So I've been playing with this 6 cylinder I have in a '63 F100 and the head has me a bit stumped as to which direction I should go.
A little background on the 215/223/261 motor series in case anyone's unfamilar. The head is a 10 port design. Yep, you read that right. 6 seperate exhaust ports, and 4 intake ports (2 are straight shot and 4 are siamesed). WTF? Otherwise, it's pretty conventional: OHV, typical valvetrain, roughly "square" bore/stroke, etc.

While the exhaust ports are pretty small from the factory, with a bit of exploratory surgery it looks like it can flow OK for an engine of this size. What I did was take the ~1.1875" square port and shape it into a trapazoidal shape. I wanted to preserve the velocity as much as possible while still gaining a bit more flow to extend the rpm range somewhat. My gut told me to leave the floor pretty much untouched, except for mildly reworking the short turn radius, and work on the roof and upper sides. Looks like it'll be OK.

The intake is where I'm stumped. If they were all siamesed, OK fine. Again, if they were all independant, OK fine- I can work with that. What I'm not sure about is how to go about balancing the flow as much as practical between the sia. vs the ind. The siamese intakes share some features with the Chevies, but they don't have the head bolts going through the middle. What they do have is "wings" right at the valve bowl/seat area on the floor. Actually, they seem to have more in common with the 235 heads, portwise. I'm not sure if lumps would really work here. I suspect they would, but I'm worried they would make the port volume too small as compared to the ind. ports. I realize I'm not looking for double the volume of the single ports, but still...

All this leads to my questions: (and thanks, if you're still hanging in there after this lengthy diatribe )
1. Should I eliminate the wings or just profile them bit?

2. What's the best way to balance the flow between the differing configurations?

3. Thinking of the intake as an extension of the port-should I build a: A) divided plenum, B) log plenum, C) IR-ish intake with 4 carbs.

Are the wings sorta like a prehistoric ditch cut to help "bounce" the intake charge into the valve seat at a straighter shot (vs. just spilling over the sides)? Do they help with shared cylinder reversion?

I'm thiking an IR setup, such as it is with some sia. ports, would help from a reversion standpoint but probably not be so good from a flow balance perspective. That leaves the log and the divided plenum. The log won't help with either the balance or pulse reversion-but lots of manufacturers have built them that way over the years, so am I overlooking something? That leaves the divided plenum by default. What am I leaving out?

Finally (hang in there, almost done), the truck will be used as a daily beater/hauler/sometime tow vehicle. So economy and efficiency are probably more important than raw horsepower. I'm looking for a good torquey motor in the 1500-4000 rpm range, and a smallish cam is in the cards once I have some flow numbers on the heads. Headers are being built now; 3-1.5" long tubes per side(about 30-32" if I can make them fit) feeding into a Y after the collectors to a 2.5" exhaust is the current plan. As is a duraspark conversion.

I'll try to post some pics to better explain what I'm rambling about

Err, do you perchance have any pictures of the "wings"?

Having a hard time visualising them.

Does sound like a neat project though.

Have you had this head on a flow bench yet? Get some good numbers of all 6 cylinders and see how far off the two odd ones are. Some heads flow more air when the port turns left instead of right into the bowl area, or vise versa so the "wings" may be there for a reason you can't see yet.

Keep the air velocity high no matter what since you are after low rpm power. Concentrate on low to mid lift air flow, in this case peak air flow will not help if you kill the low lift to get it. Get a camshaft in mind and don't over port the head for more air flow at higher lifts then the camshaft has.

Joe

I think that it is starnge for it to have both siamese and single intake ports like this. Improvements can of course still be made, and like Joe said, keep the velocity high. Even if you had access to a flowbench, you still might not be able to get equal flow capability between the siamese and single ports, but doing the best you can do, is still a gain over what you have to start with. Pics also would help. Welcome to Inliners.

