484/284 cam from MP...any thoughts.?

[Jetstar]

Thinking of using the 484 lift/284 duration Mopar performance cam and lifter combo on my buddies 318,in his 67 Belvedere.Will be using a stock 4 barrel 360 intake,a edelbrock 600 electric choke carb,360 heads,Double roller chain and gears,eventually headers,but for now(moneys tight) the stock exhaust manifolds with duals.Any input on expected idle quality ,or driveability issues that we havnt figured on.Hows about converter stall speed issues?Were thinking of going to 3.91 gears too.This will be a daily driver and dont want to go too far overboard! Thanks

[pishta]

That cam kicked some butt in my 3.91 geared 340, I had good headers and a single plane intake and my Idle was steady and strong at 700 RPM with a 650 carb. It will be a little more radical in a 318, but not much. I would worry about the compression of a stock 318, I think that cam is made for a little more squeeze that 7.8:1

[Kevin Garceau]

Just something to think about. That cam and most of Mopar Perf cams were designed in the 60s. Alot has been learned since then. I would look for a similar size from a new manufacturer. Hell I would look for a bigger one too....lol

[Jetstar]

Was thinking of going also to maybe a 268h comp cams,to get up to date,so to speak.And with slightly shaved 360 heads,figured the compression ratio shud be a little higher.I thought the 67 318 had like 9 to 1 anyway?Im a little evasive on going too big on the cam...this car aint light,and dont want to have to rev it hard to get up in the workable,driveable range.Or a dead bottom end...

[ajmopar]

In a mostly stock 318, a 268 degree cam works very well. It gives a slight lope to the idle, has tons of torque and will rev out nicely. Much better for this combo than the street hemi grind. BTW, I ran that cam in a 360 with stock compression and it was a dog until I cut the heads .060 to bring the compression up, and then it went like hell, so a 318 I would think to be a real pig with it in there.

[cuda66273]

Write this down:

I will not put a Chevy base circle or Asian ground cam in my Mopar.

Now write it down 100 times.

[Dart]

Cuda66273 I assume you are referring to comp cams? I totally agree.

I also call BS on the MP cams being old. The MP cam profiles have a decent rate of lift and are tried and true. The newer version of the .509 and the .484 are kind of cool with the new centerline. Besides I can get the MP cams with the lifters for $125 out the door. The Hughes cams are $150 plus the lifters ($35). No knock on Hughes because they have good products, I just think they are a little overpriced.

[Dart]

I also thought the compression ratio in '67 for the 318 was more like 9.2 to 1, not the 7.8 to 1 mentioned. I agree that the .484 may need a bit more compression. I also think you are better to be under-cammed than over-cammed, so maybe you should think about the .474 or the "Improved Driveablity" version of the .484.

Part numbers:

.484/.284 P4120231
.484/.284 P5007695 (w/improved driveability)

.474/.238 P4452992

[beepbeepsrule]

In general a cam that "big" in an engine that size will move the powerband up in the rpm range quite a bit over the stock 2bbl setup. If you are stuck on using that cam then I think the gears should be towards the top of your list. Especially in that size car with that size engine even with a higher stall converter. Higher stall with 3.23 or 2.94 gears equals higher tranny temps and lots of inefficiency at normal cruising speeds. The 3.91 is a good choice, 4.10's might limit your cruising speed unless you run tall tires. You probably have 2.94 now so even a 3.23 would make a difference. Any mechanical driveline advantage you can give the engine will let it move the car and rev even better. Gears are also "generic", meaning they work with any engine combination you may throw at it later! A good investment with immediate returns in performance.

All that said, a "smaller" cam would probably be your better choice.

[cuda66273]

The only problem with the MP cams is they admittedly farm out the grinding to the lowest bidder which is almost always a Asian shop. We have profiled some of these sticks and the numbers are poor at best...yes they will run OK but there just not the best choice available.

I'd pay Hughes the extra $35.00 anyday to get an Engle over a MP..and what lifters are you getting with the MP cam?

Lifters are a serious consideration .......

We have a limited source on the Johnson lifters still but the supply is VERY limited and we're selling them only with a complete cam kit.

Hopefully they'll last untill the plant get's either relocated or re-opened, maybe by late 2004.

