For a Ram-Jet ? .030 flat-top, worked vortecs, Hooker LongTubes, T56, 3.42 gear? I want decent street manners, but some top-end also. Slight choppy idle ok..........I have several cams here......can't decide. Suggestions?

 

ZZ9
LPE 219

or similar grinds from Comp. (= Cheaper)

With that Ramjet if you port those heads and your bottom end is up for it try the CC306 .

 

I've got a Gm "846" sitting here...............Just wonder how soft it would be until 2,000 rpm's? I could do 4.10 gears if I had too. But in my experience I would be shifting all the time(with the T56).

 

Anybody else? I mean really one person? There is not a lot of people trying this intake, but any educated guesses would be appericated.

 

 

Something around 218 degrees on the intake side. It will give you some lope. I would look at the Comp Cams Xtreme line.

I don't see any heads listed. IMHO that is the most important choice. If you have good flowing heads on both the intake and exhaust you can go with a single pattern cam such as the LP219. Otherwise a dual pattern would be better. Allen

 

"worked vortecs" count as heads right?

what are the specs on the '846'? I know the GM 847 is pretty aggressive, moreso than the CC306 which would probably be the most extreme cam on my list if i wanted "decent street manners". I think the LT4 hot cam would be a good compromise, or for a bit more top end, a COMP CC503 grind (CCA-07-503) with some 1.6 rockers

 

Thanks!

 

Oh and the "846" cam is 222/230 @.050 .509/.528 on a 112 center.

 

I think that is a Crane cam that GM uses in it ZZ383, I had it in a carb'd 350 eng with CNC trick flows and 1.6 rockers, it rocked up to 6000 and a little more. Idled like a muscle car should and had decent low rpm manners, really kicked in at 3000.

 

XM262H It doesn't look all that impressive on paper, but it will make the vortec and ramjet intake stand up and say hello. The throttle response is almost on the verge of telepathic, and a monkey with no hands can tune it in. just my two cents.

 

You have experience with this combonation? what are the cam specs?

 

Ok just found the specs. It's a flat tappet marine cam no thanks. I've still got a Tuned-Port Corvette if I want all low-end torque. Hot-Cam is looking betteror Maybe a "845".

 

Well i ment to select the marine cam, but not the flat tappet. I guess i do not have the catalog memorized totally yet. At any rate the two choices I would go with for roller are the XM270HR or the XR264HR. These will give you lots of lift with a sensible duration, this works well with multiport and particularly well with vortec heads. I have built a number of vortec motors with these cams, and I stand by the throttle response comment it is unbelieveable. Sounds extremely mean when you lean on the pedal. One thing to watchout for though is the valves hitting the pistons. These cams have extremely fast ramps. Sorry for the confusion. Sounds like whatever you choose it is going to be a good combo.

 

IMO go bigger. I say at least a 224 duration on the intake side w/ it but thats just me. The 847 is a great cam. Great for the short runner setups...

why is everyone so worried about power under 2k. You will have plenty for every day driving, more than needed under 2k in a 350. Its over the 2-3k mark that you want the power for racing. Torque is great, and its cool to have. But moving the power up in the band is what makes you go faster. That is what a bigger cam does. You move it up in the band and make it more useful in racing... Under 2k You would never see it...

 

12370845 Hydraulic roller design I:214 E:224 I:488" E:509" 112

12370846 Hydraulic roller design I:222 E:230 I:509" E:528" 112

12370847 Hydraulic roller design I:234 E:242 I:539" E:558 112

The CC306 is considered to be an "old" design cam and the 847 is supposed to be better and newer. Those threee are GM/Crane cams. I believe that GM and Crane have a close relationship and Crane makes those three, something like that. Stick with the '846 or "Hot" cam. The LPE 219/219 is a good cam that can act like it is a bigger. Or you could go to a solid roller....

 

.I am by no means a cam expert and I am sincerely asking this question so please do not take it the wrong way. What do you guys consider a big cam? Are you going by the duration numbers or are you looking at the lift? I consider the LPE grind pretty healthy with over .510 lift on each side.

in my own personal experience tuning multiport fuel injection, I have had better results going with less duration and more lift, maybe I am short changing myself

 

Well if you don't gain a whole but loose alot of street manners. Then I guess it's best to error on the small side. At least that's what I've always heard. This won't be my daily driver, but I plan on enjoying it quite abit. I would like a sound that isn't stock, but not get followed by the police. I want more of a topend than TPI. Which I think the Ram-Jet Intake will help with. I also don't want to leave alot on the table by selecting too small a camshaft. I guess I'll use a two-piece timing cover. Just in case I don't like my first choice.

 

It has been debated. Do you get more water by leaving the hose on longer or by turning it up higher? The ramp rates on the camshaft and the piston clearence are the issues for lift. So most people stick with higher duration when they want more power (air). Lift is not as important as people think. Duration and valve timings are important.