782 head porting

[jackerman]

I have a fully ported 2 piece intake on a smoothed only 782 head. I know since the head is not port matched that this can be a problem. So question of the day is i remember reading a post that you cant deshroud or something along these lines on the 782 head. I have a spare head and was going to port match it to the intake work the short turn very slightly since im not that good at this stuff and was wondering if i can deshroud the head also. Really just cleaning it up. Thanks.

[cordes]

I would get a practice head to work on. I fancy myself to be very good with a die grinder due to years of flat repairs in the tire shop. It has taken me a long time to get to the point that I would mess with a head. Even then I'm not sure that I would be comfortable doing any chamber work.

[jackerman]

I really want to try with this head. If i mess it up ill send the one i have on the car to steve. So im ill change the question to any suggestions on desrouding the head and what others have done with success. Tips on how to make the 782 just a bit better

[cordes]

Use an old head gasket to scribe the fire ring into the head lightly. IMO there's not a whole lot of room to play with there, but I'm not an expert or anything. Make sure when doing the runners into the head that you leave the floors pretty much alone. As you said it can help to lay the short turn back a bit. I would focus on having a nice consistent taper into the bowl area.

[jackerman]

Thanks i think this will be a fun thing to try.

[moparzrule]

You'll want an electric die grinder, and a non ferrous bit. I use a 3/8'' radius end bit to do my aluminum porting.

This is the die grinder I use actually-
http://www.ebay.com/itm/390719331447?_trksid=p2060778.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

It's very light, and easy to handle. Basically a generic Makita. And the bit looks like this-

http://drillsandcutters.com/sc3nf-3-8-x-3-4-cyl-radius-end-carbide-burr-1-4-shank-aluminum/?gclid=CjwKEAjwwo2iBRCurdSQy9y8xWcSJABrrLiSKNbpxqN lkqKFyHL0f-jy8v-lsij1Am0MZVkuHEV5CBoCFJbw_wcB

Deshrouding the valves and the bowl work is the most important things for flow on a swirl head. As Cordes said, lay the gasket on the head (a used compressed one is best) and I use a marker to make a nice fat line. I set my calipers to 9mm, then I stick a valve into the head. While holding the valve up level with the surface I run the calipers along the valve and scribe a line into the head but not going past the black line. Since this is your first time, stick to an 8mm deshroud though.

To do Chamber work you'll need an old junk pair of valves to protect the seats because you WILL hit them if you don't. But, grind them down on a belt sander or bench grinder so they don't stick up so high. If you do a practice head than you'll have plenty of junk valves too :)

This was my first head I ported, so the port work isn't the best but OK-

http://i105.photobucket.com/albums/m216/87wagon/chamber1.jpg~original (http://s105.photobucket.com/user/87wagon/media/chamber1.jpg.html)

http://i105.photobucket.com/albums/m216/87wagon/Chamber2.jpg~original (http://s105.photobucket.com/user/87wagon/media/Chamber2.jpg.html)

Onto the bowl. Take down the sharp edges and just smooth everything. You shouldn't touch the floor in the runner too much but you should radius the floor going into the bowl a little better than stock.

http://i105.photobucket.com/albums/m216/87wagon/Portedswirl3.jpg~original (http://s105.photobucket.com/user/87wagon/media/Portedswirl3.jpg.html)

Then the runners. Again use the marker and mark to the gasket on both the intake and exhaust. Just on the outside, the last 1/2'' or so that the bit will reach in, take the intake all the way to the gasket (except on the floor), and take the exhaust about 1/16'' from the gasket line (again except the floor, but on the exhaust you can remove just a quick swipe from the floor which will remove about 1/16'' of material).

http://i105.photobucket.com/albums/m216/87wagon/portedswirl2-1.jpg~original (http://s105.photobucket.com/user/87wagon/media/portedswirl2-1.jpg.html)

After you have all the rough cutting done, you're going to need to use some sanding rolls. 3/8'' coarse (like 60 grit) rolls work the best to get it smooth fast, then finish with finer grit like 120.

[2manyturbos]

I have a fully ported 2 piece intake on a smoothed only 782 head. I know since the head is not port matched that this can be a problem. So question of the day is i remember reading a post that you cant deshroud or something along these lines on the 782 head. I have a spare head and was going to port match it to the intake work the short turn very slightly since im not that good at this stuff and was wondering if i can deshroud the head also. Really just cleaning it up. Thanks.

Quote:
I have a fully ported 2 piece intake on a smoothed only 782 head. I know since the head is not port matched that this can be a problem...
Ironically I'm about to replace my 1 piece with a ported 2 piece intake and don't plan on doing any head work, also a 782 head. What problems are you referring to?

[shackwrrr]

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[jackerman]

Im just guessing but would the air coming from the intake be hitting a wall on the head since its not matched

[2manyturbos]

Im just guessing but would the air coming from the intake be hitting a wall on the head since its not matched

Right, agreed. I'm sure it's not the ideal setup from the performance stand point however, you got me curious of any known problems with this setup.

[jackerman]

The only thing that was a problem was my car was sensitive to knock at 20psi on 93 octane but not sure if that was a product of that. It was brought to my attention from brian but i have not had that problem with new turbo and brian degreeing the cam but i also have pushed the boost past 15 because as soon as i do some vacuum lines shoot off

[turbovanman²]

Right, agreed. I'm sure it's not the ideal setup from the performance stand point however, you got me curious of any known problems with this setup.

No problems, just not 100% if your anal about every last drop of HP. Engines are mass produced, so with core shift, different flowing injectors, restrctions, every engine won't put out the same amount until you blueprint the engine. Just put the 2 piece on and enjoy it.

[going4speed]

Unrelated to the 782 portion of this threat but I learned something recently.

Polishing the tops of pistons and chambers in the head can cut back on knock sensitivity. YMMV.