What carbs?

Need some help with a technical problem - ask away and let's see if we can all help.

Moderators: hot66, impmad2000, Nige

Post Reply
haasad
Me and DDK sitting in a tree! KISSING
Posts: 2568
Joined: Tue Oct 19, 2004 8:46 pm
Location: Dorchester

What carbs?

Post by haasad »

The body on my 75 911S fun car is progressing nicely so its time to start planning the motor. I am not looking for mega power hikes and intend to fit exhaust headers (no heaters) onto the rebuilt standard engine with an RSR style three outlet muffler. I really dislike the CIS fuel injection set up fitted as standard and want to fit carbs. What should I be looking for that wont break the bank or is it a waste of time and money?Opinions and advice appreciated.
Nick Moss
Nurse, I think I need some assistance
Posts: 9424
Joined: Sat Nov 08, 2003 6:59 pm
Location: East Sussex
Contact:

Post by Nick Moss »

The usual carbs to fit are Webers. You will need to have the chokes changed and get them re-jetted to suit your motor. Cost with manifolds and linkages about £800

There are lots of Zeniths around for about £250, they are cheap copies and noyt as popular. They too will need re-jetting

A more expensive but easier solution is to fit PMOs, available for around $2500 jetted to suit your car.
Nick Moss - early911.co.uk - Fuchs refurbishment
07980 017994
nick@early911.co.uk
Lightweight_911
Nurse, I think I need some assistance
Posts: 18004
Joined: Wed Nov 12, 2003 10:48 pm
Location: Worcs/W Mids border

Post by Lightweight_911 »

Or you could always buy these 46IDA's from me (currently set up for a 3.2):

Image

Totally rebuilt by Bieker engineering in the States & complete with tall manifolds & watershields.

Or these 46IDA's on their own:

Image

Neither set are cheap though... :shock: :wink:
Andy

“Adding power makes you faster on the straights;
- subtracting weight makes you faster everywhere”
domo1977
DDK addict
Posts: 101
Joined: Tue Mar 16, 2004 9:11 am
Location: Oxfordshire

Post by domo1977 »

Just to defend the Zeniths (but not hoping to start a big debate!)
They are pretty much just as good as Webers and, having just rebuilt some, just as easy to work with. They mainly suffer due to there not being much easily accessable information on them. Gary71 has just put this right and now has a great website for them, search for his post on Zeniths in the 911 section of this site. Rebuild kits are available, but jets are not, but as long as you are increasing in engine size you can drill your existing jets out, no problem! Not saying to discount any of the other information already posted as it is all valid, but worth a look if on a budget and dont mind getting your hands dirty!

A general note when buying used carbs: check for wear in the throttle shafts, can cause bad running and is a pain to fix. Also unless recently done, budget for a rebuild kit (£40 to £60 and easily done by any home mechanic) will save alot of time later when you're trying to tune the car prevents getting odd results due to blocked jets etc.

hope that's of some use!

Dom
haasad
Me and DDK sitting in a tree! KISSING
Posts: 2568
Joined: Tue Oct 19, 2004 8:46 pm
Location: Dorchester

Carbs

Post by haasad »

As usual DDK turns up trumps.

I do have a lot of experience with sidedraught webers so applying that to downdraught shouldn't be too difficult. I definitely don't mind getting my hands dirty so will be looking for Webers and manifolds / linkages etc needing rebuild at the right price soon.

Lightweights lovely rebuilt kit looks great and if the quality of other parts I've had from that source is anything to go by should suit someone with deeper pockets than me very well.

911 2,7 S (R) themed rebuild
Post Reply