Legendary "Purple Cam" question

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i really like that cam for a 318 and if you install it down at 105~106 it flat rips.

while it's 340 adjacent, it doesn't act so much like one. but you do need a little compression for it to really sing.

because you're rolling a magnum it's a totally different cam (roller) so like demonracer mentioned i'd call up oregon and talk to get and see what he's got that's similar or if he'll grind one to spec.
 
I talked to oregon, heres one of his grinds he reccomended me

#1617

220/224 @ .050", 270/274 adv, .506"/.506" lift, 112 sep
 
Dusty 997 said:
I talked to oregon, heres one of his grinds he reccomended me

#1617

220/224 @ .050", 270/274 adv, .506"/.506" lift, 112 sep
Click to expand...
i'd go on ken's rec if you gave him all of the information and you were honest with what your expectations were and what your set up was.

keep in mind that when you approach .500 lift you may be reaching the limitations of the factory keepers and locks clearance wise.

a buddy of mine runs oregon's 2204 grind in his 5.9 mag with an airgap and an AVS and it gets good.
 

Did ken say if that was ground on a new cam blank or an old cam? Ask him what tightening up the lsa to around 109 would do.
 
ch1ll said:
Did ken say if that was ground on a new cam blank or an old cam? Ask him what tightening up the lsa to around 109 would do.
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Would be ground on my old magnum cam. Ill ask about the LSA
 
ch1ll said:
Did ken say if that was ground on a new cam blank or an old cam? Ask him what tightening up the lsa to around 109 would do.
Click to expand...
he said it would give it better throttle response and seat of the pants feeling but will adversely affect idle quality and require a bit more stall. My factory converter already sucks so i was planning on upgrading that anyway. So i think i will go with the tighter LSA.
 
Please don’t take this wrong,,,,but isn’t that amount of lift a little high compared to the stock grind Purple Shaft ?
I’m not against more lift,,,I’m just wondering why it has to go to over .500 ?
Because,,,like was stated,,,it will be at the top of the range for the guides and retainer clearance on a Magnum .
And it will require a good converter,,,assuming you choose the correct stall to use .
Picking a stall range can be a tricky endeavor .

Since the roller will already produce more power than the factory cam specs. had ,,,,I don’t see the need of that amount of cam ?
If you go that route,,,,you should adjust up your compression ratio accordingly.

I’m sorry about the statement,,,,maybe that is more in line with what you are looking for anyway?

Tommy
 
Desoto291hemi said:
Please don’t take this wrong,,,,but isn’t that amount of lift a little high compared to the stock grind Purple Shaft ?
I’m not against more lift,,,I’m just wondering why it has to go to over .500 ?
Because,,,like was stated,,,it will be at the top of the range for the guides and retainer clearance on a Magnum .
And it will require a good converter,,,assuming you choose the correct stall to use .
Picking a stall range can be a tricky endeavor .

Since the roller will already produce more power than the factory cam specs. had ,,,,I don’t see the need of that amount of cam ?
If you go that route,,,,you should adjust up your compression ratio accordingly.

I’m sorry about the statement,,,,maybe that is more in line with what you are looking for anyway?

Tommy
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so, what happened was while researching cams i kept seeing the purple one pop up, and then i contacted Oregon cams and just described to him what i was wanting to do with the car, he came back at me with two different cam profiles he thought would be a good fit, and i gravitated to the larger of the two.

For reference, here's the other one he sent me.

#1341

218/224 @ .050", 270/276 adv, .482"/.482" lift(1.6:1 rocker), 112
 
Dusty 997 said:
so, what happened was while researching cams i kept seeing the purple one pop up, and then i contacted Oregon cams and just described to him what i was wanting to do with the car, he came back at me with two different cam profiles he thought would be a good fit, and i gravitated to the larger of the two.

For reference, here's the other one he sent me.

#1341

218/224 @ .050", 270/276 adv, .482"/.482" lift(1.6:1 rocker), 112
Click to expand...
is this for a 5.9 or a 5.2?

if it's 5.2 get the smaller one.

heck, i even say get the smaller one for the 5.9 too.
 
Shes a 5.9

What do you like better about the smaller one? Im still trying to learn
 
Dusty 997 said:
Shes a 5.9

What do you like better about the smaller one? Im still trying to learn
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what else is your set up? what are your expectations?

anytime i've gone one size smaller on cams and i've never been disappointed, cain't say it's the same the other way.

specifically for the 1341 you can run a stock spring, retainer and lock-- if you wanted to.
 
junkyardhero said:
everybody over here buying cams and carbs like they's tiddies.

well all that's gonna get you is back problems and fouled plug if you ain't careful
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so you know my wife.....
you only need so much on a daily ....now if you plan on going motor boating ..........
 
junkyardhero said:
everybody over here buying cams and carbs like they's tiddies.

well all that's gonna get you is back problems and fouled plug if you ain't careful
Click to expand...

