Hello Small-Block enthusiasts:
I'm a shade tree mechanic who enjoys a challenge, and here's one: A friend dropped off a 1977 Chevy C30 Motor Home for me to look over. He's leaving Wisconsin for Arizona soon, and wanted to know if the beast was roadworthy. She's powered by a 400cu inch Chevy V-8, drives dual rear wheels through a propeller shaft attached to a TH400 transmission, and has 109,000 original miles on the odometer. Her curb weight is a hefty 10,500lbs.
He paid $1500 for it, and the sale included a very complete (and very LONG) maintenance history.
The engine has burned valves in two of the rear cylinders. (Is anyone surprised?) I read that one solution to this is to, during a rebuild, install heads that have added steam holes. Have any of you done this?
And although it is a 1977 model year vehicle, the engine block may have been in storage after it was manufactured. I mention this because it may have been made in 1975 or 1976 when leaded fuel was intended to power the engine, and hardened valve seats may not have been installed. Now the 1977 Owner's manual clearly states that unleaded fuel be used. But leaded fuel would have allowed the valve seats to operate at cooler temps than unleaded fuel. This suggests a snafu that doomed the engine to burned valves.
Any tips on how to prevent a recurrence of burned valves is very welcome.
But I also suggested to him that swapping in a Chevy 350 might be a better fix. It appears I could bolt it right on to the TH400, and the 350 does not appear to have the cooling problems that can damage the 400cu inch engine. But does the 350 have other quirks or limitations that prevent a swap in this instance?
It seems, too, that he would end up with a power plant of very comparable horsepower and torque. But what else do I need to know?
I'm a shade tree mechanic who enjoys a challenge, and here's one: A friend dropped off a 1977 Chevy C30 Motor Home for me to look over. He's leaving Wisconsin for Arizona soon, and wanted to know if the beast was roadworthy. She's powered by a 400cu inch Chevy V-8, drives dual rear wheels through a propeller shaft attached to a TH400 transmission, and has 109,000 original miles on the odometer. Her curb weight is a hefty 10,500lbs.
He paid $1500 for it, and the sale included a very complete (and very LONG) maintenance history.
The engine has burned valves in two of the rear cylinders. (Is anyone surprised?) I read that one solution to this is to, during a rebuild, install heads that have added steam holes. Have any of you done this?
And although it is a 1977 model year vehicle, the engine block may have been in storage after it was manufactured. I mention this because it may have been made in 1975 or 1976 when leaded fuel was intended to power the engine, and hardened valve seats may not have been installed. Now the 1977 Owner's manual clearly states that unleaded fuel be used. But leaded fuel would have allowed the valve seats to operate at cooler temps than unleaded fuel. This suggests a snafu that doomed the engine to burned valves.
Any tips on how to prevent a recurrence of burned valves is very welcome.
But I also suggested to him that swapping in a Chevy 350 might be a better fix. It appears I could bolt it right on to the TH400, and the 350 does not appear to have the cooling problems that can damage the 400cu inch engine. But does the 350 have other quirks or limitations that prevent a swap in this instance?
It seems, too, that he would end up with a power plant of very comparable horsepower and torque. But what else do I need to know?
