2 easy mods that will improve that carbs performance are to drill out the idle mixture screw holes to .090" then set the idle mixture screws about 4 turns out from fully seated. Also drill out the accelerator pump discharge holes located underneath the airhorn to .028" Lastly, remove the float needle/seat assembly and drill out the seat to .130" and set the float level at 1/4" down from the top of the float chamber measuring the float at the toe end.
@327pd Thank you very much for the advice. It is much appreciated. I will apply these things if time permits at this point. The modifications you present make very much sense to increase fuel flow.
To add some performance for a demolition derby car, you can modifiy the accelerator pump discharge holes ,the idle mixture screw holes,the needle/seat assembly and several other passageways on that dualjet taking it to a mild performance 2 barrel carb. As it is just like a qjet it can benefit from some of the same performance mods. Don't forget to check the throttle shaft for excessive play as this can cause poor idling and stalling(not good for a derby car) Good Luck!!
@327pd Thanks very much for the tips. I will look into this. My modification 'skills' on Q-Jets has been jets/metering rods on the primaries, and metering rods on the secondaries, I will look up and see about the mods you mentioned, but will take it easy, for like you said, stalling is a no-no on a derby car! The mileage seems low on the carb in question, for the throttle shaft has barely perceptible play in it, in fact I would almost say nil.
Thanks for the kudos and confidence in the work I am contributing to this. My role in the project of the derby car is but a tiny one. The Q-Jets and related spinoffs are pretty decent units, doing a very capable job of metering fuel if only understood a little.
Never saw one apart before. Your'e right it's a 2 barrel Q-jet. I'm sure the "bumper" car will run like snot when you get it back together! I've always liked the Q-jets! RW
2 easy mods that will improve that carbs performance are to drill out the idle mixture screw holes to .090" then set the idle mixture screws about 4 turns out from fully seated. Also drill out the accelerator pump discharge holes located underneath the airhorn to .028" Lastly, remove the float needle/seat assembly and drill out the seat to .130" and set the float level at 1/4" down from the top of the float chamber measuring the float at the toe end.
327pd 1 month ago
@327pd Thank you very much for the advice. It is much appreciated. I will apply these things if time permits at this point. The modifications you present make very much sense to increase fuel flow.
spikedpunk 1 month ago
To add some performance for a demolition derby car, you can modifiy the accelerator pump discharge holes ,the idle mixture screw holes,the needle/seat assembly and several other passageways on that dualjet taking it to a mild performance 2 barrel carb. As it is just like a qjet it can benefit from some of the same performance mods. Don't forget to check the throttle shaft for excessive play as this can cause poor idling and stalling(not good for a derby car) Good Luck!!
327pd 1 month ago
@327pd Thanks very much for the tips. I will look into this. My modification 'skills' on Q-Jets has been jets/metering rods on the primaries, and metering rods on the secondaries, I will look up and see about the mods you mentioned, but will take it easy, for like you said, stalling is a no-no on a derby car! The mileage seems low on the carb in question, for the throttle shaft has barely perceptible play in it, in fact I would almost say nil.
spikedpunk 1 month ago
I used to have a 82 Olds Brougham with a 267 V8.
monarch1957 1 month ago
@monarch1957 Now that must have been a car that needed a little patience to get up to speed!
spikedpunk 1 month ago
Thanks for the kudos and confidence in the work I am contributing to this. My role in the project of the derby car is but a tiny one. The Q-Jets and related spinoffs are pretty decent units, doing a very capable job of metering fuel if only understood a little.
spikedpunk 1 month ago
Never saw one apart before. Your'e right it's a 2 barrel Q-jet. I'm sure the "bumper" car will run like snot when you get it back together! I've always liked the Q-jets! RW
Radiowild 1 month ago