Good info guys! I am also looking more into this DIY porting. but i think ill go with just removing casting defects and polish her up. this all really helped tho! thanks!
Porting questions..
- Thread starter sporty982000
- Start date
It doesn't have to be hugely complicated.
Polish up what you have without taking much metal off or changing much.
Polish the exhaust side and feel free to leave the intake side a bit rough.
Without a rechambered head or ports raised you will not see much effect from this.
If you want a hint at what porting can do for you, put 2 basegaskets under the cylinder jug.
Yeah, that is it right there. Put 2 of them in there:
Now file the head down 0.030" (thirty thou) to make up for the extra gasket. Yeah, it takes a while. Big coarse file.
Heck, file another 0.010" -0.020" off just for fun, yeah, its getting complicated now. Just file the little lip right off.
Stock is on the right, file the lip off so it looks like on the left. Ignore the front head.
See lip?
No Lip!
Sand the head flat on a piece of sandpaper sitting on a sheet of glass.
Now put it back together and be amazed. It hauls and it screams.
This is just a hint of what is available. If you play with squished solder and got a proper head made, you can fly!
good info best! I think i might do that. will it need to be rejetted after that?
oh, and does this give you more top end or bottom?
edit- also it looks like the one on the left has a bigger bowl shape to it? is that a different mod and how did you do it?
oh, and does this give you more top end or bottom?
edit- also it looks like the one on the left has a bigger bowl shape to it? is that a different mod and how did you do it?
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Raising the cylinder gives you more top end rpm (revs)
Lowering it gives you more bottom end torque.
It doesn't take much, 1mm will do it. It is in effect changing your port timing without porting.
You need to check jetting with every change you do to an engine.
You cannot blindly hope, you have to check things like jetting and clearances and leaks along the way.
Yes, the bowl is larger, but it is the lip at the cylinder bore I was illustrating.
The cylinder head chamber was cut at a machine shop and is a different (and recommended) mod from planing the head face.
