Note that the indentation above the intake port to the left is not actually a port but rather a casting that can facilitate a port. On the 6 port engines this is quite round and on the 4 port renesis motors this has been squared off at the bottom as in this case. You can also see it's not going anywhere.

Paul.

Good catch on the port. I've never seen a 4 port Renesis plate and now that I know what it looks like, it's the same thing. I really wish they hadn't have used the same basic castings.

Having seen 4 port renesis side plates in person, they look EXACTLY like that.

They have a hole for a 5th and 6th port, but its filled in.

Based on that, I can say that mazda may be planning to make a 4 port and a 6 port version of the 16X.

4 port can have some advantages tho... all boosted rotary engines were 4 ports while their N/A counterparts were 6 ports. BOOOOST maybe for the 16x??? One can dream...

(alas I know the reason for the 4 port renesis was to keep the redline down to keep the auto tranny alive)

so 6port rotaries aint good for boost?

I think it has more to do with 6 ports being exclusive to the Renesis.

Uhm, no. There were 6 ports on the nonturbo FCs as well.

Really. Cool. This would be the reason I lurk more than post.

more of no need for 6 when your fi

well, the 4-port obviously wasnt required for keeping the redline down seeing as the 6-port AT still has the 7500 rpm redline. But that does bring up a question: what was the reason for only having 4-port? I'm sure it's been mentioned before but some reason until I just thought about it, I didnt realize that I wasnt sure why.

Sorry mate. Unless the 2nd port alongside (not above or below) the main port on the centre plate photo is a reflection, then the centre plate "Primary ports" are "Bridge ported". You can see the "bridge" for the corner seals of the rotor to travel over between the two ports.

The 6-port part appears to be on the front (not pictured) + rear plates for reference. Thats also assuming the port above the secondary port on the rear plate in the pics is actually an intake port & not something else.....???

REgards

I dont see the bridge your talking about.

Certianly not on the primary ports. The primary ports we have pretty good pictures of.

I cant see mazda doing a bridgeport in a production motor for a number of reasons. The main one is the whole purpose of a bridgeport is to significantly advance port timing. With emissions in mind, this is not a good idea at all.

You might be able to get away with a little bit more with emissions than with a peripheral exhaust ported motor, since the side port exhaust doesnt allow port overlap. However port overlap might occour if you have a bridge on the intake.

Not to mention the low vacuum, poor idle, and gas sucking abilities of a bridgeport. And the powerband is totally impractical for a production car.

NO WAY IN HELL ITS A BRIDGEPORT. You guys are crazy to even consider it.

The final two ports were not necessary until 6750 RPM or something along those lines. When the 6 speed slush box came out, it was able to handle more RPM than the previous 4 speed, thus making the final two ports relevant again. Thus, they upgraded the engine. They most likely saved a good deal of cash doing so.

Ok, I think I stand corrected. The "Bridge port" as I saw it may be a reflection as shown in trhe pic below.
I say this as the exhaust port has a similar reflection on the chrome rotor housing too.

http://www.dmrh.com.au/web/16X MSP.jpg

http://i230.photobucket.com/albums/e...10-2007728.jpg

Bear in mind that a bridge port may not work on the REW design (production version) but thanks to zero overlap on the MSP engines, it may work.
Just hasn't been tested to my knowledge.

yes, I agree the low rpm air speed would be an issue.

REgards

That just looks like a reflection to me???

That, and the fact that the original poster of those photos looked into the aux. port runner and saw that it was only a provision (i.e. not connected to an actual port, exactly as I was saying).

See post #18 here.

This brings back my previous speculation: couldn't the (possible) third spark plug be reserved for the 6 port engine?

remember the firts cut away of the current renesis? it had that twin throtlebody desing that latter when to a single TB, so this is a prototype engine some things will change before production

Of course we're looking at a prototype also at this time. Mazda's not finished development and may not be revealing all their cards (I don't blame them either).

Paul.

Leo, you beat me to the 'prototype' punch so to speak :)

Paul.

^^ :)^^

I think we may see in a production 16x a few changes it all depends on the aplication and its ETA, it is very probable we may see a 3erd spark plug as Paul mention, a 6 port, more fuel injectors and even FI but I really doub this

4 port = 250 hp 195 lbft
6 port= 280+hp 190 lbft

what do you think?

afther a long talk with some rotary experts they are really happy about what mazda did, I got the feeling they like the 12a more than the 13b and are really happy that mazda is going back to 70mm wide rotors, they did make a couple of points I like to share:

-weight will be the same if not less, most guess make it to be 20 to 30 lbs lightter
-lower red line means less strees on internal parts and drive line components
-sympler intake manifold due to the fact that its a 4 port
-DI more eficient fuel delivery
-more torque
- better oil metering, means cooler combustion chamber and much better lubrication
- polar moment of inertia will not be afected on the car this goes in, this is because of the light weight of the engine and since its a 4 port the intake manifold can be made lower closer to the engine and lighter and since the engine is shortter the weight will be closer to the fire wall for a 50/50 weight distribution
-they agree with Paul it is almost certain that the engine will or was/is intended to have a 3rd spark plug
-they agree that the limiting factor of this engine will be the exhaust

this is not oficial info, just a few friends talking possibilities

the million dollar question to me is: will this 4 port be the only sized engine they come out with.... (6 port in the works??)

Im sure they will

How does adding a 3rd plug change the dynamic here? I can see ensuring a complete burn but thats about it...

Imagine the tuning with a 3rd plug...

They certainly had to move things around to fit the 3rd spark plug. They moved the dowel location as Paul mentioned.

I really want to see the 3rd spark plug, coupled with DI, we might see some large gains in fuel economy. The 787B gained 3-5% in fuel economy I think.

The location they want to put the 3rd plug in is the same as the 787B, if you compare the pictures.
________
Cheap Condo Pattaya

I honestly can't see only a 4 port coming out. The whole point of a 6 port, or any variable valve timing on piston engines is to increase efficiency over a wider range. All engines are moving towards this. The American V8's are the last to move to variable valve timing but they are getting there. Soon all engines will have it. It doesn't make sense that the rotary would go backwards in this regards.

The whole point of a 4 port with turbo applications is that the turbo makes up for intake tuning. They don't need the aux ports although it does work very well with forced induction. It's all about keeping things simple. The aux port system adds alot of complexity and takes up space in the small area where a turbo would normally be mounted. It's simplest to just use a 4 port with a turbo.

I find it interesting that Mazda dropped the 4 port from the Renesis line yet we see a larger 4 port here. Even the computer image shows a 6 port so I highly doubt the 6 port is going anywhere. I actually like 6 port engines although most of the rotary community would prefer the 4 ports. At this stage it's just too early to draw any definitive conclusions based on what we see here.