kevinkal

The machinist that is working on my 3VZ-E valves seems to really know what he's doing. He asked me today if I would like him to smooth out the intake and exhaust valve ports. He showed me how they have sharp edges and "bumps" cast into them that would slow down flow. I said yes, as it sounds like a good idea. Does anyone have experience with this type of mod? Is this a good idea?
Thanks.

SR5

sounds like a good idea to me
better flow= more power

dijlop

sounds like a good idea, but who rly knows till ya try it? lol. please do tell how it all works out, and see if u cant get some pics of how he does it and how it looks.

the_gunslinger

if you have a stock intake manifold and exhaust system you might not feel much of a difference, but if you get a header with a free flowing exhaust, and a free-er flowing intake, your engine (which is a glorified air pump) will flow much better.

INFINITY

sounds like a "polish" job. the second part of the port and polish. i have heard to be careful with the intake polishing, something to the effect of if the IM is super slick and smooth below the injectors it wont keep the the fuel atomized as well. do a search for port and polish.

justinking060310

I would say that it depends on how much he wants to charge you -- anyone with a dremel could clean up the edges --

I did on my heads before I put them on - will it make much of a difference? probably not, but i figured with a full exhaust/headers/cams upgrade it couldnt hurt.

Kat

kevinkal

I figured it *can't* hurt anything to smooth out the ports. But Infinity's comment re fuel atomization has me concerned. Perhaps there is some expectation of turbulent flow into the cylinder when the injector fires to mix the air and fuel better?

I don't have plans to do anything with the headers or exhaust. (unless they rust and fall off)
The machinist is going to charge me 1 hour of time. Sounds more than reasonable to me.

If there were more flow to/from the cylinders, I'm assuming that the ECM will adjust the injector charge to get the proper Fuel:Air ratio. What feedback sensors would be used? The Oxygen sensor?

CJM

YES! Smoothing out the head really will do wonders! It is an old trick used my hotrod and enginebuilders alike to allow better flow!

kevinkal

Below is a picutre of the bottom side of the intake(left in photo) and exhaust valve ports.

The cast intake flow path is not concentric with the intake valve seat. You can see that by the machine mark left from machining the valve seat counterbore. Material is removed on the right side but not the left. This intake bore will be ground out to be more concentric with the valve seat.

For the exhaust side, in the picture, below the top side of the exhaust valve seat there is a lip of aluminum. This lip has a very sharp edge at the base, where flow is supposed to round the corner and go out to the manifold. This lip will be ground down to a smooth radius and blended with the existing side contour.

kevinkal

Update.. the porting was completed yesterday. I took some pics of the porting work and shiny new cut valve seats before they put the valves back in. Below is a picture of both heads after cleaning, porting and valve seat cutting.


A close up showing the porting work, smoothing the sharp corners and removing the eccentric counterbore step.