Hand porting my 243's
 

So this week I've dove into my C6 LS2 Corvette for a cam swap and a few other goodies. While I've got it apart I've decided to port the heads. I've been reading about LS head porting for months leading up to this, and watched a ton of videos. So far I've blended the bowls to the seats and opened the bowls up just a little. I removed the rocker stud hump, and cut out the casting flash on the intake side. I also cut out the swirl ramp and narrowed the bosses. One picture shows a cutaway I found online, and the black line I drew shows approximately where I took just a mm or so off the short turn. The more I read the more I regretted touching the short turn. Willl this small amount of material I removed hurt anything? I'm thinking of taking a strip of sand paper and smoothing down the area I already touched on the short turn.

I don't have access to a flow bench, but cc'd the intake and exhaust on all ports to 83/224. I'm sure I could get a few more CC's out of them but I'm happy with these numbers.

Does anyone have any input based on the pictures I've included? Any helpful advice or feedback would be great. especially regarding the short turn.

https://cimg3.ibsrv.net/gimg/ls1tech...ec36bac73f.jpg

https://cimg2.ibsrv.net/gimg/ls1tech...d1b65d8ddb.jpg

https://cimg1.ibsrv.net/gimg/ls1tech...e603a6239f.jpg

https://cimg0.ibsrv.net/gimg/ls1tech...895bc12b6b.jpg

https://cimg9.ibsrv.net/gimg/ls1tech...893aaf44a9.jpg

I left about 1/8th of material on the seat past where the factory valve angle is cut. I'm getting a 3 angle VJ after I finish these.

Some of the pics look like a butcher job. Your brave though I wouldn't feel comfortable taking this on w/ my only experience being watching a few video's.

Only the exhaust ports are completely finished. I agree the intake sides need a bit more work.

I get that GM put the swirl ramp on the "wrong side", but I think it's still better than no swirl ramp at all.

If Tony mamo is still putting swirl ramps in his badass afr castings, then I sure wouldn't have ever cut them out of any heads I planned on using.

Spend some quality time with a bunch of various grits of sandpaper and finish up those ports, then get them flowed on a bench.

Thanks for the advice. I'll post a few pictures of the intake side cleaned up soon.

This is one of the bowls after some more sanding.
https://cimg0.ibsrv.net/gimg/ls1tech...252398096a.jpg

Worst case is you need a new set of bare heads.

Go for it.

I will echo stay away from the short turn and you might even want to step back a bit and snag a set of any aluminum heads for an LS you can get cheap to practice your skills some more before you finish yours up.

There's always a lot more bitching in these threads than there is helpful or encouraging.

It's hard to see in the pictures, but it looks like you need to spend more time sizing the throat and blending in the valvejob. Are you planning on cutting a new valvejob, or just leaving the stock angles?

the short side radius is the "make it or break it" part of the cylinder heads. this is where you either make good flowing heads or expensive boat anchors.

I really like your exhaust to intake runner volume ratio. If it's in any way conducive to the exhaust to intake flow ratio, then you should have a really strong exhaust flow/scavenging.

Even if the short side radius shouldn't have been touched, and even without the swirl ramp, I bet these would make some excellent forced induction heads when the ports are all finished.

I recently hand ported a set of 243's myself. It's not black magic like people make it out to be.....Without a flow bench you should stay away from reshaping the runners. Focus on blending, smoothing and matching ports. I don't have before and after dyno or bench results, but the hand ported 243's picked up 3/10ths at the track over stock 853's

On the section view of the intake runner, you can see a contour change on the roof of the runner, about an inch from the mouth. Would it be advantageous to raise the roof and smooth that out?

Probably not, most ported heads don't really mess with that area. It's just the fuel injector cavity.

http://www.advancedinduction.com/Ima...AiCathInt2.jpg