What Cam???

[mopowers]

Hey there.  I'm new here, but thought I'd ask for some opinions on a cam choice.  I'm shooting for around 600 hp +/-

I'm looking to send my RPM heads off for cnc porting, but I've been told that I need to pick a cam first so they know what springs and spring pressure to go with.

I've already got a Victor manifold and Bigs 950hp carb.  I'll probably end up at either 470, 500, or 512ci (low deck).  I need to keep compression at 10.5:1 to run on CA pump gas.  Should I go with a solid flat tappet, or a solid street roller?  I know a lot of it is preference, but I need some advice.  I'm no engine builder, so choosing a cam is over my head a bit.  I'm looking for something that will be streetable, but also scream at the track.

Gears are 4.10 w/ 30" tires if that matters.

[Rolling_Thunder]

ummmm    with a 500ci low deck stroker...    your victor, large tube headers, 950 carb, and 10.5:1 compression...      My suggestion would be the following

Solid: Engle KV7 KV8 110LSA
      should give about 625hp @ 6500rpm and 575tq @ 4500rpm

(these estimates are based on stock Edelbrock RPM flow numbers)

[firefighter3931]

First you need to pick a displacement then decide on a stall speed and rear end gearing.....then and only then can you pick the right cam profile 


Ron

[mopowers]

I'll probably go with the 470 since I've got the RPM heads.  Plus I like the idea of having taller pistons.  The rear gear is 4.10 with a 30" tire.  I don't have a converter yet.  I figured they would need to know what cam I'm running in order to build me one.

[firefighter3931]

What's the budget ? Roller cams require more maintenance and upkeep and there are "wear" items to consider as well as the other associated costs. The springs, roller lifters, bronze bushing all need periodic attention. Limited life cycle on street applications. You also need to use a quality rocker arm like Harland Sharp or T&D which adds cost to the overall package.

If you're willing to stay on top of things then a roller cam might be for you....they do make lots of power. 

Realisticly though, a flat tappet solid will make 600hp with ported E-heads and 470 cubes....and be a lot less expensive on the initial buy in.



Ron

[mopowers]

I'm leaning more towards a solid flat tappet.  In that case, what specs would recommend?  Or should I call up a cam company and get some specs for a custom grind?  Thanks a lot for the help!

[firefighter3931]

Something like that will need a custom stick. I like the Comp SQ profiles....easy on parts and lots of power. Give Dwayne a call and outline the build....he can order you up a Comp Custom as he's a Comp WD. Something in the 265@.050 range should get the job done nicely. 

Crane Gold rockers, Isky 8005 valvesprings and the EDM solid lifters with priority lobe oiling 


Ron

[mopowers]

Thanks for the help!  One last thing, have you heard anything about Chet Herbert roller cams?  I hear they are affordable.

[firefighter3931]

Thanks for the help!  One last thing, have you heard anything about Chet Herbert roller cams?  I hear they are affordable.

Yes they are less expensive than the other name brands (Comp, Crane, Isky etc...) but you still have the same maintenance issues to contend with. Figure about every second driving season on changing the valvesprings and lifters. The Bronze distributor drive gear is also a wear item and needs periodic replacement(8k-10k miles). It's not so much the cam and lifter buy-in costs that are expensive....it's all the additional maintenance and upgraded parts to make it live that add up. You have to consider everything when making the jump to a roller cam. 


If you're willing to do all those things then the extra 30-40hp is worth it....if that's what you're really after. 




Ron

[mopowers]

I really appreciate you breaking it down for me like that.  My goal is around 600hp on pump gas, which should be do-able with a solid flat tappet and 470ci.  Plus it looks like the valvetrain will thank me as well.

[mopowers]

One last question Ron, would running a hydraulic roller be as hard on valve train components as a solid roller?

[firefighter3931]

I really appreciate you breaking it down for me like that.  My goal is around 600hp on pump gas, which should be do-able with a solid flat tappet and 470ci.  Plus it looks like the valvetrain will thank me as well.

No problem....just trying to get you to see the big picture. With good flowing heads i don't see why 600hp/600tq isn't possible....the right combination will get you there. 

One last question Ron, would running a hydraulic roller be as hard on valve train components as a solid roller?

The Hyd rollers are easier on parts...less agressive ramps means longer service life from all the parts. The billet core hyd roller cam still requires the bronze distributor gear though. Many flat tappet solid grinds will outperform hyd rollers so it really depends on what your goals are. The nice thing with a hyd roller is that you don't hav to worry about wiped cam lobes....but the EDM mech flat tappet lifters are a great equalizer if used properly. Hyd rollers shouldn't be rpm'd past 6500 but that isn't a concern for you with this type of build, inmo.

For me, the roller cam upgrade would have to be a solid roller in order to justify the increased cost/maintenace. Put another way ; the hyd roller wouldn't be worth the additional expense in terms of a perfrmance upgrade vs a well designed flat tappet solid profile. 



Ron