17 replies to this topic

[EuphoricBlue]

hmm i would like to go one step further and add a bigger butterfly. the only thing holding me back is what tool i would use to open up the hole. anyone got any ideas? i have a dremel, but that is just too week to do shit, then ive got a die grinder. maybe a tip could work with that? im not about to take it to a shop to bore it out, so anyone got any idea for a home tool i could use to experiment?

If you are going to go that rout, you need to be very careful and delicate. The butterfly bores aren't as crucial as, say, valve seats... but they still need to seat right. If you take a look at the edge of the OEM butterfly you'll see they machine a slant into it to sit perfectly against the intake bore, that's how seriously the factory takes the seating of the butterflies.

Think of it like this, the little butterfly controls idle. It is slightly cracked to allow a set flow through when closed. Now imagine that you don't get the large butterfly sealing right. You could easily double the amount of air getting by the butterflies.

I'm not saying it can't be done with hand tools, I'm just suggesting that it might be far more trouble than it's worth.

[icebox187]

big ass die grinder, most say big is better because the control you have over it.. havent tried with one yet, but i can see their justification, look at larry's at theoldone.com in the b16 head port work article click here
i'll probably try to do a da (works on b16a) tb with my dremel within the next couple weeks, just for fun hopefully remember to get back to ya

[kaymo]

IBCNYA- little quote i read off that "the one old" site about porting. pretty much describes the "unfinished" look of my TB

"Pretty doesn't mean beans to flow (or your engine), so do not get off on some kick where you think that every part of a port needs attention...it doesn't work that way."