Cam choices - your advice appreciated!

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sharpie

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I'll try this here since moparts' technical forums bite balls.

I'm about to order my camshaft for the 5.9L Magnum with LA timing set/fuel pump, and I have come to a crossroads. I need your advice on which path to take.

Right now, I am cylinder-headless. I have the original iron Magnum heads, but they each have a couple of, from what I can tell shallow, cracks between the valve seats. This precludes me from just slapping on the cylinder heads and running them, as some work should(I think?) be done to make them work optimally.

So now I need a push in the right direction. If I go with my first cam choice (int: lobe lift: .361/dur @ 50: 230.00; exh: lobe lift: .358/dur @ 50: 236.00), I will have a large valve lift, but I will not be able to use the stock Magnum heads. They just can't handle that lift. However, if I go with this cam, I also must purchase new heads, and could that take almost half a year.

However, if I go with the second cam choice (int/exh lobe lift: .305/dur @ 50: 214.00), then I can run stock milled heads for the time being, while saving for Edelbrock heads. However, this will obviously yield much shorter valve lift, robbing potential power.

And there's a third option, I guess. I can buy the high-lift camshaft, but leave it in the box for now. I can purchase a fuel pump eccentric for my stock Magnum cam (LA front cover), which looks fine, and run it with the stock Magnum heads for now while I save for Edelbrock heads.

Which would you choose? I would love to get this motor running by January, and would stand a real chance of that without having to buy new heads. But buying new heads gives me lots of other perks, like more power and better heat dissipation. I am pretty set on one of these three options and I'm definitely set on either of the cams, I just don't know which one. Your help's greatly appreciated!
 
Keep in mind that the bigger roller is a much larger cam than you may realize compared to a flat tappet, the ramps and "area under the curve" is much greater due to the roller design. Your best bet is to call crane or comp cams and tell them what you want to do. Dont forget to have ALL your engine specs along with axle ratio, car weight, transmission, exhaust system etc to give them - in order for them to make a recommendation.
 
Why do you list the cam lift at the lobe instead of at the valve?

I'd wait it out for a set of Edelbrock Magnum heads and be done with it that way.
 
rumblefish360 said:
Why do you list the cam lift at the lobe instead of at the valve?

I'd wait it out for a set of Edelbrock Magnum heads and be done with it that way.
Click to expand...

because those are the numbers I got from Comp Cams itself. The cams including the 1.6 rockers would be:

int: lift: .5776/dur @ 50: 230.00; exh: lift: .5728/dur @ 50: 236.00

int/exh lobe lift: ..488/dur @ 50: 214.00

Would you see any problem running the stock stuff for the time being though while I save for the Edelbrock heads?
 
Honestly, most of the same guy that do tech here, do it at moparts... but the general members here are a lot less likely to have keyboard balls...lol

on th camshaft... what are you doing with the engine? What is the rest of the combo? Is there a certain reason it must be running in January? Are you certain you are running either RPM Magnms of stockers?(are you open to other suggestions?)
 
(For clarity, no MoParts foe me.)

Sharpie;

Total lift at the valve and the abilty of the head to handle said lift without mods. I am not sure where the Magnum heads limits are in it's total valve lift abilty.

Moper, do you know off hand?
 
I think the limit with the rockers is .500ish. You need to replace the springs anyway. really, on moparts, Patrick (that's his screen name) is the tops in terms of Magnum head parts usage and not a dick about things.
 
Ahhhhhhhh, a normal person on Moparts huh?
I do know the screen name. One of the few with an actual name.
 
lol... he's been there longer than me.. I've been a member and friend of Toms for a while. Patrick was one of the first I saw building with Magnums on a regular basis. I was thinking of the Engine Quest heads for Sharpie...
 
moper said:
Honestly, most of the same guy that do tech here, do it at moparts... but the general members here are a lot less likely to have keyboard balls...lol

on th camshaft... what are you doing with the engine? What is the rest of the combo? Is there a certain reason it must be running in January? Are you certain you are running either RPM Magnms of stockers?(are you open to other suggestions?)
Click to expand...


Thanks for the replies. Let's see if I can help shed some light. This will be a 99% street 1% road race motor. Right now I have .030-over Speed Pro pistons and rings, clevite bearings, Melling hi-volume oil pump, Comp timing set, an LA timing cover and water pump, Fel-Pro gaskets, and a MP electronic ignition distributor and module.

I want to purchase these:
Edelbrock or MP dual-plane intake for a Magnum
Hooker Competition headers for A-body (black-coated is okay with me)
Kevko oil pan and pickup
MP balancer
MP flexplate
Torque Converter (2800 stall or so, but the number is negotiable based on the motor)

I am sort of following the Hot Rod Magazine build: http://www.hotrod.com/techarticles/engine/hrdp_0804_small_block_mopar_engine/index.html but I'm not stuck to the idea of almost 450hp. 400hp and 400ftlb torque would be an optimal area to shoot for.

The only vacuum I'll need to make is for the distributor (i have manual brakes, no AC), but I would like a cam that idles around 1000rpm and won't idle overly-lumpy (though I want some throat in the idle).

I'd like it running maybe not by January but soon because my Jeep is getting really unsafe to drive, and I would like to have a reliable driver while I put the Jeep on stands for a couple months.

