Compression Spec. 8-cylinder

[Jim Kilday]

What is the compression specification for a Hudson 8-cylinder engine? I found a spec sheet for the Six on the 'net but could not locate one for the Eight. If there is one for the Eight, could someone kindly direct me to it?

Thanks,

Jim Kilday

[Park W]

Jim, I don't recall ever seeing a spec, but in my experience one is in very good shape if it tests at 100 psi or better. Maybe Clutch Guy has a more precise figure.

[Geoff C., N.Z.]

The 8's were made from 1930 through to 1952, so there will be some variation depending on what year we are talking about. However, as a ball-park figur, Park's comment is right, something around 100 is correct. The main thing is that all cylinders are equal. Compression readings can be affected by temperature and cranking speed. For comprehensive diagnosis of engine condition I recommend not only a compression test, but a vacuum gauge test as well.
Geoff.

[Jim Kilday]

The engine is the original in a 1946 Coupe. Thanks for the comments.

Jim Kilday

[Geoff C., N.Z.]

Okay, I should have looked at the pic in your avatar! I looked in the 1952 workshop manual, and it states 100 lbs compression for all models, so there we have it, officially.
Geoff.

[Jim Kilday]

Thanks, Cobber.

[Clutch guy]

Okay, I should have looked at the pic in your avatar! I looked in the 1952 workshop manual, and it states 100 lbs compression for all models, so there we have it, officially.
Geoff.

As Geoff points out here,look in the specification table of your shop manual and it gives this info for both 6&8.