Port and Polishing

[84ptype]

How far down do you have to take the head to do an "at home" very mild port and polish (mainly just polishing)

Cause I have everything removed except the valves and valve springs. Do I have to take those out too??

[Tire Shredder]

depends on how far you want to go.

I would never consider doing a port job without the valves removed though. There is no way you'd be able to get a reasonable amount of light into the ports to see what you are doing, let alone ensuring all the metal filings are out.

toyota heads aren't that bad...they certainly aren't like honda heads for casting quality, but are miles better than domestic heads. I honestly think most o the gain will come from removing the shoulder near the short side radius of the valves. check my build thread in the engine section to see how far I took mine. I didn't do anything drastic but did my best to optimize the head without using a flow bench. no radical changes....do everything one step at at time to keep the cylinder similar to one another.

[84ptype]

I already went through the intake side the best I can with the valves inplace. All i did was polish. I am doing this to mainly prevent grime build up and carbon build up on the exhaust side. I will probably remove the springs and valves tommorrow and get even more cause i could only make it in through one side so far.

I am still planning on taking it in and having everything checked out by the shop I am using, mainly just cause a profesional opinion cant hurt, Im going this far why skimp now.
I will post pictures and such when im am done, along with a complete build thread at some point.

[84ptype]

alright well after searching I have decided I am gonna just pull the valves and springs tommorrow at school so i can get it done and the right way.

I will gasket match the intake side of the head and the intake manifold.
as the the exhaust I am just going to get rid of any ridges, and/or casting flaws/ridges etc, and polish.
From what i have read its best to leave the exhaust slightly smaller than intake. But I will polish it to eliminate areas for carbon and crap to stick to.

I will update this thread later.

[Tire Shredder]

it's smaller than the intake by design. the exhaust doesn't need to be very large, because it has mechanical force (and pressure) behind it. The same reason precious combustion chamber space is sacrificed to larger intake valves and not exhaust valves. unless you are using a larger primary size (custom) and have a flow bench on hand, do NOT increase the size of the exhaust ports...that is to say, do NOT gasket match them. you want the inner diameter of the exhaust port to be 2mm smaller than the inner diameter of the exhaust primary. This is because you want to create a reversion dam. The "lip" that is created will help prevent backflow of exhaust that's already left the head from entering it again...usually in valve overlap conditions. Also, the diameter change to the larger runners creates a lower pressure in the exhaust than in the head. This lower pressure helps encourage exhaust gasses to leave the head.

Remember, if it was easy to make drastic changes in the engine's power without side effects, toyota would have done it from the factory. Port and polishing is very time consuming with minimal gains, so don't expect much...especially if you are doing just a "mild" job. that being said, it is a good thing to do. Just let it be clear that the port sizes are about what they should be so don't go hogging out material without knowing what you are doing. gasket match the intake side, clean up the exhaust side. remove rough shoulders and casting edges.

Steve

[84ptype]

Cool...That is exactly what i wanted to do. Thanx for your input.

[83CelWA]

Wes does have a whole site that is pure awesome: http://www.tscperformance.com


Then if you go here: http://www.tscperformance.com/cylinder_home.html , there is a writeup on porting.

[StanS]

A few peeps have reported power loss from porting the intake and as Tire shredder says "do not port the exhaust".

[Norbie]

Head porting is something of a black art, and it's VERY easy to get it wrong and make the head flow worse than before. This is something I'd leave to the professionals unless you're doing very basic stuff like cleaning up casting dags and smoothing sharp edges around the valve seats.

[84ptype]

doing very basic stuff like cleaning up casting dags and smoothing sharp edges around the valve seats.

this is what i am doing...
I dont wanna screw anything up. I just wanna clean up the head and polish up the insides 1) to clean up lips/edges/casting imperfections 2) prevent crap build up in ports.


On a side note i got the valves and springs out today and friday I will finish up. I will post up my pictures.


I have read wes' site about porting, but thanx for posting that here to. Should help with further searches.

[StanS]

Use inexpensive fuel solvent every few thousand miles to clean crud buildup in ports and to keep injectors clean so the spray pattern is correct.