K, this is my third time asking and i was wondering how to get into those hard to reach places with the bits to port and polish my intake manifold.

It takes 8,460 bolts to assemble an automobile, and one nut to scatter it all over the road

There are flexible extensions, but it will take you putting the drill at a very low speed and take a long time to port.

I have heard of people cutting intakes in half or long runners to port or hollow them out.
But of course it will take a long line of weld to mend it back, and there is a chance of a leak if not thoroughly checked.


2003 Sunfire with 2 1/4 inch turbo muffler, 2 1/4 piping, 2 1/2 inch resonator, a 2 1/4 inch catalytic converter, 2 1/4 inch down-pipe, a ported LSJ manifold, E-bay strut brace, and an AEM true cold air intake NOPI edition.

Extrude-Hone... It's the only (And best) way.


Go beyond the "bolt-on".

and also expensive.....but it IS very good.

Extrude hone>>> total waste of money

cut and weld... only real way


sig not found

cut and weld, that's gonna end up more expensive, im not a very good welder.

It takes 8,460 bolts to assemble an automobile, and one nut to scatter it all over the road

Just use regular flex bits and try. You wont be picking up huge numbers off the intake unless you need the extra flow. Also just so you know, the intake is not suppsoed to be polished. It is supposed to have a semi-rough finish on it. Only the exhaust side is supposed to be polished.

Here check out this website: http://www.sa-motorsports.com/diyport.aspx

I know its for cylinder head porting, but the basic concepts apply. Read about the intake side porting. It says "The 80-grit gives you the smooth, but not polished, surface that is correct for intake ports"



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The rough texture is used to keep the fuel suspended in the air stream. This was a problem with carburated motors and the long runner lengths leading to the intake valve. The fuel would literally pool in the runners. The rough texture would create a boundary layer of turbulent air, keeping the heavier fuel from settling in the runner.

Being as this is a port injected motor, i.e. the fuel is injected directly at the intake valve, there is no need to have a rough surface.

protomec wrote:Extrude hone>>> total waste of money

cut and weld... only real way

I know I'm nobody as far as you're concerned but that's total BS. I'm curious as to your logic Todd... no extrude hone machine to use?

I've seen several Extrude Honed manifolds and tons of hand port work. I'll take the extrude honing on manifolds with hard to reach areas.




Edited 3 time(s). Last edited Monday, September 15, 2008 7:55 PM

Well i have finished and its been almost totally polished. I left the bends rough. so is it a bad thing to have a polish intake manifold?


It takes 8,460 bolts to assemble an automobile, and one nut to scatter it all over the road

No, it's not a bad thing... Just not something you want in a "wet-flow" application (TBI, carburated). In the case of a port-injected engine, it's very good. It's part of why the factory has moved away from cast-metal manifolds & switched to molded-polycarbonate ones! But just to be safe, there's an old rule about leaving the floor of the intake port on the head rough to help keep fuel in suspension, and the way I see it if that's done with port-injection it'll help with the fuel mixing by introducing a lil' bit of turbulence. Not much, mind you... Just enough to help the spray mix with the airflow. Just a thought...


Go beyond the "bolt-on".

Thanks so much. What should i use to make the rougher surface?


It takes 8,460 bolts to assemble an automobile, and one nut to scatter it all over the road

take some pics of the work you have done. I am interested in seeing it

____________________________________
Primer Counts as Custom Paint Right?
BTW: This is my Sig.

@!#$, its all back together, i was up all night finishing it. sorry man.


It takes 8,460 bolts to assemble an automobile, and one nut to scatter it all over the road

Is there a certain tourqe i should have on the intake to the head? or can i just tighten it pretty tight?


It takes 8,460 bolts to assemble an automobile, and one nut to scatter it all over the road

The intake gets torqued to 22 ft-lbs. Just snug the nuts onto the studsthen do the to 11 ft-lbs then to 22 ft-lbs. Tighten them in the following sequence:

7\\3\\ //4//8
9\6\2\ /1/5/

Note: this is from the intake manifold side view.

Madjack i already tightened them and i did them in kinda of an order from furthest apart to the closest. but should i still torque them? what is the worst outcome?


It takes 8,460 bolts to assemble an automobile, and one nut to scatter it all over the road

KFLO wrote:

protomec wrote:Extrude hone>>> total waste of money

cut and weld... only real way

I know I'm nobody as far as you're concerned but that's total BS. I'm curious as to your logic Todd... no extrude hone machine to use?

I've seen several Extrude Honed manifolds and tons of hand port work. I'll take the extrude honing on manifolds with hard to reach areas.

Back from the dead because it was referenced in another post:

My logic....

I was a big part of the development for the Contour SVT engine team. If you are unaware, the SVT engines had Extrude Honed intake manifolds. At the time, mid 90's, Extrude Hone was the latest rage, so it was hot on the management's minds at the time. It was tested and it did do a small amount for power... <5hp (allowable test error was +=3hp). So the cost was too great, even in the quantities that were planned (~4000 units + service parts). A genious at Ford decided to promote it as an emission/economy improver and got the government to pay for most of the costs as a government sponsored study. The final cost to Ford was about $10 per manifold. If you were to ask anyone on the engine team if the costs were worth the investment, there answer is usually that Ford paid too much for it. In other words, its not worth paying even $10 to get done for the gain.

The idea Extrude Home only seems to make sense, but deep down it loses value. The biggest issue is that air does not move through passages in the same way that their honing media does. I know it looks like a liquid in promotional pics, but its more like something between playdoh and silly putty. I have jars of it here at home if you are interested in seeing it. And silly putty does not bend around curves in a manifold like ultra light (low momentum) and flexible air will.

In the end, its a cool concept and a cool process, but it not really worth the money they want for it for the gains it will truly produce.
Its also no surprise that you hardly hear about it anymore as I suppose many people have now come to the same conclusions a decade later.


sig not found

Wouldnt you want to smooth out the joints you welded thereafter?

I know its not car related, but my dad used to work for a company that made some pumping systems for pharmaceutical companies. He would have to weld (or use their robotic welder) a joint, straight, curved, whatever then polish the inside of the weld. Granted these welds had to be strong enough to hold their test of 20000psi, so the welds had to completely penetrate the metal. They needed to be polished on the inside so they were completely flat (you couldnt tell it was welded when he was done)

wouldnt cutting/welding the manifold cause this problem as well?

Just a thought, not trying to start an argument or anything


"A car just isn't a car without a little blood, sweat, and beers." -- Shadowfire

The weld would be along the flow path, so while it would technically decrease the cross-sectional area, it wouldn't really hinder flow.




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