Tips for boring throttle bodies

[honkysXJ]

I recently scored about a dozen throttle bodies from the yard,my first attempt at boring it out was somewhat of a learning experience ,first notable issue is its aluminum and that shiatt is soft, my main issue is the butterfly ,I was attempting to bore the bottleneck out of the bottom and got a little heavy handed with the drill press! I guess my questions are where can I source bigger butterfly valves? The first one I bored isn't screwed but you can see light through it and when I put it on my idle was jacked up ! I got a good grasp on how to approach this but I'd like to go as big as possible,and would like to see how big these suckers can be reamed? This is all an experiment so I'm open to ideas and suggestions!!!

[Muad'Dib]

Most people make new butterfly valves for the throttle bodies.. although IIRC some are difficult because they are not actually round but oval.

Seeing light through a throttle plate isn't a bad thing. They are not supposed to be super tight against the walls of the throttle body. They should hit the stop before the inside walls.

Oletshot (and maybe some others) on here have already done a lot of this work.. so you may be able to get this information without spending too much time on it.

[SilverXJ]

The bore where the throttle plate touches is a precision bore, like a cylinder in the engine block. That kind of precision you can not achieve with a drill press and a sanding drum or hole saw. I recommend junking that throttle body or sending it to someone that has the equipment to bore it out to 63mm. 63mm is about the larger you can go.

Since you already did it, you can try adjusting the stop to get the buttery fly to close more. But you don't want the blade to touch the sides of the throttle body.

[honkysXJ]

Well worse case I got 11 more attempts the one I'm on now I didn't remove nearly as much and hopefully won't be another fail ! If I have to my machinist will hook me up ,it can't be out of my element I'm not the first one to do it. Even if I gotta tear a few up oh well, thought about opening up my intake as well

[cruiser54]

Why not get ahold of Jeff at www.strokedjeep.com and see if he'll trade those cores for a finished tB from him?

[honkysXJ]

That was actually a thought I had and probably good advice
Just like working on my heep and want to be as hands on as much as my abilities allow
I'll know tomorrow if my second attempt was a success or (FAIL) but honestly strokedjeep.com has been marinating in the back of my mind since I scored all of those