Jeezus

iTrader: (4)

In a huge Bridgeport like this, where you have to cut into the housing:



What do you do about the inner coolant seal around the port area?

EDIT: Do you still run it around the inside of the port? I can see a ledge of where it sat before the porting was done, but if you put it there, wouldn't the seal swell from the fuel? I was told you could put the coolant seal in the housing, then cut the part with the bridge and silicone it, but he never went into specifics on if you just put a dot on each end of the seal (wouldn't coolant leak through into the port?) or physically make a bead on the outside and around the port?

-xlr8planet-

iTrader: (3)

If you cut at a 45º angle, you dont cut into the coolant seal

I wouldnt go that big... unless its a racecar

Jeezus

iTrader: (4)

Yeah, I know, I am not going to do this, curiosity.

Jeezus

iTrader: (4)

Ok, so, bored and curious again. So, looks like the coolant seal to inside housing is 4mm.



Would 1mm be enough support to hold the coolant seal in?



Then I was looking at how far in you would cut it. Going in at a 45* angle would put me at 3mm in, which looks to do little to nothing. So I went with lucky number 7:



This way I can more curve it instead of a straight line so the air flows better.I am aware that when you port the exhaust you have to leave a 10mm on the sides of the housings minimum so the apex seal won't fly in. Is there a danger of doing it this way, with 7mm in? I would think not since I remember seeing a side-fed PP picture and they went in about a third of the way into the housing on both side.

Now, one final question. The corner apex piece. The bridge holds the corner seal in, and the lateral of the corner apex piece. How would it support the upper part? Actually, thinking about it, I thought the corner piece was upside down. Forget the last question.

-xlr8planet-

iTrader: (3)

In the pics I´ve seen, no one goes that deep (7mm)

This thread is good

trochoid

iTrader: (6)

I cut the housings at 45* when I notched for my 1/2bp, then reversed the apex seal so the long side runs over the notch. Don't take more than 1/2 of the lip. There used to be a good writeup with pics on how to do J-ports over at NoPistons. Unfortunately that thread got lost in a hack a few years ago.

-xlr8planet-

iTrader: (3)

what do you mean with "dont take more than 1/2 of the lip"? whats the lip?

Jeezus

iTrader: (4)

Ah, so I found the Image I was talking about, the side fed PP's. Turns out I had it wrong. I blame my memory:



That is good to hear Trochoid. What about if this was on a full bridge engine? The apex seal wouldn't matter as to which side had the smaller triangle piece. I started a thread a while back on who makes 1 piece seals, but could not find any info

Jeezus

iTrader: (4)

I was thinking about the 45* angle earlier and that is why I was thinking about going 7mm (just a number thrown out there, could go 5, 6, 8, whatever, just more than 3).

Actually, just typing that sentence made me realise something, if it is 3mm up towards the inner coolant seal, and 3mm inside the housing (giving it the 45* angle), it does not have to be a straight line.

Please excuse my poor MSPaint drawing:



This is why I was wondering about the curved cutting vs straight. Sure, picking at nits here, but I would think that a 5+mm interior housing cut by 3mm coolant seal cut with curved would flow more than a 3mm by 3mm straight 45* slice.

Which brings be back to the first unanswered question, would 1mm be enough "sidewall" clearance for the coolant seal to be supported?

Thanks xler8, this thread is just one of those daydream threads

trochoid

iTrader: (6)

Now that's one PP I've never seen, lol. As far as 1 piece apex seals, carbons are an option if you're going for a high rpm engine. Otherwise, I believe the major rotary sellers offer 1 piece steel seals, or you can drop the big bucks on a set of ceramics.

Lip may not be the best descriptive word. Don't take more than 1/2 of the material between the coolant ring groove and housing face. Some have cut deeper, but then what's left will need support, often by inserting an old side seal.

Jeezus

iTrader: (4)

Yeah, people used that when they banned PP's from racing way back when.

If I had the bucks, I would definitely spring for some ceramics. But with a port this big, I would think that 95oo would be the limit. Any higher and you might as well go PP, eh?

Lip was pretty weird to use, my brain resembles apple sauce right now from reading up on stuff all day. So people insert a side seal into the coolant seal groove when they port more than halfway? What happens when they go to torque the engine together? I would assume they grind the face of the side seal to a certain extent to avoid damaging the iron. Wait, I would think it would damage the housing first since it is aluminum.