LOL :thumbsup:


At idle, you wouldn't notice the difference between the two. They are so close, it would be insignificant.
The higher lift might require something like the hughes springs being over 500 lift. Smaller one may use the factory spring. You'll have to inquire about that.

After the idle, the higher lift cam will make more power, just a smidge...
 
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junkyardhero said:
what else is your set up? what are your expectations?

anytime i've gone one size smaller on cams and i've never been disappointed, cain't say it's the same the other way.

specifically for the 1341 you can run a stock spring, retainer and lock-- if you wanted to.
Click to expand...
air gap intake, dougs long tubes, avs2 carburetor dual exhaust, 3.73 suregrip rearend behind a 904. 275 60 15 tires.

Wanting as strong of a low- mid range, 1500-4500ish as i can get without spending 3000$ on heads. Stoplight to Stoplight street driven performance, and a decent bit of chop but doesnt have to be wild or sacrifice performance just for sound.
 
both the 1314 and the 2204 are probably the better pick for what you're specifically trying to do.

the 2204 is very similar but has slightly more duration and is on a 110.

either are good choices, but given your operating RPM range the smaller 1314 is likely the more suitable one. but you've got gears, so you can't really go wrong with the bigger 2204.

i'd see if you can get the 1314 on a 110... or just splash for the 2204 and get a converter too.
 
Desoto291hemi said:
Please don’t take this wrong,,,,but isn’t that amount of lift a little high compared to the stock grind Purple Shaft ?
I’m not against more lift,,,I’m just wondering why it has to go to over .500 ?
Click to expand...

The lift of a camshaft at the lobe is the overall height of the lobe minus the overall width of the lobe. When you start regrind cam lobes there is only so much you can do with them. However the roller is easier to change around because the lifter can follow a more aggressive shaped lobe profile than a flat tappet can. .506" lift (.506/ 1.6 rocker ratio) equals .31625" lobe lift and since you're grinding away at the lobe sides (making it more narrow) to change the characteristics you're adding lift because it's lobe height minus lobe width to get the total overall lobe lift. The whole grinding/ regrinding process is very interesting how it all works. That's my guess why it ends up at .506" lift, but also if you're regrinding you probably want more lift for performance. I am sure they could make the lobe height shorter and get it back in the .480" lift range. Duration is far more important than .026" of lift is going to matter.

Tom
 
RustyRatRod said:
This is like sayin, "Ma'am, I caint date you. Your titties are just too big."
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Lol,,,,,Yes you are right !
But if they are hanging down around her belly they won’t be any good to you .

Cams are a different animal,,,and are very important to the end result .
As the guy stated,,,he is interested in low and mid range power,,,,,that larger cam is not in that power range .
It will run just fine,,,,but at a different spot entirely .
The Purple shafts were made for a certain level,,,,and worked very well for what they were .
But the Magnum has some limitations,,,and,,,unless they are addressed,,,,might cause issues .
It’s an excellent engine,,,,just like the old 340,,,or 318 .
With the right combination,,,,they will fly !
The same is true for converter range,,,,,the wrong stall will make a very good engine seem like a Dog .

I just hope the Op chooses the right combination,,,otherwise he might be dissatisfied with the outcome.
The bigger cam will run great,,,,no dissent from me,,,,but it must be what he is really wanting .
And then all the other components have to match it too,,,and higher compression is a definite plus for the end results .

Tommy
 
I don't know much about magnum valve train as I consider ball stud rockers to be a cheap terrible design, no wonder shivvies had them. Most of the purple camshaft up to the street hemi grind were designed to work with stock valve train components. The closer to. 5 lift you risk putting a push rod through your stamped steel rocker arm mostly cause you need stronger springs to keep the lifter on the cam profile.
 
Desoto291hemi said:
Lol,,,,,Yes you are right !
But if they are hanging down around her belly they won’t be any good to you .

Cams are a different animal,,,and are very important to the end result .
As the guy stated,,,he is interested in low and mid range power,,,,,that larger cam is not in that power range .
It will run just fine,,,,but at a different spot entirely .
The Purple shafts were made for a certain level,,,,and worked very well for what they were .
But the Magnum has some limitations,,,and,,,unless they are addressed,,,,might cause issues .
It’s an excellent engine,,,,just like the old 340,,,or 318 .
With the right combination,,,,they will fly !
The same is true for converter range,,,,,the wrong stall will make a very good engine seem like a Dog .

I just hope the Op chooses the right combination,,,otherwise he might be dissatisfied with the outcome.
The bigger cam will run great,,,,no dissent from me,,,,but it must be what he is really wanting .
And then all the other components have to match it too,,,and higher compression is a definite plus for the end results .

Tommy
Click to expand...
I think im gonna run the smaller one and have him tighten up the LSA to 10. He reccomended a 2000 stall for the smaller one i believe.
 
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