Removed 3/16" off of the OPENING edge of my secondary intake port... Too much?
 

I'm now 3/8" away from the water-jacket seal slot (near the top). Stock the opening edge is about 9/16" away from the water-jacket seal.

It doesn't look like there's a lot of support for the corner-seal, but I could be wrong... Did I go too far?

I heard that at least HALF of the corner-seal needs to be supported, to remain safe. Is this true?

I have a large extended port and I measured 10.8 mm from the water seal groove to the edge of my port opening. This works fine. Because not much of the corner seal is supported I removed the rubber inserts from the corner seal otherwise they would just fall out into the port. I have done 4,000 miles at 1.2 bar with no issues wit this setup.

You have side seals / corner seals to lose if your guess is not correct. A piece of plexiglass costs ~$4 at Home Depot.

The corner seal won't fall out even with a quater of it being supported.

How about the side seals? How well are they supported?

Good question. I used a fat, juicy dry erase marker to color in around the intake port. I installed the rear-gear, put in corner-seals and springs, and used the e-shaft to rotate the rotor over the intake port. As the corner-seal rubbed on the dry-erase marker, it showed the path it took... There was about 5/32" of the corner seal supported. I use solid corner-seals, so maybe I'll be OK?

I can't find a frikkin' metric measurement device of any sort! (I will) and I'll compare mine to the 10.8mm that BNA ellis runs.

I'll post back with the results.

I'm also going to have to re-check the 'Judge Ito' side-seal clearance info over at Fc3spro.com

Thanks guys,

(n00bs and die-grinders... bad times, lol)

Alright, so I found a ruler with metric measurement and I measured about 9.7mm away from the water-jacket seal slot at the closest point.

There is about 3.5mm of support for the corner-seal which is approx. 10mm in diameter...

Too risky?

(I'm checking the Judge Ito side-seal page right now)

So, according to Judge Ito, I simply need to chamfer the edge of the modified intake port, so that there's not an abrupt edge for the side-seal to catch on... Is this what you were concerned about peejay?

Anyways, you (peejay) also mentioned that the corner-seal only needs 25% of itself supported... I'm at 35% at the 'worst' spot... Should I trash the end-plate, or is it agreed upon that I'll be OK...?

Also, if it's OK for me to use this end-plate, SHOULD I PORT THE OTHER SECONDARY INTAKE PORT TO MATCH, or should I take a safer route and have the shape be slightly different?

Which is the lesser of two 'evils'?

TWO intake ports with little corner-seal support, or two MISMATCHED intake ports....?

Thanks for the help guys.

Plexiglass. Take it from a guy who lost about 7 side seals from guessing port shapes.

I guess I don't understand what exactly you DO with the plexi-glass... (...shoot)

Let me take a stab; Lay the glass over the rotor, trace where the side-seals lie, cut a hole in the middle of the glass the same size as the e-shaft lobe, place the cut glass over the e-shaft lobe and spin it around?

What do you look for? Overlap of the seal edges with the 'port' edges? Cause if that's the case, can't you just bevel the edge like Ito suggests? Or, is there a point of no return, where the seal could potentially have TOO much of itself over the port at a given time, therefore causing the majority of the seal to fall into the hole, regarless of the beveled edge...?

yeah...

Here is a pic, hopefully it explains what you do. Basically you make a port template out of the plexiglass and then lay it over a half assembled motor, spin the eshaft and watch where the side seals go when moving past the port opening that has been traced on the plexiglass.

https://oregonstate.edu/~quinnj/FCNAEPtemplate.jpg

The little line drawn at the top of the port is a reference line to show the scissor angle the port has with the side seal when it closes the port. Not having an angle there will eat side seals faster than anything else I've seen.

One more thing, now that I think about it, depending on how high up your port goes, if you took away 3/16" from the original port opening edge on a TII plate (secondary I'm assuming) you might still have opening side seal support, which is a good thing IMO. I may have removed 1/4" or more to get the port shape you see up there.

I'm gonna try and get some pics and plexiglass... Thanks Integra.

Don't worry about the cornerseal.

Worry about the trailing sideseal.

Look at 88IntegraLS picture. The top sideseal (leading) in the pic can have the end where it meets the cornerseal fall into the port and everything will be fine as long as you scissor and champher the port top to gently guide it back onto the plate.

The lower sideseal (trailing) end right where it meets the cornerseal MUST stay on the plate at all times through the intake stroke for any kind of reliability. If that end falls into the port you can see how it will crash into the port top tip first as there is no way to gently lift it back to the plate from the end that is already on the plate (like the scissor of the top sideseal).

ahhh... Ok.

So, looking at the pic, the seal in 'danger', is just baaarely supported in the pic... Correct? Like it'll just barely make it without falling in.

I'm actually planning on getting another motor to 're-do' everything on. I'm afraid that porting through 3 irons is kind of unacceptable :eek:

Lesson for the kids: "Going just a littttle farther... Is too much, lol."

Whatever, thanks for the help guys. I'm all around going a more 'conservative' route with my porting.

My focus will be on shape, quality and velocity-- not size and aggressiveness.

I'm also going to be upgrading my porting tools. A 'die-grinder' is too fast with not enough 'touch'. I think I'll be using it in conjunction with a high-speed dremel--which should have any easier time "getting in" the rotor housings to more easily shape them. Wheras the die-grinder is like a long, heavy wand that needs a side-angle approach.

Yes, you want about 1mm of metal past the very tip of the leading edge of the lower side seal so its tip won't stiff-arm the port corner when it goes past it. :)

Very high closing edges like what I did also require that the opening edge of the port won't get in the way of the very tip of the top side seal as it closes the port.

You'll see all this when you get the motor there in front of you with a port traced out on the plexiglass.

Good deal, thanks for the great help. "stiff arm" is the perfect word-choice, lol.

I should be getting some new irons pretty quick here.

Yes. IMO the closing edge of a port should *always* be chamfered, for flow reasons as well as for seal friendliness. (I was shocked that this was a "secret"!)

Err... What I was getting at was that the corner seal was not quite the limitation of a good sideport, as much as the sideseals. How crazy you can get depends on how good of a fit the corner seal is into the rotor, if your corner seal is a sloppy fit then you'll want more support on the side housing. (Kinda like in a boinger, if you heavily cut down the valve guide you better make damned sure that the valve to guide clearance is on the tight side)