Inliners International Forums General Discussion Swap Meet Chevy 216 camshafts

Good evening! I'm looking for regrindable camshaft cores for Chevy stovebolt 216 engines. The 216 had a forged steel cam, and a custom cam manufacturer in California tells me he can regrind steel cams for use with roller valve lifters. Cast iron cams won't make the cut. I'm in the process of designing a couple of bored and stroked stovebolt engines based on the 216 that run MOPAR big block roller lifters in slightly sleeved-down lifter bores. I'm elininating the rocker arm shafts and rockers, and replacing them with stud mounted roller rockers for a big block Chevy V8. The engines will end up with as much as 258 cubic inches with aluminum pistons and H beam connecting rods, and a compression ratio around 9.5:1 in an engine that looks like a completely stock 216 from the outside. I'm expecting to get around 150 HP, nearly twice as much as an original Babbit-rod spray oiler 216. Please PM me with availability and price if you have a 216 cam that's gathering dust on the shelf. Thanks!
Jerry

I wish you had posted this a month ago. I have been helping a friend's family sell his stash of 216-235 engines. No one here was interested and at least a dozen 216 cams went to the scrapper.

"OUCH"!!!!!! The 216 cam can also be made to fit the later model 235 or 261 engines by shrink-fitting a sleeve over the bearing journals and machining/grinding them to the larger bearing diameter. A roller cam/roller rocker arm "261" of around 300 cubic inches is also on the drawing board, using pistons for a 231 Buick/Olds V6 engine. Those pistons are available as hypereutectic, or even forged variants for the turbocharged V6.

I just made a commitment to buy a bunch of spray-oiler engines, 216's and early 235's that will have those cams onboard, from a guy who is downsizing his stash of parts. One engine has the updraft intake manifold and corresponding exhaust manifold used on cabover trucks, if anyone is in the market for that item.
Jerry

This is fun to think about. Just when you think an old engine is dead something pops up. Someone still pushing the boundreis, Thanks.

I have at least two steel camshafts cores in my garage. I am northern Ohio.

Curious to hear more about this roller conversion you describe. The original lobes are not centered on the lifter bores (to promote rotation of the solid lifter on lobe). Does the sleeve center the lifter over the lobe?

No, the sleeve reduces the diameter of the lifter bore slightly to match the smaller diameter MOPAR lifter body. A flat strut between the intake and exhaust lifters keeps the roller aligned with the lobes. The roller is narrow enough to ride fully on the slightly off center lobe. Running a roller lifter eliminates the concern with the reduced level of zinc additives (ZDDP) in modern motor oils intended for use in roller cam engines. The rotating friction of a flat tappet cam and power loss associated with a sliding, rather than a rolling motion of the cam and lifters results in more usable power being delivered to the flywheel. There is also no "break-in" required for a roller cam, and a greatly reduced risk of cam lobe failure during the initial run-in of the engine.

On the top end, I'm using stud mounted roller rocker arms designed for a big block Chevy V8, with a 1.7:1 ratio- - - -which increases the total valve lift without needing a radical camshaft lobe shape. Higher lift promotes better low end torque, since the stovebolt manifold runners and port shapes pretty much make high RPM impossible. The really nice thing is that all these modifications are invisible from the outside, making an engine with almost 40 extra cubic inches and more torque a "sleeper"!

Please send me a PM if you'd like to give those 216 cams a new home. Thanks!
Jerry

Would love to see some photos of the valve train conversion. Are you adding bar-stock on top of the head to retain the studs? Never wrenched on Mopar. Is the distance between the push-rod and valve stem similar to the stovebolt?

I'm using a piece of rectangular steel bar stock instead of a rocker arm shaft to mount the roller rockers. The spacing from the rocker arm pivot to the valve stem is set by the length of the long end of the rocker, and the pushrod hole in the cylinder head is slotted to allow a slight tilt of the pushrod to align with the short side of the rocker. Pushrods are custom made- - - -3/8" seamless stainless steel thick wall tubing with ball ends to match the sockets in the lifters and rockers. Valve lash is adjusted like any other stud mounted rocker, with long nuts and Allen set screws. If I can figure out how to add photos to this site I'll post some pictures.


Jerry

Is that rocker the right ratio?

The original stovebolt rocker is close to 1.5:1. The 1.7 allows for more valve lift without radically modifying the cam lobe. It might be necessary to flycut the piston crown a little, but the piston I'm using has a dish top, so the cut into the piston crown will be minimal. The compression ratio with the stroker crankshaft will be around 9.5:1. About the only thing original about the engine will be the block and head castings and the timing gears. A "216" becomes a 258, A "235" goes up to 270, and a "261" gets 300 cubic inches. Externally the engines look completely original- - - -single carb and exhaust, even!
Jerry

Very practical approach to getting the rocker studs parallel to the valve guides. Canted push rods remain a head scratcher for me. On a flat tappet cam they inhibit rotation which creates excessive wear on all the mating surfaces. Roller rockers eliminate this wear but don't address the dynamic 'bending' of the rods during lift. As RPM increases the lifter's acceleration will flex the push rod further. Curious.

Stovebolt valve springs have approximately the strength of a Sealy Posturpedic innerspring mattress, and we're talking about an engine that will be lucky to see 5K RPM at most. It's not going to race Formula 1 at 12K! The pushrods will be 3/8" diameter .060" wall thickness seamless stainless steel tubing, not the 1/4" solid soda straws Chevy ran for about 3 decades. Everything in the modification is 300% stronger than it really needs to be, so I don't have any worries that it will self-destruct as long as I can make it work on paper before I start whittling on metal. The BBC rocker arm is not quite long enough on the "short" side to end up directly above the lifters. Look at the pushrod cant on a MOPAR 426 hemi sometime- - - -I've built a few dozen of them for the 4WD truck pullers in my area. The most recent one I built was 547 cubic inches, the block cooling passages were filled with epoxy, and we only ran coolant in the aluminum cylinder heads.

Not my first rodeo- - - -I'm the middle guy of 5 generations in the automotive business from my grandfather in the 1920's to my grandson who is a line mechanic working six days a week after getting medically discharged from the Marine Corps from serious physical and emotional injuries in the sand box. Dad was winning 1/4 mile dirt track races with an alcohol-fueled flathead V8 in a 34 Ford 3 window coupe in the late 1940's. I taught auto mechanics in Tennessee state trade schools and high schools for 30+ years, and built round trackers for a little over 30 years before I "retired" in 2011.
Jerry