Author Topic: Cam Profile (Read 6343 times)

440Charger · « **on:** January 14, 2007 - 01:51:41 PM »

Hey guys,

I'm trying to understand my cam and how it compares with others. I've been googling away trying to find the stock 440 '68 or '69 cam specs but can't find them. I really need to understand what I have in this cam and, in theory, when components should compliment it.

My cam: http://www.holley.com/00032.asp
Advertised Duration IN/EX: 292/292
Duration @.050 IN/EX: 230/230
Gross Valve Lift IN/EX: .480"/.480"
Lobe Sep Angle / Intake Ctr Line: 109/
Valve Lash IN/EX: Hyd/Hyd
RPM Range: 2500-6000

Of course I've read the Lunati spec where it says hi-po street and mild bracket racing. The guy who helped us build the engine said the cam wasn't that big. From what I've seen, the lift (.480) isn't that radical, but the duration (230 @.50) might be a bit high...?? Also, from what I've learned, the lobe separation of 109 means that higher RPM is needed to create the vacuum needed to clear the cylinder of exhaust and pull in fresh mixture...

I have 452 casting heads with no machining work done. We did a valve job...I'm going to call the machine shop and determine if it was a good 3-angle valve job..it just says "valve job" on the sheet.

Thanks
- Doug

Chryco Psycho · « **Reply #1 on:** January 14, 2007 - 03:15:20 PM »

that is a slow ramp cam 292* ad & only 230 @ .050 with .480 lift
compare to Engle [ www.englecams.com ] their K58 is 230 * @ .050 / 276 ad with .520 lift & 110 CL & the powerband starts 500 rpm sooner
I would use a Holley street dom intake 2800-3000 stall converter , port the heads
do you have headers or exhaust manifolds , if you have manifolds I would swap the cam as well to a 112* + CL cam

440Charger · « **Reply #2 on:** January 14, 2007 - 03:42:22 PM »

Hedman headers, 2 or 2.5'' I can't remember.

I think I understand the lope separation angle (increase distance between when intake/exhaust lift occurs) , but not the centerline. What would a higher centerline degree do?

What makes it a slow ramp cam? Isn't the #@.50 a standard benchmark? So why would these two cams have a different ramp up since they're both at 230@.50?

- Doug

Chryco Psycho · « **Reply #3 on:** January 14, 2007 - 04:00:21 PM »

the difference between the ad duration & the duration @ .050 show how slow the ramp is
you have the same duration at .050 but less ad duration so the ramp is faster + it has .040 more lift , I alwys compare cams a .050 it is more accurate
changing the centerline of the intake lobe away from TDC widens the lobe separation angle so both valve are open at the same time for a shorter period of time so less scavenging occurs , so with manifolds you want less scavenging [overlap ] as the exhaust is restictive , with headers you want more scavenging [overlap]

440Charger · « **Reply #4 on:** January 14, 2007 - 04:50:03 PM »

So what's the point of having a cam with a slower ramp up? Why would Lunati make a cam that was slower to gain power?

Chryco Psycho · « **Reply #5 on:** January 14, 2007 - 05:03:04 PM »

some engine will not flow more with more lift so why beat up the valve train , Comp on the other hand designs most of their cams for small block chev which need a slower ramp speed because of the smaller diameter lifter

moper · « **Reply #6 on:** January 16, 2007 - 10:34:53 AM »

Cam companies deal with all kinds of variables when designing lobes. CPs partially right. Most cam manufacturers have generic lobes. They take two lobes from thier inventory and put them together to make a cam. To be honest, the cam doesnt know what engine manufacturer it's for. So saying "Its a chevy lobe" is a crock of

. The limitation comes from each engine manufacturers' valvetrain design. Small mopars have terrible pushrod angles, and a shaft system. So you cant have a cam that's really huge without flexing the rockers and shafts, and running thru those steep angles. They are very stable with milder cams, but when you start getting cigger, they have issues fairly quickly unless you update things. Big mopar heads flow much better at low lifts in stock form, and the manifolding is some of the best. Where GM and Ford's are some of the worst. The fact is, any increase in the rate of lift of a lobe will make more usable power for the same given max lift. The wider the lifter base is, the faster you can make the valve move off the seat, and more "time" in degrees you have to let air into and out of the combustion sapce. So the mopars can lift faster. But it comes at a price. You need to be able to control that valve motion. Faster ramp speeds require bigger springs. Bigger springs make things flex more and can wear out valve springs faster. So the cam guys walk a line between what can be a good result, and what may be pushing the factory design envelope but still be usable for regular guys like you and I. Looking at duration .050 lift is really only a small part of a lobe profile. It's more accurrate to say 230� at .050 lift" than to say "I have a 280� cam". It's not really accurate to say all cams of a specific type (meaning hydraulic or solid or roller) with advertised .050 lift figures of 230� are the same. Some cam places use a "take up ramp" to make the valve not bounce or to work with hydraulic lifters and avoid valve float. Some (like Ultra Dyne and Isky IIRC) use "steps" in the closing ramps to slow down the valve again to avoid bouncing it off the seat and also to help scavenging. Comp uses a faster rate of lift for thier XE line, but the XE-HL cams are the real fast rate for use with mopar .904 lifters. Hughes Engines "real chrysler cams" uses similar ramps to the Comp HL line up, and you can tell by the heavier valve springs they are spec'd with. A nasty by product of fast ramp speeds and heavier springs combined with different oils now is what is killing all these cams. SO choosing a cam is a big deal. No company by itself can make every perfect cam. At least I havent seen any. There are drastic differences in quality control tho. I use a lot of Comp Cams products. But lately, it's been more about Crane, because they have gentler ramps than many, and they like split patterns. I use Mopar Performance as a last resort. I havent used them in years because of poor quality control. Your Lunati is a single pattern cam. That means teh intake and exh lobes have the same shape. Taht assumes the ports have the perfect flow relationshipo of about 70% exh flow to intake flow. Factory heads arent even close. Factor in exhaust with mufflers and it gets worse. I wouldnt run a single pattern cam with stock heads anymore. I tried it for a few years. I get more drivability and usable power with splt patterns now. Even this 505" with cleaned up Edelbrocks is getting a split pattern Crane. My $.02 anyway...

