so i finally decided to try and port and polish my intake manifold.

 

Very nice, it's amazing sometimes how much intake manifold flange - head ports and head ports - exhaust manifold flange are so off. A friend had a head done by Headgames and the difference is quite astonishing, there's so much left on the table from factory.

 

I see the port part but where is the polish? Lol

 

Its no were near done I was just showing how much can be taken off. I still have to sand and polish but ill keep the pictures coming

 

just curious, but what year sc4 is this off of? also was the porting done somewhat randomly/intuitively, or were you able to do any flow testing before/after?

lastly while good porting leads to good things, i have read a few times that polishing sometimes can have negative effects on the air flow, and if not negative, then no effect. i dont know how much this is true or if it is applicable to certain designs/materials, but perhaps you could shed some light on it if you know?

 

He did a gasket match which is not messing with cyl head ports where shape ,flow and velocity comes in to play so not very critical as you are not re shaping the port where the power is made.
To pay for flow bench testing would be silly as there is very little to be gained although it by no means can hurt as the 1uzfe is full of restriction but the heads,plenum and cams work very well in a stock only set up as Toyota did a good job and made one of the most reliable engines ever to hit production.

Also polishing is not needed and will impede atomization as 80 grit rolls leave the desired finish for mixing the air/fuel in the most efficient manner.

 

Correct, port and polish is porting the intake side leaving a somewhat rough finish for fuel atomization as xspsi6 said. Polishing is typically on the exhaust side, leaving a clean surface so carbon cannot build up on the walls.

 

No sry It was spur of the moment so I didnt plan on any flow testing. And I am gasket matching plus a little bit of porting. The ports seemed small and restrictive so I widened them. I did both the top and the bottom manifold. I had read somewhere the porting and gasket matching gained an ls1 something like 35hp so I am hoping for something decent. I am gonna try and dyno test it after this is over.

 

nice! looking forward to see your results.

 

finished the upper manifold and starting on the lower

 

the lower manifold

 

wow! thanks for the pictures! i hope, you give a response, after install and the first drive

 

there is alot you can take off the bottom manifold. its ports are alot smaller then the gasket

 

and finally last putting everything back together which is a pain lol

 

when i drove it i really didnt know what to expect but after three days of grinding and sanding i have to say its worth it. i really cant say how much horsepower i get until i dyno it but it takes less to go fast is the easiest way of putting it lol. i feel like i gained alot of torque and midrange. i havent been on the freeway so i cant tell you about top end. the transmission seems like its not used to the engine revving that fast plus its alot smoother acceleration and im on bad oil and need to flush my tranny so i am kinda excited once it sees that new mobile one. i'll put a video on youtube and paste a link