HEMI Tech: Camshafts.. new? Regrind? solid or Hydraulic?

Unfortunately (or fortuneatly) I scored a new-in-the-box set of LA Rollers for $100, so I'm pretty much commited to them. Heres a picture of the High Deck DeSoto engine that went into my Avitar. You can get an idea of where the slot needs to be cut to get the lifters/connecting link to drop straight down. It doesn't need to be a great huge chunk...just a slot. The 291 I'll be using is a low deck...that's why they won't slip up and over/into the lifter bores...

 

Shifty, read throught this other stuff and you'll find a pic of the side-by-side in post #23 IIRC

http://www.jalopyjournal.com/forum/s...d.php?t=335727 <!-- / message --><!-- sig -->

It looks like this, on the right is an original HT 812.


My question is why MotherMopar used such a large oil feed 'groove', I will assume that there is a need for alot of oil...

Gary

.

 

My best guess is that the oiling system for the top-end changed. I believe that before the magnum series that the oil to the top-end was passed from the deck, through the head to the rocker shafts (like an early Hemi). This means that there was no oil passed via the pushrod - so a little groove worked fine (didn't need a long groove to give enough time of the oiling hole to move the oil volume).

On the magnum engines the oiling system was changed to be like a SBC - lifters fed the pushrods, which fed the rocker system. You need lots more oil volume in this later setup.

Hope this is correct - makes sense to me!

Dale

 

That's a great idea Budd...I hadn't thought of that!!


Thanks for the side by side pics of the lifters 73RR!!

So since the Hemi is still oiled throught the rocker assembly is it really necessary to modify the lifter oiling holes or the lifter bores in the hemi? There should still be sufficient oiling for the hyd. roller lifters?

 

Just my 2 cents worth but I have not heard anyone mention Jerry Cantrel at Schnieder Cams (619) 297-0227 he built us a great cam.
As for Neilson's in Utah they made our roller rocker and they are a great piece too.Forgive me if I misspelled any names you will still get my point.
All our stuff is for a 392 but these guys make them for the 354 I am sure. I am not aware of how they swap with the 331 stuff, sounds like you guys know that better.

 

I talked with my core supplier today about getting sets of roller lifters-links and spyders. The supply is somewhat sporadic but they can be had for about $150 + freight. PM me if there is any interest.

Gary

.

 

Hey 73RR, I might take you up on that !

It appears the Magnum lifter/spider can be made to work in the tall deck Desoto with some spider mods.

My question is, will OEM new/rebuilt hyd roller lifters take 380-400 lbs of pressure on the nose and 130-160 lbs of seat pressure ?

Internally, are the lifter components up to it?

Thats what my concern isotherwise it looks like a feasible swap that will cost waaaay less !

Your thoughts?

Rat

 

Rat, although you are looking at a pretty stiff spring I would think that the internals of the roller unit are up to the task. It would not be alot different than asking the HT2011 lifter to do the same job (and we do...) and it is oem for such engines as a 273-318 with fairly soft springs.


Gary

.

 

You'll be changing rockers, pushrods, and rocker shafts on a regular basis with that amount of spring pressure. Unless this is an all out race engine, I'd investigate a bit weaker spring and a rev limiter.

The rockers will tend to gall and the pushrod ends will wear right into the oil feed hole if you put some miles on the engine. Wind it up once or twice and you'll be swapping out parts.

Been there, done that, wiped out two lobes on the cam now I run weaker springs and a rev limiter.

 

Hey Desoto,

Did you have problems with a hyd flat tappet or a solid flat tappet? Was the cam new or a reground original with a smaller base circle?

BTW, the late model roller lifters oil thru the pushrod. By using a non oiling pushrod, Im guessing this will prevent oiling to the rocker/shafts.

Will this adversely affect the roller lifter's operation?

Anyone know where the cheapest place to score a set of hyd rollers, the lifter spider/yoke and the lifter link bar ? I know a there are OEM parts sellers but can anyone recommend someone? Im interested in trying the later model setup as its cheap, parts are easy to get and the mods red to retrofit are'nt difficult.

Anyone?



Rat

 

It was a roller cam. a brand new solid lifter roller tappet cam. I ran stiff springs for years and was constantly swapping out pushrods, rockers, rocker shafts (hard chromed shafts) and rockers. I eve had to replace a couple of lifters then I lost a couple more and they took out the cam.

Crower welded if back up and reground it and I dropped my spring pressures down and I use a rev limiter. Haven't had a lick of trouble since 1994 when I dropped the spring pressure.

 

BTW, You HAVE to oil the rocker safts or the rockers will gall on the shafts, especially with higher spring pressures.

 

Rat, a proper fitting pushrod will close the oil flow at the lifter (and your rockers get oil through the head). The lifter will continue to operate like a normal hydraulic.

...used magnum parts are available, see earlier post #186.

Gary

 

This is a great thread - thanx to all for puting in !!

Yeah Gary thats what I thought. Good news ! What size is the pushrod cup on the OEM rollers ? Im guessuing 5/16", do you know for sure?

Desoto, this is why I dont want to run a solid roller on the street. Even "street" solid roillers have ramps that need decent spring pressure and it pounds out the needle bearings on the roller lifters. Seen it before in many other engines, esp ones that are idled a lot on the street - no dice.

