394 compression issue

[Guest mortsciguy]

My 64' 394 seems to have a 15 to 20 psi drop on the center pair passenger side cylinders, compared to the others. Does not improve with light oil application to bores. It has been suggested that those valves may have a carbon buidup, keeping them from seating fully. Any thoughts or suggestions to improve condition?

Kelly:confused:

[rocketraider]

Are you losing any coolant or noticing it in the oil? Low compression on two adjacent cylinders is symptomatic of a head gasket problem.

Does the engine run well or does it have a spitting sound at the tailpipe, which could indicate a burned valve. What are the manifold vacuum readings doing?

If you have a carbon problem, odds are it traces back to the exhaust crossover in the intake being plugged with carbon and soot. Does the choke function well or does the car take an abnormally long time to go to off-choke operation?

I hate to tell you to start a teardown, but this is the type of problem that doesn't go away.

[Guest mortsciguy]

Glen,

No coolant/oil problems, vaccuum steady in fat area of green, no exhaust popping. No issues with choke. Idles well, runs good. As mentioned in an earlier thread, can be a little persnickity off idle. Even though she's a heavy beast, it just seems a little light on torque and power off the line. That's why I was looking at compression.

Is there a good technique for carbon clearing without removal/boil out? Again, I am at a loss. I can pull the top end this fall IF needed, but at 49,000 miles I would prefer not to. I'm hoping I am just dealing with 12 years my uncle's lack of running, except for an occasional parade.

Kelly

[rocketraider]

Can you get any GOOD high-octane fuel anywhere? As in 100+ octane. A couple of good full-throttle hard acceleration blowouts may be all it needs, but you always worry about doing that on an older engine. I wouldn't do it on currently available pump premium.

[Guest mortsciguy]

Glenn,

I do have a 100+ source. I'll give it a shot.

Kelly