Compression Test

[Artie]

Hey guys I just ran a compression test, but I cannot figure out for the life of me how to figure out what my variance is. Engine was warmed up to 80C, and did the test with a screw in tester and the throttle open fully

Cyl 1(front most) was 158psi

Cyl 2(next back) was 160psi

Cyl 3(third back) was 160psi

Cyl 4(rearmost) was 158psi

Come on Travis I know you know!

Artie

[Vulcan Grey]

Hey guys I just ran a compression test, but I cannot figure out for the life of me how to figure out what my variance is. Engine was warmed up to 80C, and did the test with a screw in tester and the throttle open fully

Cyl 1(front most) was 158psi

Cyl 2(next back) was 160psi

Cyl 3(third back) was 160psi

Cyl 4(rearmost) was 158psi

Come on Travis I know you know!

Artie

For an 89-95 S4s (910 & 920 engines) Turbo's.

Compression pressure is 9.5 bar (140 lb/in? minimum When warm and at sea level.

For reference the manual says

COMPRESSION CHECK

1. Warm the engine to its normal operating temperature. Switch

[Artie]

For an 89-95 S4s (910 & 920 engines) Turbo's.

Compression pressure is 9.5 bar (140 lb/in? minimum When warm and at sea level.

For reference the manual says

Lotus gives no spec for allowed variance, but you are showing very good numbers (above 140) and your variance is only 1.25%, which is very very good.

I knew you'd know! Thanks! How's your rebuild coming by the way?

Art

[alan]

Just to add to this - the compression figures are just about perfect for an Esprit so no problems there.

Alan

[Artie]

Just to add to this - the compression figures are just about perfect for an Esprit so no problems there.

Alan

, thanks. I've been testing everything to be sure I'm starting with a "fresh" engine, before I start turning up the wick!

[karmavore]

Those numbers give me a chubby. What's the serice history and mileage on the engine?

[Artie]

Those numbers give me a chubby. What's the serice history and mileage on the engine?

Head was replaced with new valves and fitted with a new head gasket 2002. Engine history is a bit hazy. I have some records for regular oil changes but there are holes in the history from 1993-1999. Some info but very limited. I put on a new timing belt 400 miles ago and am running Amsoil 20W50 Series 2K oil. Had a shop do a compression test but never gave me the results, they just said it was "within Lotus specs.). I now plan to tackle the asthetics department, knowing that the engine is in good health.

Mileage is 64,339 currently, bought it with 62, 457.

Art

Edited August 23, 2006 by Artie