.484" purple shaft cam question

[lil red]

hey fabo

comp sells a nostalgic purple shaft cam and its specs seem similar to MP's cam but the Mp cam is straight pattern 241 duration and the Comp cam has 239/246

this duration aside does anyone know what other differences there are between these cams - does the comp version offer newer designs in camshaft design such as rate of lift or other design improvements?

I had Comp suggest an extreme energy for a 408 build i've been planning, and just wondering what this line was like

any inputs - anyone use this nostalgic line

thanks gurusrayer:

 

[rumblefish360]

Well, IF the Purple cam was done right, the Comp Cam is still a better choice due to the split duration in helping the exhaust gas in getting out of the engine. The Purple cams have been known not to be cut to well sometimes, there just wacked. Idle quality is normally crummy, the cam has a light switch feel and is peaky in power. Not the best for the street these days. Fine for the track, but better is out there.

Talk to Comp Cams again and ask them about the ramp rate differences between the two lines. While a quicker rise on the ramp will increase power, the difference in a mild street engine is small and you'll never know the difference.

 

[Snake]

Well, IF the Purple cam was done right, the Comp Cam is still a better choice due to the split duration in helping the exhaust gas in getting out of the engine. The Purple cams have been known not to be cut to well sometimes, there just wacked. Idle quality is normally crummy, the cam has a light switch feel and is peaky in power. Not the best for the street these days. Fine for the track, but better is out there.

Talk to Comp Cams again and ask them about the ramp rate differences between the two lines. While a quicker rise on the ramp will increase power, the difference in a mild street engine is small and you'll never know the difference.

I beg to differ its all in the tuning,my 360 with the 280 474 MP works perfect with 11 inches of vacuum.

 

[lil red]

I noticed that MP lists the comp purple cams in their catalog...

 

[rumblefish360]

Don't beg! LOL! Just playin Snake.

Snake, I first have to say, the cam is small and it should be fine for the street.
Second, It sounds like you have it all dialled in.
3rd. I think the cam cut on your cam is probably a good cut. I myself can not complain on my 3 purple cams that I have used.
4th, seldom do I see a single pattern cam out perform a split. Actually, never have. All though, a split isn't always the perfect cam for every application and a single pattern cam can be just as effective as a split pattern cam.
The better the balance between the intake and exhaust flow of the head, the less of a split pattern cam is needed to maximize an engines output at a given cam spec or performance level. A very well ported head with a better than normal balance between ports can use a single pattern cam. Also, a split cam will really perform no better than the single pattern.

As long as the cam is correctly ground, you'll be fine. As of late, MoPar cams have come under fire by a few that have taken the time to measure them carefully and correctly. MoPar cams are also not the only cam to not be properly ground. In fact, no company is exempt from crap grind work to out right **** up's. Non, bar non from this.

 

[lil red]

thanks Rob...good responses

I run a smaller MP now (.450/.455) in my 360 and was always told years ago that they were the cams to use in mopars , not chevy grinds

its been a few years, but it seems that other manufacturers seem to have produced a superior mopar camshaft

 

[skrews]

The MP cam specs are incorrect.
Claimed specs are
284* adv. Actually measures 294*
241* @.050 Actually measures 238*
duration @ .200 is 143*
.484" lift Actually measures .480" (not that 4 thou is something to cry about)
108 LSA is correct, cam installs at 108 dot to dot (in the motor I tested in)
This lobe profile isn't even aggressive for a .842 lifter motor. The only advantage is that milder profiles are easier on parts and will turn RPM with less stability issues. I think the quality is hit or miss. MP is probably farming their cams out to the lowest bidder. That being said they were a good cam back in the day and still work fine, there are just better grinds out there now. You don't hear the Chevy guys using the Duntov cam anymore because of the same reason.

 

[moper]

This lobe profile isn't even aggressive for a .842 lifter motor. The only advantage is that milder profiles are easier on parts and will turn RPM with less stability issues. I think the quality is hit or miss. MP is probably farming their cams out to the lowest bidder. That being said they were a good cam back in the day and still work fine, there are just better grinds out there now. You don't hear the Chevy guys using the Duntov cam anymore because of the same reason.

x2

 

[MopaR&D]

What kind of springs are recommended for the 284/484 cam? I have one lying around and was thinking of swapping it for the small voodoo cam in my 360 but I don't know if the current springs are too stiff

 

[K.O. SWINGER]

Split profiles have been around for ever but ramps on the purple plus are little more aggressive may come on little quicker but some very good cam grinders dispute the need or advantage of a split pattern cam in a good breathing motor

 

[Gator]

All I can say is I love my MP .509 purple cam in my 340.. That BB screams once the rpm's hit 5500...