Help - Search - Members - Calendar
Full Version: CIS on a /6 2.0 911S Engine
914World.com > The 914 Forums > 914World Garage
SLITS
Ok, just a quick question.....

Would the CIS system off a 2.4T work on a 2.0S engine? Are the cams so different that the "flapper" would bounce and cause driveabilty problems (not that the S motors don't have them anyway)?

Now's yer chance motorheads..............

lapuwali
My guess is no way. The S cams are very wild, and CIS really hates wild cams. It would idle very badly, and have really crappy low end.
Aaron Cox
stay with the 2.4. driveability wise its better.....

go woth the 2.0 S motor if it is a racer smile.gif
goose2
S cams won't work with CIS...too much overlap
Allan
So what's the best fuel delivery system for an s cam?
Aaron Cox
QUOTE (Headrage @ Nov 17 2005, 09:43 AM)
So what's the best fuel delivery system for an s cam?

carbs and MFI smile.gif and PEFI
SLITS
QUOTE (Headrage @ Nov 17 2005, 09:43 AM)
So what's the best fuel delivery system for an s cam?

The carbs that came with them I would suppose..... One site I visited for "S" motors recommended that you carry a spare set of plugs as they would foul in traffic at low RPM. sad.gif


Thanks for the answers guys.....it was what I expected, but I'm no expert on /6 motors.


Whatza matter Aaron...you don't want me to cream you with a 2.0S motor? laugh.gif It might fit real nice in that flared roller you have unsure.gif
Aaron Cox
lol... the 2.4 should rock me also....

not on an AX biggrin.gif
Allan
QUOTE (Aaron Cox @ Nov 17 2005, 08:46 AM)
QUOTE (Headrage @ Nov 17 2005, 09:43 AM)
So what's the best fuel delivery system for an s cam?

carbs and MFI smile.gif and PEFI

So what would an MFI set up normally run?

$?
$$?
$$$?
$$$$?
Root_Werks
Carbs are the easy answer. smile.gif
Allan
QUOTE (Root_Werks @ Nov 17 2005, 09:05 AM)
Carbs are the easy answer. smile.gif

I love the sound of them.

Sounds like they are gonna suck the back of my head off. aktion035.gif
SLITS
QUOTE (Headrage @ Nov 17 2005, 10:07 AM)
QUOTE (Root_Werks @ Nov 17 2005, 09:05 AM)
Carbs are the easy answer.  :)

I love the sound of them.

Sounds like they are gonna suck the back of my head off. aktion035.gif

A BJ and you're complaining! ph34r.gif
Aaron Cox
QUOTE (SLITS @ Nov 17 2005, 10:16 AM)
QUOTE (Headrage @ Nov 17 2005, 10:07 AM)
QUOTE (Root_Werks @ Nov 17 2005, 09:05 AM)
Carbs are the easy answer.  :)

I love the sound of them.

Sounds like they are gonna suck the back of my head off. aktion035.gif

A BJ and you're complaining! ph34r.gif

laugh.gif smilie_pokal.gif
lapuwali
QUOTE (Headrage @ Nov 17 2005, 09:05 AM)
QUOTE (Aaron Cox @ Nov 17 2005, 08:46 AM)
QUOTE (Headrage @ Nov 17 2005, 09:43 AM)
So what's the best fuel delivery system for an s cam?

carbs and MFI smile.gif and PEFI

So what would an MFI set up normally run?

$?
$$?
$$$?
$$$$?

MFI is pretty major money. Rebuilding the pump runs about $1500, on top of sourcing the pump, the throttle bodies, the injectors, the plumbing, etc.

Carbs also aren't cheap, at $1500 or so a set for used ones. I don't want to know what PMO charges for a new set.

For PEFI, however, you can use TWM throttle bodies, and get the same look and sound of Webers, but they won't foul plugs constantly. Webers on an S motor have to be set up pretty rich to have any drivability at all. PEFI could be tuned much better. This is still not a cheap option, but you'll get better drivability, and it would be cheaper long-term than MFI.
Root_Werks
Yup, if you start out with MFI it's worth saving or keeping up on it. If you don't have it, carbs will do 95% what MFI will.

Hey Allan, remember those carbs are 46's and that engine pulled 155-160 across all 6 cyl's so yeah, it sucks BIG TIME! laugh.gif
sixnotfour
Pre74 S cams are one thing , Wild mueba.gif
74 and later US car S cams are designed for CIS
Mark Henry
QUOTE (lapuwali @ Nov 17 2005, 03:05 PM)
Carbs also aren't cheap, at $1500 or so a set for used ones. I don't want to know what PMO charges for a new set.

PMO's are $3500....I think that's Canadian $.