Zac, if memory serves me correctly 1&6 are single port runners and 2/3,4/5 are shared runners.....if that is the case then velocity in 1&6 will be critical because the pulses per runner will be at less frequent intervals...2/3 and 4/5 will handle more volume with pulses closer together...been years since I worked on one but it seems like the ports would have to be planned around this.....you may effectively come up with two different configurations before you're done....welcome and keep us posted

Thanks for the welcome guys. Yeah, I def. want to keep the velocity up for the very reasons mentioned. I think this could be a neat little project, but if it all goes to hell, I can always swap in a 300 from a later Ford. But, ehh..., that seems like the easy way out.

While I don't personally have a flowbench, there is one close by, but I'll probably only flow it when I think I'm at the final, detailing stages. This isn't an all out engine build, so it's kinda hard to justify the expense for multiple passes on the flow bench just for grins. Also, I'm not looking to radically reshape the ports/chambers just clean them up and balance them as much as possible.

The wings aren't really that big, just a lip that surrounds the seat entry on the port side, with a flat back wall. So think of the shared port as a "tee" intersection with the valves at either end and little dams or lips continuing the port entry walls. Clear as mud? Or said another way, think of the floor as a trough with the lips being the side walls. Total height is probably only 3/16" or so, but if I wanted to put a nice, say, 1/4-5/16" radius I would have to drop the edge by a fair bit more. The other ports look surprisingly good considering the era of the design.

And KS, the single ports are 3 and 4 with 1&2 and 5&6 being shared. So from a valve timing perspective, IIRC, it's equally spaced, just goofy in regards to flow and runner volume...


The pics kinda flatten out the "trough" a bit, but here they are. It's hard to get lighting in there without killing definition and dimensionality.

http://i213.photobucket.com/albums/cc219/octoberdoll/DSCN2208.jpg

http://i213.photobucket.com/albums/cc219/octoberdoll/DSCN2209.jpg

http://i213.photobucket.com/albums/cc219/octoberdoll/DSCN2214.jpg

http://i213.photobucket.com/albums/cc219/octoberdoll/DSCN2207.jpg

Yeah the pics really help out. I see your from Pismo Beach, is Wilcap/Sharp still hanging in there. They might still offer some dress-up goodies for this engine. Stop in and see Pat, he's a real cool guy.

From reading the thread on the 848 head, that's kinda where I'm thinking the work will lead to. I.e.-trying to radius the front edge of the tee intersection and like Tlowe stated, maybe doing some kind of lump or ridge on the back wall to help bisect the flow to each side, and to possibly help with reversion. Although I suspect that the lips or dams are doing some of that now. And just chopping them off for the sake of outright flow may unleash a whole slew of reversion/dilution problems. Maybe a staggered valve timing cam ala Headrick will help offset that?

But then that brings it back to the cost/benefit ratio. Anyone know what an approx cost for a staggered timing cam would be over a regular custom grind? Can you even find a grinder willing to go to those lengths for such an oddball engine? My last name doesn't sound anything like Crower or Sissel or Kirby

Since I'm looking for low-mid power anyways, wouldn't the short(er) cam timing negate some of these potential problems without the need for a custom timed cam ? If I kept the lobe centerline fairly wide for the duration I could potentially sidestep some problems, no?

I'm not trying to overthink this (ha!), but my thought process is with a little more attention and thought put into the engine combo, I can have something quite a bit better than stock without getting radical in the expense end of it.

I have enough of those projects already.

You shouldn't have any problems finding a camgrinder to take care of this for you. Schneider or Clay Smith seem pretty flexible to help accomodate most regrinding chores for inlines that need to be done, as are Isky and many others out there, so you shouldn't have any problems with that.

Zac, I think your plan of approaching the project from the 848 perspective is a good one .....evidently my memory is failing more than I thought; the 1/2 and 5/6 shared design does help....years ago a local fellow here in Ks. ran one in a hobby stock and I was always impressed with it even though it gave up cubic inches to the chevies....thanks...fats