3.0 on carbs

TheMonkey · Post by **TheMonkey** » Thu Jul 13, 2006 9:55 am

Morning,
I'm sure this post should be in another section but i needed a quick answer. Some git is stealing my 2.2 from my 914 (my Dad) and I need another engine. I was thinking about a 3.0 SC engine for easy torque/grunt etc. My question is, can these be easily made to run on carbs or am i best off sticking with its fuel injection?
One concern I have is whether all the air box and guff would fit under the lid of the 914.

Thanks in advance for any assistance/advice any of you might have.

Cheers!

Mark

speedysimon · Post by **speedysimon** » Thu Jul 13, 2006 10:57 am

Hi - I dumped all the CIS off my 3.0 SC engine and stuck Webers on - had to have rolling road to set up jetting, needed to really reduce fuel pressure, but otherwise it runs really well, with a straight line of torque up to 7000.
Regards
Simon

TheMonkey · Post by **TheMonkey** » Thu Jul 13, 2006 11:18 am

Thanks Simon,

Just what I wanted to hear!!!

The other thing I forgot to ask, is whether the engine will mate up to a 901 box. I thin it should, but needed to ask!

Also, what size Webers are you using for the engine?

Any idea of final power output? The engine I'm looking at is 188bhp unit from an 1980 SC. I will have headers with no heat exchangers and a pre '74 Dansk sports exhaust.

Thanks again,

Mark

stevieboy · Post by **stevieboy** » Thu Jul 13, 2006 1:47 pm

Stick some webers on, mine has and it flies with a bit of tuning, also have twin outlet exhaust on, sounds fantastic.

I,m running 48 IDA,s, on a Carrera 3.o Targa (76)
Ask Dyno, Higgs or Gilbert.

Webers are the way forward......... for me anyway.

stevieboy · Post by **stevieboy** » Thu Jul 13, 2006 1:48 pm

Sorry meant to say you might get the odd flame out the back............

Putting out over 200 bhp ( have been told its about 220).
But you never know.

TheMonkey · Post by **TheMonkey** » Thu Jul 13, 2006 2:21 pm

Again, thats just what i needed to hear! Flames - even better!

Plans to convert the 914 back to original in order to race in the HSCC, have been put on hold and i think i will stick with flat six power for a while yet.

Thanks guys for your help.

I think I may have found an engine, in fact, I might have an option on another 3.0, but will have to wait and see. Trouble is, I now require some Webers. How much will carbs for this particular application cost, or is it worth looking at PMO's? Also, what size am i looking for. The car is purely for a laugh and possibly some sprints/trackdays.

Thanks again,

Mark

Alan @ CanfordClassics · Thu Jul 13, 2006 2:28 pm

For 3.0ltr engines the general consensus is 40mm. My advice is to go with PMO if you are certain carbs are the way to go.

Alan

stevieboy · Post by **stevieboy** » Thu Jul 13, 2006 2:40 pm

Where abouts are you Mark, if your close enough you could look at the engine, carbs in mine.
Cars over in Essex close to the M11 M25 junction.

TheMonkey · Post by **TheMonkey** » Thu Jul 13, 2006 3:28 pm

Thanks again guys for your advice.

Alan, I've had 40mm Webers on a 2.2, which strangely enough I bought from you!!!!! This is the engine my old man is liberating from the 914. He has bought a 2.2E to race with the HSCC, but the engine is smoking like a trooper and I reckon it's down on power too. So gallantly, I offered him mine. (Fool)
I would however, like to say that the engine has ran faultlessly since it was put in the car (slight oil leak from thermostat housing) and did a spanking good job of getting me to Le Mans and back at mostly three figure speeds!

I think it's time to go GT.

Subsequently i need more power!!!! My question is this: If I was using 40mm carbs on the 2.2 and they were just fine, are they going to be big enough for the 3.0? I was thinking of 46mm PMO's (If i can find the cash!!)
Also, anybody know of any carbs for sale anywhere?
And what ignition system will i have to employ? Is it a case of using the existing system, or will i need a recurved dizzy and other assorted expense?

Hmmmm, i can see the noughts adding up!!!!!

Thanks again!

Mark

TheMonkey · Post by **TheMonkey** » Thu Jul 13, 2006 3:31 pm

Sorry Steve,

I also meant to say, thanks for the offer. I'm in East Dulwich, but it's not far to jump on the North Circ to the M11 junction. Trouble is, the 2.2 is coming out of the car this sunday and saturday is looking busy too.
However, if you're not doing anything much next weekend, I could trundle up in the 924.

Let me know your details and I'll be in touch.

Thanks again for the offer, much appreciated.

Mark

914-6 · Post by **914-6** » Sun Jul 16, 2006 6:18 am

Hi, I have used pmo 40's on my 2.7 rs type motor in my '14-6 race car--excellent. I do not get any of the fuel starvation problems I experienced with webers--I tried 3 different sets including baffling one set-this improved it but on hard cornering, with 10" slicks , the fuel still ran away from the pick up point in the bowls. Not so with pmo's they pick up the fuel in a different way.
When my carbs arrived ,jetted and set to my engine, we fitted them straight on and havent adjusted since.!!
I suggest you go for the taller inlet manifolds-they appear to work better.
Richard--I belive that's his name, at pmo is very difficult to actually get to talk to--he prefers to do everything by fax, however, if you can get to talk with him he's very knowledgable about porsche/carb set ups.
Give me a ring if you need further info.
Cheers

Ian
07785 792412

davidppp · Post by **davidppp** » Sun Jul 16, 2006 8:55 am

Hello, Mark.

There are several issues when fitting an sc into a sixer.

First I'm sure you already know the box will sooner or later break if full throttle is used in first gear; and the bearings in the intermediate plate likewise will not last long..
Second you need a special and rather costly flywheel, and a heavy duty clutch to match.
Third you need to change the oil system which is different from the 2.2..I can help there..
Finally, filling the petrol tank can be a costly chore..!

EFI would be the best set-up of course..

Does Dad want to sell the core 2.2?

Or is he ready for a pukka race motor?

Good luck!..the sc is bulletproof really..

Kind regards
David

fourteener · Post by **fourteener** » Sun Jul 16, 2006 9:16 am

As said above the 3.0 has a 9 bolt flywheel. PMS sell flywheel for mating 901 to 9bolt cranks. I know that the SC engine has been fitted into the fourteen engine bay with the K-Jet still on - (Wayne Dempsey of pelican parts had one fitted and this is the engine featured in his 'how to rebuild a 911 engine book). Depends on what engine mount you have and how high it's mounted -but it can be done with out cutting into the rear boot -need to remove the engine lid catch.