rcknrolfender79

Hey guys, just wanting to expand my knowledge a bit with roller cams. I honestly don't know much about them so forgive me for seeming a bit dumb lol. My first question, if I bought a roller cam and lifter kit for my 440 would the stock rockers work fine with it? Or do you have to go with roller rockers as well? I've seen the term hydrolic roller lifters and mechanical roller lifters thrown around whats the difference? I do know that going with a roller cam the biggest benefit is the fact that it takes away a ton of friction, and therefore letting it run a little cooler and it takes a ton of stress and wear off the cam. But is there any power to be gained by going with a roller set up? Also if the stock rockers can be used in place of roller rockers with a roller cam and lifters, is there a big difference between the roller rockers and stock rockers? It doesnt seem to me that there would be enough friction on the rockers that it would make a huge difference.

PK1

A hydraulic roller camshaft valve train uses an oil pressure filled lifter to set lash thru expansion while having a roller bearing on the contact are that meets the lobe of the cam. Most OEM applications now use this.

This GREATLY reduces friction and increases durability. It also allows the rate of opening ( lobe ramp angle) to be increased. So the valve can open quicker allowing for less duration yet obtaining the same realized "open time". This is a plus to MOPAR guys as we have the biggest rollers of the big three. So the ramp can be aggressive without accelerating wear.

You do not need roller rockers when using a roller cam. The two are not required to allow the other to work. You can use roller rockers on hydraulic cam and non roller rockers on roller cam. The latter is still used in OE production.

PURPLE HORONET

If your spending the money on a roller cam buy some good adjustable rockers. That is the first thing I change on any mopars. And this is the number one thing Mopar owners cut corners on.

rcknrolfender79

Thanks guys I learned a little something lol. And Purple Horonet I'm not sure if i'm going to go with a roller or not. Probably will when I get around to it. But I've got a little too much on my plate at the moment to be thinking about doing any work on the engine. I'm still looking for a fender and trunk lid so I can get some paint on the coronet. My Challenger is getting to where its going to need some attention on the body as well. But when I get around to beefin up my 440 I will probably go with a roller set up. Was thinkin about getting some Eddy performer heads or some indy heads a little bigger cam and maybe some higher compression pistons to get the comp up to 10 : 1. Would like to get it around 450 hp to 500 hp at the crank. Just want a really fun street car lol. Which it already is but maybe a little funner lol.

Chryco Psycho

Hyd roller self adjust lash / preload , solid rollers do not either way you will need some type of adjustable rocker to adjust them , most adjustable rockers are roller design & i agree that upgrading them is a must . The hyd rollers do offer better design than the flat tappet & can open & close the valves quicker but are limited by spring pressure which can collapse the valve inside the lifter , meanwhile solid rockers have no limitations as long as you match the spring pressure to control the valve & valvettrain movement . you do need special dist drives & fuel pump pushrods made of bronze to last on the billet cams , the bronze drives do not last very long . The other issue is oiling , rollers need to have adequate oil supply & can starve for oil with a lot of idling , hyd rollers seem to have been worked out by the car companies to give long life .

Moparbob

"

IMO,
You don't need any kind of Roller Cam to attain 450-500hp with a 440 Engine, if that is your goal ?
Pretty K.I.S.S. thing to do these days, akin to childsplay, even with ootb Eddy's, 10 and a bit to 1 Compression, and even a Flat Tappet Hydraulic Camshaft in the high 230's/low 240's @ .050 duration, Performer rpm intake and honest 800 cfm carb(preferably Mech).
Good adjustable Rockers are a must.
Been there, done this 25 times in the last 5 years, and these were the low power engines, all Dyno'd on a Superflow SF902 CRANKSHAFT Dyno.

jacilynn_s

Something nobody covered I'll throw in. Less friction in an engine means less horsepower robbed. This is one of the reasons people use clutch fans normally. I prefer the flex blade fans myself for normal applications.

THe cam is geared as such that the hp gain wont be a huge amount but it still will help over all.

One thing about cams is that many of the aftermarket cams are cut for the chevy/fords even though they are supposed to be fore chrysler. This is a horsepower torque loss.

If you look at an ordinary cam shaft original to a chrysler engine the lobes are more oval where the ford chevy cam lobes are more triangular.

The mopar style cam lobe has less impact on the valves but requires a bit more hp to turn them. Some think this is strictly a duration issue when it isnt. I do know the clyinders breathe better with a mopar cut cam than with a chevy cut cam.

If your going to go with a roller cam I would suggest getting a roller cam with the mopar cut. I unfortantly do not have experience with these myself in small blocks. I have installed them for customers who bought them but I did not myself choose them. I usually go with the 340 mopar purple cam in small engines and magnum cam in bigblocks with new lifters all in the kit.

I have removed a number of cams however because of the"barely running with no power issue" replacing them with magnum cams.

