Moon Assad

Thanks, lifes about to change alot.

jskup1

iTrader: (7)

yep, but it's so worth it. congrats!

olddragger

iTrader: (3)

i have raised 3 ( still raising--it never stops!). So if the time comes--shout out.

Well for my build i have decided to go with the low compression rotor set up. Cam will be doing this of course. I just like the extra tolerance for error that the low compression set up should give you while running pump gas.
It address's charge temps and detonation in ways that I like.
Matter of fact i think i started a thread about the difference between low/high compression with boost somewhere?
If I ever learn how to tune i may later also go with E85?
TeamRX8 said something on a thread that suddenly registered in my old brain. He said in essence, People have a basic misunderstanding of what is happening with the left over gases and apex seals. How they can flow from chamber to chamber.
In thinking about that, he is right. This side exhaust port engine is a totally new world and to have a resilant engine on a road circuit, i am convinced for now that what he has pointed out is part of the problem?
Lower compression rotors+ rx7 tall seals should help with this also?
Now to get with Rote and see what all he has done and who does his tuning?

zenrx8

iTrader: (4)

I'd forget than, OD. Ethanol is a stoich killer and power robber. Scrubs oil off off metal and out metal pores. Increases friction. Leads to increased failures.

Sound Familiar?


I'd spend my time on methanol or plain, good ol' hi test.

Galen Darkmoon

OD sez: Now to get with Rote and see what all he has done and who does his tuning?

Damn straight, like I told the boss. It's not if the engine goes its when.
Very interested in his build and how it performs, and how he likes it. How its used? would you make any changes. Out with it, Don't make me put a cigarette out in my eye.

JMKuco

Hi guys,

It's when you want to sell that new thing occures...
I've got ignition problems...
I changed my spar and still the same problem...
can the ignition wire (I have the one bought with the S/C) be dead (as the MSD coils might be too powerful)?

little video just after installing the sparks :
http://www.youtube.com/watch?v=6XRNbzcvOeM

olddragger

iTrader: (3)

Why dont they make round apex seals? Dang things wouldnt break then. Of course the rotor would have to be modified to accept a dowel pin looking seal--but seems to me that since a circle is the strongest geometrical shape--why not use it for this part that is under so much stress and cause's so much trouble?
HUHHUHUHUH??
Someone do it?
OD

alnielsen

iTrader: (4)

Wouldn't the hot gasses push the apex seal up into the rotor if the tip of the seal was rounded.

olddragger

iTrader: (3)

no more so than it already does? Maybe even less?
The top of the current apex seal has a kinda round shape to it--right? But the seal breaks further down from the top part---thats were the strenght of a circle type would be advantageous?
OD

Brettus

iTrader: (2)

It still would need to move up and down in a groove so the 'land' or point of contact would be low in the groove . So you effectively have a gap which will be a perfect place for carbon buildup .

Moon Assad

I like this discussion. I've also have put some thought into a new apex seal. People have tried a lot of different ideas and haven't gotten to far. One I like is 2 seals at each point. Seems from what I've seen from R&D of the rotary not much has changed other then size, shape and materials. It is the weak link. You have wear and tear, cracking and carbon build up. I like the round idea, id say like a bearing of some sort but that point about the combustion charge slipping under the round bearing makes sense. So what if you put a thin seal that can handle some flex in front and behind a solid rotating needle bearing so it keeps anything from sneaking under.

olddragger

iTrader: (3)

now we are thinking.
time for an OD intense contemplation moment........
ok--the O seal would have to move a small amount vertically --agreed.
But like what Moon said --have two small seals ( maybe out of ceramic?) that would close the gap left when the O seal moves at the base? Those seals would not have to reach the summit point of the O seal.
Also the clearance would have to be such as to allow some rotation movement of the O seal--that would help with carbon buildup much like a piston ring that is allowed to rotate on the piston?
So I see a O seal with a ceramic half wrap? Carbon will not stick on ceramic will it?
OD

Moon Assad

Maybe a ceramic roller and not so brittle material for the outer seals. It also might be possible to make the outer seals one piece, just cut the slots in the rotor bigger. Something like this.

olddragger

iTrader: (3)

Bingo--you are reading my mind
i dont see why that would not be a stronger set up. More friction--yep--maybe---but no engine destroying moments.
with the heavier weight wouldnt the higher rpm sealing be better also?

hornbm

iTrader: (1)

I disagree about no engine destroying moments. Extreme cases of detonation are strong enough to leave a visible dent in the rotor. I like the idea, but extreme detonation will still kill this thing.

