Topic: 4 Banger Intake work

[chrisfranklin]

I know you can buy 4banger intake manifolds for $25-$75 bucks at auction. 

For about 5 minutes the other day, I had a thought to buy one and send it out for an extrude-honing job.  Then I got an idea for prices -- $400-$600 for extrude honing on a, say, $50 used manifold. Nevermind. 

Still, I wouldn't mind at least sending out a used 4banger intake manifold to a shop to work on it a bit -- bore out to match my 62mm TB, hone interior intake surfaces as much as possible and, if needed, grind out to better match intake ports. 

Love to DIY, but don't have a shop or even a garage to do the work.  Anybody know of a place or are good with this kind of work? 

[VA_YJ]

You should reconsider DIY.  Porting and polishing is not real hard, it's just time consuming.  Use the gaskets to match (scribe) TB to intake and intake to head.  Powerblock TV Horsepower has a show on this that goes through all the tools and techniques.  You could work on it outside on a nice day...

[andpgud]

What do you guys mean by use the gasket?

[sharpxmen]

What do you guys mean by use the gasket?

use the gasket to mark the cyl head and intake manifold and the match port the runs.

[andpgud]

I only have to bore the intake and the TB right?

[sharpxmen]

I only have to bore the intake and the TB right?

the discussion was regarding the intake where it meets the cyl head, for throttle body i don't recommend boring it out by hand but if you're asking about matching a bored out t/b (60mm or larger) then yes, you will have to match the intake manifold with the t/b.

[andpgud]

What I want to do is to  put a 62mm TB with a spacer on the intake. IS that to big?
I will have to bore out the Intake also. I will have it all done by a machine.

[sharpxmen]

What I want to do is to  put a 62mm TB with a spacer on the intake. IS that to big?
I will have to bore out the Intake also. I will have it all done by a machine.

is not too big

yes, you will need to match the intake to the spacer, it a machine shop does it it's a walk in the park

one thing you might want to do: look at the way the intake is rounded smooth right under the t/b gasket (where it meets the throttle body) - after the machining you'll end up with an edge there, i advise you to work the 2 surfaces in round so there is no hard brake in the surface (so it's continuous), will help lots with airflow and avoid turbulence (the air braking off the surface). A dremel with sanding drums would do, if you have deburr bits to do the coarse part it's easier.

[FourbangerYJ]

http://4bangerjp.com/forums/index.php/topic,6008.0.html

Here is how I enlarged my TB opening. I am happy with the results. 

[andpgud]

That sounds sweet. So I should use a dremel tool? Can I let a machine shop drill it out for me?

[FourbangerYJ]

That sounds sweet. So I should use a dremel tool? Can I let a machine shop drill it out for me?

It depends if you want to take the manifold off to bring it to a machine shop. The Dremel worked great for me. A drill would work fine too. With a new rotary rasp the Aluminum cuts easy.

[sharpxmen]

mrcabinet used a holesaw - so far the most elegant and precise way to do it without taking the intake off. He made a guide with 4 holes out of thick mdf by copying the spacer (plywood would also work) and dril the hole firs in the mdf with the holesaw, then bolt the mdf to the intake and the holesaw would center it's outside diameter on the mdf piece, very nice solution.