Rat

 

The stiff spring pressures weren't a problem when the revs were kept below 4,500. It's when I occasionally reved to to 6.200 that I'd wipe out a rocker or two.

I'd blast out of a toll booth and within a hundred miles, I'd have a noisy tappet. Pull the valve covers to check the lash and the pushrod would have eaten it's way into the rocker (the adjuster nut would be up against the rocker because the end was worn off) because the rocker was galling on my hard chromed shafts. I learned to keep my foot out of it most of the time.

When I fially lost both lobes on #7, I dropped the spring pressures. Now the rev limiter is set for 4,500 to keep the valves from floating and I haven't had any issues at all with the rockers in 89,632 miles.

In the 143,000 miles before that I replaced close to a eighty rocker arms and pushrod ends, as well as half a dozen rocker shafts. (That's why I have drawers full of disassembled and cleaned rocker assemblies) It was, almost always, an intake rocker that'd gall, BTW.

 

BTW, we never had that problem on the AA/FD I crewed on in the sixties but we tore the engine down every other Monday so stuff like that got replaced before it caused problems.

 

I'll check and report back.

Gary
______________________________________________________________

 

Frank, sorry that it took so long, got side tracked.... 5/16" dia.


Gary

.

 

Thanx for that 73RR !!

Lets keep this thread goiing 345 Desoto, post up your progress with those rollers when you get back end of April !!

Rat

 

Wow, that's lots of parts, but 4,500 RPM doesn't sound like much fun . . . why not put a milder flat hydraulic cam in there and rev it normally?

 

sounds like there might be some oil starvation issues or impropperly set clearances if rocker assemblies and push rods are committing suicide at a very mild rpm. however if the Rome are being pushed with a rev kit, that could potentially be a source of the mess as well. after a few nights of lost sleep and a few PMs to a few other hambers I think I'll be going with a solid flat tappet cam and exercise it's capabilities to the best of it's abilities with the supporting engine components and modifications.

 

I drove it for 28 years with masive torque and horsepower and RARELY used it (the excessive horsepower) yet I spent a LOT of time keeping it operational.

Now, I still have the torque and have the dependability I can live with. I can jump in the car on Sunday morning in Loisville, KY and be home (outsde Boston) Sunday night. That's a 1,000 mile trip in 15 hous and I don't have to pull the valve covers off and adjust a few pushrods. I can live with that.

 

BTW, 4,500 rpm is where my bought-new '68 GTX ran out of steam, too, because that's when the hydraulic lifters started breaking down so what's so bad about 4,500 rpm in an engine that produces a ton of torque?

 

Just in case I missed this link...

345 DeSoto has some great roller application info brewing for Desoto engines! Check it out HERE:
http://www.jalopyjournal.com/forum/showthread.php?t=335727

 

Can any body suggest who grinds and or supplies hydraulic roller cam and lifters for 392 hemi, want it for blown 392 with electronic injection

 

Herbert Cams can grind a cam them for Chrysler and Desoto Hemis. Check out the thread link posted above by Scooter.

Rat

 

Lifters Important info 1/2 way down the linked thread.

 

If I'm not mistaking all Chrysler lifters have .904 body this also includes AMC. The LA hydraulic lifters will drop in but the block has to be machined for the guide plate or aligning yoke retainer. The aligning yokes have a small arrow that points toward the cam. Now what I'm not sure of is if the yoke retainer needs to be modified for the early Hemi, that will become apparent on installation. The down side to the LA hydraulic rollers are they are not high performance pieces so spring loads cannot be too high and unfortunately I do not have any parameters on spring pressures for these. If I come across any info I'll pass it on. The other info I wanted to share is the motor oil you use. The new API service has forced oils to be blended with out the adequate amount of zinc, phosphorous and oil soluble molybdenum which makes up the wear additive. This is a concern because cam, lifter, rocker arm and pushrod failures will occur in the older engines.

 

I don't know if this is the right place to put this, but here goes. I have a new, unused, Herbert (Chet) #7 roller cam which is (was) for a 276/291 DeSoto. I sent it to Donny Johansen and had the snout cut off, center drilled for a retainer (cam gear) bolt, and polished. Had this done so I could save 4 1/2" (and a bunch of lbs) off the front of the engine to use a mechanical fan (55 291). I'll be using a Hot Heads aluminum chain case cover/SBC aluminum water pump. I had NO idea what I could use for a timing set...other than spend $150 to have a sleeve pressed on the end/new key way cut to use some other whizz-bang ($$$) timing set. Well, I started playing around with the old stuff that came off of my stock cam. Parts included the fuel pump eccentric, cam gear, cam gear spacer, and a special dowl that held all three pieces together, and indexed the cam...the dowel being the key part. The spacer with the key way goes onto the shortened cam snout, then the cam gear, then the dowel. The eccentric, needless to say isn't used. The entire thing fits like Factory under the cover...eliminating about $200+ worth of expense. The dowel needs to be shortend a slight amount, and a tack weld on the end to retain it, which the eccentric did. This might be old news to some, but to me it's a revelation...

 

Tony, Just make sure that your washer laps the sprocket by a wee bit and your set.
Man, nothing like saving money!!


.