Zyglo Testing of Cylinder Heads for Cracks

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audioresearch
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Zyglo Testing of Cylinder Heads for Cracks

Post by audioresearch »

I own two 460 engines, but my question here is about a Ford 1.6L oem aluminum cylinder head used on my 1983 Mercury LN7 and the more well known Ford EXP during part of the 80s. I ask my questions here because from past experience, the people here really know their stuff on engines and besides, the answer to my questions may very well also apply to the 460 engine too.

From your own personal direct experience with cylinder heads have you found that if a head has one or more cracks that at least one crack will always show up in the combustion area using a Zyglo test? If your answer is yes, estimate what percentage of heads it is true for please and please estimate how many heads you have tested/inspected for cracks.

With a Zyglo test, is it necessary or even allowed to bring the head up to normal operating temperature or have you found that is not needed at all for the Zyglo test to show cracks?

Have you found that a pressure test, including those done at both cold and at operating temperature, does sometimes find a crack that Zyglo misses? If so, about what percentage of the time have you found that to be true?

Do you think that pretty much all aluminum heads will crack within 10 years no matter how well you treat them?

If you know of any aftermarket manufacturers that make replacement heads for the Ford 1.6L aluminum head used on the 83 Mercury LN7, please recommend some.

Thank you, thank you, thank you!!!

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Re: Zyglo Testing of Cylinder Heads for Cracks

Post by action »

The only question I will answer is this one:

"Do you think that pretty much all aluminum heads will crack within 10 years no matter how well you treat them?"

The answer is NO.
I have four vehicles with aluminum heads. Two V-8s and two four cylinders.
The newest one is 11 years of age.
All have mileage in six figures. Two are approaching a quarter million miles

Aluminum is the preferred metal for all new Ford engines designs since the early 1980s.
With care, they have a great track record. With poor maintenance, they have a very poor track record.

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2006 Lincoln Navigator Limited 5.4l 3V
1996 Lincoln Mark VIII 2DR Coupe Diamond Anniversary 4.6l DOHC, 4R70W, 3.07
1970 Continental Mark III Triple Black 460 4v, C6, 2.80 (Used for Woodward Dream Cruise or just generally stored in Michigan)
1966 Lincoln Continental 4DR Convertible 462 4v, C6, 3.00
1966 Mercury Park Lane 4DR Breezeway 410 4v, C6, 2.80
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