BLUE TII

iTrader: (9)

I have been giving thought to building up Halteched supercharged engine based off a 13bt/rew for my TII (stock turbo is insufficient boost/efficiency- larger turbos have lag). If your S/C could povide high boost at low rpm would this solve the velocity drop at the ports on a siamesed 6port side housing? I was thinking- big ported rew rotor housings (low backpressure true dual exhaust) , siamesed 6port sides (looking for extended duration), hardened/oil modded internals, S/C off MILLER CYCLE 6 cylinder Millenia S (provides in-cylinder compression for the super late closing valves-so great for extended port?) Please don't just say its not worth the effort just get a big turbo 'cause I have $$, the S/C, big I/C, running 6port and 13bt, another car to drive and like to tinker. Or am I totally deluded thinking this would have more port duration a huge streetported 4port? Would rather not do bridge or p-port for longevity reasons.

BLUE TII

iTrader: (9)

O.K, how about-Does/can 6port have more duration than ported 4port intake?

j9fd3s

iTrader: (3)

to get the port opening and closing times you can look in the shop manual. the miller supercharger is setup to make crazy boost plus you need to find the flanges for it ans make a manifold.

mike

FPrep2ndGenRX7

www.atkinsrotary.com might be a good starting point. I've got a friend with there SC setup and its on a stock TII engine. The engine is in the neighborhood of 200 HP. He has to be careful not to over rev the engine least he over spins the SC and it will possibly grenade. The power delivery is very linear and instant when the throttle is applied. He bought an intake piece and is running a weber sidedraft fuel injection unit. Its awesome as far as I'm concerned.

BLUE TII

iTrader: (9)

Thanks this is good info. J9fd3s- I know I can find the stock port specs, but I have heard the 6port can be ported just a bit, whereas the 4port has enough metal around the port to make it alot bigger. I chose the "crazy boost" of Mazda's Lysholm for its flow and its efficiency, I figured I could gear it down (and so build the engine w/ high rpm capabilities) and replace the bypass valve w/ a "wastegate" that I can adjust for whatever max boost I want or controll w/ EBC. I can deal w/ the flanges etc, though I think I might have to get the Millenia S manual to figure out the damn oiling passages. Since the 6port mani. may be too restrictive I was thinking sheetmetal mani. TB is another item I would have to find less restrictive replacement for.
Fprep- for 200hp at the wheels I was happy w/ stock turbo at near stock boost w/ full open exhaust and TID. There is no lag- 7psi anything over 2000rpm, you can rev to the limiter no problem. The Millenia S supercharger boosts more than I want at stock gearing and obviously doesn't grenade at Millenia S stock redline.
My general thoughs were big turbo has lag, but is thermally efficient and since it doesn't have parasitic loss to drive it even more efficient. The right S/C will have no lag, the same thermal efficiency (but still parasitic loss) and being able to run an exhaust w/ no restrictions (like turbo in the way) and being able to have high duration ports to boost VE would at least make up for the parasitic drive loss. Feel free to point out the faults w/ this logic; I would appreciate it. Basically, I want to change the Otto cycle Wankle to a Miller cycle Wankle w/ out the reliability concerns of monster bridge or P-port.

mazdaspeed7

The 6 port end housings can have more duration than any of the 4 port housings. You could also do a partial bridge(bridge port the 6 port end housings, but leave the middle housings street ported) for incredible power, but this might be too much for what you want.

You are correct in assuming the 6 port intak emanifold is too restrictive for that engine. Sheet metal would be best for this application. Since you appear to have the $$$, it would most likely give the best results, and you can have the runner diameter/taper matched to the port size, timing and area.

Sounds like a good idea, keep us posted on how it goes. BTW, you much use S5 middle and end housings to use the FD rotor housings.

BLUE TII

iTrader: (9)

Thanks Mazdaspeed. What is the average lifespan on such a partial bridge engine, I would like to get over 50k miles on this theoretical build up if it survived "tuning." Thanks for the info on S5 housings for FD rotor housings, so the NA housings changed as well? As for updates, I will certainly post if I find out this is a stupid idea, but it may be a while beore I actually build anything since I want to learn how and why this would/wouldn't work first.

mazdaspeed7

The lifespan on a normal bridgeport(not j-bridge, which violates a water seal) is dependent on the seals. you can use the stock 3 piece seals with the partial bridge(not a full bridge though), so tuned correctly, it could easily last 100K miles. I have a 6 port engine torn apart and cleaned, so if you want some pics of the stock ports, I could get that for you. If you are going to build this engine, you are really going to need rotor and main bearings designed for a motor capable of 10K all day long. You can get 3 window main bearings and race rotor bearings that have a deeped oil groove, but Im going a different path on the j-bridge 12A Im building right now. This engine might get the porting necessary for 13K+ rpm. I am going to modify the stock bearings(rotor and main) to hold oil better and the ecc shaft to put a little more oil to the bearings. Ill give you more details once I start working the bearings, which will probably be next week sometime.

RETed

I personally think you're crazy.


-Ted

mazdaspeed7

We wouldnt even have rotaries if it wasnt for Felix Wankel going against everything in the world of engine design to make the rotary, and Im sure people thought he was crazy too, until they saw how it worked. So I say Go For It!!!

And Im guessing by your reply that you didnt find anything mechanically wrong with his idea that would keep it from working.

BLUE TII

iTrader: (9)

Yes, I think I'm a bit weird in the head as well.:p Like Mazdaspeed mentioned, I expected a string on reasons why it is a bad idea from you Ted. Mabye I can start one and you can add to it. 1) lots of fabrication/$$ 2) loud as hell 3) smog, ha ha 4) either have to clutch the S/C for cruising or have bypass valve open or fuel consumpion will be gastly 5)hasn't been done before (that I know of), so don't know what mistakes to avoid 6)...

mazdaspeed7

People tell me Im crazy when I tell them about the 12A Im building.

SuperchargedRex

Hey, I thought being an oddball was a prerequisite for owning a rotary engine. I get funny looks when I talk about a 9 port 20B NA. I don't know why: power, torque, smoothness, revs, and reliability; it would have it all. The only downside would be fabricating the intermediate housing for the 9th port.

mazdaspeed7

Housings, plural. You would need to intermediate housings. The S5 eng housings *might* work, but Im not sure.

RETed

Well, what I meant was that this idea is going to either cost 1) a lot of money, or 2) a lot of time and effort (OR BOTH!).

Sure, the original poster has some "interesting" part horded, but it's going to take a lot of money and/or effort to get everything to work together.&nbsp In the end, it's basically bragging rights.&nbsp I can build an FC that does 95% of what the original poster wants with a turbo'd FC with a lot less hassles.

This is why I called him "crazy".




-Ted

mazdaspeed7

I like being different, and I get called crazy all the time for it. For me I would rather put more work into something that is totally different from everything else, even if it doesnt perform any better. I just like being different.