Compression Ratio, Will I be able to tell the difference? Options

[sdoolin]

Rebuilding(ish) my 2056. On my first build I was able to achieve a compression ratio of very nearly 9.0:1. With this build, I am having to add .020 spacers below the jugs to get any measurable deck height in the jugs. I am calculating a compression ratio of 8.6:1.

Will I notice the loss in compression ratio?

[Jack Standz]

Rebuilding(ish) my 2056. On my first build I was able to achieve a compression ratio of very nearly 9.0:1. With this build, I am having to add .020 spacers below the jugs to get any measurable deck height in the jugs. I am calculating a compression ratio of 8.6:1.

Will I notice the loss in compression ratio?

To answer your original question, probably not from just a small change in the CR.

That's with all things being equal. But, if your actual deck height is too large (and before it was "spot on"), and the quench is negatively affected, it will affect the motor's output.

Our 2056 has a CR about 8.5 or 8.6 (if I remember correctly, I have some notes somewhere). Nice motor & no complaints here. It turned out to be just what we wanted for a street motor in our '74.

LN Engineering heads are very very good. Would like a set or two for some upcoming projects. Their RS+ or LE200 heads are expensive too. When the motor is built according to Len's instructions, you will notice a huge difference in performance with these heads compared to standard heads or heads from mere mortals. Best wishes for the rebuild.

[sdoolin]

Rebuilding(ish) my 2056. On my first build I was able to achieve a compression ratio of very nearly 9.0:1. With this build, I am having to add .020 spacers below the jugs to get any measurable deck height in the jugs. I am calculating a compression ratio of 8.6:1.

Will I notice the loss in compression ratio?

To answer your original question, probably not from just a small change in the CR.

That's with all things being equal. But, if your actual deck height is too large (and before it was "spot on"), and the quench is negatively affected, it will affect the motor's output.

Our 2056 has a CR about 8.5 or 8.6 (if I remember correctly, I have some notes somewhere). Nice motor & no complaints here. It turned out to be just what we wanted for a street motor in our '74.

LN Engineering heads are very very good. Would like a set or two for some upcoming projects. Their RS+ or LE200 heads are expensive too. When the motor is built according to Len's instructions, you will notice a huge difference in performance with these heads compared to standard heads or heads from mere mortals. Best wishes for the rebuild.

Thank you sir, I appreciate this input. I am re-using a set of HAMM RS+ spec cylinder heads. They have about 4k miles on them and I agree with you about them. This motor ran very very nicely on its first build.