617 Compression Test Results!!!!!!!!!!
 

1- 360
2- 360
3- 350
4- 360
5- 340

Yee-haw, I think......
Please confirm the urge to celebrate.

Thanks again.
Jay

pretty nice.

people get so concerned about the value of the compression when its the relation of all the values that makes for a smooth running engine.

thats what you have.

Whoo Hoo!!

Elaborate, if you could.
I'd like to know a little more about what values to consider.
Thanks in advance.

The first whoo hooo has arrived....this is good.

the factory spec for the engine is 10% (someone correct me) variance between all cylinders at most.

your highest and lowest scores are well within that.

although the factory spec for highest value of compression is a bit higher than your numbers, you are within the "healthy" engine range.

I definitely give you a "woo-hoo" too

What is the factory spec for highest value of compression?

wow many exclamation points with the good #shttp://www.peachparts.com/shopforum/...ons/icon14.gif me hopes for similar with the ones sitting around-have to take the head off one.

30 bar

or

435 psi

is the best "normal" compression value given.

The 617.95 service manual lists normal compression as 24-30 bar. Minimum is 15 bar. Maximum difference between individual cylinders is 3 bar. (These figures are with the engine at normal operating temperature.)

Hi
Those are good solid numbers! Was the engine at operating temp (85C.) just before testing?
Joseph

The engine was cold.
Please tell me about how this affects the test.

A cold engine will generate a lot less pressure in the cylinders for two reasons.

The rings seal better at temperature, and the heat from the cylinder walls increases the temperature of the compressed air a bit.

Plus the fact that the valve-clearances are smaller when cold, and affect compression measurements....

And, Cranking will be slightly faster, as there's less drag of thick oil....

Prolly add maybe 50 psi to those 'cold' numbers for a good, hot engine....:)

Where did you take the readings from? Glow plug or injector? Which tester?