440Charger · « **Reply #7 on:** January 17, 2007 - 11:23:50 AM »

Right on man - I'm seriously considering switching to a dual pattern cam because of the exact reason you mentioned. Also would like a degree or two more on the lobe centerline...currently at 109 which I believe is one reason I have to spin up so much to get any power.

My current 1st choice is this one: http://www.holley.com/60403LK.asp

440Charger · « **Reply #8 on:** January 18, 2007 - 05:53:19 PM »

Need an opinion from you guru's:

My Hedman headers are 1 3/4 inch tubes with a 3 inch collector, part#50078036

What do you think the highest lift/dur cam I could get away with before the headers become a restriction?

Thanks,
- Doug

MEK-Dangerfield · « **Reply #9 on:** January 18, 2007 - 06:16:11 PM »

Quote from: 440Charger on January 18, 2007 - 05:53:19 PM

Need an opinion from you guru's:

My Hedman headers are 1 3/4 inch tubes with a 3 inch collector, part#50078036

What do you think the highest lift/dur cam I could get away with is before the headers become a restriction?

Thanks,
- Doug

I'm a little out of my element here in talking about cams. I have those same headers on my Challenger. I have a 440 with a Lunati cam. 292 duration is what I was told by the previous owner. It is lumpy at idle, so I don't doubt that. It is definitely tuned for high speed driving, I will say that. I would say, unless you have some kind of radical setup, these headers are fine.

Mike

440Charger · « **Reply #10 on:** January 18, 2007 - 09:41:56 PM »

That's a sweet lookin ride Mike. Been wanting to say that for a while.

What is your duration @.50? My Lunati is also 292 advertised, but 230@.50

moper · « **Reply #11 on:** January 19, 2007 - 10:36:22 AM »

An update...Crane cant grind what I need a tthis time...lol. So I put a call to Engle. Talked to Mark Engle personally. (Thanks CP!) So I will be ordering a cam from them for this 505. Because of the factory 6bbl (restrictive as heck on a 505) I am getting a split pattern, more on exh, but a lot of duration on the intake side. If your heads were never flow tested, you cannot guess what the port and header together will do for exh flow. The general guide is you want the exh port to flow within 70% of the intake. Then you use the header that puts the torque peak where you want it using those heads and your exhaust system. On most street cars, that is reduced to "X brand because they are cheap and bolt on.."

If you have a good exhaust, and 1 3/4 headers, the port should be your restriction. If the heads were ported right, a single pattern cam should make the most power. But a dual pattern cam can make that power more usable and easier to drive. Hope that helps..lol.

MEK-Dangerfield · « **Reply #12 on:** January 19, 2007 - 03:34:41 PM »

Quote from: 440Charger on January 18, 2007 - 09:41:56 PM

That's a sweet lookin ride Mike. Been wanting to say that for a while.

What is your duration @.50? My Lunati is also 292 advertised, but 230@.50

I'm sorry, I have no idea. I was just told 292 by the previous owner. That's all I know.

Mike

440Charger · « **Reply #13 on:** February 17, 2007 - 11:56:55 AM »

I just read this article http://www.iskycams.com/techtips.php#2001

He talks about how needing a dual pattern with more exhaust duration is a "myth" once you dump manifolds and go with headers. Check it out(use links at top of page). Does anyone have experience with dual vs single pattern when using headers? Got any #'s or proven results?

I guess I'm questioning my need to dual pattern now - any input would be mucho appreciated!

Thanks,
- Doug

Chryco Psycho · « **Reply #14 on:** February 17, 2007 - 12:45:23 PM »

If I had unlimited budget & time I would have an engine dyno , test combos constantly .... any sponsors

Ok I tend to agree that a split pattern will work better with manifold over headers BUT I have no solid evidence trying for example a K56/ K 58 with headers & with manifolds & then comparing just a K56 Single pattern with both as well
The knowledge I could gain if I just had the $$ to go after ti

Author Topic: Cam Profile (Read 6343 times)

440Charger

Cam Profile

Chryco Psycho

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440Charger

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Chryco Psycho

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440Charger

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Chryco Psycho

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moper

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440Charger

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440Charger

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MEK-Dangerfield

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440Charger

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moper

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MEK-Dangerfield

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440Charger

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