I decided to ransack a 1993 ramcharger that was almost ready to be crushed, it had it's 5.2 and A-518 laying out where it was accessible so I decided to pull some parts since the roller camshaft question comes up as often as the 'supra head', quench chamber aftermarket head, etc...(hey $15 for a camshaft, roller lifters, keepers, etc... wasn't too bad... the guy behind me in line at the counter who ransacked a chevy got hit for $75 for an HEI distributor!!!)
so I snapped a few pics and will leave this thread open for some discussion so when someone wants to go down the rabbit hole they might have a 'start' at it...
This picture should show with some squinting the difference between the roller lobes on the left, and our 'peaky' mechanical lobes on the right...
Since the roller lifters have to track straight or cause disaster they use a set of 'keepers' to keep then lined up and straight during movement... different manufacturers use a different type of keeper, here's the OEM version that presses into a machined recess above the lifterbores... so in a slant you may either have to drill a stud hole for the keeper, or buy a $$$ set of aftermarket mopar lifters that use a 'strap' style of keeper (the lifters have 'lugs' that are fitted into a slotted keeper strap.
Here's a comparison of a mechanical lifter vs. the hydraulic roller lifter (I have tryed to keep the 'cups' even in the top so you can get an idea of how tall one is over the other...
I know the Cox Bros. offer a machined billet roller cam blank that is... well out of range for anything but a full blown race car ($1200 was the last quote for the 'blank')... Doc had tryed a cast version that was austempered or nitrided as a cheap 'alternative' but ended up with some 'technical difficulty' as well as an oil pan full of cam shavings
A few interesting things I'd like to know if anyone has the answers...
1) what does Mopar make their magnum camshafts out of? it 'looks' like the same stuff the old camshafts are made of (or at least wears the same after 100+K)
2) It almost seems as if one could 'reverse' engineer a hydro roller cam conversion out of a hydro block as long as: a) you used a 'top oiled' lifter(AMC right?) b) put in stand off plugs in the lifter valley to keep them bathed in oil c) rig up a spray bar to keep the lobes oiled as well as the valve tips... which might be too much work for most hobbyists... of course depending on the lobe specification... this might just create a low rpm flat heavy torque band monster....which would be great for a truck and not much use for the rest of the playing field....
Good Luck,
-D.Idiot
