Stovebolt.com Forums The Shop Area The Engine Shop Question for the engine design gurus- - - - -

What's the chance that roller lifters would run on a (new) stovebolt camshaft without damaging the lobes? I realize the lobe lift curve would look a little oddball- - - -just wondering if the combination might "Gee-Haw" without causing a major disaster of some sort! That would certainly solve the "ZDDP in the oil" problem!

Edit: It looks like a hydraulic roller lifter for a late-1990's Dodge 3.8 Liter V6 will fit the stovebolt lifter bore if the bore is sleeved down to a .904" diameter. With a little tinkering with pushrod design, I believe I can come up with an ultra-quiet engine that never needs a valve adjustment, and one that can run modern motor oil to boot!
Jerry

Which camshaft, Jerry? That engine used a retainer appliance to keep them from rotating, didn't it?

I've got a couple of used 235 cams to use for mockup purposes, and it will be fairly simple to fabricate an alignment fixture to keep the rollers aligned with the lobes if the OEM fixture can't be adapted to a stovebolt engine. Eventually, I plan to use an Elgin or Melling solid lifter cam to gain a little extra duration from the clearance ramps on the lobes. I'm also tinkering with the idea of fitting an external oil gallery to 216's and early 235 blocks to allow hydraulic lifters to be used on those engines.
Jerry

I have been trying to remember, but I think those used a dogbone-looking collar that sat atop the lifters to keep them from turning. But I probably need to look, Jerry. I could be off-base on that. This sounds like a good idea and definitely would help.

This sounds like a very interesting idea!

You could use a degree wheel to see how the roller lifters change the valve event timings of the original flat tappet cam profile.

The material of the original camshaft may or may not be a problem. I would imagine with the conservative lobe geometries and low valve spring forces, you might get away with running roller lifters. Here is a link to a video I found that might help:

Cam Core Materials [youtube.com]

If you mock this up, please share.

David

I'm in the process of incorporating all sorts of modifications into the "Frankenstein 216" I'm building, so by the time I'm done, about the only things that will be original will be the block and the cylinder head. That one's intended to be a "Sneaky Pete" engine, with the outside appearance of a bone-stock 216, but having almost all modern internal parts. I believe I can get it up to around 260 cubic inches while maintaining the outward appearance of an unmodified 216. To run hydraulic roller lifters in a 216 block, it would require an external oil manifold to supply oil pressure to the lifters. A late model 235 with a drilled oil gallery would be a lot simpler to modify for hydraulic rollers.
Jerry

I've got one of those here, Jerry (1956). Just a matter of getting it over to you.

A neighbor who sold his farm and moved away left an early-1960's 235 engine behind. The current owner of the property has given it to me- - - -I just need to go pick it up! If you happen to head east anytime soon and have room to haul that block, I'd love to have another one to tinker with, however!
Jerry

A gentleman in the LA CA area a few years ago built an outside manifold on a GMC 302 to run juice lifters. Don’t how well it worked, though.

Ed

As long as an external manifold gets plumbed to the main oil gallery with a big enough hose or hard pipe, and the oil pump has sufficient volume, I doubt if whether it's inside of outside the block will make much difference. Dry sump oil systems keep NASCAR engines alive at 9K RPM or so. "You can't do that" usually means "Nobody's done it yet!"
LOL!
Jerry