62mm Throttle Body Boring Query - AUSJEEPOFFROAD.COM Jeep News Australia and New Zealand

ako · #1 30-12-2007

I have been give a spare throttle body which I want to try and bore out, maybe 62mm.

I have read the write up here:

http://www.go.jeep-xj.info/HowtoTBboring.htm

But one thing I was unsure of, is the butterfly replaced with an oversize one? It doesn't seem to mention it here.

Looking at the spindle the butterfly sits in, it looks a bit difficult to cut the slot from 55m to 62mm.

Sorry if I am being a spazzy, but to me, having a 3.5mm edge gap would give problems at idle or over-run.

Any help would be greatly appreciated,

Mick

turbomart · #2 31-12-2007

If you read "go-jeep"s instructions carefully you will see the i6 throttle body tapers down after the butterfly & all you are doing is removing this so its the same dia. all the way.
Btw i did this mod on my old ZJ & it did help a little in conjunction with a spacer.I also fitted a sports (pod style) air filter which increased intake noise.

Gojeep · #3 01-01-2008

Yes that is right, the taper below the butterfly only is removed and the bore around it remains at 60 mm. The 62 comes in as I tapered it out to suit the 62 mm hole found in the intake manifold.

ako · #4 10-01-2008

You know how you get a new toy/tool/whatever, and you are supposed to read the instructions first, well I never do that.

Anyhow, now I have a throttle body that is 62mm all the way through. Looks pretty cool except the gap around the butterfly plate!

Now I am trying to make a 62mm plate.

Thanks for the replies anway, will post a pic if this thing actually works.

Gojeep · #5 10-01-2008

They are very hard to make due to the 8 degree tilt. This means that it is a slightly elliptical shape and not round.
I remember a long time ago I came across being able to buy just the plate.

Just did some looking for you and found it again.
http://www.xj-armor.com/engine.htm

Jeepology · #6 10-01-2008

What is the rough cost of a bored TB - if you exchange yours etc?

I have not a clue but am thinking about it

frankcj7 · #7 10-01-2008

what about the benefits?
according to Hesco you will gain some HP @ hi rpm loosing something at the bottom (torque)
I'm running a 4.2 I6 with 4.0 ported head, stage 1 cams and mopar fuel injection, 2 1/4 " sport exhaust and K&N filter .I also installed a 62mm Hesco tb spacer, many people suggested me to keep the tb standard and add the spacer to gain some torque...
Just wondering if you got some major benefits without affecting the low end