Cam selection help

-
63dartman

63dartman

Well-Known Member
Joined
Dec 11, 2005
Messages
2,230
Reaction score
24
Location
rio rancho, nm
I need help selecting a cam. I am putting my la 360/clearwater magnum heads back together soon and need some help. I am running the speedpro hyper pistons with 5cc valve reliefs at zero deck. Heads are limited to stock lift values. I am planning on running the new hughes shaft mount roller rockers at 1.65 ratio. Using a magnum rpm airgap intake and holley 670 avenger carb. Thinking about going to a 750 vac secondary holley.So to stay within the lift limits and intended use what would be a good cam? Mostly street driven 8 3/4 with 3.23 gears, occassional trip to track, spitfire headers into 2 1/2" H-pipe duals, 904tf and converter to be selected to match build. I want to keep the rpm's under 6k. Not sure if I got all the info needed so just ask and I will try to help. Thanks
 
Sorry as I'm not sure what a Clearwater Magnum is. Are they ported or just the place you bought them?
 
i think that you dont need those 1.65 ratio roller rockers, because there's a lot of camshafts on list, which have valve lift enough for street driving.I think, you should call mancini racing for exsample and ask them, there's a lot of information.
 
Clearwater is the company that makes the engine quest iron ram heads like the RHS heads.. They are the basic Iron ram aftermarket heads with the thicker casting and better design. I was thinking about calling hughes and see what they say. I really don't want to use the 1.65 rocker but it is the only rocker that hughes offers for magnum shaft mount rockers. And I really don't want to redrill the pedastal and run the chevy style setup.

http://www.hughesengines.com/Tools/...file=/HPCDataDir/Images/Hug1555.jpg&title=HUG 1555
 
Hey There is a guy over on Moparts, who is an Engle Cam dealer, that can help you pick out a custom grind for probably the same price as an over the counter cam. He is pretty sharp, also does alot of Fast Class Racing. [email protected] is his email.
 
Thanks FC7. If I don't get a good response here or from hughes I might give him a holler. Thanks again.
 
Why Spitfire headers? They aren't much better, if at all, than stock exhaust manifolds.
I had a set on my 340 and was glad to get them off. I went with TTIs. They breathe much better and the power increase was very noticeable.
 
I would go for a fast ramp cam like th new xe from comp. A single pattern works best in the mag but if you end up with a dual and have too much exhaust flow,use a 1.5 rocker on th ex.
 
I think I will go with the mopar purple P4452761 it's right in my rpm range and lift is low enough to use the 1.65 rockers and not exceed stock magnum limits. As far as the spitfires. I got them cheap and on the early a's the drivers side exhaust is very restrictive if you ever saw it. Definately an upgrade for mine. Someday I may fork out the money for the tti's.

Adv. Duration: .268°/272°
Dur. @ .050'': 228°/231°
Lift: .450''/.455''
Centerline: 110°
Basic RPM: 1500-5800 RPM
 
I think that might be a decent choice. I hate MP cams but you want something with a slower ramp speed and not too much lift. Just make sure it's degreed when you put it in.
 
Don't take this as I'm knocking Hughes rockers but why not save a bundle of money and use Harland Sharp 1.6 ratio arms on it? I just bought a complete HS kit for my Iron Ram heads from Mancini's for $300 for the set and they are super nice sturdy arms and with the slightly lower ratio won't put the lift up so high like the 1.65 arms do. With that you might have a few more cam choices.

Here's some pics I did while mocking things up. The geometry came out perfect as you can see in the bottom pic. They don't need hardened pushrods or guide plates either so if your using a small cam you can save money there.

Just thought I'd throw out another option.
 
Check out what Don (Cuda66273) has at http://www.4secondsflat.com/. He uses Racer Brown Cams. And has his own set of rockers that have a 5 year guarantee on them. He has them setup with the EQ Magnum Cylinder Heads. He helped me my 392 and it runs great.

rocker arms 111.jpg


rocker arms 11.jpg
 
Comp cams XE line doesn't take advatage of the 904 lift . The XE -HL line does. You could order a custom cam from them or anybody that takes advantage of the 904 lifter, though, it's not a needed issue.

IMO, a cam between 216*/218* @ .050 for a daily driver from 1500 RPM and up.
and a 230* cam for a hot street cam for a 2000 to 6000 RPM, a converter should be upgraded with this cam.

If you look at a split duration cam, with the Magnum head, 6* split is fine, but I myslef wouldn't go to far on a split. No more than 8* IMO.
 