Moon Assad

Your right, I've seen housings blown apart and cranks broken in extreme cases also. There's always that case and risk but mostly on high power and crazy amount of boost engines. There's always a cause, bad gas, no gas, to much timming, boost spikes, you name it. The point is trying to design a seal that can handle a good amount of abuse. Any ideas that are thought of should be taken into account. If its a better idea its always a step foward.

Rote8

Your bearing speed would be in the S/C range (or higher) for that little roller apex.
Maybe just three giant ceramic rollers AS the rotor?



I always wanted a mushroom shaped apex, that combustion pressure could press tighter to the housing.


Or no apex seals on the rotor, but put seals continuously, side by side, in the rotor housing.

Or, two side by side counter-rotating rotors with the combustion chamber between them, (a diesel?)

olddragger

iTrader: (3)

yep i have seen that--but i didnt explain myself well when I said no engine destroying moments.
What I really meant to say is it would take away some of the fragility we now have...a lot of FI renesis engines now only takes 1 small detonation to be toast! And the tuning has to be pretty spot own for the gas that person is running.
I do hear that the 16X sky rotary engine will have ceramic apex seals--maybe mazda also wants a stronger seal?
I like the O seal with pre and post scraper seals idea--that should really help sealing at low to midrange and maybe no more flow between chambers?
Put a 3 sparkplug set up with that?

hornbm

iTrader: (1)

Now that is very interesting and the first Ive heard of. Mind sharing where you heard this? If mazda went to ceramic apex seals for the 16x that would be a dream come true. I just wonder what it would do to the cost.

09Factor

Or maybe they are heading in a direction of no oil in the combustion chamber.

hornbm

iTrader: (1)

explain.

Flashwing

Just couldn't wait could you.

Moon Assad

Would be nice.

olddragger

iTrader: (3)

that makes sense with the higher compression and the direct injection.
Less holes in the housings the better.
I wonder if thay are also going to do the L shaped side seals?

Pondering about why the vacuum line popping off made my engine blow....... then suddenly it dawned on me. The vacuum line that popped was the one that went to the ssv vacuum chamber/solenoid unit. I bet that when it did that the ssv closed during full boost leaving the intake with the primary and APV valves open. That was enough to cause the engine to hiccup.
I was probably for a split second in a boost spike since that intake valve closed and that may be what also caused the side seal to blow ( we think the side seal is blown) and all that oil to come out?
In thinking a little further it may be my side seal ONLY that blew--wont know until tear down off course.
It will really tickle me if my housings are ok

Now this raises a question for me---HAS ANYONE GIVEN THOUGHT IN KEEPING THE SSV OPEN ALL THE TIME?
This may have some advantages? I am considering locking the ssv open during track events.

By the way you should see the cribbing boxes i built to put my car up on--I can now roll freely under it while working---much safer than jack stands also. It makes the under the car work So much better and those pesky jack stands are not there to get in the way at all. Wish I had done this a long time ago.
OD

Beodude

iTrader: (3)

E85 can put out some good power in FI setup. My friend Tom has a WRX/STi hybrid engine that he has been tuning for E85. I think he made a good 20whp more with ethanol. I don't have the number off the top of my head though. You can run more timing, and I think intake temps are a bit lower since E85 has a higher amount of heat it can absorb (there is a scientific term for it, but I forgot it... Specific heat something?).

As far as I know, Mazda designed the engine to carry over some exhaust into the intake cycle. They also put the cutoff seal in there to help prevent too much from going over. I'm sure you know all that already though. So what is it that people misunderstand? Obviously having leftovers in the intake is going to heat up the incoming charge, and you will have reduced space to pack in air as well. At really low engine speeds, you might have ignition problems if there was too much exhaust left over... But with two spark plugs per chamber, I don't think that would be too much of an issue.