One thing people seem to forget when they build a street car is vacuum. Power brakes and interior controls require vacuum on many cars. The wonky performance cams provide no vacuum in the engine and the vacuum that the booster and control will take, or try to, kill the engine of any power. The fuel jsut puddles in the bottom of the intake and so forth.

While it is a nice idea to run high lift cams for engine power you also have to be aware of the application it is going in to. Moparbob pointed out in another thread that choosing a cam takes into consideration the tires, gear ratio, and so forth for performance. A street car will likely have power brakes and vacuum controls for the heater box and maybe even a cruise control unit. Please keep that in mind.

Note in some performance engines for drag strip we found that even a pcv valve effected the running of the engine to much and had to remove it as the darn thing never closed.

Gorts 5th

jacilynn_s has good points i regret installing the comp cams im running now not to say that it's none functional it function better than any set up to this point great torque/hp. but it's the whole combo.
when i'm able i'm going to swap the cam for a lunati voo-doo cam there 268 cam has more lift than the cam i'm running now at 275 dur.
what i did was installed a chevy grind cam not taking full advantage of the mopar long rods which is way different than chevy

Gorts 5th

i will use a solid flex fan in the summer here in flroida in the winter i swap back to my clutch fan.
i run a large flex fan and boy you can hear it roar.
but when sitting in traffic with the AC running it sure helps...also help's recover from heat soak quicker.

rcknrolfender79

thanks everyone. I didn't know they sold chevy or ford grind cams for mopar. Definitely something good to know! And moparbob someday I would like to see it putting out 450 to 500hp... if it isn't already lol. I honestly don't know. The guy I bought my car from said its exactly how he got it and as far as he knows its a stock motor, that has just had an aftermarket weiand intake, carb, and headers thrown on. Its the quickest car I've ever driven by far. I just bought a 70 roadrunner for resale a couple days ago. The guy put a bunch money into the engine on it. Its a 440 4 speed as well with a dual 4 barrel set up... its running a dana 3.54 as well. Its had the intake and exhaust all port matched. Not sure how big the cam is in it, I'll have to get the papers out and look. But for some reason the car doesn't feel anywhere near as torquey or powerful as my R/T. The R/T would leave this car in the dust with no problem. So IDK. I need to have it put on a dyno and find out where it's running at. They both supposedly have a dana 3.54, at least thats what the tag says. But I think my R/T is lower geared. As the roadrunner feels like its more for the highway than it is for take off. I'm wondering if the 4 speed in my R/T may actually be a granny gear? Would that be a possibility? And would it make a HUGE difference? In the R/T at about 65 mph I'm turning 2,500 rpm in 4th gear. So its not like super low. at about 70 its turning 3,000 rpm... Would it be a better possibility that the gears in the dana have been switched with 3.73's or 3.91's? Or would a really torquey motor make it feel like it's geared lower?

HEMI-ITIS

Picking a camshaft profile is better left to the guys that build these engines and cylinder heads.Especially the guys that do porting and have a head flow bench.It HAS to be looked at as a complete package with the crank and pistons being taken into concideration.Do it right the first time,don't cheap out 'cause that will cost you double down the road.
On my buddys big block,we used a solid roller with lifters that can also provide pushrod oiling.That helps eliminate burnt P/R cups.

Moparbob

Just me, or has there been lotsa questions about Camshafts on here of late ?
I'm wondering if a Ford/Chev Cam Lobes vrs .904" Mopar Lobe discussion might be kinda fun ?
IMO,
I think there might be a lot of mis-conceptions(just my opinion), out there on the Internet regarding .904" specific Mopar Cam Lobe profiles ?

Might be a great way to learn how to get the best "bang for the Buck" outa those .904's ??,
or conversely,
"What" applications they(.904's) provide an advantage over .842" Cheb/.812" Ferd designs, and what applications they provide NO advantage, hence, why some manufacturers transfer "common" lobes onto various brand Cams ?
Are they really "Chebby" lobes on "Mopar" Cams ?

Some concepts in Engine Dynamics for background understanding as we tackle this, before moving forward, might be helpful.

* Where in the Cylinder, does the Piston reach maximum speed/velocity ?
* What determines that Maximum Piston Speed attained between TDC and BDC ?
* What determines how fast the Piston reachs that maximum Speed ?
* What pressure, fills the low pressure area created by the Pistons downward movement ?
* If a 440 Mopar Crankshaft Travels 180* from TDC to BDC, How far does the Piston travel in the first 90* after TDC ? Less than 1/2 total stroke ?, exactly 1/2 of total stroke ?, or more than 1/2 of total stroke ?

Honest to gawd here fella's..not trying to confuse anything here, this is NOT a troll, or I wouldn't go to this extent trying to "open" a valid discussion ?
I just think it may be helpful for many to understand the "WHY" behind doing something ? other than just because so-and-so who's "supposed" to know salesman, says so ?
Everybody wants to make correct purchases, based on "knowledge" right ?
or,
at least ask the "right" questions ?