NZConvertible

Flaming won't convince people you're right. Since when? Why is drag racing any different? If you're right, you'd better go and tell all those professional drag racers running 7's and 8's that they're doing it all wrong. None actually (I've watched a few), because I look after my engines so they hang together. That doesn't mean I'm not very familiar with the inner working of a rotary. But that's irrelevant, because we're not talking about rebuilding engines, we're talking about the mods required to reliably pull high revs. I think you're the one who's unwilling to listen, especially considering not a single post in this thread has backed you up, but plenty of people have been trying (unsuccessfully) to give you advice that is based on the experience of many other experts over many years.
No one here really cares what you do with your engine (like you said, it's your engine), we're just trying to share some knowledge with you. Do with it what you will, but don't get all upset about it and resort to name-calling.

Merciless

better becareful with choice of words when replying.......

von

Chill out about the name calling baby.

Expierienced advice huh NZ ?

Gluing my side apex is good advice ?

Whatever I dont care im not trying to convince anyone I really dont care.

Does anyone know the answer to my ? or do I have to use new side plates and report ???

SonicRaT

iTrader: (6)

Well, just think about it. You put 400 miles on that engine without the seal falling through, it seems a little odd that it'd just fall through all of a sudden after 400 miles instead of 1 or 2, I'm guessing you detonated and cracked it. Solid would help keep them in one peice better, but I don't think 'falling in' was your problem to start.

von

Good logical thinking. well that brings up other issues then. Thnx I didnt think of that but the best guess now would be heat from the timing cracked it. Mabey detonation but I was only cruizing during break in. So I guess I will use the old housings and start over. Although My car is parted out already Im going to need a doner car or someone to just buy it.

Henrik

What do the exhaust ports look like?

Henrik
87TII

j200pruf

iTrader: (4)

Alright Von my N/A buddy, ya need to clam down a wee. But personally I would get new irons and report. I have been spending a bit of time at pine appleracing, and I have never seen rob make a port anywhere near that shitty. I would suggest taking it to a different place to have them ported, cuz that dude didn't do a very good job.
Hell that port looks as crappy as me trying to blend my AFM adapter, and my hands shake like a sun ofa bitch.

West TX RX-7

MY GOD thats a Huge Port!!!

von

The exaust ports are fine. Its not that huge. Its just matched to the Sleeve. If you feel with your hand thiers a lip between the sleeve and the housing. That lip was grinded away much less than the mazdatrix websites exaust porting. Also the port does not have to be pretty in order to amke power. I dont know where you came up with that idea. It obviously flows way more than stock. These guys port for basically free anyways. I wouldnt pay 700$ for a bridge or whatever mazdatrix charges.

Jimmy325i

This is highly relative to RPM and you have absolutely no proof of this port making any power within a useable powerband.

I'd bet my car that a stock N/A primary port flows more than that port below 6K. You even said it wouldn't idle below what was it... 3K? I can take my car down to 399rpm (which is where the computer thinks the car is no longer running) and it will hold an idle on that line. (lopes like mad, but stays running) And I have more port timing than you do! I also have close to 7K on my engine without any issues.

You've killed the intake charge velocity, which has far more to do with flow characteristics than the throat of the port. If you don't believe me, think of which will flow more, a garden hose at 1psi or a soda straw at 100?

projekt

soda straw! soda straw!

i'm glad he's still arguing or else this thread would die and that would be bad. My official Idea is to weld the housings to each other, then you can spin to 12K just like you want to, since you don't need and hardened gears. oh, and next time, port into the water jackets, i heard that increases flow too.

SaabGuy

I have no engine building expirience but maybe I can offer you some advise.

If you think the corner seal actually tweaked itself into getting caught slightly in the port then maybe you can try a different design corner seal spring?

Maybe if you get the type which has the 2 tiny springs it wont tend to tweak the seal like the stock 1st, 2nd, and 3rd gen springs. I dont remember who makes them but you can find them easily Im sure.

Again I have no real clue.

Rotary Racer

First off I can’t believe that you did not break into the water jacket port. 2nd Was that port design carefully designed/engineered, or was it done on the fly? It does not look like any time or engineering was taken into account when it was made. IE port timing, volumetric efficacy, usable RPM range, taken into account the primary use of the vehicle. In just my opinion your engine builder went mad and just started grinding away with out taking into account the ton of things that need to be addressed before something like this is done.

I would start with new housings do a good street port and if you “really” need more power then do a small bridge port. This is a proven, engineered, and carefully thought out way to port a motor. But do remember this proven idea of port design will change the dynamics of the motor making it less efficient down low and thus not a good drag car.

projekt

he doesn't engineeer, he takes chances like all 'true' racers

hybridracer

No offense man but you dont sound to knowlegable about what your doing. Looks like you just had them go at it without even really planning anything. The corners on the ports are all pointy and jagged which doesnt help flow characteristics, I mean, werent you the guy asking if you could "cheat" and just let the car idle for a long period of time to break it in?

