can i enlarge the IM opening matching TB diameter without disassemble IM ?

or is impossible to prevent metal shaving to come into combustion chamber?

any improvements without enlarging IM outlet ports in the block??

boring IM, as onpol does, means enlarging diameters of all 4 IM ducts in all their lenght???
or boring terminal holes?

this because i've a 1.6 beta intake mainfold to enlarge.
it seems to be different from 2.0 according
to "displacement mark" on the top of IM that i've sseen in the car.
if i send my mainfold to onpol car will not be used. sorry for my english

 

You must remove the IM to bore the opening. Anyone who tells you otherwise is crazy! I bored out my IM, and after boring it I cleaned it out, and even with some rags and grease in there THERE WAS A HELL OF A LOT OF SHAVINGS that made it past the rags and were stuck to the sides of the IM and runners. I washed it out for about 15 minutes with diesel fuel and then blew it out with the air gun.

Its not hard to remove the IM, about 25 mins.

-Steve

 

actually i beleive that brendan has done this with his elantra. It involves a rag and alot of grease. if you not 100% familiar with your car like he is, i'd HIGHLY recommend getting onpol to do this or a professional.

Onpol does excellent work.

 

BV1 did you see any gains boring your IM?

 

how to bore?
if i put out my intake mainfold
i realized how to match TBIM opening to TB
and IM-head holes
but should i bore all 4 duct in all their lenghts?

 

The "ducts" you are refering to are commonly called the runners. Because of their complex shape it is all but impossible to mechanicaly bore them out or what others would call polish. The common procedure is to just bore the intake, on the throttle body end, to match whatever your throttle body bore is. On the other end the practice is just to bore the ends of the runners to match the gasket. You don't don't wan't to go up into the runners because you most likely will screw up the injector seats and destroy your im.
The other option is to have IM polished using a fluid method. I can't think of the name right now but it involves forcing an abrasive clay through your IM at high preasure. It will effectivaly remove all the casting flaws such as burrs or sharp corners and also polish your im so that air flows better.

 

Extrude Hone is the most famous company that does this, but there are others.

It is possible in theory to bore out your IM while it is on the car, but I would NOT reccomend it. If you just miss one or two bits of metal shaving...they will end up in your combustion chamber...and that would NOT be happy.

I would also NOT reccomend this unless you are DAMN good with an air grinder, dremel or hand files. Getting a perfectly round hole with good edges is DAMN HARD.

In regards to gasket matching the IM to the im/head gasket, there is NO WAY, I would attempt this myself. If You do a search on the pics that have been posted between the units that have been send to Onpol vs the stock unit, you can see how much work needs to be done, and how precise the work must be. I would not reccomend you tangle that one yourself unless you have experence porting. Those ovals are damn hard to work with/on.

 

The port SHAPE is easy to do, it is the depth and consistency of your job between the runners that has to be dead accurate or you will have uneven air velocity between the cylinders at mid or high RPMS. Lots of "tuning shops" here do this, and that gurgle you hear from the beng-mobile engines is usually NOT because of a set of cams as tall as the Empire State Building, you know what i'm saying? It takes an experienced hand to do this with carbide burrs and paper rolls, looking at OnPol's work I gotta say he beats a lot of the shops here hands down, you really oughta think about giving him a little $$$$ to make sure your TB and IM runners are done really well.

 

Yeah i could see doing the inlet for the IM, but the runners would be nearly impossible to do by hand. You wouldn't be able to get all the full effect of the BIM if you messed it up.

just for visual here's some pictures to see

stock
http://www.rai-usa.com/tibby/BIM/tibby_bim...m_imrunners.JPG
bored
http://www.rai-usa.com/tibby/BIM/tibby_bim..._bimrunners.JPG

 

Where would you go new gaskets for the throttlebody and IM once having them bored? I am have a stock TB AND IM sitting at home waiting to be sent to onpol to have the work done :-)