1500 Cracked head?

[SilentUnicorn]

Here is my situation.
#1 9% leak down 120# compression
#2 9% leak down 120# compression
#3 6% leak down 122# compression
#4 4% leak down 126# compression

#1 and 2 i can hear leaking in adjacent cylinders, also in the tail pipe. #1 i can hear slightly in the intake. 3 and 4 nothing in the intake or tail pipe but hear a very slight leakage into the sump.

Car smokes blue black. it is running rich as i am still sorting SU needles

Opinions?


what is it with these 1500 heads? i went thru three last summer before i found a good one for a different project. Both heads i had checked were cracked between the valves on # one cylinder. judging from my readings above i may find the same situation when i pull this head.



mark

 

[Shealey]

Anything happening if the cooling system? bubbles, pressure?Maybe just rebuild time.

 

[SilentUnicorn]

didnt check the cooling sys when i ran the test. I am hoping it is just a blown gasket...Engine might have 20 k since rebuild. head was cleaned as well as block at the engine shop.

mark

 

[jcatnite]

Mark,
I'm not sure I would be too upset with those numbers. The valves might be getting close but overall they don't seem too bad. I am attaching a hyperlink to an article by Dave Russell that he gave me a couple of years ago. Maybe you've read it maybe you haven't but as far as engines go. I consider the things Dave says to be gospel. 1/2 way through the second file is a discussion on lead down testing. I also have it in Word format if you like. Can't attach docs here.
Dave Russell article Page 1
Dave Russell Article Page 2

JC