Compression Test

AA Ford Discussion Group relating to the repair and restoration of your AA Ford.
Post Reply
David R.
Posts: 78
Joined: August 17th, 2019, 1:52 pm
Body Type: Chassis
Model Year: 1930
Location: WV

Compression Test

Post by David R. » November 16th, 2019, 5:25 pm

Just got starter rebuilt and installed and ran compression test. Likely not the most accurate gauge in the world but according to it I have a consistent 75 psi on all four cylinders. Is that acceptable?
FF173E9A-8E64-48EC-A3E7-FDEEAE7ACD59.jpeg
FF173E9A-8E64-48EC-A3E7-FDEEAE7ACD59.jpeg (1.31 MiB) Viewed 162 times

User avatar
1crosscut
Posts: 817
Joined: December 25th, 2010, 7:22 pm
Body Type: 82-A
Model Year: 1929
Location: Lincoln, NE

Re: Compression Test

Post by 1crosscut » November 16th, 2019, 5:45 pm

75 on all for would be excellent compression. Stock heads usually give up to around 65 lbs compression. Is this a high compression head?
The main thing even if compression on the lower side is to have all 4 cylinders to have readings that are pretty close to each other.
------------
Dave

David R.
Posts: 78
Joined: August 17th, 2019, 1:52 pm
Body Type: Chassis
Model Year: 1930
Location: WV

Re: Compression Test

Post by David R. » November 16th, 2019, 6:10 pm

How do you tell if it’s a stock or high compression head?

User avatar
1crosscut
Posts: 817
Joined: December 25th, 2010, 7:22 pm
Body Type: 82-A
Model Year: 1929
Location: Lincoln, NE

Re: Compression Test

Post by 1crosscut » November 16th, 2019, 6:25 pm

You would need to have the head off to look at the shape of the domes in the head.
------------
Dave

Post Reply