Hi all,
My kit car is running a 2.0L pinto with twin 40's (dellorto's). I have come across various opinions on the forums about choke sizes. Some
saying 32mm, 34mm, 36mm, etc.
This is all good and well but how/what do I measure to ascertain what I have fitted in my carbs?
After I establish what I have fitted, what are your opinions on ideal choke size?
Lastly, for track use, would I see a benefit to use bike carbs instead of these? Would the ideal choke size be specific to the engine or specific to
the carbs fitted?( I am also running megajolt)
Thanks
Duncan
If you take the chokes out they will be stamped with their size.
There is no universal right or wrong size, it depends on engine spec, camshaft, compression ratio, where you want the power, high or low revs etc.
etc.......
Hi there.
There's loads of info on the web regarding choke sizing.
See the following
link...LINKY
I have 36mm chokes in my Solex 40's fitted to a 3SGE Toyota 16V which made 167HP on the rollers if that is of any help.
What is the spec of your Pinto and what power figure are you aiming for?
A standard Pinto will probably be OK on 32mm chokes.
As for bike carbs I would imagine that there may be a benefit as the biggest choke size possible in your 40's is 36mm and you could fit bigger
bike carbs than that.
Biggest is not always best, however.
Try to put as much info in your post as possible to help the forum to help you.
Geoff.
If you look down the throat of the carb, from the trumpet end, you will see a narrowing where the main jet is. If you measure this it will give you
your choke size.
For a track day engine I would go for the largest size (36mm) this will compromise idle and low revs but will give you more power at the top end. But
you should match your choke size to you cam, as there is no point in fitting a choke that will allow you to rev to 7000rpm if your cams max power is
produced at 6500rpm.
If you change the choke size you may also need to change the emulsion tube and progression drillings to regain some mid range powe/torque.