[440Ramcharger]

Listen to Cuda66273.
I have this cam in my 340. See link for info on cam-desktop dyno info.
http://www.moparchat.com/forums/show...threadid=73746
For this cam to work properly, you will have to change gears to at least 3.91, bump you compression up to 9.5:1 (watch the octane of the gas) and get some free flowing heads. My stock 2.02" heads were barely sufficient. You are pushing some serious weight around.
If you go with a Hughes bump stick, you will need to get their springs also, $80 or so. Also stock rockers will not be able to handle any of their slightly bigger cams = enter more $$. The Hughes site goes into this in detail.
My suggestion would be an HE1423 (no bigger) cam. or a pn 4452757 MP stick.
More info
http://www.geocities.com/alwest_83/318.html
http://www.sweptline.com/tech/cam_comparo.gif

[Jetstar]

Thanks to all that replied.After consulting with the owner of the car,and of the actual timing of when and what combo of parts that are affordable right now,such as converter,gear,etc.we have decided to go with the stock 340 grind cam Part#4452782,which we think will present the best drivability and performance that he's looking for.Going to use for now a dual plane stock cast intake,with probably a 650 Holley spreadbore carb that we have.Yes ,money is an issue...and the heads still have to be done,which are 86HP 318 police units...and we still need a gasket set,and a double roller chain...yadda,yadda.....As long as the chamber volume of the HP head is close to the origional heads volume,we shud maintain the origional compression ratio,which is 9.2to1.....Money depending,a shave will bring that up a bit.Oh,the present gear is 3.23,just in case anybody was wondering.Anybody know if theres a diff in chamber sizes? are they close?What do you guys think of this combo for a daily driven land barge?

[rustycowl]

I think you made a wise choice. In the case of street driven cars, less is often more.

[mopower440]

so whats the difference in the new 284/484 from the old 284/484 MP cams? i bought the old version last year, whats the deal with this new one?

[440Ramcharger]

The new 284 .484 cam has a 114 centerline instead of 108. The new cam also has 56 degrees of overlap instead of 68. This equates to better vacuum and better off the line take off from idle.

[Jetstar]

Ram...how much power gain do u suppose we will see out of doing the above mentioned mods to the 318?Im guessing around 275 to 290 horses and possibly 375 torque?Stock with 2 bbl and small heads it has 230 and 340....Thanks for the comments earlier.No low end got owner scared I think...

[platboy]

Okay - I have the Mopar 484/284 cam in my 360 with 9.8:1 comp, intalled at 109 centerline (instead of 108) - is this advanced or retarded?? And what does this do to the powerband?? Cheers, James.

[renee]

Just my 2 cents, I've used Comp Cams on more than one occation and have had great luck. The 268H runs great in a stock small block. I've heard some bad things about MP cams (who really makes them?). I'm currently running a Comp Cams 270S in a 440sixpack and have been very happy!

[LA360Dart]

Hello All;

The Mopar Performance cams as of June 03 were ground by Federal Mogal ( could been ground in Asia ). I'm Hearing a rumor that all new grinds are coming, with newer profiles. Grinder being looked at is a company is Santa Monica.


Denny

[6 packin]

Originally posted by platboy
Okay - I have the Mopar 484/284 cam in my 360 with 9.8:1 comp, intalled at 109 centerline (instead of 108) - is this advanced or retarded?? And what does this do to the powerband?? Cheers, James.

The Cam is retard 1 deg, and wont make a diff on that engine. Retarding a camshaft will move the power band up in the rpm range, giving it better pull on topend, so its taking it from the bottom end grunt. Advancing the cam will do the opposite, making more bottom end torque and running out of rpms much quicker. I know that advancing the cam does help on engines that are being raced on lazy compression like uder 11:1 or so. It builds more cylinder pressure for sure. Muscle Motors recomends running the engines all at 103 thats 6-7 deg advance in most cases. The say yes it may hurt on topend, but it makes so much diff on the take off and 60 ft that is worth it. The only real test is to do this at the track, and see. You wont see much diff in 1 deg, maybe 3-4 deg though.

[mopower440]

Damn, thats lovely, i sure wish i would have known that last year when i ordered my 284/484 cam, sounds like i would like that new one better, so does all that difference take away from the top end any, does it still pull through 6000 like the old one?

[jasontlit]

Jetstar,
I have a hughes he1423 in my 340. Specs are in my signature thing at the bottom of this post.

That size or the next one down would probably work great in your 318.
Dual pattern grind, proper lobe size, lots of lift (relatively speaking), short duration, keeps the power band lower in the rpm range, still has good vacuum, plenty of top end. All the things a mild street car needs.

I didn't go with new springs figuring that the specs weren't out of sight for stock springs already on the head. I may be gambling a bit, but so far everything is cool.

I would have went up one size , but I have power brakes...

[440Ramcharger]

The Mopar catalog rates both 284 MP cams at 2600 - 6000 rpm

[platboy]

Thanks 6packin',

the launch is okay and spins the wheels easily but not what I would call hard. Would it be worth advancing the cam to get a better bottom end (this car will see more stop-light action than the strip)- especially as this cam is not such a torquey cam? (in my limited experience anyway). Cheers, James.

[darren509]

If you want the bottom end grunt, then go with 6PACKIN's advise on going 3-4 degrees. You will definately notice performance gains! If you do this its always good to re-check the PTV clearence, your better off buying gaskets then parts.

[platboy]

Yeah its not a bad idea - once I get it dyno tuned, I'll see how it goes then I might get them to spin it around a few degrees if the torque numbers need improving. Cheers, James.