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914World.com _ 914World Garage _ CIS on a /6 2.0 911S Engine
Posted by: SLITS Nov 17 2005, 10:07 AM
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..............
Posted by: lapuwali Nov 17 2005, 10:16 AM
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.
Posted by: Aaron Cox Nov 17 2005, 10:25 AM
stay with the 2.4. driveability wise its better.....
go woth the 2.0 S motor if it is a racer 
Posted by: goose2 Nov 17 2005, 10:28 AM
S cams won't work with CIS...too much overlap
Posted by: Headrage Nov 17 2005, 10:43 AM
So what's the best fuel delivery system for an s cam?
Posted by: Aaron Cox Nov 17 2005, 10:46 AM
| QUOTE (Headrage @ Nov 17 2005, 09:43 AM) |
| So what's the best fuel delivery system for an s cam? |
carbs and MFI
and PEFI
Posted by: SLITS Nov 17 2005, 10:49 AM
| 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.
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?
It might fit real nice in that flared roller you have 
Posted by: Aaron Cox Nov 17 2005, 10:51 AM
lol... the 2.4 should rock me also....
not on an AX 
Posted by: Headrage Nov 17 2005, 11:05 AM
| QUOTE (Aaron Cox @ Nov 17 2005, 08:46 AM) | ||
carbs and MFI and PEFI |
So what would an MFI set up normally run?
$?
$$?
$$$?
$$$$?
Posted by: Root_Werks Nov 17 2005, 11:05 AM
Carbs are the easy answer.
Posted by: Headrage Nov 17 2005, 11:07 AM
| QUOTE (Root_Werks @ Nov 17 2005, 09:05 AM) |
| Carbs are the easy answer. |
I love the sound of them.
Sounds like they are gonna suck the back of my head off.
Posted by: SLITS Nov 17 2005, 11:16 AM
| QUOTE (Headrage @ Nov 17 2005, 10:07 AM) | ||
I love the sound of them. Sounds like they are gonna suck the back of my head off. |
A BJ and you're complaining!
Posted by: Aaron Cox Nov 17 2005, 11:18 AM
| QUOTE (SLITS @ Nov 17 2005, 10:16 AM) | ||||
A BJ and you're complaining! |
Posted by: lapuwali Nov 17 2005, 01:05 PM
| QUOTE (Headrage @ Nov 17 2005, 09:05 AM) | ||||
So what would an MFI set up normally run? $? $$? $$$? $$$$? |
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.
Posted by: Root_Werks Nov 17 2005, 01:09 PM
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!
Posted by: sixnotfour Nov 17 2005, 01:27 PM
Pre74 S cams are one thing , Wild 
74 and later US car S cams are designed for CIS
Posted by: Mark Henry Nov 17 2005, 01:33 PM
| 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.
Posted by: goose2 Nov 17 2005, 01:41 PM
| QUOTE |
| 74 and later US car S cams are designed for CIS |
Jeff...his 2.0 S would be pre '74 though, right?
Posted by: sixnotfour Nov 17 2005, 01:43 PM
yep 
Posted by: SLITS Nov 17 2005, 01:53 PM
'67 to be exact
Posted by: lapuwali Nov 17 2005, 01:54 PM
| QUOTE (goose2 @ Nov 17 2005, 11:41 AM) | ||
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.
Posted by: goose2 Nov 17 2005, 01:55 PM
aluminum case huh?
Posted by: Cap'n Krusty Nov 17 2005, 02:40 PM
| QUOTE (lapuwali @ Nov 17 2005, 11:54 AM) | ||||
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
Posted by: tracks914 Nov 17 2005, 06:18 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?
Posted by: brant Nov 17 2005, 06:24 PM
| 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
Posted by: SLITS Nov 17 2005, 06:25 PM
I believe the CR on an early "S" was like 9.8 or 9.9:1
Posted by: tracks914 Nov 17 2005, 06:27 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!!!!
Posted by: r_towle Nov 17 2005, 06:37 PM
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
Posted by: brant Nov 17 2005, 06:37 PM
| QUOTE (tracks914 @ Nov 17 2005, 05:27 PM) | ||
$4.50 a gallon - I wish I could get 85 octane for that cheap!!!! |
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
Posted by: SLITS Nov 17 2005, 06:38 PM
| QUOTE (brant @ Nov 17 2005, 05:37 PM) | ||||
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.........
Posted by: brant Nov 17 2005, 06:41 PM
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
Posted by: Headrage Nov 17 2005, 06:47 PM
| 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???
Posted by: Duffster Nov 17 2005, 10:46 PM
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. 
Posted by: airsix Nov 17 2005, 11:12 PM
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.
Posted by: Headrage Nov 18 2005, 08:11 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.
Sorry Ron.
Posted by: Root_Werks Nov 18 2005, 10:02 AM
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? 
Run W7DTC's in there, good heat range tripple electrode plugs for a street car.
Posted by: SLITS Nov 18 2005, 10:34 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. Sorry Ron. |
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
Posted by: Aaron Cox Nov 18 2005, 10:36 AM
| QUOTE (SLITS @ Nov 18 2005, 09:34 AM) | ||
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 |
Posted by: Headrage Nov 18 2005, 10:57 AM
| QUOTE (SLITS @ Nov 18 2005, 08:34 AM) | ||
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 |
I gotta go find my wife some Birkenstocks.
Or is that for the gender challenged?
Posted by: SLITS Nov 18 2005, 12:54 PM
Hijacker notice....Alert.....Alert
The last post was not PC....it will be ignored unitl the word "L........n" is changed to "sexually challenged".
Hijacker Notice Alert Over
You can now return to your normal voyeurness!
Posted by: SLITS Nov 18 2005, 06:38 PM
Sehr gut mein irregeführter Freund.
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