Boring out throttle bodies

[daves97sport]

Has anyone experimented with boring the stock OHV throttle bodies for a larger plate? The existing plate is 58MM dia. I've been searching for aftermarket plates and could only come up with a Holley 65MM as a replacement, but not sure if the stock casting could be opened up that far. Does anyone know of any part numbers for stock plates for other vehicles that could be purchased? I know Jeeps use a 62MM TB but not sure if the plate is actually 62MM.

Reason asking is I sent mine out for "porting and polishing" and got burned by an eBay seller that does this for SOHC versions, and got mine back disassembled (he couldn't remember how it went together) and the plate bore area was opened up with a hone so the plate doesn't seal anymore.

 

[Anime]

While it's certainly doable, I wouldn't bother with boring out a stock TB since the removal of 2-5mm of wall material seems like it would leave some parts of the TB pretty thin and weak. Also, the cost of the plate hardware and whatever else would make it only slightly less expensive than just getting a larger throttle body, assuming you got a deal on the machining and maybe on the new parts, too. If your TB is bored out to 62mm, I'd say check if any jeep dealers or parts stores have the plate, then taking your TB to test the fit.

 

[aldive]

Not sure of the value of this on the OHV motor, but it worked wonders for my SOHC.

http://www.explorerforum.com/forums/showthread.php?t=172480