No compression
 

Hi everyone, I have a 1948 ford f1 v8 flathead with no compression on 4 cylinders. I have removed the heads and intake and valves are free, what could cause this. I was told from Previous owner that the truck was running fine with no problems but due to his health condition he had it park for 9 years.

Re: No compression
 

Are the 4 cylinders on the same bank?

Re: No compression
 

No 2,5,6,7 no compression

Re: No compression
 

One on passenger bank and three on driver's bank. Engine sat for 9 years. What do the valve seats look like, and what is the compression, zero?

Re: No compression
 

You have to move air to get compression, could it be plugged intake or exhaust?

Bill

Re: No compression
 

Valves seem to be fine, the gauge just moves up and down from 0 to 5 psi, I was trying to start it all i would get was backfire threw the carb, I rebuilt the carb.

Re: No compression
 

How could I clean the valves?

Re: No compression
 

Hi, Not a motor guy, but if the valves are happy then the rings would be the next likely culprit. I assume you're getting a good fit on the compression gauge.

-VT/Jeff

Re: No compression
 

Give us the readings on all 8 cylinders.

Re: No compression
 

Cylinder 1 100 psi
Cylinder 2 0 psi
Cylinder 3 95 psi
Cylinde 4 95 psi
Cylinder 5 to 7 0 psi
Cylinder 8 90 psi

Re: No compression
 

It would seem that your gauge was working, therefor most likely it is the compression rings that need to be replaced. Mic the cylinders, check for wear. You may need to rebuild the engine if the cylinders are worn. How many miles on the engine?

Re: No compression
 

The valve has to mate properly in the valve seat (NO rust or corrosion anywhere)
and make sure the valves arn't burned or compression cannot build. ;)







.

Re: No compression
 

After sitting so long without running there is a good chance the valves are stuck due to rust and corrosion. I am not familiar with flat head V8's but i assume there is a valve cover on the side of each bank. If so, remove the covers, turn the engine over and see if the valve stems are moving freely. That may reveal the pproblem.

Re: No compression
 

Zero compression indicates open valves more than bad rings. Bad rings will generate at least some compression.

Re: No compression
 

valve covers ...!!!! rocker-arms? Maybe check the ECM, just a thought.

Re: No compression
 

most likely carbon under the valves..pretty common condition....hand rotate the engine ,when each valve is at its highest.a tooth brush type wire brush with a little kerosene or diesel fuel scrub the seats in the block and each troubled valve..clean them up and ck compression again..if the compression improves,you might get away with lapping the valves....poor fuel,,short trips doesnt heat the engine enough to burn off the carbon..on and on!

Re: No compression
 

Those valve covers must be collecter items. Henry Ford is still looking for them. LOL Walt

Re: No compression
 

ARDUN.......................
Paul in CT

Re: No compression
 

What's a valve cover?

Re: No compression
 

Valve train seems to be where problem lies is.You should always have the correct valve in the compression tester as a tire valve is incorrect.Tire valve is not sensitive enough.

R