AF16 Window cleanup/port

[johnny248]

Tried searching, didn't find much but I was trying to find some info on cleaning up the intake window on the block? Any pictures or info on this?

[cruzingratiot]

some pics
some mild just cleaned up some ported more

viewtopic.php?f=1&t=30677&hilit=build
viewtopic.php?f=4&t=30594#p264313
viewtopic.php?f=20&t=27850&start=15#p244099
viewtopic.php?f=20&t=29557&hilit=build

[johnny248]

Thanks!

They level of porting there varies quite a bit. Do they need to be opened as much as the first post? Is there such a thing as too much with this?

Btw- going corsa with naraku intake and 21mm polini carb

[johnny248]

I was just going to try to smooth it out a little, open it a little. I don't know if I need to go hard core with it or not.

[ped]

hi johnny. For a 72 cc just open it up a little bit.
the first 1 is ported for a stroker.
that's a great setup your going with.

[paulpauly7]

Bigger is not always better .i went all out and open it as much as i could but it made tuning for round town driving very fiddley so i got another case did another port job i opened the ports 2mm higher knife edged the centre brace and both sides of the port windows straight (as they are tappered stock) this made my corsa sing low and high and was very easy to tune .

[johnny248]

OK, so you knifed the center and did you widen the sides? Or just smoothed the edge into the intake opening to transition better?

[ped]

Johnny, Paul is right. Just go very little on the top and clean the edges around. You should be fine.

[johnny248]

OK. From looking at the stock casting, my plan was to open IP the top a little bit and clean up the center section and blend the sides in where there is currently a step.

[ped]

OK. From looking at the stock casting, my plan was to open IP the top a little bit and clean up the center section and blend the sides in where there is currently a step.

johnny. exactly what paul said. 2 mm from the top. Blend the sides 1mms. put a knife edge on the center, you don't have to touch the sides of the center.

[johnny248]

OK. From looking at the stock casting, my plan was to open IP the top a little bit and clean up the center section and blend the sides in where there is currently a step.

johnny. exactly with paul said. 2 mm from the top. Blend the sides 1mms. put a knife edge on the center, you don't have to touch the sides of the center.

Awesome guys, thanks. I'll post some pics when I am done.

[DirtyE]

A link to my novice work. I forgot to take a pic when i was done. Maybe a link to it in the above posts already. You really want to consider flow while youre cutting. Think to yourself how much flow do i need and how will the mixture travel mosteffectively

http://www.hondaspree.net/phpBB3/viewto ... =4&t=30594

[johnny248]

I should have taken a before picture for reference before I started working on this. Does anyone have a picture of un-tpuched window?

[johnny248]

Well I started working on this. My intent was to open the top of the ports just slightly, knife edge the center splitter, and smooth all of the port intake transitions, and finally put a textured finish on it all.

I don't think that I removed that much material, and pretty much all of the work is done on the intake side.

Now I am looking at the other members photos without any reference to what it originally looked like and I am preying that I didn't remove too much or open it too much. The tops look tall, but it also has to do with the beveled edged I put on them.

Someone please tell me that I didn't ruin this case :/

[DirtyE]

viewtopic.php?f=4&t=30594

The 4th pic down of the first page is an untouched intake window. Trust me, you will be fine. If you went to far (highly unlikely) you can fill there with JB weld or quicksteel. The only place you cant use those 2part metal epoxies are in high heat situations like the combustion chamber or exhaust area.

Porting and flowing is art. The math behind it is beyond normal the capacity of a normal person. I would take your cases and make the best art you can and youll be fine! Put your manifold up to it and see how the mixture will flow through it. If it looks good you're done. If you see sharp or square edges hanging out, round them of so the mixture moves effortlessly around it. Knife-edging is questionable to me. Im not saying you should not do it, im saying you should read about it before you do it. Regardless, knife edge or not in the intake window will make a difference of .001 hp. They key to maximum power is finding all the little .001 gains and making them work together. You have to look at the big picture. Its in the fine details.

EDIT: If you look at my thread, I did one window, then the other so I could use the untouched window as a reference.