PMO 46 carbs on a 3 litre

[matty74]

I'm doing a 3 litre engine build and I have decided to shell out for PMO carbys. It is for my street rod, not for racing.

I have the following

DC 60 cam
JE 9.5:1 pistons
single plug

Do I go for 40mm PMO's or should I go for 46mm PMO's.

I'm likley to want to do a 3.2 or 3.6 later in laife and would like to keep the carbs.

[matty74]

See I own the 60's so I'll go a set of 46's I reckon.

what should I go higher compression 10:1?

then I'd need twin plug, or could I run 98 octane on single plug?

[matty74]

I get mixed messages about this go 40 go 60 not sure what to do now.

[randywebb]

well, street driving depends on the street -- are you in the outback or in Sydney??

the more congestions or twisty, lower speed roads the more torquey a motor you want

the more open straight hwy, the more of a higher rev type motor you want

I use a 3.2L with 40 mm PMOs and fairly mild cam in a light wt. car.

If the car is "overcammed" it will bog on you and be a mess.
The general tendency is to over-cam and over-carb a car.

[matty74]

City driving, so yeah I want torque

with 46mm PMO's I can use a smaller venturi on a 3 litre, I'm thinking, if I rebuild the motor to a 3.2 or 3.6 I can rebuild the carbs and change the venturi size.

[VA911]

matty,
i have spoken to a few sydney gurus on the matter and they all reckon go the 46's just incase you ever want to go bigger.. but there is no harm in contacting PMO themselves to get there opinion.
http://www.pmocarb.com/index.htm

[matty74]

VA911


cheers mate thats what I reckon I'll check with PMO before I buy.

[rfuerst911sc]

I have a 83SC with stock engine internals but with SSI's and a 2 in 2 out muffler. About 6 weeks ago I had brand new 46mm PMO's installed and had the distributor recurved to be used with carbs. The car runs fantastic and I can only imagine how much power I have in the engine waiting to be released by cams and piston upgrades. When you order these new they will be sized for your engine meaning jets,venturis etc. will be correct for your setup.

[rhk109]

I have a 3.0 with 46's. During my various tuning questions Richard from PMO has told me several times that 46's are just fine on a 3.0. He's the expert as far as I'm concerned.

[81 911 SC]

I have 40 mm PMO on my 3.0 but as others have said PMO will set up the carbs based on the type of engine and information you give them. You should be ok with using 46 mm PMO.

[bkreigsr]

although others may vehemently disagree, I've run 10.37:1 cr in my single plug 2.5L for over 15,000 miles (still counting) with no problems.
east coast premium at 93 was fine, (Sunoco used to be 94) but I always add some octane boost at the track.
Bill K