Hope this post doesn't sound too negative but i have not heard many good things PR-wise about Hughes. I find, the bigger and wealthier the company, the worse and less the good advice. Also, there are many better cams than the old school MP range. But unfortunately, if you are restricted by your Magnum head rocker setup, it probably the best you can do. I'd tend more towards the biggest cam you can get for those springs while retaining the 1.5 rocker ratio. The 1.65 ratio will have a tendancy to increase the ramp speed -which is what you want to avoid don't you?

340 A833 -l like your signature panel - if everyone took heed of those simple rules, 90% of thee mistackes in riting wuld not be their. !
 
Fishy, I noticed that those rockers you are using require the 3/8" studs. They want $111.00 for the stud kit. Is this right? I want adjustable rockers. I like their setup just confused about what would be needed to use these.
 
63dartman said:
Fishy, I noticed that those rockers you are using require the 3/8" studs. They want $111.00 for the stud kit. Is this right? I want adjustable rockers. I like their setup just confused about what would be needed to use these.
Click to expand...

No they didn't require anything to complete the valve train except pushrods. Mancini's has it screwed up on their website. Everything was in the kit and they use 5/16" grade 8 cap screws so they bolt directly to the heads without modification.

BTW:When I found out they use 5/16" cap screws I was a little concerned about strength and e-mailed Harland Sharp direct to see how strong they were and Randy Becker @ HS they told me they are strong enough to handle 500+ lbs. of spring pressure.

If you have trouble figuring out what the part number is for the complete kit I can look up my invoice and get it for you. Just let me know.
 
Fishy68, thanks for the info on the rockers. I think I may try those instead as long as they don't use a ball/cup pushrod. So with those rockers I was thinking about this cam.....Let me hear it:)



CCA-CL20-214-4

Cam Style Hydraulic flat tappet
Basic Operating RPM Range 1,800-5,800
Intake Duration at 050 inch Lift 224
Exhaust Duration at 050 inch Lift 224
Duration at 050 inch Lift 224 int./224 exh.
Advertised Intake Duration 270
Advertised Exhaust Duration 270
Advertised Duration 270 int./270 exh.
Intake Valve Lift with Factory Rocker Arm Ratio 0.470 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio 0.470 in.
Valve Lift with Factory Rocker Arm Ratio 0.470 int./0.470 exh. lift
 
Fishy that's a nice set of rockers for 300 bones man.
I didnt know they existed.

And those racer browns are nice too!
 
63dartman said:
Fishy68, thanks for the info on the rockers. I think I may try those instead as long as they don't use a ball/cup pushrod. So with those rockers I was thinking about this cam.....Let me hear it:)



CCA-CL20-214-4

Cam Style Hydraulic flat tappet
Basic Operating RPM Range 1,800-5,800
Intake Duration at 050 inch Lift 224
Exhaust Duration at 050 inch Lift 224
Duration at 050 inch Lift 224 int./224 exh.
Advertised Intake Duration 270
Advertised Exhaust Duration 270
Advertised Duration 270 int./270 exh.
Intake Valve Lift with Factory Rocker Arm Ratio 0.470 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio 0.470 in.
Valve Lift with Factory Rocker Arm Ratio 0.470 int./0.470 exh. lift
Click to expand...

The Harland Sharp rockers do use ball and ball pushrods. If you only had 9.5 to 1 compression I'd say yes on that cam but... I ran it on a calculator and if I did it right your engine is going to be 10.72 to 1. That's alot of compression for a small cam even if you do have closed chambered heads and zero deck pistons. I personally would prefer a little bigger cam, about 6-8 degrees more duration, so I'd know it'd run on pump gas. The Mopar cam looks better (because of more duration) but like Moper and me feel they aren't the highest quality anymore. The last one I degreed in was 8 degrees off. That's junk in my book. But I do know guys that have gotten good ones too. It just seems to be a crap shoot. Something else to think of is a custom ground cam. That way you can get the duration without so much lift. Jim @ Racer Brown is a super nice fellow and very knowledgeable about cams and you can probably buy a custom ground cam from him for the same price an off the shelf cam costs. The last one I bought from him was only $250 shipped for cam and lifters. Jim's # is 410-866-7660 and the best time to catch him is 2-9 pm eastern. You might give him a call and see what he says.

POS Dakota said:
Fishy that's a nice set of rockers for 300 bones man.
I didnt know they existed.

And those racer browns are nice too!
Click to expand...

They sure are a great deal at that price. Alot of generic ones are close to that price and aren't near the quality of Harland Sharps. I think all three brands mentioned here are real good rockers. Just the price is so much lower on the Harland's.
 
Thanks for all the help fishy. I hate to say it but my build may change tomorrow. I'm going to look at a 360 magnum a guy pulled from his brothers truck with 40k on it when it was wrecked. 100$ for it. I may be building a magnum block instead. I'll keep you posted.
 
You must log in or register to reply here.
-

Back
Top