Guys, I've done an extensive search and have e-mailed a couple of you who were kind enough to offer some advice. I am now ready for a debriefing on what I've "learned" and would appreciate any final comments from all before I take the big leap.

I'm going to call the tech departments at Summit and Jegs. What you tell me will minimize the "how much of an idiot is this guy, anyway" thought which is sure to pop into the mind of the poor tech that has to deal with me! The situation:

Basically stock L98
Cam choice narrowed down to:

Competition Cams Grind CS 262H-R12
Duration 206/210 Lift .45/.48

Crane Grind 2030
Duration 214/220 Lift .452/.465

GM HotCam
Duration 218/228 Lift .525/.525

Objectives:

1. An increase in low and mid-range torque; less likely to fall "flat" while cruising on the highway and pedal goes to the metal :-)

2. Smooth idle, although, I can deal with some "roughness" if it means there's significant gains, powerwise and if it it sounds GOOD


Mods:

to install: 1.6 roller rockers

With the exception of this and the free mods and dynomax mufflers, I don't plan on doing anything else, i.e. no intake, no headers

My thoughts about the cams above:

Someone said "lift is torque" Are these specs among cams so significantly different that I have to worry about torque difference?

In the HotCam situation, will putting 1.6 rockers with a lift already so high be impossible or not desirable?

I believe the Hot Cam set up will have to be installed 4 degrees advanced. This was suggested because, the HotCam was meant for a higher revving engine and would compromise low end torque. Does the advanced setting give up higher end?

The Crane cam, and I believe, the Comp as well, are made to run with stock computer programs, what kind of mods would have to be made to the chip if I opted for the HotCam? Would proper tuning with a HotCam make the other two pale in comparison?

And finally, is it unreasonable to expect 40 crank hp increase from cam and roller rockers?

Again, I'd appreciate any thoughts you may have and other things I should consider.

 

I would first get headers... otherwise you may only have slight power gains..
Depending on your engine's current configuration, you could indeed get a 40hp gain, but that may prove to be a bit more difficult without at least a shorty header system.

 

I'm shying away from headers because I've heard the gain is minimal (around 5 hp). The CompCams and Crane are supposed to work with fairly "restricted" exhaust.

 

ttt

 

My choice.

Don't overcam (hot cam) a stock L98 engine.


[Modified by STL94LT1, 2:41 PM 7/6/2004]

 

Since there are bound to be lots of opinions on this, I figure I'd give you mine.

Considering your goals and the mods you plan to make (or don't make) here's what I'd do.

The 206 cam is too short and the HotCam too long in duration.

I WOULD NOT order any cam from Summit/JEGS or any other mail order house, I'd go straight to the cam company to get it.

Over the past 35+ years I've installed and run - at one time or another - just about everyone's camshaft in both street and race engines. CompCams is hands-down the best, with Crane a close second.

I'd choose a CompCams Xtreme Engery series cam with their CRC ramps. I'd choose 214/224 duration @.050.

The specific lobe numbers are 3190 intake, 3192 exhaust. I feel you need to stretch the exhaust duration a bit more considering the stock type exhaust you'll have on the engine. This will help the engine breath better as the RPMs climb into the mid-range but there'd be NO downside. TPIS stretches it even further with their ZZ9 hydraulic roller.

6 degrees is usually the norm for duration difference between intake and exhaust, but when you factor in the added restriction of the exhaust system you'll be running, the extra 4 degrees of exhaust duration will pay dividends.

I'd have the cam ground on 112 LSA and have 4 degrees of advance ground into it. This would be the perfect cam for your setup.

So, you'd have 214/224 @ .050; 266/276 advertised; .530/.567 lift with 1.5 rockers; 112 Lobe Separation Angle.

Idle will be just barely noticable with excellent vacuum for the brakes. Throttle response will be crisp and torque will be excellent.

Of course, with any of those cams, you'll need to correct valve train parts: lifters, pushrods, rockers, springs, etc.

If it were my engine, that's what I'd do.

Jake

 

I'll leave the cam choice to those better informed than I am, but I disagree with the headers only offering you 5hp gain. The headers, random cat, and exhaust mods that I did to my car were some of the best money spent on mods in the early days (before things got crazy).

Personally, if your goal is only 40 crank HP, I would avoid camming the motor altogether. I think that with some of the exhaust mods, and perhaps a set of 1.6 roller rockers, you can get close or beat that 40chp goal.

When you get into camming the motor, you're opening yourself up to a ton more work including such things as head & intake porting, valvetrain upgrades and PROM tuning.

That's a lot of money once you start adding it up. Get all of the free mods done and do the exhaust work and you'll be really close to your goal all without having to worry about not having a matched streetable combo.

Good luck,

Ron

 

The lift numbers on the Hot Cam are rated with 1.6 rockers. If you put 1.5 rockers on it you'll only be .492

That being said the hot cam is not a good match to the TPI.

 

Jake,
You've got mail.

 

I agree that you can easily add 40chp without doing heads or cam.

Concentrate on exhaust mods with FL headers, cut lid with K&N, toss the frisbee, install cut back spark plugs, add under drive crank pulley, install a 160 deg T-stat & fan switch and maybe 1.6:1 RRs & new springs.

By the time you consider the cam and/or heads you should have a pretty clear picture of where you are taking your engine so that all work together well.

 

If your valve springs are tired or worn out you could get 5 or more just by freshening them up. You should consider spring rates based upon the lift to prevent valve float.

FWIW, there are a lot of bolt-on mods that should probably come before heads and cam.

Good luck!

 

I agree, swapping the cam is a lot of work for less than 25 RWHP. Some long tube headers, 1.6 roller rockers, and a good cat back system would net you close to the gains you are looking for.

In response to your orignal question though, I would pick the hotcam, with 1.5 rockers. That way, if you decide to port the intake or something later on, you can take advantage of the cam by just going to a 1.6 rocker.

 

What about the ZZ4 cam, 208/221 .474/.510, they are really low in price and the ZZ4 engines use the same heads as what you have.

 

Where do I source these, Shotch?

 

You can usually find new ZZ4 cam pulls for ~$135, they are on eBay all the time, and I've seen several of the parts places selling them from time to time. SDPC used to list them, but doesn't seem to anymore.

 

I like Jakes suggestion, except that the duration is a hint long- which could force you into a custom chip (no problem if you want to DIY), and his lift is a bit high. Your factory heads will run out of flow before you hit those numbers, so that added lift will just put added stress on valve train parts. If you went with those numbers- ditch your intent of 1.6 rockers.

I too have installed numerous perf. cams in my time. I prefer Comp Cams.

Yes with the 4 degree advance you will lose top end power, but your TPI wont make power at those engine speeds anyway. Get a bigger base, port your base, get better runners, or even a whole superram combo and then install it straight up. For a stock TPI I would run the hotcam (and Jakes) 4 advanced, the others straight up.