Weber 40 IDTP Throat Overbore

[JonnnyBeeG]

Hi All,

I am in the process of rebuilding my Weber 40 IDTPs and the old throttle plates have worn a groove into the side wall. I have sourced 41mm throttle plates and so am going to bore out the throats to 41mm, and I was wondering what the tolerances are for this overbore. If the throttle plate is 41mm, do I bore it exactly to 41mm. I understand that tolerance is 0.05mm and that each throat should be within 0.05mm of the other.

So this means that if you are in tolerance in bore diameter with 40.96 and 41.03, you will be out of tolerance as the two bores will be 0.07mm different.

Just want to make sure I have that right.

Warmly

Jon G

1970 911T - Conda Green Targa

[75 911s]

Don't know, but interested. Reach out to Paul Abbott / Performance Oriented and or Eurometrix as they are experts in this type of thing.

[Dpmulvan]

Just don’t use a Chinese boring bar.