Stag owner. I think he said readings close to 150 would indicate a Stag engine in tip top condition. Can't remember now what mine were, but there was quite a bit of variance between cylinders and I think the best was about 140. This is for a TV8 by the way.
Memory's not too good these days so can't swear that I've got these figures right.

[Iain]

imported post

Thanks, tought i'd check them whilst fitting new plugs, what else do you do on a cold, wet, Sunday aftrenoon!! :dude:

[redstag]

imported post

Iain wrote:

Hi there,

just checked my stags cylinder compressions to see what variance there might be, range from 105psi to 120psi, anyone out there know what manufacturers specification is, am struggling to find any information.

:?

Mine were about 165 after I rebuilt the engine.

Are you checking them with the throttle wide open? You will get poor readings if the throttle is closed.

Pete

[Iain]

imported post

Throttle was closed, didn't realise it would make such a difference, looks like I've found something to do next weekend!

[pennine]

imported post

Mine varied from 165 to 155 on one bank and 125 to 130 on the other.

Adding oil brought the readings up so it was a rebuild for me.


The car ran sweet as a nut but drank nearly as much oil as it did fuel.