Help!

[Anonymous]

Last year I became the proud owner of a '68 coupe. This car has only 48,000 miles and has been owned by my wife's grandmother since about 1970. She was very meticulous with the car, having it serviced often, whether it needed it or not. She gave me all receipts, service records, etc. I essentially know the history of the car since it had a few thousand miles.
Anyway, just before I got it, she had it at the shop to get a tune-up. It was running rough. The service record indicates no compression on the #2 cylinder. I have changed the plugs and checked the spark but haven't done a compression test. My question is whether anyone has experienced this on an I6 with less than 50k miles? I understand these engines are supposed to be long lasting and don't want to believe I will have to do a complete rebuild already. I know the car has been babied. It hasn't spent a night out of the garage since at least 1970 and has been driven very conservatively. Any ideas? I would really appreciate any advice or suggestions! Thanks in advance...

 

[61Futura]

Unleaded gasoline burns out the exhaust valve seat. You'll have to have the head rebuilt and get hardened seats installed. At least that is what I see in my crystal ball

 

[rbohm]

8) first run a dry and then a wet compression check and see what the pressure is in each cylinder. that wya you will have an idea of where the compression is going. if the pressure comes up on the wet test, then the rings are sticking. if not then usually either a burnt valve or bad head gasket.

 

[Anonymous]

Thanks for the info . I intend to pull the head this weekend and see how things look. If I am going to the expense and labor of doing this, would I be better off replacing the head/intake with another? I tend to appreciate my classics close to original, but am not afraid to make minor modifications that will improve driveability, reliability, etc. Any other suggestions??????

Thank you!

 

[Hot 6t Falcon]

68Coupe,

Things to think about.

If you get another head, get a 77 to 83 head. It already has the hardened seats. It also has bigger intake (1.76 vs 1.69) valves. BUT it will use a different one barrel carb and a throttle cable instead of a steel rod. So, if you get the later head, get it with the carb and throttle cable, and gas pedal too. Along with a valve job (goto the High Tech part of this Forum and read my Sticky about three angle valve jobs - especially the part about back cutting the valves), this head will need to be milled to maintain your compression ratio.

If you decide to keep the orginal head, some things for you to think about. If you need to relace the intake valves, have the shop use the 1.76" valves. Replace the seats with hardened seats. A 3-angle valve job will probably cost $30-40 more. Back cut the intake valves. Mill the head to maintain, or even increase, the compression. Doing these things will give you most (you'll still have a smaller carb) of a later head w/o having to switch.

The down side is that if the rings are stuck, none of this will do any good.

Good Luck