A 911 guy had a set at the PCA show, very pretty but at that price tag I'd take the PEFI.
goose2
QUOTE
74 and later US car S cams are designed for CIS

Jeff...his 2.0 S would be pre '74 though, right?
sixnotfour
yep beer.gif
SLITS
'67 to be exact
lapuwali
QUOTE (goose2 @ Nov 17 2005, 11:41 AM)
QUOTE
74 and later US car S cams are designed for CIS

Jeff...his 2.0 S would be pre '74 though, right?

Yes, the '75 and later (there was no '74 S) is a 2.7, and the S is strictly for marketing purposes. The 911 and 911S made the same power in the 2.7 era. The S may have had some different options on it, but the engines were all the same.

The differences in the 2.0 engines were much more marked. The 2.0 911T engine only made 110, where the 2.0S made 160hp, and most of the differences were down to the cams used. The 2.0, 2.2, and 2.4S engines were all tuned to the very limit of streetability.
goose2
aluminum case huh?
Cap'n Krusty
QUOTE (lapuwali @ Nov 17 2005, 11:54 AM)
QUOTE (goose2 @ Nov 17 2005, 11:41 AM)
QUOTE
74 and later US car S cams are designed for CIS

Jeff...his 2.0 S would be pre '74 though, right?

Yes, the '75 and later (there was no '74 S) is a 2.7, and the S is strictly for marketing purposes. The 911 and 911S made the same power in the 2.7 era. The S may have had some different options on it, but the engines were all the same.

The differences in the 2.0 engines were much more marked. The 2.0 911T engine only made 110, where the 2.0S made 160hp, and most of the differences were down to the cams used. The 2.0, 2.2, and 2.4S engines were all tuned to the very limit of streetability.

No 1974 911 S? You are mistaken. The standard 911 made 150 HP, the "S" made 175. The 1974 Carrera model was a tarted up "S". There was no 911 T. Rumor floating around the Pcar school in LA was it was because of the short-lived gummint price regs which were in effect at the time. They couldn't raise the price of the 911T, so they renamed it the "911". BTW, one of the big differences between the 2.0 T and the S, besides the cam profile and timing, was the CR. T pistons were nearly flat with partial cutouts for the valves, the E's somewhat domed with bigger cutouts, and the S's had large domes with big valve pockets. CIS probably wouldn't even run with early S cams. E and S cams won't work with T pistons, nor with CIS pistons unless you cut huge pockets in them. The Cap'n
tracks914
Were there any early engines that had to run on high octane fuel (because of high CR's) or will they all run on regular gas?
brant
QUOTE (tracks914 @ Nov 17 2005, 05:18 PM)
Were there any early engines that had to run on high octane fuel (because of high CR's) or will they all run on regular gas?

fuel has changed a LOT!
The testing, rating, and composition has all changed so much...

but I think the early motors still like higher octane.
I know we run actual 98 octane gas on our 1967S 2.0/6
(stock 1967S compression)

We blend race gas and street gas to get 98 octane.
comes out around $4.50/gallon

not absolutely necessary... but I wouldn't go throwing 85 octane into the gas tank of ANY early motor... and since were under high load and thermal stress I'm fine with this conscesion.

brant
SLITS
I believe the CR on an early "S" was like 9.8 or 9.9:1
tracks914
QUOTE (brant @ Nov 17 2005, 04:24 PM)
We blend race gas and street gas to get 98 octane.
comes out around $4.50/gallon

$4.50 a gallon - I wish I could get 85 octane for that cheap!!!! mad.gif
r_towle
There is a porsche shop here in the East that has developed a new FI system to replace the costly to fix MFI.

Check out Autosport Engineering in Stow MA.
Ask for Lenny.
They have a web site also.



Rich
brant
QUOTE (tracks914 @ Nov 17 2005, 05:27 PM)
QUOTE (brant @ Nov 17 2005, 04:24 PM)
We blend race gas and street gas to get 98 octane.
comes out around $4.50/gallon

$4.50 a gallon - I wish I could get 85 octane for that cheap!!!! mad.gif

Well part of my deal is that I'm legally not using it in a registered street vehicle.

so I'm blending LEADED - offroad use only fuel to get that price.....

that and my government places the cost of a gallon of gas above alot of other priorities...

oh crap am I going to get this thread banned?
I'll retract if necessary.

brant
SLITS
QUOTE (brant @ Nov 17 2005, 05:37 PM)
QUOTE (tracks914 @ Nov 17 2005, 05:27 PM)
QUOTE (brant @ Nov 17 2005, 04:24 PM)
We blend race gas and street gas to get 98 octane.
comes out around $4.50/gallon

$4.50 a gallon - I wish I could get 85 octane for that cheap!!!! mad.gif

Well part of my deal is that I'm legally not using it in a registered street vehicle.

so I'm blending LEADED - offroad use only fuel to get that price.....

that and my government places the cost of a gallon of gas above alot of other priorities...

oh crap am I going to get this thread banned?
I'll retract if necessary.

brant

You get the taxes back on the fuel then.........
brant
hmmm....
I really shouldn't of said that..
just messing around...