Rotary Racer

Ahhh Tru Dat' Yo

TonyTurboII

Why dont you use a bridgeport, or peripheral port? Im sure they will work alot better than the godzilla port, or whatever port your using thats been proven by thousands of racers over years.

von

Jimmy ? what are you talking about...I never said I want usable power. I dont drive it on the street at all. Its just my project car to **** with so if you can idle at 400rpms woopy what the hell are you trying to say ? I was just going for as a narrow powerband as possible.

By the way on my stock port I was hitting 100 rpms

Hybrid racer ? Thiers a reputable shop that says you can let it idle to break it in...Especialy if its just for short period drag racing so this doesent really help you belittle me.

von

Tony turbo11 ! yeah thats what Ill do... A bridge is coming next but its not going to be a full bridge. the dising of it should make it last as long as a streetport. Hopefully if it works I will post them up if the meckanics cool with it.

Rotary Racer

Usable power is a term not only for the street but the track as well. Lets put it this way if you built a motor that is power band is only from 5,000 - 10,000 RPM's and you Auto-X the car I would have to say that is UN-usable power.

mazdaspeed7

Von, youre arguments are the stupidest things Ive ever hears. Wanna know what seperates your port from people like Ito and Rob's? QUALITY. Ask anyone who really knows rotaries, and has experience with ports, and they will tell you smoothness is where power and reliability is. Your seals broke because they couldnt take the abuse from those sharp corners.

Back to your port design. It is simply the wrong shape for a n/a. The port is too long and narrow. It has more timing than a PP, but wastes a whole lot of that timing because it opens so late. So you would have a shitty low end, and the top end would not make up for it.

That flywheel *might* be able to take 13K, but everythin else that spins will have grenaded by 11k. at 10.5K, the shaft flex is enough to cause the rotors to start hitting the side housings, which breaks things very quickly. And thats with S5 rotors. S4 would happen a little sooner. Then your clutch or PP would explode, because stock type clutches are NOT made to go past 11K, and even thats pushing it.

I hope you werent planning on using stock bearings. You would spin a bearing the first time you hit 10K.

Do yourself a favor and have someone who actually knows what theyre doing build your engine, without you ever getting close to it until its together.

rotarygod

iTrader: (1)

Big big big port. There is a guy in Houston that has an engine with a port about that size but with a bridge also. The intermediate housing is also as large as he can get it. He is using a Holley carb and manifold in a tube frame VW dragster that weighs less than some of my turds. He has run in the high tens. Impressive yes but then you look at the reliability and powerband. He rebuilds his engines after about every 20-25 passes down the track in other words every 5 or 6 miles of use. He has tons of parts, lots of time, and too much money so he doesn't care. His power band STARTS to kick in at 8000 rpm and he shifts at 13000! Let me reiterate the lifespan of his engines. There are some times when he doesn't even get that many uses. If you want to make more power and be usable, take a different approach to it. Bigger is not always better, especially when it comes to port design. Velocity over volume (to a point). Clearancing is an issue on any engine that you intend to actually start and run at all. The reason you can't rev sky high (regardless of if its a rotary) is because of flex. The lack of a center bearing and therefore center support on the e-shaft causes it to flex at high rpm's. The more flex, the more clearancing you need right up to the point that the shaft stays bent or your rotors hit the side housings. Get a guru racing center bearing and rev up to about 9500 or so max.

Have you optimized your transmission and rear end ratios to match your new power band? If not you will never make impressive times on the street or track. Design around what you have. We all have neat ideas that we'd like to test. I at least applaud your willingness to try regardless of how it turned out or what it looks like. Do some more research, be a little more patient, and re-evalutate you goals and abilities at this stage. You'll get there one day.

rx7_ragtop

READ the rules, flames are not permitted. This is your first warning.

projekt

so what's the highest street rpm on a built motor? what things other than lightest rotors, hardest gears, flywheel/clutch are necessary?

von

Ok mazdaspeed7 I guess you would know from expierience and the edges did not break my corner seal. We already established that. And whats all this reving beyond 10K rpms ? You talk about flex at 10.5 and grenading at 11k but I never said I was going to spin that high did I ??? Please stop making up fabrications

Rotorygod. Thnx ,,, I try

I knew about that VW with the same port. In fact I was also going to bridge it but I figured I would really need some of those previous mods mentioned for sure. Im possitive im in the safe zone with my current setup regardless of what people say...

I have another port desin. Instead of bridging im going to drill holes for the bridge that way the bridge will not crack...The combined volume will be bigger than a streetport but slightly smaller than a bridge...I will do it with new housings but the enginen will have to go in someone elses car because I striped mine already.

Any doners ? I will install myself !!!