Hows my porting? (AV7)

Frostback Ditch /

Alright, so this is my first official porting job, and in my defense I've left a little extra material for any fixes I need to do. So what do you think?

So this is the exhaust, I've noticed in the top right corner that it seems to be a little too curved. Guess that's one thing I've gotta fix.

1226617631_p1000064.jpg

Re: Hows my porting? (AV7)

cool pic

Re: Hows my porting? (AV7)

Frostback Ditch /

And this is the intake. I never realized the bottom was so uneven. The other problem I see is in the top right, I got a little to close and ended up raising the port in the corner accidentally. How bad is this?

1226617841_p1000067.jpg

Re: Hows my porting? (AV7)

Frostback Ditch /

I hope the pics worked, sorry that they are kinda big :D.

Re: Hows my porting? (AV7)

Frostback Ditch /

Bam, just in case the others take to long to load.

Re: Hows my porting? (AV7)

Well, how much material did you remove? Dimention wise I assume you like most follow the wiki but I'm curious. The intake is pretty rough and still seems very small overall. Did you start with a 20mph cylinder perhaps? The intake itself should be much smoother than that. Not glass like smoothness but much smoother than what you have there. Also the opening should be matched to the intake you have mounted to it. You want the air to flow very smoothly so match the intake to the intake port. It's pretty easy to do with the benty intake but again smooth. Try using some rough sandpaper, a different cutting bit (I find a good dull but cuts smooth and doesn't cut very fast). Make sure you camfer the edges on the inside of the cylinder. You can do it with a file or very carefully with the dremel. And make sure you clean everything super well with qtips and dish soap. You don't want any of the powdeer in the engines parts. It may take a while but you can do it. And once it's done it's done so take your time with it. Also what is the rest of the setup if you don't mind.

Re: Hows my porting? (AV7)

Frostback Ditch /

Actually I realized I took .3 mm off the intake, not 3mm, lol. I forgot about the matching of the intake to the port, I'll be sure to do that. I've read though that if you make the intake rougher, it allows for better atomization of the gas/air particles. The exhaust though has to be as smooth as possible. FYI, it was actually the fast cylinder I started with, the reason it's looking the way it is is because I've only been using a dremel, I'll bust out the files and flatten everything. Maybe I'll do a before/how not to have it look, and a after/final product, lol.

Re: Hows my porting? (AV7)

the porting on the exhaust looks pretty good. let us know how it performs. do you happen to have a pre and post porting port map?

Re: Hows my porting? (AV7)

it shouldnt be rough like with ridges and shit. just like sand it down after you get it all smooth to get it roughened up.

Re: Hows my porting? (AV7)

Frostback Ditch /

Alright, thanks for clearing it up. I wasn't sure how "rough" it should be, but now it makes more sence.

Re: Hows my porting? (AV7)

You can probably clean it up by hand with a file pretty easily.

Re: Hows my porting? (AV7)

That intake could be a lot wider.

Dont forget to do the crankcase "devil horns" and the piston mod.

Re: Hows my porting? (AV7)

Frostback Ditch /

Ya, I started the crankcase already, but decided to finish the cylinder first. I've wondered how wide people have made the intake, it says 4mm in total, but on the left side I'm already getting close to where the case bolt goes through.

Thanks for the advice guys, I'm gunna go do some more porting :D.

Re: Hows my porting? (AV7)

hey there

you are doing just fine

you can raise the exhaust port at the cylinder side to increase scavenging

dont worry about the intake that will be just fine

you can widen the crap out of it

Ill try to get some pics of a cylinder I did but it is for a crappy chinese engine on my bicycle

this saab guy may know a ton about porting :-)

hey there saabsonnett :-)

IM a big saab geek too :-)

www.jakstollperformance.com

take care

JAK

Re: Hows my porting? (AV7)

think about the exhust like a funnel

it can be bigger toward the cylinder & smaller at the studs

the intake I usually dont taper like that but you want to leave enough for the gasket to hold in there :-)

take care

JAK

Re: Hows my porting? (AV7)

Re: Hows my porting? (AV7)

Frostback Ditch /

Hahaha port map, thats all greek to me. I do have my measurements of the ports before I started however, so if someone could use that then all the power to them.

Re: Hows my porting? (AV7)

look into the intake manifold...

see how rough it is....

ur work is fine.

exhaust is nice and smooth... looks good

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