Which one? At the rate I'm going I'll need to live another 73 years! I'm not really impressed with how many 216 engines are going to scrap because people think they're some kind of fragile antiques. Spray-oiler engines aren't all that difficult to keep running, and with a few upgrades, they can come very close to the performance level of a later model 235. Let's look at some of the downsides to running a completely original 216:
Cast iron pistons- - - -heavy, rough on rod bearings, and they limit top RPM.
Babbit rod bearings- - - -these things are a really good design, and they can be adjusted with shims to maintain close oil clearances, but the old geezers like me who remember how to work with them are getting long in the tooth!
Low oil pressure- - - -Chevy just didn't put a big enough oil pump in the 216, so once the bearings wear a little, the oil pressure goes away.
Rear main bearing rope seal leaks- - - -just like other stovebolts, the performance of rear main seals are mediocre at best!
Now- - - -here's the plan- - - -Machine the rods for insert bearings- - - -not the pricey, scarce OEM-replacement ones; use Massey-Ferguson tractor bearings intended for several sizes of Perkins Diesel engines. They're plentiful and cheap, and it doesn't take much work to make them suitable for spray-oiling. An added advantage is the fact that these bearings have a crankpin diameter .060" smaller than stovebolt connecting rod journals. That "worn out" 30 undersize 216 or spray-oiler 235 crankshaft can be reground for a std. diameter Perkins bearing instead of being welded or scrapped.
Next- - - -bore the 216 for std. diameter 235 aluminum pistons. The wrist pin height and diameter are identical to the 216, and the .062" overbore brings the displacement up to 224 cubic inches. Aluminum pistons are much easier on rod bearings and the engine can rev quicker and run faster without damage or vibration.
Oil pressure- - - -fabricate a spacer about 1/4" thick to fit between the oil pump housing and the cover and run a set of 235 pump gears- - - -about 20% more volume, more pressure, and no problem maintaining 30-40 PSI at cruise RPM.
Leaky rear main seal- - - -machine the block and rear main cap for a full circle lip seal- - - - -no more drippy bellhousings!
Add a HEI distributor if the truck has been converted to 12 volts, or put a Torrington needle bearing into the top of an OEM point type distributor, and eliminate all the top end shaft wobble that messes with spark timing between cylinders.
All the above upgrades can be incorporated into a routine major engine overhaul with only moderately more cost than building the engine like they did in the 1940's! Other than the HEI, the engine will still look original, also!
Jerry
