Bill Verburg

Can anyone provide some feedback and or info on the cams available for 964/993. Both hyd. and mech. are of interest. I am interested in specs and general feel/drivability impressions from users. The Webcam 20/21 and 993 Carrera RS are the only ones I've been able to get any info on. this is getting a little frustrating as I've had zero response from my last 4 posted questions. Have I offended everyone?

richard glickel.

Bill,

You haven't offended anyone. I just figured that you know more than the rest of us anyway so, if you don't know the answer, how the hell should I know?

I've got the WebCam cams in my 3.6L. Rick DeMan described them as "993 super sport" cams. He's got the specs. I've just got the little generic booklet that came with the cams, no specific info that I can provide to you (hey, I know where to put the key, left side, right?). :-)

Email Rick @ Demanmotorsport.com, and ask him for the specs. As a matter of fact, why don't you ask him for the entire build spec on my engine? You certainly have my persmission to obtain the info.

Richard
'87 Carrera-3.6L

Bill Verburg

Thanks Rich, I have talked to Rick, among others. I need to make some informed decisions, Generally what I hear is a name say "993 sport cams" but no specs or feedback from users. Can you describe the torque characteristics of your car, I know its tough, but wide power band/ narrow power band, neeed to shift constantly to keep revs at****, comes on like gagbusters at **** etc. can be useful.

richard glickel.

VERY wide power band. The sucker just pulls and pulls. Originally, the engine revved very freely past 7,000 RPM (I believe we have the rev limiter at about 7300 RPM). Lately, I've been experiencing some mid-range hesitancy when accelerating in second gear at around 4000-4500 RPM (not every time BTW). I only encounter this problem in second gear. And, some backfiring after letting off the gas. No problem on the upshift to 3rd (@ 7000 RPM). . . and away we go!

The car ran very well on the track at Watkins Glen last weekend. I have no idea how fast I was going on the back straight, but I did hit 5th gear(briefly) after shifting from 4th at 7100 RPM! So, 5400 RPM in 5th? I'll have to check this out on the Thruway (I know there's probably a mathematical formula to determine the car's speed, but what's more fun?).

I would love to try headers and super traps. But, I still like to drive the car on the street and can't make that switch until I'm prepared to give up the "boulivardiering". When the car was dyno'd after replacing the clutch last Spring, HP was 259 at the rear wheels and torque was in the same range - 249? (Rick never did fax me the print out off the computer, but I did see it with my own four eyes on the monitor).

Hope to see you soon!

Richard
'87 Carrera-3.6L (fast car, slow driver)

Bill Verburg

Thanks again Rich, thats exactly what I am looking for. When I listen to your car at idle(I still have the recording from Ricks Dyno day) it doesn't sound lumpy, I am looking for good power and torque up to ~7000 maybe a little more, broad torque is important. Rick recommended the 993 sport which is what you have, now I need to know if the hyd. version is similar. For all I know its the same thing as the 993 RS which is only marginally happier than the regular 993 cams. The Webcam 20/21 sounds interesting also.

FWIW I've recently had some interesting discussions w/ Joel Reiser. He's fairly adamant that the stock 993 headers are the best way to go for street driven 964 or 993, he feels that the 1.625" oem 993 header w/ or w/o cat is an excellent exhaust choice. For use w/o the cat cut the ends of the collector off and plumb to the muffler similar to what I did.

Yeah, Rick's hard to get ahold of sometimes, it's tough running a small business these days.

Howard

Bill,

I'm a little puzzled over your question about hydraulic versus mechanical versions of cams. I was under the impression that the cams for te 964 and 993 were identical in design although the rockers became pressure fed for the 993 which would eliminate valve adjustments. You can convert the 993 back to solid rockers for racing (which all builders have advised me to do ). I'm just looking for information, I've started a 3.6 racing engine build going with solid rockers and RS cams, RSR heads and I don't want to make any mistakes along the way.

Bill Verburg

Howard, I didn't know that. I have 3 different 993 projects to chose from.

2 are '95 993 1 of which has the factory 3.8 kit inc heads & cams, it is not a concern as the package has already been built, the second also a '95 993 w/3.8 can either go w/ 993RS hyd. cam which only has 3 deg more intake and 2 degrees more exhaust duration than a regular 993 or backdate to mechanical rockers and use the mechanical 993 super sport(which I havn't been able to get specs for yet, Rich has this cam in his 964 3.6) I am wondering if there might be a better street cam with lumpier lobes, the Webcam 20/21 seems to be the limit w/ motronic, if so is it compatible w/ hyd rockers, Rich's mech. 993 super sport sounds good.

The last is a variram 3.8 where the same cam concerns arise. 993RS, or some other slightly happier cam. Here the variram my allow the use of bigger lumps, but again I don't know.

I do tend to think that I want to stick w/ hyd. rockers for maintainance reasons.

Bill Gregory

[quote]<strong>I do tend to think that I want to stick w/ hyd. rockers for maintainance reasons.</strong><hr></blockquote>


Bill,

You may already know that many who track their 993's remove the hydraulic lifters and replace them with mechanical lifters. As I recall, as the hot oil thins out under track condition, it can affect the hydraulic lifters operation. For street only usage, they hydraulics are fine, however, if you plan to track your machine, you may want to consider mechanical lifters.

Bill Verburg

Bill,
From reading the 993 section here it seems that there are a lot of tracked 993s w/o any rocker problems. We're talking a street engine here w/ ocasional DEs. I certainly have no experience in this area, that's why I am looking for feedback, it almost seems as if the 993 owners are a bit clickish, maybe just my imagination, but I've gotten no reponse there.

By the way thanks for the reference I'll call Tues.

Howard

Bill ( Verburg),

Maybe you should give Gordon a call at Autometrics, he would certainly know which cam would be best for you, or Laurie at Webcam.
I have a close friend in the POC who was running RSR cams but he complained that the peak power came on too late,which was in the 7200-8,000 rpm range. He said it was just too hard on the engine so he swapped to RS cams instead.(3.8) fyi.
BTW, I was also advised that since the hydraulic rockers are drilled for oil passageways that it makes the rockers prone to breakage. If you go with RSR rockers the adjustment is with shims (a PITA ) and very expensive as well. again fyi.
good luck!

Bill Verburg

Thanks for the info guys!
Howard, I looked into a 3.8RSR, it is not suitable for what I have in mind for many reasons, you just mentioned 2 of them. How'd your friend like the 3.8 w/993RS cams? Did he retain the hyd rockers or convert? Is it a dual purpose or strictly track car?

Bill Gregory

[quote]<strong>By the way thanks for the reference I'll call Tues.</strong><hr></blockquote>

Bill,

Also ask him about 993 hydraulic lifters. I know he just finished replacing a set with the mechanical variety.

Also, did you post your question on the rennlist racing or 911 email lists? Perhaps another source to get some input.