The Ford Barn

Fordors · 02-11-2018, 10:12 AM

We have heard a value for the compression test but nothing for % of cylinder leakage. How are you performing the leak test, and also is it a homemade leak down tester? There is nothing wrong with a home made tester but is should incorporate a restrictor of .040 or so. Next, where do you hear the air escaping, can you hear it at the carburetor, exhaust, or is it at the crankcase breather?
Some will say a homemade l/d tester is not calibrated, or not proper for FAA testing, blah, blah, blah. It will serve as a good diagnostic tool and if used correctly will give good comparative results.

Jack E/NJ · 02-11-2018, 11:45 AM

>>> The 276 has excellent compression>>>

Does this mean the 276's (pressure/atmospheric) nearly equals (BDC cyl volume/TDC volume)? IOW, does the 276 perhaps have higher compression heads than the 221? Jack E/NJ

36tudordeluxe · 02-11-2018, 11:48 AM

It's a factory leak down tester. The amount of leakage varies from 9 to 27%. I hear air escaping at both the intake passages (manifold off) and out the exhaust pipe.
I believe another trip to a machine shop is in order here.

02-11-2018, 10:12 AM	#21
Fordors Senior Member Join Date: May 2010 Location: Orland Park,IL Posts: 1,402	Re: Leaky valves We have heard a value for the compression test but nothing for % of cylinder leakage. How are you performing the leak test, and also is it a homemade leak down tester? There is nothing wrong with a home made tester but is should incorporate a restrictor of .040 or so. Next, where do you hear the air escaping, can you hear it at the carburetor, exhaust, or is it at the crankcase breather? Some will say a homemade l/d tester is not calibrated, or not proper for FAA testing, blah, blah, blah. It will serve as a good diagnostic tool and if used correctly will give good comparative results. __________________ My school colors are black and blue, I attended the School of Hard Knocks where I received a Masters Degree in Chronic Mopery.

02-11-2018, 11:45 AM	#22
Jack E/NJ Senior Member Join Date: May 2010 Posts: 2,173	Re: Leaky valves >>> The 276 has excellent compression>>> Does this mean the 276's (pressure/atmospheric) nearly equals (BDC cyl volume/TDC volume)? IOW, does the 276 perhaps have higher compression heads than the 221? Jack E/NJ

02-11-2018, 11:48 AM	#23
36tudordeluxe Senior Member Join Date: Feb 2012 Location: Las Vegas, NV Posts: 1,260	Re: Leaky valves It's a factory leak down tester. The amount of leakage varies from 9 to 27%. I hear air escaping at both the intake passages (manifold off) and out the exhaust pipe. I believe another trip to a machine shop is in order here. Last edited by 36tudordeluxe; 02-11-2018 at 01:32 PM.