911S powerband, 904 Carrera powerband, "Mulsanne powerband".....

[Jim Ratto]

Considering a few older Porsche high-output engines, specifically:

911S 2.2L: 180hp@ 6500, 84 x 66mm, 320' duration @ .15mm, 82hp/liter (366cc per cyl)
904 (587/3) 2.0L: 185hp @ 7000, 92 x 74mm, 352' duration @ .15mm, 94hp/liter (492cc per cylinder)

Obviously, Porsche saw the need for some generous valve overlap to achieve power, especially, considering the valve timing on the 911S was the same used on the smaller 2.0 6 cylinder. While I've never driven a 904 and never will, I have driven a few early 911's, my most vivid memory was the 2.4 1973 that McKenzie owned for a while. The powerband of that engine was thrilling.

So my question, considering the weight and stock 4.37:1 gearing of a Type 1, and your typical 94mm stroker engine, how would you duplicate the "powerband" of the old 911S or 587 4-cylinder motors? Not that horsepower numbers need to match, meet, exceed, but that the "camminess" and surge above 4000rpm resemble them. With the light weight of the VW, and the relatively "short" gearing of the 4.37 box, AND with the torque made by a 2.2L+ 4 cylinder (550cc per cylinder), a large amount of duration should get the car off idle fairly and give the "rush" above 4000 as well, right? But how much is enough, too much, just right? The Porsche cams were checked @ .006", we check at .050"...
Some sources list 911S cam intake duration @ 267' @ .050".... Engle 130? Of course, the VW motor has much bigger lungs to fill... (550cc vs. 366cc)...

again STREET motor.
ANY thoughts, feedback would be appreciated. Thanks guys,

Jim

[Dougy Dee]

What compression were these motors?

What gas was available?

[Jim Ratto]

What compression were these motors?

What gas was available?

911S and 587/3 (904) both ran 9.8:1

[sheep]

OH BROTHER

[Jim Ratto]

OH BROTHER

yeah hown long have I been whining about THIS huh?

Too bad Engle doesn't have an "FK-904-Carrera-cam-profile-for-Jim's-Bug" grind. 

[sheep]

hahahaha

[Jim Ratto]

hahahaha

maybe Ty's uncle can just take the 904 motor out of his lane-painting buggy and give it to me. he still owes me for the kadrons.

[lawrence]

Some companies offer custom ground camshafts, right? It would be cool to use some specs from hi-po vw and porsche engines from the past. Inch pincher II, 911s etc..

[stealth67vw]

What cam did they use in the Sport-O-Matic 911s?

[Jim Ratto]

What cam did they use in the Sport-O-Matic 911s?

funny.   

No ideas from anybody? To get a 2200cc pump gas Vee dub motor to come on @ 4000 and go to 7000?

[louisb]

What cam did they use in the Sport-O-Matic 911s?

funny.   

No ideas from anybody? To get a 2200cc pump gas Vee dub motor to come on @ 4000 and go to 7000?

Run that 86c a few degrees retarded? Sounds like you want something close to an FK-87 or FK-89.

--louis

[Harry/FDK]

Jim, the same you advised me... Best Of Both Worlds.

[nicolas]

hey please give some more input on the matter guys. i am not an expert, but lately i have found the duallobe cams an interesting option to overcome some of the troubles of long duration cams on the exhaust. so maybe that is a way to go.

[Johannes Persson]

Hi Jim,
What you need is:low comp ratio, slow opening and closing cam, short overlap, late intake closing and a big intake port.
This gives you a low dynamic cyl pressure at low rpm and when the rpm is going up VE increases, and at a point when the engine starts to tune there is a sudden rush of power thanks to higher dynamic cyl pressure.
It is actually a very sporty attitude and fun to drive.
Normally you want as much low end torque as possible in a streetdriven car but they often suffer from lack of torque at higher rpm.
I like both attitudes but the "slingshot" attitude at 4000rpm is really something, but it has to be drivable under 4000rpm or it is not worth it.
Regards
Johannes

[Rennsurfer]

Maybe I should just run off and buy a 911.

Careful, Jim... I'm sure you've driven a few. But once you own one, you'll never look back. They're just too much fun. Best sportscar ever built... PERIOD. Well, in my not-so-humble opinion. HA!

Back to thread content; I'm sure that there are people that have achieved the same thing(s) that you're mentioning in your posts. It would be cool to see something like that in action and to hear of it's specs.

[Cornpanzer]

How about a laggy turbo?  Doesnt wake up till 4k and then zing, all the way to 7000 in an instant! 

Seriously, the early 911 engine is a jewel.  Friends of mine who dont understand the "Porsche thing" are shocked by how hard I beat on my 2.2 S.   7200 rpm every shift!  Wheeeeeeeee
The best part is that I can beat on it today, and then hop in and drive cross country in it tomorrow with no worries, spinning 4000 rpm for hours on end. 

Ahhh, I cant wait for spring!

[Jim Ratto]

back to this old post..

I did discuss all this (after shopping for valve springs) with Pauter and yes they did me a nice cam... we'll see how it works, hopefully later this year. R6E8 grind.

[lawrence]

Jim, is that a custom grind. I do not see that cam listed here http://www.actionimport.com/Tech_Files/cam_information.htm I printed that list out and keep it in a drawer for reference. Good stuff!

Do you plan on putting that cam in your current motor? 2165, right? Break out the cam card for both motors and do a comparison. Come on buddy, don't hold out on us.

[Jim Ratto]

it's 272 deg @ .050 and 304 deg at seat.

[Udo]

Jim, is that a custom grind. I do not see that cam listed here http://www.actionimport.com/Tech_Files/cam_information.htm I printed that list out and keep it in a drawer for reference. Good stuff!

Do you plan on putting that cam in your current motor? 2165, right? Break out the cam card for both motors and do a comparison. Come on buddy, don't hold out on us.

Pauter has something about 100 cam grinds . Ask them for your application .

Udo

[John Rayburn]

Jim you're talking about my old 78.4 X 94 . W130 and Jeff's super whammy nonwelded 44X 37.5, and 48 Dellortos.

[John Rayburn]

Also, you're a homo for this Porsche talk... You're liable to summon a certain Porsche Gorgon. Also, my brother's old 74X 90  W110 and 10.5 to 1 acted like your talking.

[Jim Ratto]

Also, you're a homo for this Porsche talk... You're liable to summon a certain Porsche Gorgon. Also, my brother's old 74X 90  W110 and 10.5 to 1 acted like your talking.

so I have this Stuttgart skirt......   

[John Rayburn]

You're askin' for it!!!!

[Jim Ratto]

 

[Peter]

What i was thinking when i was reading your post..
didnt you have this cammyness with your 86 c?
or was it still different?

cheers, Peter

[Jim Ratto]

What i was thinking when i was reading your post..
didnt you have this cammyness with your 86 c?
or was it still different?

cheers, Peter

The 86C is an amazing cam, but not cammy, at least in my car. I'm still toying with the 86C but with as many miles as I run my car, the extreme lift has me reluctant.

[John Rayburn]

How your heads flow and venturie size has a big effect on the "camminess". The 86C in my combination isn't the least bit cammy.

[Peter]

how does it drive then John?
is it more linear or something?

[John Rayburn]

Yes, the power seems to be there full time , kind of like injection. You just put your foot in it at any given RPM or gear and it just goes. No bog , no stumble, no " coming on". It's just there.