I guess I'm reaping the benefit of US fuel prices versus Canada and europe... thats all I meant.

(hey I heard that premium in Kuwait was at $.85 a gallon this week....)

brant
Allan
QUOTE (lapuwali @ Nov 17 2005, 11:05 AM)
For PEFI, however, you can use TWM throttle bodies, and get the same look and sound of Webers, but they won't foul plugs constantly.

Got a good recommendation on plugs for a '77 2.7 S motor running 46mm webers???
Duffster
Hey Alan... 46s might be a little heavy duty unless you run something like 906 cams. On the other hand, I'm at 36mm in mine and still lean out a little too much when the holy sh*t pedal is all the way down at high RPMs. Twin plugs maybe? Gotta get all that gas burned somehow. wink.gif
airsix
ANY digital programable ECU (Megasquirt, SDS, PerfectPower, Link, etc. etc.) and a set of individual throttle-bodies is a better-than-MFI MFI replacement. Any modern ECU can be programmed to run using only temp, rpm, and throttle possition as inputs (no manifold pressure) - just like MFI, and do it well. My ECU has a map sensor but I ran it MFI-style for a while once just for the heck of it to see how well I could program it. I was utterly SHOCKED at how easily it was tuned and how accurately it maintained the mixture once tuned. Piece of cake. IMHO if you are sourcing induction for an engine there is no reason today to use anyting but a digital ECU regardless of whether it's a tame-cammed or wild-cammed engine.
-Ben M.
Allan
I'm getting alot of feedback from the 911 guy's telling me that the 46's may be too much. Most of them are running 40's on the 2.7 S cam motor...

I gotta call the Cap'n today.

hijacked.gif Sorry Ron. biggrin.gif
Root_Werks
Those 46's might be jetted a little much for a 190hp 2.7, but I don't think they are too much. Porsche ran 46's on 911 2.0's at 200hp in the 60's I thought? idea.gif

Run W7DTC's in there, good heat range tripple electrode plugs for a street car.
SLITS
QUOTE (Headrage @ Nov 18 2005, 07:11 AM)
I'm getting alot of feedback from the 911 guy's telling me that the 46's may be too much. Most of them are running 40's on the 2.7 S cam motor...

I gotta call the Cap'n today.

hijacked.gif Sorry Ron. biggrin.gif

If you're going to defect to the dark side for information, we're gonna have to ban you forever.

You are now in the middle...Not a NARP and Not a "real" six....you have no home...you have no country....you can only lift your pinky halfway and eat semi-rotten cheese....

Looks like we'll have to set up counseling for you chairfall.gif
Aaron Cox
QUOTE (SLITS @ Nov 18 2005, 09:34 AM)
QUOTE (Headrage @ Nov 18 2005, 07:11 AM)
I'm getting alot of feedback from the 911 guy's telling me that the 46's may be too much.  Most of them are running 40's on the 2.7 S cam motor...

I gotta call the Cap'n today.

hijacked.gif  Sorry Ron. biggrin.gif

If you're going to defect to the dark side for information, we're gonna have to ban you forever.

You are now in the middle...Not a NARP and Not a "real" six....you have no home...you have no country....you can only lift your pinky halfway and eat semi-rotten cheese....

Looks like we'll have to set up counseling for you chairfall.gif

laugh.gif
Allan
QUOTE (SLITS @ Nov 18 2005, 08:34 AM)
QUOTE (Headrage @ Nov 18 2005, 07:11 AM)
I'm getting alot of feedback from the 911 guy's telling me that the 46's may be too much.  Most of them are running 40's on the 2.7 S cam motor...

I gotta call the Cap'n today.

hijacked.gif  Sorry Ron. biggrin.gif

If you're going to defect to the dark side for information, we're gonna have to ban you forever.

You are now in the middle...Not a NARP and Not a "real" six....you have no home...you have no country....you can only lift your pinky halfway and eat semi-rotten cheese....

Looks like we'll have to set up counseling for you chairfall.gif

I gotta go find my wife some Birkenstocks.









Or is that for the gender challenged?
SLITS
hijacked.gif Hijacker notice....Alert.....Alert

The last post was not PC....it will be ignored unitl the word "L........n" is changed to "sexually challenged".


hijacked.gif Hijacker Notice Alert Over

You can now return to your normal voyeurness!

SLITS
Sehr gut mein irregeführter Freund.
This is a "lo-fi" version of our main content. To view the full version with more information, formatting and images, please click here.
Invision Power Board © 2001-2024 Invision Power Services, Inc.