After 14 mounths of collecting parts ,i am starting all over

mopar_mark · Post by **mopar_mark** » Sat Oct 11, 08 1:12 am

Brutus wrote:Gonna be usin a roller in the 572 , street motor too.

Got a roller in my 572

Mind you, lately motor seems more of a pusher than a roller

AllKiller · Post by **AllKiller** » Sat Oct 11, 08 8:28 am

Brutus wrote:Gonna be usin a roller in the 572 , street motor too.

Not takin any notice of Firefighter, etc then Adam ??

Ignore at your peril

Firefighter........
A mild street roller/endurance grind will give up some power vs a race stick but it will live much better on the street. You can get away with 200lbs on the seat and 500lbs open on the valvesprings. The more agressive rollers need some pretty stiff spring pressures to keep the valves stable which in turn accerates lifter wear and increases valvespring replacement. Even a mild roller will require some routine maintenance depending on miles accumulated over the course of the driving season.

Challenger 340.............
Apologies for the questions, just trying to "nail" this application.
RACE Rollers that make REAL power, the trade-off is durability on the street, like there is none,
and,
up to and including the point where it's not IF, but WHEN, ya got an Oil Pan full 'O broken trunions.

What are you looking for ?

Challenger 340.................
The "trick", if your gonna do the street driving thing, is to pay very close attention to "thermally stabilizing" the engine & valvetrain prior to any rpm whatsoever !
Just because the temperature gauge reads 180 F, doesn't mean squat !

If you are determined to street it, Do THIS;
Start it, let it bump and fart around at the 1100 rpm, or whatever, NO RPM !,
and wait until the gauge gets up.
Then shut it down and let it sit for 20 minutes for the Springs, etc., can "heat soak" . Usually a good time to quickly pop the covers and do a lash check.
Then, after it's "soaked", re-warm and go toodling, setting off the neighbors car alarms.

ps; you'll know when it breaks a Valve Spring, it'll miraculously pick up power. Then it's Time to go looking seriously at the inners.

You got a V/spring # you are using, I may be able to help with that for longevity.

Firefighter...............
Steve, your assumption is correct....the agressive roller profiles are spring killers. These types of cams are not designed for extended use at low engine speeds. This was what i was alluding to in the previous post. The rocker arms also take a beating with the big spring pressures and the ICH (Dove) rockers won't last long in a street application. Some guys have reported issues with the Comp chrome moly steel (non rollerized fulcrum) rockers with roller cam spring pressures.

The other wear issue is the needle bearings in the roller lifters. Depending on the cam profile you could be looking at new lifters every season or even less.

For these reasons, my preference is towards a milder "endurance" profile that is easy on parts and will live reasonably well at low engine speeds.

Challenger 340................
OK, I'm gonna speak from the heart here.
Just my opinions, thats it, thats all.
I ain't trying to start any wars, just what 'I think" from my experiences.

Skip the Mechanical Roller, if you're gonna do any street driving at all.

Mopars ain't Chev's, 'nuff said.

Like I said before in another thread, I'm just finishing off a "pump gas" 540 Cheb right now, Merlin 111 & Brodix BB2 heads, and I'm using a "Street Roller" Mechanical Roller Cam profile, that uses springs with a "street friendly" seat pressure of 154# and high 400's # at lift.
From my experience, and others we've done & dyno'd, we'll top 700 h.p.
"It works" !

Now on to my Mopar experiences.
Mechanical Roller Cams, at least the ones that would be similar to the "street friendly" type spoken of above, (that we use in the Cheb's),

just plain don't work sufficiently well enough, in the Mopars we've done, to justify the added expense, parts cycling, and overall eventual grief that we've encountered for "street/strip" engines.

Our opinion, for ANY street driving at all, is that the Flat Tappet .904" dia. Solids available today, can provide equal or better performance in a Mopar, given the precarious Spring Pressures required to really make the Roller "THAT MUCH" Superior.
Comes back to the Spring Rates.
How much better can a Roller Cam be, That uses 150# seat pressure(street frindly) and lower duration @ .050, over a Flat Tappet Solid using 135# seat and big .050 numbers ?
The answer, in my opinion, is "not very much".

Don't get me wrong here, I've used RADICAL RACE Mechanical Rollers on the street, at anywhere between 200#-300# seat pressures, just because I wouldn't use "steriods", and wanted to stay out front.
Those profiles DO make more power, but they just don't "LIVE".
And with Lower "Semi-Race" Mechanical Roller stuff in the 200# seat range, IMHO, it just doesn't make sufficiently more power over many solids, to justify the costs in $ and reliability for the street.
It does make MORE, just not enough MORE, IMO.

In a "nutshell"
I couldn't find that "68364" Crower Spring. It said discontinued. But I suspect from the Cam grind you have, if it was the matched spring, that it's probably around the 200 plus # seat, and a 500# rate ?
If you're intent on a Roller, that Cam setup, imo, just ain't gonna make enough extra power over "half a dozen" Flat Tappet Profiles, to justify the grief I think you'll experience. But the INDY "kit" rockers will survive with it.