I forgot who said it on the forum (there goes my memory again), I believe Steve, but said he uses silicone and 18g wire for a coolant seal. Messy but works? I wonder if that would have any bearing in an application of this sort?

-xlr8planet-

iTrader: (3)

gotcha

trochoid

iTrader: (6)

Side seal is simply there to add support for the edge of the groove. It's used in repairing grooves that are thin on the side support or have been eaten way. As long as the the seal isn't taller than the groove, it works. This is one of Judge Ito's tricks that I read.

I can't see how that port gets around the peripheral port rule. Any port that goes directly into the housing and not the iron is peripheral. Making an intake mani for that dual design must be a pita.

DivinDriver

iTrader: (15)

This book:

http://foxed.ca/rx7manual/manuals/ho...20your%20rx-7/

...has a section (section 8) that references Rick Engman's monster bridge ports from the IMSA championship days. Check out the port on pages 87 & 88.

My paper copy was my bible when I first started learning rotaries.

Jeezus

iTrader: (4)

It is not directly into the housing, per-se. It is still fed by the stock side port inlet, just not fed through the stock side port outlet. The ports are filled in on the irons, and they run the new one through where the water jacket is in that area. Quite ingenious, but the instant 90* bend doesn't seem too happy. I can't say much, as the Renesis engine has the same(ish) 90* bend for the exhaust.

So, you put a side seal that is ground down to be no higher than the groove, around the area where it is worn down, for more support. I assume the soft coolant seal will still sit in the groove, just a tight fit? This would be a good way to get the 3mm notch and still have enough support.

Jeezus

iTrader: (4)

Ah! You are awesome. I will look into it. We need more ink in the printer, I have so many more pages I need to print.

w00t

iTrader: (-1)

I have that book sitting next to me. Each page stored in it's own protective cover and inside a binder.

Jeezus

iTrader: (4)

I assume this book is very valuable now a days? Not something I can go to Barnes and Noble or whatnot and buy?

t_g_farrell

iTrader: (1)

You can still get copies I think. I have one from back in the day.

DivinDriver

iTrader: (15)

Per Mazdatrix:

My copy is full of margin notes, and grubby fingerprints; it was a gift from a friend that used to race RX7's in SCCA, and was on my workbench through my first engine rebuild.

I have seen them up on e-bay from time to time.

There are 12 used copies up on amazon ATM. Cheapest one's almost $60.

http://www.amazon.com/gp/offer-listi...9763008&sr=8-6

trochoid

iTrader: (6)

After taking a closer look at that ported housing, I see that it is a side feed instead of a PP. It's still a very odd setup.

I have the Emanuel/Downing book, very good read. It's been out of print for years. I bought mine on eBay, which is still the best source. there are a couple for sale on Amazon.com in the $300-500 range, mine was around $60.

Yes, there is enough room in the groove for the side seal and o-ring. One needs to be very careful during assembly so the o-ring doesn't pop out and get pinched. Hylomar or silicone will hold both in place.

I've been looking all over both hard drives trying to find the pics I took showing how the bridge and the notch mate up. Lost a lot of pics in a comp crash this summer.

Jeezus

iTrader: (4)

Yeah, it is a very interesting job. Would be a hoot to tell people you have a PP and show them the engine... looking stock

I'll go find some side seals in a bit and take some pictures of them in the coolant seal groove. Sadly I do not have any good coolant seals handy with me.

t_g_farrell

iTrader: (1)

Wow! I feel lucky to have bought mine for list ($12.95)) back in the day. Had it ever since.

Ok, thread jack over back to Stus' huge BP discussion now in progress

Jeezus

iTrader: (4)

Lol thanks Tim.

Anyways, here is a picture of the side seal in the coolant seal groove.






Lot of trimming to do So, I went to bend it to conform to the inside wall of the coolant seal, and it was quite tough. I am worried of it pinching the coolant seal with it just being in there. Odds are, when I get it trimmed down, the slimmer side seal will bend easier to conform to the groove. I just hope it does not get too fragile and snap :X

trochoid

iTrader: (6)

Side seals do snap fairly easy, make sure you have a few to work with. Howard Coleman posted a few pics at NoPistons on how to treat the sealing issue when going with J-port, which cuts well past the inner seal. I don't know if those pics are still up, but reading through the Engine Building and Porting forum over there is well worth the time.