Resolved Port And Polish 1g Head?

[Drifter27_04]

I will be port and polishing my head. This will be my first.

I am waiting on the 4 layer exhaust gasket from slowboy, could someone tell me if the gasket ports are the same as a stock gasket so I may proceed with the porting of the exhaust side? The only difference i see is the 4 layer deal, am I correct or should I wait on the 4 layer gasket?

Porting out the intake side of the head should I leave the port kinda rough or should I polish it out smooth? I was once told that it would be better just to match port it to the intake and leave unpolished (rough). What are your thoughts?

Please give me any tips you can supply as it will be helpful.

Thanks to all

 

[TSIfreek]

The intake ports should be a little rough and the exhaust ports should be smooth to prevent carbon build up.

 

[blackGSX2g]

I will be port and polishing my head. This will be my first.

I am waiting on the 4 layer exhaust gasket from slowboy, could someone tell me if the gasket ports are the same as a stock gasket so I may proceed with the porting of the exhaust side? The only difference i see is the 4 layer deal, am I correct or should I wait on the 4 layer gasket?

Yes, the 4 layer is the same as stock. I had my 1g head ported and polished and it matched up perfectly to both the stock composite gasket as well as the 4-layer.

 

[SlowboyCSE]

Yes, the 4 layer is the same as stock. I had my 1g head ported and polished and it matched up perfectly to both the stock composite gasket as well as the 4-layer.

AGREED, Same size for a two layer or a four layer.

cragger

 

[4pistons]

Theories say to leave the intake port walls a little rough on naturally aspirated engines, where fuel and air are mixed, to induce some turbulence right along the port walls to keep the fuel from "puddling" and falling out of the air. On fuel injected engines the only thing moving through the port is air so polishing it to a mirror finish would result in the best flow. Now, is all that work polishing worth the gains? No. You won't see any difference on a street engine from a sanded port to a polished one.

If you're going to put in the effort then spend the time where it makes the most improvements. The bowl area just under the valves is probably the best place. Knock back any rough edges and smooth the entry/exit from the valve seat into the bowl. On the intake side, knife edge the divider wall and smooth any lumps or casting flash. Port matching isn't really necessary on the intake unless you have a significant mismatch. 1G DSM intake ports are huge to start with. On the exhaust you can match the port to the manifold smoothing it in about an inch or so.

Anything more than this and you'd better know what you're doing and have access to some more sophisticated shop equipment.

Rick - '91 GSX

 

[AntixTSi]

When you finish the intake side the sanding drums should have their grit # on them, try to use 140 grit or something close. Smooth polishing the intake side is normally not a good idea; and the other important thing on the intake side is to get center divider as sharp as you can. Be careful not to thin it too much, but sharpen it.

 

[Drifter27_04]

Thanks to all you guys, this info was alot of help.