Mancini's Purple Shaft cams

[bigbluedodge]

Has anyone used or heard anything (good or bad) about the Purple Shaft grind cams that Mancini lists? Interested in a .590 flat tappet or equivalent to duplicate past performance out of a 440 with iron heads. Just saw them on their website.

Bry

 

[BeepBeepRR]

I purchased one they told me 4 weeks out I waited 3 months and still no word. I gave up and got a refund.

 

[PRHeads]

I can’t offer any insight about the Mancini cams, but what was the previous combo and performance you’re trying to replicate?

Another consideration might be, what does anyone actually have on the shelf, or what are the lead times involved if they don’t have one on hand?

 

[mmissile]

Cam/valve-train technology has changed since the 70's. More power, smaller cams. Less parts breakage.

 

[BeepBeepRR]

I ordered the 284/484 Mancini Racing PurpleShaft Cam & Lifter Kit The site doesn't say they are in stock and also doesn't say they have to get them custom ground I assume per batch. But Anyhow I wanted to do business with them but I think 3 months for a cam and lifter set was being very patient. Honestly a got a little pissed with them. I would suggest call and confirm in stock availability. Their number.... 1-800-843-2821

 

[bigbluedodge]

I can’t offer any insight about the Mancini cams, but what was the previous combo and performance you’re trying to replicate?

Another consideration might be, what does anyone actually have on the shelf, or what are the lead times involved if they don’t have one on hand?

OK, the story is this: My son and I pulled a much higher horsepower engine out of this car to use in a chassis car that he is building. The engine with these specs is on an engine stand in my shop with a Bullet cam installed for my Charger. It's fairly mild and designed for a slightly heavier car with a 4000 stall converter:

pocket ported heads big valves 214 181
TRW 2295? 11 to 1 pistons 030 over
M1 intake
850 Holley
h beam rods (Scat, if I remember right)
camshaft: .502 lift 255 duration at .050


The car is:

68 Barracuda coupe
Car weight :3294
Dana 60 430 gear
727v
Caltracs

This engine is identical (in fact, the same heads, intake and crankshaft) to one that was in this car in the past with a 590 flat tappet cam. At the time, the car had a j converter and super stock springs. It went 6.75-6.80 in the eighth. This what i'm trying to get back to. The reason the .590 is attractive is I know there would be no piston interference at this level and the engine didn't have to spin very high to perform.

bry

 

[PRHeads]

That’s interesting you had no V/P clearance issues with the 2295’s and the 590 cam.

Years ago I went thru a 446 that had 2295’s in it along with a 590.
It was running ported 346’s with bigger valves.
Most of the exhaust valves were bent from contact with the pistons.
I don’t recall what the clearance was, or where the cam had been installed…… but I did end up flycutting the pistons before putting it back together.

I built a 446 close to 20 years ago using the Diamond domed piston that they used to offer as a substitute for the 2295’s.
It had a better valve pocket situation(and was lighter).
In that engine I used a Comp 23-632-5(264/270-108).
It had ported 452’s, an RPM intake, long fenderwell headers, and an 850 Holley.
Made about 540hp and ran like 10.80’s at 3500-ish.

Eventually the heads cracked and started leaking water, so they got replaced with some std port EZ heads.

Heads got swapped with the engine in the car, and it picked up a couple tenths.

If you have enough valve spring to handle it, a Howard’s 722422-08(or the Hughes equivalent) would be a good option too.

 

[bigbluedodge]

Thanks PRheads for the advise and or experience.......not to mention the seed of doubt about getting away with valve piston clearance!

bry

 

[PRHeads]

If you end up with a cam in that same size range, I’d def take the time to check the V/P clearance.
Obviously there are plenty of variables between different engines(deck height, head milling, how deep the valve job is, what size the valves are, valve margin thickness, where the cam is installed, etc), but it’s nice to know what you have before firing the engine for the first time.

 

[bigbluedodge]

If you end up with a cam in that same size range, I’d def take the time to check the V/P clearance.
Obviously there are plenty of variables between different engines(deck height, head milling, how deep the valve job is, what size the valves are, valve margin thickness, where the cam is installed, etc), but it’s nice to know what you have before firing the engine for the first time.

Oh yes. I have check springs ordered (always before I used clay) since I would prefer not to remove the heads.
Since a purple shaft is not available, it looks like I'll wind up with a .600 lift, approx. 270 @ .050 from someone. I've used Ultradyne in the past.
Thanks again.
bry

 

[RemCharger]

A comp cam .585 310 is very close to the
590. Not sure if they still make them, but they were good grinds and good quality.

 

[1danc]

Gasket thickness - Plas-t-gauge - always check the 4 corner pistons minimum , not worth the risk - check ️ or check $$$

 

[1KoolBee]

Has anyone used or heard anything (good or bad) about the Purple Shaft grind cams that Mancini lists? Interested in a .590 flat tappet or equivalent to duplicate past performance out of a 440 with iron heads. Just saw them on their website.

Bry

.590 is not a bad cam , actually came in. 2nd in “fading color” cam comparison article several years ago, despite the heavy media spin to try and not embarrass major cam advertisers who were given free reign to spec their best cam. Hughes won the shootout with the .590 and lunati close behind. I was so disgusted with the magazines spin on the story I cancelled my subscription after that one!! See attached chart

 

[bigbluedodge]

Not sure if I should have started a new thread but here I am.
I bought a Comp Cam 30-632-5. Specs are:

Duration at .050 270/278
Lift at valve .567 .579
Sep angle 108
Intake centerline 108

Just to review:
68 Barracuda coupe
Car weight :3294
Dana 60 430 gear
727v
Caltracs

The problem is with my 3 key timing chain set I can't get closer on intake centerline than either 109 (straight up) or 105 with the 4 degree advanced position. I'm already over budget on this project so I REALLY don't want to buy another timing set. I'm looking for Opinions on which way to go. Thanks for the patience.

Bryand

 

[PRHeads]

I’d go with 105 and check PV clearance.
If there’s room, that’s where I’d leave it.

 

[1danc]

Offset keyway, i know my cam ( Engle ) had 4° advance ground into it purposely ! You can move it around to your preferences - are you checking with a degree wheel ? Call Comp and discuss your setup and seek guidance !

 

[33 IMP]

I had a 440 with 2295s and a .590 purple shaft in it, with no p/v clearance problems. But the block wasn't decked, and the 2295s were about .050 in the hole. I'm sure that had something to do with it.

 

[1KoolBee]

Make sure you are finding tdc accurately. I rotate engine clockwise, find tdc, set wheel and pointer, then do the same rotating counterclockwise. Repeat 2-3 times until you are certain you have found tdc. I’ve found that the end result is about 2-3 degrees different from the first measurement. Especially with long rods.

 

[Budnicks]

Racer Brown Cams (were org. Purple shaft grinds, for DC)
look at the them in the link from go to the extended list,
do an internet search 'Racer Brown Camshafts MoPar', it will come up FBO Ignition
ST or STX cams,
Mopar specific grinds, pretty sure they still make them
sorry I don't have the direct link

www.fboignition.com

not sure they still do it,
but they are better than the org. DC Purple Shaft grinds too
I have no idea on the Mancini Racing, MRE PurpleShaft cams