Weber IDTP 40 jetting/setting for 2.4T

[DionRonio]

Hey Collective,
I have a 914-6 conversion. 2.4 liter. T cams.
‘67 aluminum case, 2.7 counter weighted crank and rods. (Rods balance by Ray Litz). MAHLE P&C
46mm intake and 40mm exhaust valves.
Rebuilt motor has around 25K miles on it.
123Ignition distributor with OEM CDI.
Carbs are 40IDTP3C. They were rebuilt for a 2.7 engine. Owner states they ran brilliantly.
On my 2.4 configuration, I get a lot of popping upon initial acceleration dip in.
They are nicely synchronized and it idles on cold start perfectly around 1100rpm.
Wondering if the jetting/set up is too much for my 2.4. Any insight. Is there a list of what the carbs should be running for a 2.4T
Thanks in advance. Also posted in 911 forum. Wasn’t sure what was best one to get eyes on.
Cheers, Dion

[buster73]

My 2.4T with a PMO Weber conversion came with the following jetting

Weber 40 IDA 3C
Main jet: 130
Idle jet: 55
Air correction jet: 180
Emulsion tube: F1
Venturis: 30 mm

If your carbs were set up for a 2.7 you will probably have to reduce main jet size. Optimizing jet sizes is a lengthy process but worth the effort. Just went through the whole process and am very happy with the outcome.

[DionRonio]

buster73 . Thank you very much for this information. I will make a note of your settings. Time to take these apart then.
Thank you

Cheers,Dion

[Trackrash]

You will be shooting in the dark, unless you can measure your air fuel ratio.
And you are leaving a lot on the table with T cams IMO.
Buster has a good starting point.

[Dpmulvan]

I have a set of 30mm venturis if you need them $80.