The Ford Barn

rustynutz · 07-09-2013, 08:46 PM

What is the procedure a machine shop uses to pressure test a block? I have a 59 block with no visible cracks. I'm thinking if I seal the deck and water pump surfaces, and the water jacket holds 10# of air pressure for 24 hrs. it would indicate no cracks. Am I thinking correctly or am I missing something?

Karl Wolf · 07-09-2013, 08:58 PM

I have done this a lot... Block all the water holes. Use 30 lbs air. Take a squirt bottle with a bit of soapy water and look for bubbles inside, outside, pan rail, behind valve springs... With my pressure test rig, I find that I can get 80 plus lbs air to hold- with minor leakage...
Pressure test will find leaks, but not all cracks leak... I'm thinking in the cylinder/ valve seat area. Magnaflux is also called for in these areas, and if you think to, you could look for cracks around the center main bearing.
Karl

Ronnie · 07-09-2013, 10:54 PM

Hold at 40 psi is adequate.

R

D. Jones · 07-10-2013, 08:25 AM

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A word of caution about pressure testing to very high pressure. I was given the remains of a 59-ab engine by a friend after someone pressure tested it at 165 psi and blew out a pea sized piece of the block in the #5 intake valve guide pocket. That is a very thin area and with many years of rusting it just couldn't take that high a test pressure. Some guys test to 100 psi, but I don't see the need as stock they only ran at 4 to 7 psi. My personal feelings are that 20 psi is more than enough. Fortunately I was able to repair the damage and am running that engine in my 46 1/2 ton.

07-09-2013, 08:46 PM	#1
rustynutz Member Join Date: Feb 2012 Location: birdsboro, pa. Posts: 75	Block Pressure Testing What is the procedure a machine shop uses to pressure test a block? I have a 59 block with no visible cracks. I'm thinking if I seal the deck and water pump surfaces, and the water jacket holds 10# of air pressure for 24 hrs. it would indicate no cracks. Am I thinking correctly or am I missing something?

07-09-2013, 08:58 PM	#2
Karl Wolf Senior Member Join Date: May 2010 Location: Mill Valley,Ca. Posts: 1,509	Re: Block Pressure Testing I have done this a lot... Block all the water holes. Use 30 lbs air. Take a squirt bottle with a bit of soapy water and look for bubbles inside, outside, pan rail, behind valve springs... With my pressure test rig, I find that I can get 80 plus lbs air to hold- with minor leakage... Pressure test will find leaks, but not all cracks leak... I'm thinking in the cylinder/ valve seat area. Magnaflux is also called for in these areas, and if you think to, you could look for cracks around the center main bearing. Karl

07-09-2013, 10:54 PM	#3
Ronnie Senior Member Join Date: May 2010 Location: Canada Where it snows Posts: 2,058	Re: Block Pressure Testing Hold at 40 psi is adequate. R

07-10-2013, 08:25 AM	#4
D. Jones Senior Member Join Date: Jan 2013 Location: Bend, Oregon Posts: 514	Re: Block Pressure Testing Sponsored Links (Register now to hide all advertisements) A word of caution about pressure testing to very high pressure. I was given the remains of a 59-ab engine by a friend after someone pressure tested it at 165 psi and blew out a pea sized piece of the block in the #5 intake valve guide pocket. That is a very thin area and with many years of rusting it just couldn't take that high a test pressure. Some guys test to 100 psi, but I don't see the need as stock they only ran at 4 to 7 psi. My personal feelings are that 20 psi is more than enough. Fortunately I was able to repair the damage and am running that engine in my 46 1/2 ton.