whats with mp cams

[l8rg8r]

Alright I have been out of the loop for a long time I guess the last time I was building mopars (25 years ago) mopar purple stripe cams were it. Now I get the feeling they are junk or a least a good way to waste a couple hundred bucks so what changed? Why are they no longer the hot cams they used to be? I am building a 383 for my 68 rr bored .030 over 9.5-1 cr. with 906 heads,headers,eddy torquer intake and carter 750 comp afb I was going to run mp 284/484 cam but am having second thoughts what cam should I run with this set up and 3.91 sure grip

[skip68]

Welcome to the site LaterGator,  I mean l8rg8r    I'm sure Ron will chime in soon. This is his specialty    Chuck.........

[firefighter3931]

Alright I have been out of the loop for a long time I guess the last time I was building mopars (25 years ago) mopar purple stripe cams were it.

so what changed?

It's called progress 

The Purpleshaft cams are lazy old school cam profiles that don't perform up to the same standards as today's modern grinds. Engle, Lunati VooDoo and the Comp xehl grinds are all much better. Superior idle quality, street manners and power vs the old MP purpleshafts. 

What transmission....auto or 4 speed ? If auto...what stall speed ? Power brakes ?


Ron

[l8rg8r]

Curently i am using a stock 727 with no power assist on the brakes but going 4 spd asap

[Ghoste]

MP basically sat on the same cams they had developed during the Direct Connection years (maybe even as far back as Hustle Stuff?) and that was fine when all their competitors offered us nothing Chevy cams ground on lobes to fit a Mopar.  But the day they all clued in to taking advantage of Chryslers bigger lifter diameter, MP was screwed.  There has been little budget alloted to MP for many many years and now they lag far behind in camshaft development for the older engines.

[firefighter3931]

Curently i am using a stock 727 with no power assist on the brakes but going 4 spd asap

With a stick and 3.91's you can go a little more agressive on the cam choice. 

I like the VooDoo 268* cam for that combo. 

http://store.summitracing.com/partdetail.asp?part=LUN%2D60303&autoview=sku



Ron

[l8rg8r]

Thanks for clearing that up for me I will take your advice and run the voodo cam

[firefighter3931]

Thanks for clearing that up for me I will take your advice and run the voodo cam

That's a nice cam 


Ron

[l8rg8r]

What should I do with my 906 heads I plan on a good valve grind replace what guides are worn and new springs but witch springs and I know I am forgeting something what else

[firefighter3931]

What should I do with my 906 heads I plan on a good valve grind replace what guides are worn and new springs but witch springs and I know I am forgeting something what else

The Comp Cams #911 spring will work fine with that cam or you can purchase the springs recommended by Lunati.

The 906's won't have hardened valve seats so using unleaded fuel will eventually sink the valves into the heads. To correct it you should have hardened seats installed and use stainless steel valves.

Another option would be to look for a set of the (76-78) 452 heads that allready have the hardened seats installed from the factory and use those instead.



Ron

[moparguy01]

whoa whoa whoa. Did my eyes deceive me? Did Ron actually suggest a cam which isn't a engle?!?!?

[Nacho-RT74]

whoa whoa whoa. Did my eyes deceive me? Did Ron actually suggest a cam which isn't a engle?!?!?

specifically K56 or 58