VCCA Home Forums TECHNICAL - 1945 AND NEWER 1949-1954 Mystery Truck: generator/regulator this time

Your 216 engine bored out to 235 piston size makes it a 224 engine. This combinationwas used in Canadian Pontiacs years ago.
Were the pistons cast iron or aluminum?

Thanks, Gene, the pistons are aluminum and have a letter on the front side indicating the front side of the piston - the oldcarmanualproject manual doesn't tell me if the orginal are cast iron. I see a lot of cast iron pistons and cylinder liners in old Allis tractors.

Were the pistons in '50 cast iron?

HS

All 6 cylinder Chevrolet engines had cast iron pistons through 1953 - except the 1953 Power Glide car engines....and they also had full pressure oiling. Many rebuilders used aluminum pistons. The 1953 and up aluminum pistons can be used in the 1941-53 235 engines. Using the Chevrolet brand of aluminum pistons in the engines that had cast iron will raise the compression ratio about .4 becuse they are slightly taller.

Gene what do you mean by full pressure oiling? Mine is a dipper oiling for the rod bearings.

HS

Full pressure oiling refers to the rod bearings being oiled under full oil pressure. The crankshaft has passages leading from the main bearings to the rod bearing journals.
With this system the rod bearing receives oil for the complete revoultion of the carnkshaft, not just at the bottom of the stroke. Works much better at high engine speeds.
Most engines had full preaaure oiling back in the 1920"s. For some reason Chevrolet stayed with the "splash" system (it was cheaper than drilling the carnkshafts)....The Model Ford had splash as well as the Hundson 6 Cyl up to 1947 and the Hudson 8 Cyl till 1952. The Hudson lubrication system didn't even have pressure to the main bearings, they were gravity fed (like a 1929 Chevrolet).
The Chevrolet system worked OK as long as the oil pipes in the pan were clean and aimed properly at the dippers. Above 3500 RPM it became iffy so has higher speed engines came along it was switched to pressure.
I have driven splash Chevrolet engines since 1949 and never had a problem .

I mis-read your previous post and believed you were saying that the Chevrolet engines were all full-pressure. The rod dip system at high rpms is iffy because all the oil is flying around in the crankcase and "they ain't none fer dippin'" ! A good argument for slowing down every once in a while....

HS