The Stovebolt Site Forums The Shop Area 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

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

You will need heavier valve springs to hold the heavy lifters to the cam, will the valve train take the extra pressure? Seems to me you could buy a lot of oil additive for the price of machining and adapting you are looking at. For those without a machine shop on hand, the price will go up pretty quickly.

At the RPM most stovebolts are operated, I doubt if a little extra lifter weight would be a factor, especially considering the fact that most of the snowflakes get a case of the vapors at any speed above what used to be considered a fast idle. I'm aware that most stovebolters don't have machine tools or the skills needed to run them, so a lot of what I dream up isn't practical. It's just an exercise in what's possible, given enough time, energy and skill to think outside the box.
Jerry

Jerry, the fella that did the exterior manifold was most likely Gene Beck, I had a nice long conversation with him a few years back. As far as cams, Howards cams, which isn't really howards cams anymore, it was named after Howard Johanson, (you may already know this) but has been sold to someone else, but they can get you in touch with his son, who a couple of years back could get blank cams for the large bore cams, which I'm thinking could be sent to Delta cams to have the lobes ground to a more suitable profile for rollers. I may be wrong, but I'm thinking there is plenty of meat in a 216 to cut the cam bores to fit the large bore cams.

I do it the other way- - - -I use my lathe and tool post grinder to reduce the diameter of the big journal cams to fit the 216 block. I've fitted a couple of 235 cams to 216 and early 235 blocks that way, and it's a fairly simple process. I use a carbide cutter bit to rough out the journal a few thousandths oversize, and then surface finish the journals with the grinder, and do a final polish with emery cloth. I'll be using the Melling CCS-1 cam in my prototype. If dyno tests look promising, I might commission a custom grind cam for a later engine. I'm looking for good low end and midrange torque, as attempting to get high RPM performance from a stovebolt with its stone age port design is a fool's mission. The Ford 300 or the International/Jeep 4.0 Liter head would be a much better candidate to use as a starting point to make a hotrod inline six.
Jerry

yes, I went that way, but I had to have the cam reground because it wouldnt' fit through the last hole. Just as an idea, some form of supercharging seems like it would overcome the intake port issues.

Were you using a stock cam, or a high lift regrind? The ones I've reworked have dropped in without a problem so far. One way to avoid that problem would be to install the last bearing after the cam was partially in place.
Jerry

it was a brand new cam, which started my relationship with Howard cams, when I had ordered it, I told the fella what I was doing and he said he would take extra off the back so it would fit, but it didn't. I don't recall what the grind was, it was some sort of performance type cam, but it ended up costing me a fortune, and then when I sent it to Delta to be ground to fit, (one of the parts of the cost) they lost it and I ended up with one that had been ground at least twice, the lobes were just itty bitty, which is why I was thinking about the larger lobes. It was a very frustrating period.. Then the exhaust valves seized up in the guides, and ruined a couple of the lobes, so I had to get ANOTHER regrind. Had to pull the head AGAIN. But as an aside, during my research, I found that generally roller cams are steel, and very hard as the point of contact at the peak of the cam is pretty small.

Yep, nothing bumps the frustration level up like repeated screwups on the part of somebody who supposedly knows what they're doing. That's one reason I just bought two crankshaft grinders! I got one parts machine at less than scrap metal price, and the other one in complete, running condition. It looks like the first one has less wear and tear than the one I got from a NASCAR billet crank builder! I just couldn't find anyone who was willing to grind cranks "my way" without demanding prices that would make Jesse James blush in shame!
Jerry