RonGinger
Well-Known Member
Many years ago I built a 4 cylinder engine, mostly following the PANTHER PUP design. I made it water cooled, so the block and head are completely my design.
It eventually ran, but I had a tough time getting the valves to seal, and I dont think I ever got all 4 cylinders to fire. I ran it at shows for a few years, but it eventually refused to start.
Today I decided its time had come, so I tore it apart
I first tried to measure compression. I made an adapter to fit my car compression tester, but all I got was a needle flicker, no pressure at all. I suspect the total volume of the air in the hose and gauge is much more than the displacement of the engine, so it doesnt read.
Has anyone found a way to measure compression of a 1" bore cylinder?
My valves all show a shiny ring that looks like a reasonable seat, and no signs of any leak spots.
The valves are tight fit in the valve guides. I have read that loosening that fit can make a valve seat better. Anyone have experience with that?
Should I try to lap the valves in, as with big engines? I have heard this causes more problems with small valves because the seat becomes to wide and the effective pressure is to low to seal/
Im thinking about installing the head and using shop air through the spark plug hole to pressurize each cylinder an see if there are any leaks. Has anyone tried this?
Id like to get this thing running again.
It eventually ran, but I had a tough time getting the valves to seal, and I dont think I ever got all 4 cylinders to fire. I ran it at shows for a few years, but it eventually refused to start.
Today I decided its time had come, so I tore it apart
I first tried to measure compression. I made an adapter to fit my car compression tester, but all I got was a needle flicker, no pressure at all. I suspect the total volume of the air in the hose and gauge is much more than the displacement of the engine, so it doesnt read.
Has anyone found a way to measure compression of a 1" bore cylinder?
My valves all show a shiny ring that looks like a reasonable seat, and no signs of any leak spots.
The valves are tight fit in the valve guides. I have read that loosening that fit can make a valve seat better. Anyone have experience with that?
Should I try to lap the valves in, as with big engines? I have heard this causes more problems with small valves because the seat becomes to wide and the effective pressure is to low to seal/
Im thinking about installing the head and using shop air through the spark plug hole to pressurize each cylinder an see if there are any leaks. Has anyone tried this?
Id like to get this thing running again.