PMO or Webber

[hienz]

If money is not a factor, which carbs are the best for 1975 911s stock exhaust with thermal reactors removed?
I have heard a lot of goods about PMO's
I am hunting for Carbs and trying to rid of CIS because they do not look so nice and clean in engine compartment. My car has lot of carbon fibers pieces in engine compartment and I would like to see them. Thanks

[dwelle]

might take a look at PMO ITB's before you commit to carbs...

[1QuickS]

Weber, not Webber

Used Webers are routinely worn out & need refurbishment which will probably equal the purchase price. Add intake manifolds, air cleaners, throttle linkage, re-jetting & fuel pressure regulator & you will see that PMO carbs are a bargain.

If your car came with Webers then Webers are the better path but this is not your issue.

You will need to get your dizzy re-curved for use with carbs or ITBs.

Personally, I prefer Webers. I have serviced PMOs for Richard Parr and like them but I am a Weber guy. They need to be in good shape!

[JJ 911SC]

Originally Posted by dwelle

might take a look at PMO ITB's before you commit to carbs...

+1

[juanbenae]

ill repost what I said in the other carb thread you have going currently.

you don't say where you're from, but fuel quality & the seasonal additives in CA's urban areas plays havoc on my webers. a year & a half in on them I am recognizing patterns developing via an AF gauge.

there's something to be said about getting a new set PMO's somewhat set up for your car instead of a set of weber that you may need to spend a few $$ on in addition to the $2500 entry fee. things like throttle shafts & other rebuild wear/maintenance items can be present in a older set of carbs. additionally set up may require multiple jet packages... more $$


lastly, forget the naysayers! carbs will wake up even a stock CIS motor nicely if you get the dizzy recurved and early or SSI exhaust. plus, they sound & look cool..
__________________



you're still spelling "weber" wrong too.

[faverymi]

If I had to do it again in 2018

Al Ikosmal ITBs complete package.

[hienz]

Paul,
Thank you for pointed that out that I did not spell Weber correctly. I never owned Weber/PMO thus why I do not know how to spell Weber. Thank you for the info I have learned here.

[Jack Stands]

Though I have two cars running Weber’s and have always loved their performance and looks, I’d have to agree that fuel injection is the way to go these days because of the new adulterated fuel formulations. Electronic control does a better job than the Webers.

[hienz]

My final decision: Bought 40IDT Weber carbs and PMO intakes. I now need air filters and rain shields because I will be driving this 1975 911s on CA streets and Hwy and for track days I just leave filters and rain shields at home. Anyone used PMO intakes with Weber’s. Also will original distributor works with this new setup that I am planning?

[juanbenae]

Originally Posted by hienz

My final decision: Bought 40IDT Weber carbs and PMO intakes. I now need air filters and rain shields because I will be driving this 1975 911s on CA streets and Hwy and for track days I just leave filters and rain shields at home. Anyone used PMO intakes with Weber’s. Also will original distributor works with this new setup that I am planning?

webers with PMO manifolds are quite common so you're on the right track. just make sure you get the correct heat/vibration isolators for the CIS intakes. there is a void where the injectors fit at the head intake that the standard gasket can not seal properly. PMO has kits that include longer studs and a fortified area to seal off the head to the intake manifold.

as stated earlier the dizzy really needs a recurve to be most effective with additional advance. sure, you can run it as is but why go to all the trouble to install carbs and not be able to realize the full benefit? if the dizzy has never been out it does not hurt to have it refreshed entirely cause if it's tired you will have a hard time holding timing recurved or not.

[hienz]

Thanks for head up. Very helpful

[juanbenae]

check out pierce manifold in Gilroy CA for weber how to literature, parts and jets. paul's performance oriented site really can't be beat for information on these carbs for our cars. it's become the bible in my garage. pierce carrys the filters, housings & covers too I believe. you might also want to post a want to buy add in the classifieds ASAP to see if you can get the topping parts there and have them on hand to cut down on wait time in the future.

[hienz]

Juan
I do need to read some Weber bibles and maybe get some more helps here in months to come

[roblav]

IDT's will probably be OK with the 75 engine. IMHO, higher performance engines, if Webers retained, require IDA's or even IDS's. Even so, as others have said, recommend change to a decent exhaust and re-curve the distributor.

[Jack Stands]

I don’t think PierceManifolds carries air cleaners or manifolds for the triple throat Webers, but hopefully the jets are the same for all the Weber carbs. PMO should have anything you need.

[livetopedal]

Originally Posted by hienz

Paul,
Thank you for pointed that out that I did not spell Weber correctly. I never owned Weber/PMO thus why I do not know how to spell Weber. Thank you for the info I have learned here.

You are a good man hienz. Maybe too good.

[juanbenae]

Originally Posted by livetopedal

You are a good man hienz. Maybe too good.

for some context here, he was brought up to speed on spelling in another thread on carbs just a few days ago. no harm though, just good fun.


may be right on pierce not having the topping. not to diminish PMO, but Pegasus may have them?? PMO can be such a hassle at times to connect with for things. I went so far as ordering on line from an east coast vendor that had stuff dropped shipped from PMO to me! the lack of sales tax offset the slight mark up the guy tagged on and he was always great to deal with.


ive sourced a number of jet sets, emulsion tubes, and venturi from pierce and it was all as it should be. they are close so it's also a one day turn around for me on shipping USPS...

mmmmmmm,,,, carbs

[1QuickS]

You can get Weber parts and PMO manifolds from Weber Carb Parts, PMO Carburetors and Parts, Porsche Posters, engine oil testing

Be sure to get the intake manifolds that are for your year model engine. As mentioned previously, the intake ports in the heads have a "bump-out" for the injectors and PMO makes manifolds that are designed for that feature.

"Your Oil" also provides K&N filters with rain hats. Alternately, you can use an air filter housing from any Weber 40IDA3C or Zenith 40TIN carb'd engine; 911 cars from 1966 through 1971. These are a bit quieter than the K&Ns which may be nice to consider. I had both for my car and changed them out depending upon my mood.

[juanbenae]

Originally Posted by 1QuickS

You can get Weber parts and PMO manifolds from Weber Carb Parts, PMO Carburetors and Parts, Porsche Posters, engine oil testing

that's the guy! he is great to deal with.

in total jest here.... but his value is being a made man with PMO and can get right through to Richard there... it's like the mafia kinda... us low level street guys have a hard time getting a meeting with the boss...

[Trackrash]

Plus one on engine oil testing. It is a good source.

In addition to what others have said, make sure the bottom opening of your manifolds match sizewise to you intake ports. There were, are, a wide variety of PMO manifolds out there. It may be that you will have to do some port matching (opening up or "porting") the manifold's ports to match your heads. If you have manifolds with larger ports than your motor. You should sell them and get the correct ones.

The IDT Webers came with venturis and jetting suited for a 2,0l motor. You will have to change out those parts to have those carbs work well on your motor.

Good luck with the K&N air cleaners. They are like hen's teeth.