993 or 996 cams in 3.2

Larry Harris · 06-01-2004, 03:13 PM

I'm having my top end only done in a couple of weeks or so. The owner of the shop recommended regrinding my stock 3.2 cams to the 993 or 996 configuration. This car is strictly for the street and ocassional blasts up the freeway on-ramps. The engine has 115,000 miles but has 165+ compression in all the cylinders and doesn't use oil excessively, nor does it leak at all.
Wayne's "101 ways to drive you crazy" doesn't address which cam grind is best for more mid-range torque.

Any advice!

KobaltBlau · 06-01-2004, 04:17 PM

This post just made me laugh. It might be hard to get 4 996 cams into a 3.2. (I realize you mentioned the grind above)

I don't know anything about these grinds but just be careful because you don't have that much clearance with the stock 3.2 carrera pistons,

camgrinder · 05:57 PM

Larry,
With a 3.2 litre you basically have 2 options.
The 964 cam or the sport SC grind.
The 964 has a little more top end and the Sport SC has a little more in the mid range rpms.
The 993 cam grind is a hydraulic profile. It will not work with original 3.2 rockers.
The 996 has a different style valvetrain and will not work on any 911, 930 or 964 engine.

Go with the Sport SC grind and you will be happy.

Wayne 962 · Wayne 962's Garage

Right I think you meant 964 cams...

Honestly, if I were you, I wouldn't mess with it. The Motronic system is programmed specifically to work with that camshaft. Things like chips are removable - cams are not (well, not easily anyhow). Since you're in SoCal, a camshaft swap would indeed be illegal, and as the engine ages, it might make it more difficult to pass smog.

I would leave it stock for now, since your in SoCal...

-Wayne

Carrera3.5L · Carrera3.5L's Garage

Wayne,

Good sound advice, but I respectfully disagree with you. 964 cams are mild and the car will easily pass smog as long as all emissions equipment is in place and in good working order. We installed many at Andial when the 3.4/3.5 conversions were in their heyday and never had smog issues. The 964 is a good solid choice for a street car using Motronic. My buddy with his 3.4 twin-plug and 964 cams passed smog just last week with flying colors. Yes, the twin-plugs helps the combustion process but I have seen many with single plug not have a problem either.

I'm not familiar with the Sport SC profile that camgrinder offers, but the Web 20/21 is slightly more aggressive than the 964 and will still pass smog. You start getting more of a lumpy idle though so you have to determine if you want that or not. Some do, some don't.

To take advantage of the cams, make sure you get a custom chip programmed from Steve Wong. You should notice a difference both on the dyno and in real world driving.

I wouldn't tear into the top end just to change cams, but if it is coming apart anyway...

Ralph

Jeff Alton · 06-01-2004, 08:05 PM

I just did this. I got my 964 cams from John. Originally was only going to change cams, but ended up doing the whole top end. I only have 350 or so miles on the car now( engine went in on friday) but I really like the cams. I also put SSI on the car. Nice idle with a SteveW 4K chip set up for these mods. I set the cams at 1.30mm and I do not notice any lack of bottom end. The car comes on the cam at about 3500 or so and it rips up to 5000 or so. I have not revved it any higher yet with my foot in it.

If you get these cams you will like them. I have also heard good things about Web Cams 20/21 grind but have not first hand experience.

Hope this helps, feel free to email me at jeff_alton@telus.net if you want more details.

Cheers, Jeff