I am open to the thought of other heads, though they must fulfill three requirements:

1. Higher valve lift than the stock heads
2. Must not be prone to cracking
3. Must be cheaper than Edelbrock heads

The only reason I was going to run stockers was because they were available to me (read: already in my garage, just need machining) and that I already have all the rods, rockers, springs, and head bolts for them. It's mainly convenience, since I don't like the idea of them cracking again.

Anyway, hopefully this information helps. Your feedback has been helpful so far!
 
Engine Quest iron Magnum heads are new, and won't crack. (Better casting to make sure this doesnt happen). They are stock Magnums... with the same limitations. BUT, you can run a Chevy valve (taller) and end up with a range up to .550 lift. This costs a little more money, but I dont think even using higher dollar parts to complete them that you'd reach $1000 in a local shop. I have not done a set yet. But I know I can get them around $1000 in that form but I've seen several sets on Modified Tour engines making very good numbners with limited cam and induction. That would be my choice. BTW, idle speeds should be a bit lower. Closer to 750-850 rpm depending, especially with the roller lifters. Using what you have for usage, I would use the first and larger cam choice too.
 
With a roller cam, your engine will make 400 HP easy, especially with zero-deck flat-top slugs and Magnum (or Magnum-derived) heads. If I built a Magnum 360 I'd use the Eddy Air-Gap intake for Magnum heads, then rig up a battery-powered electric heat element to go under the plenum for really cold starts (although I'm not sure you'd need that in California). Get a good, mild roller cam from Hughes (if you have a core) and you could potentially get in the 20's with gas mileage and still pull a 13-second 1/4, depending on your gearing/transmission (O/D of course to do both). These engines are way more efficient than our old flat-tappet-cammed open-chambered LA high-performance engines and it seems only a few people have come to realize this.
 
I don't think I agree... They are better at detonation resistance than the open chamber iron head LAs, and the roller lifters do give a bit of a break on friction, but it's not a big difference. They are still hydraulic, and they are still bound by that for rates of lift. They are a little more efficient, but not more than 3-5% at best. In fact, the Magnum RPM heads and LA heads share chamber designs, so if you upgrade teh LA, it's just as resistant to detonation. With no OD it's easy to get close to 20mpg with LA heads iron, not RPM), a hydraulic flat tappet, 60 more cubes, and at least 60more hp. Remember the flat tappet lifters are (supposed to be ;) )sliding on oil. The roller helps, but there's not an excess of frictional loss there. At least not a lot much more than a hydraulic roller lifter.
 
Other than Hughes engines, who else regrinds stock magnum roller cams? I remember reading about another company who does it but I can't find the post.
 
Thanks billytufnuts I called them today and they will be able to do exactly what I want.
 
I had mine done from Bullet cams, the cost was 150.00, it was limited on what could be done, even though its a nice piece, it still lacks strong mid-range/upper end power, if you run gears/stall, I'd look at the Hughes re-grinds or a comp/crane cam, this way you can get it in a 109/110 @50 with duration in the upper 220s & 230s, but keep the lift around .500 so you don't have to trim down the guide bosses, but you'll still have a strong cam.
 
Thanks for the tip. I wanted to do it as cheaply as possible but after reading your post I'm not sure what I will do. What I had originally intended was a comp cams [email protected] .570 lift intake and [email protected] 565 lift exhaust at 108 or110 LSA ( profiles 3014 and 3035 comp cams xfi hydraulic roller lobes) . This is cam is 12 degrees in duration less than the cam used in Mopar Action Junkyard Jewel 360 Magnum which made 450 hp with the steeper cam and Edelbrock Heads. I was also going to use Hughes springs and retainers as they told me that there is no retainer to guide clearance problem if u use their retainers. The only problem is that the cost of the everything was close to $600.
 
dustoff440 said:
Thanks for the tip. I wanted to do it as cheaply as possible but after reading your post I'm not sure what I will do. What I had originally intended was a comp cams [email protected] .570 lift intake and [email protected] 565 lift exhaust at 108 or110 LSA ( profiles 3014 and 3035 comp cams xfi hydraulic roller lobes) . This is cam is 12 degrees in duration less than the cam used in Mopar Action Junkyard Jewel 360 Magnum which made 450 hp with the steeper cam and Edelbrock Heads. I was also going to use Hughes springs and retainers as they told me that there is no retainer to guide clearance problem if u use their retainers. The only problem is that the cost of the everything was close to $600.
Click to expand...

I'm running the RHS heads with hughes 1110 springs & there retainers, i should have had them cut the bosses down, i had my stock cam re-ground from Bullet like i mentioned, the lobes are really too small to get a good profile for optimum power that most would like, i feel i'm still leaving a good 40-50hp on the table with this cam, here is whats on the cam card, i had to sacrafise lift to get these #s & do it up on a 112 LSA, but in all, it was a better choice then staying on a 114 LSA & alittle more lift. If i were you, i would spend the extra 150-200 & get a better choiced cam.

Intake Exhaust.
Dur. @.050 216/216
Lobe lift. 2900/2900
Seperation. 112.
Timing events. .050 0 36 44 -8
Dur. at .006 282 282
Gross lift. .447 .447

This is with 1.5 rockers, i'm running 1.6
 
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