If you're intent on a Roller, The only Rollers really worth running, IMHO, are the BIG ones, with the BIG pressures, and they Don't LIVE on the street.
This Comp # 23-708-9. DOES makes over 700 H.P. on a very similar combo to yours with INDY's,
The guy drives to & from the track, albeit thermally stabilized, and easy driven, yearly lifter rebuild/replacement, and 300 run INDY rocker cycle out.

I just "cringe".
Bob

Post by **TyreFryer** » Sat Oct 11, 08 2:48 pm

Roller cam followers were fitted in early Landrovers for durability.

latil · Post by **latil** » Sat Oct 11, 08 3:09 pm

That's right,certainly into the late 80's. I've had the lifter clicking in its bore but never a problem with the plain bearing roller.
I'm currently considering hyd roller cam for my 440 build,as yet I've no idea what to go for. Some lifters don't need the gallery blocking,others do.

What concerns me is the durability of the link bars and their bearings,they all look crudely riveted on the pins.

Dave-R · Post by **Dave-R** » Sat Oct 11, 08 3:30 pm

Just watch out for heavy side loads on the roller lifters. It they have a steep climb up the cam lobe (lots of lift with a fast rate of lift) the side load can wear the lifter bores oval. Not a problem if you only do a quarter mile at a time. But a couple of thousand road miles a year could be a different kettle of fish.

As for lift and duration. Yes duration is the most critical for power as it also moves the torque peak up the rpm scale so you can make more HP. But this is also what makes the engine less and less suitable for street duty.

Lift however does increase power while maintaining streetability. But you only need enough lift to allow the head to flow.
However. Because the valve does not open and close instantaniously the valve is only open wide enough for an instant if you only have just enough lift for max flow.
So you need more than enough lift and also a fast rate of lift so that the valve is open enough on average as much as possible.

If, to make the car more streetable, you need to fit a cam that does not take full advantage of the head flow then you are much better off fitting heads that actually flow less.

Anonymous · Post by **Anonymous** » Sat Oct 11, 08 7:02 pm

Steve , Firefighter is goin Roller, @ least he was on my last post @ DC.Com.

(his stroker build)

Has he changed his mind again.

Edit... oops

, yea Steve ,he's goin solid.

AllKiller · Post by **AllKiller** » Sat Oct 11, 08 7:52 pm

Mild roller waste of time, there are many solids that will out perform it,
streetable - ish

Big roller lots of power, spring pressure and rocker loads etc....un streetable

Go mild roller to say what ?? i have a roller cam ??
then get blown away by a solid cammed car.

Or go big roller and watch the other drive by you on the motorway Hard shoulder.

Advice taken ....up to you

Anonymous · Post by **Anonymous** » Sat Oct 11, 08 7:56 pm

AllKiller wrote:Mild roller waste of time, there are many solids that will out perform it,
streetable - ish

Big roller lots of power, spring pressure and rocker loads etc....un streetable

Go mild roller to say what ?? i have a roller cam ??
then get blown away by a solid cammed car.

Or go big roller and watch the other drive by you on the motorway Hard shoulder.

Advice taken ....up to you

AllKiller · Post by **AllKiller** » Sat Oct 11, 08 8:02 pm

Adam, i meant Pete W

Anonymous · Post by **Anonymous** » Sat Oct 11, 08 9:26 pm

I feel a whole lot better.

Yea Pete W.

AllKiller · Post by **AllKiller** » Sat Oct 11, 08 10:55 pm

... dust pans ready

Well if you ask the questions you gotta take heed the answers or just dont ask
lessons learnt both ways

I asked the question...them above were the answers

Anonymous · Post by **Anonymous** » Sat Oct 11, 08 10:58 pm

Cut them nails Steve.

mopar_mark · Post by **mopar_mark** » Sat Oct 11, 08 11:01 pm

As I was trying to say earlier & better explained by Dave,

Its how fast the the rate of rise & fall that causes the problem, as opposed to the actual lift.

As springs are working harder ensuring the roller is continually tracking the roller, without bouncing as well as maintaining the valve seat shut

Steve, why do you say a Mild roller waste of time, there are many solids that will out perform it,

If I had 2 mild cams with exactly the same profile, one roller the other solid....

Looking at it logically & I know practical & theory can be at the opposite ends of the spectrum...

The roller should have less friction, easier to track, faster to do so ?

As opposed to a solid, which is purely relying on metal to metal & thin film of oil to help overcome friction ?

AllKiller · Post by **AllKiller** » Sat Oct 11, 08 11:07 pm

Mark, i meant out perform it in as...... less hassle and expense over the solid
the roller will make more power even a mild one but still a trade off against reliabilty and stability if street driven

Brutus wrote:Cut them nails Steve.