3100 UIM and TB Porting

[bkaab]

Well I have started my porting.
I got a UIM and TB off a '95 Monte at the JY for 25$

I read up a little online and then went at it with my dremel.
I took the gaskets and then colored in all the metal I could see around each hole. Then I boarded them out.
I have done 1 side of the UIM and where the TB hooks up.
I still need to clean it up and smooth it out.
Tomorrow I am going to do the other side and the TB and then smooth it all out and clean it all out.


When I am all done with the porting and polish then I am going to paint the out side of it.
I am going to do the LIM later this summer








Half of the porting done on that side

Before anything


Thats what I have done so far. Will I see any gains after all of this is done?

[IsaacHayes]

You'd be better off swapping to 3400 LIM & UIM, or the 2000+ 3100 intakes. They are bigger stock than what you can port to. I did get an increase (but used a 3500 upper too).

You have a 95, so you don't have roller rockers. The ball/pivot you and me have will hit the larger LIM, so you have to grind a bit on the LIM. You may get lucky and have notches in your heads for the roller rockers. If so you can just bolt on the roller rockers from a newer 3100/3400 (pre 2003 I think, some late year went to 8mm studs instead of 10mm) and then it will clear. My heads didn't have the notches so I had to grind the LIM for clearance in the right spots. (2 per side)

I gasket matched my 3400 upper ports to the 3400 upper gasket. Left the bottom alone since the heads were stock and not coming off. Then matched the 3500 ports to the 3400 gasket as well. I had to get a TB adapter and route a few vacuum lines differently and adjust to clear the FPR.

It's a bit more "custom" work than remove and replace to do what I did, but my top end is crazy over stock. Low end picked up some too.

There would be gains even with a 3400 upper/lower which is less work but you still gotta watch out for the rocker clearance. The UIM that way would bolt up the same as your 3100 other than you'd need the proper EGR adapter for whatever year UIM you got.

EDIT oh yeah you'll need a 96-(99?) 3400 lower from a van for the screw in coolant fitting, or tap it yourself with a NPT tap. (later years were not tapped)

I had the same "dremel" It died on me though I went between that and a $7 harbor freight air die grinder which works great other than the fact my air compressor empties in about 7 secs with it... LOL

[bkaab]

Ya I was going to go with the newer 3100 or 3400 intake but I could not find one in the local JY so I just went with the same 3100.

Ya the dremel is my grandpa's but I kind of own it now since I have had it for months now. Its pretty old he used to do crafts and used it a lot. HE don't do them now so I asked him if I could use it when I ported my TB a while ago.
Our air compressor is pretty lame too. 4 gallon 2.5HP

[IsaacHayes]

I got my parts from www.car-part.com.

[bkaab]

Got the other side done

No all I have to do its the TB and paint it all and put it back on