Compression Test Completed on 1914

E

Ed in Maine

Well-known member
I had a compression tester but did not have an adapter for the Model T. I made one this morning and this is what I found:
#1 15psi
#2 20 psi
#3 26 psi
#4 0-2 psi

I did spray some WD40 in #1 and it did not make a difference. I guess I have some valve issues. I will take off the valve covers and see if I can see if any of them are not all the way down. Will it do any good to spray some lubricant on the valve stems?

I do remember complaining about the lack of power with this car. It is a touring and if I had four people in the car, climbing hills was getting difficult.

Thanks for your help. Ed
 
Ed,

Some actual penetrating oil will help on the valve stems from above and below. (WD40 is a mild lubricant designed as a Water Displacement media, actually the 40 th try at producing an acceptable product for a govt. contract.)

From your comment on lack of power it would seem the valves are in need of attention. A T will keep on going with amazingly poor valves. New valves are very reasonable & not a major job to replace.

You could probably get it to run as well as last year by towing it & let it run a while to loosen the stuck valves. As mentioned before a little oil in the gas will help. I find 2 stroke oil works well & is meant to burn off without leaving carbon behind.
 
Even your "good" cylinders ( 2 & 3) aren't good at all. WD40 is too light for a compression test/ring check. Probably ran right past the rings. Not to be a pest but truthfully, using that light spray and on one cyl. only doesn't tell you much at all. I hope #4 is a stuck valve which you can possibly free up but it looks more like a full valve job now going only by the incomplete comp. test + the fact that it usually isn't rings.
 
The reason I had said WD 40 was the fact that it melts gasoline varnishes and softens carbon. Can the valves be seen from the plug holes? If so tap them some I have shut open valves this way but not on a T. It sounds as if it is valves but my bet is they are stuck and might not be burnt or needing any lapping.
 
J Franklin said:
The reason I had said WD 40 was the fact that it melts gasoline varnishes and softens carbon. Can the valves be seen from the plug holes? If so tap them some I have shut open valves this way but not on a T. It sounds as if it is valves but my bet is they are stuck and might not be burnt or needing any lapping.
Click to expand...

Caution! just because you see a open valve doesn't mean it is stuck. It may be held up by cam and if you try to knock it down you will bend something. Make sure it is on compression stroke before you start hitting on a valve that is up.
 
You must log in or register to reply here.
Back
Top