Help Diagnos Compression Check & Leak Down

[palerider94]

Just got done doing compression test and leak down on my 70 Cleveland. Car smokes pretty good at startup and for first minute or so of driving. or when you acclerate petty hard. I was hoping it was just the valve stem seals. Has 70k miles on engine never worked on and sat for 10 years and the previous owner put 3K on it.

In pulling plugs each one had oil and deposits 2 and 7 were the worst.

Here is the compression reading:

Cyl Reading
#1 150
#2 160
#3 155
#4 165
#5 150
#6 160
#7 165
#8 170

Form Leak down - buddy used a 2 gauge reading.

Checked 3 cylinders

2 supply 75 reading was 60#
4 Supply 75 reading was 50#
7 Supply 75 reading was 50#

You could hear some air coming out of the breather.

Based on this we are assuming I should have heads done & at least put in new rings. Plan is to sell the car so I'm not looking to put much into it - but don't want to sell in it's current condition. Compression readings were pretty good, the leakdown, and oil in plugs made us think it was than than just the valve stem seals.


What do you guys think?

 

[red65]

Based on your compression results, and the fact that the majority of your smoking happens within a minute of cold start, I think it's likely that a new set of valve seals would solve your problem. If you really want to minimize your work and expense, you can put new valve seals on without even pulling the heads (pull the valve covers, pressurize a cylinder, just like for a leakdown test, compress the spring, pull the valve spring retainers, replace seal and reasssemble).

 

[palerider94]

Thaks - going to try that first and see what happens.