mopster, nice work

I am curious as to what the Indybrock port looks like. mopsters ports look like alot of work when you can just use offset rockers and lose the pushrod pinch but i have never seen a picture of the port and would like to if someone could share

the epoxy in front of the guide will create an "anti" swirl to the natural pattern of swirl natural to the valve placement/position... ls motors have that cast in,,, you can get turbulant airflow, or air disconnecting from the short turn and the vane,, or a particular type of valve job will help the air stay connected as valve lift goes up. everyone has seen air get turbulent or a head loose airflow as lift increases,, what he did with the epoxy will help that not to happen,, and for the head to continue to gain as lift increased

putting more short side on the head with epoxy is not a bad idea..

Mopster that looks good to me,and numbers are inline with what that much effort should give. the man that ported my edelbrocks didnt have much good to say about the sb edelbrock ports out of the box,the only thing he liked about them was that atleast they where not cast iron.
i gues those wings around the valveguide is to keep the airflow away from the exhaustvalve and minimize the amount of fresh fuel/air from taking a shortcut out into the exhuast during overlap?

304 CFM or not, professional porter or not, uniform work with epoxy is not easy.

Looking at your work I imagine these are the not first set of heads you've ported. Nice looking work!

Looks like you did a lot of work developing what you wanted.I,for one,can appreciate the need/want to do things yourself.
Please,keep us posted on the rest of the build!
Keith

Nice work and I have no doubt your numbers are good judging from the amont of work I see in the shots. Also you have your base numbers for comparison which always make it easier to compare flow numbers to other benches.

What has always been interesting to me is hardly anyone talks about wet flow and that if you consider a (for example) 12:1 A/F ratio at 300cfm, 7.6 or so percent (or 23 cfm of that 300) is displaced by the Liquid Fuel in suspension and fuel doesn't always act or swirl around in the port exactly the same way that air can or does. Also everyone understands say 300 CFM for port comparison but how many think about that intake valve being shut for around 2/3'rds of that minute?

Even the more we know, we still learn more from "cause and effect." I've seen similar epoxy mods that picks up the airflow big on the flow bench but don't always correlate to a proportional increase in power. Also a port that doesn't work well with a carb may work extremely well with port injection (related to that very reason).

Ryan said something very insightful (I'm paraphrasing) that he doesn't neccessarily concentrate on the flow on the bench so much if you know from experience where to port to pick up the power...in the end that's really the bottom line becuase nobody races flowbenches

Take your intake duration at .050 and divide that by 720, take that fraction and multiply it by 60, that's how many seconds per minute your intake valve is actually open....and Unless I missed something that is constant regardless of RPM i use this to compare 2 cams @ .050 and .0200 becuase it gives you a 'real world" relative percentage comparison from one to the other.

Thanks alot for the pics. I'm doing a pair right now and I'll post pics of mine this weekend...they are right at 302cfm at .650.
It's just fun to share...that's what this site was all about a few years ago...
Brian

About the epoxy mod around the guide; it´s there to keep the port not stalling at higher lifts, just as moderncylinder said. I think It depends entirely of the port shape if it works or not. I wasn´t planning to do it at the beginning, but the way the port ended up, I felt it must be done. I Didn´t do any flowbench testing with that so I can´t be absolutelu sure if it´s needed. In fact, I didn´t do any flowbench testing with the port shape at all, I only tested a few variations in seat work.

I got the intake done today. It was a lot of grinding too, I had to remove about 25cc from each port to get the size right. Here´s a pic I took earlier. Who recognizes the intake?

OU812, I´m looking forward to see your work.

An M-1 tunnel ram?

Bingo.

I was just finishing the seat work to match the best flowing port I tested, and I thought of something... This port was my "wild card" and I didn´t expect it to be the best one, and beside the seat, it actually had one another thing different than the other ports. I have been doing some studying now with the flow sheets,and compared them to results I got from similar testing with another set of heads, and I think that this another thing is actually hurting the flow.

I arranged some flowbench time for tomorrow, and I´ll report when I have new results. I don´t know if I will gain anything, but I must do this or I can´t sleep at nights

Didn´t gain more flow, but I found out it wasn´t the seat that made the port better but this other thing, which was slightly different short turn shape. Now I´m going to even them out and thats it, no more testing.

no