rxspeed87

a 4 cycle motor has these 4 cycles in them at seperate times


intake
compression
power
exhuast

in that order they happen


on pawl yaws explanation he shows all 4 cycles

of course the first one is intake

now as you ask where does the second cycle come in that is number 4
the rotor is at BDC (max displacement in the chamber)
so now no other place to go other then compress the mixture
hence the compression cycle

number 9 is the start of the third cycle
the power cycle or as he refers to it as the expansion cycle
the compression cycle has finished compressing the mixture
only place it has to go now is to expand and that expansion puts force on the e-shaft... hence power cycle or cycle number 3

number 14 is the 4th and final cycle
the exhuast cycle
the rotor is now at BDC once again and this time it it is there to get ready to push the exhuast out... hence exhuast cycle


so we have 4 seperate cycles/events there

Icemark

Lets make it even more simple, on a two stroke how many times is the combustion chamber compressed on a spark plug? Once

How many times on a 4 stroke??? twice

How many times on a rotary is a single combustion chamber compressed on a sparkplug? Once.

rxspeed87

on a sparkplug yes

but you can't use that 4 a comparison between a 4 stroke and a 2 stroke


diesle motors don't have spark plugs correct?
and not all have glow plugs either

but they have a 2 stroke and 4 stroke diesles

the difference between them is how many different events/cycles there are in the combustion proccess

2 events on the 2 cycle

4 on the 4 cycle

and the rotory has 4 seperate cycles in there as well

just like a 4 cycle piston motor

valves,pistons,sparkplugs, all that have nothing to do with 2/4 cycle

what makes it a 2 or 4 cycle is how many cycles you have

can you deny that a rotary has 4 seperate cycles to it?

doesn't it have
intake, compression, power, exhuast cycles?
on each rotary face doesn't it go through each cycle at a seperate time?

that is why the rotary is a 4 cycle

Icemark

well I guess we will just have to agree to dis-agree on this.

rxspeed87

at least answer this

does a rotary motor have an
intake cycle
compression cycle
power cycle
and exhuast cycle?

if you said yes that it has all 4 cycles

do each of them happen at different times per rotor face?



I can in a way see where you are comming from with this.
but can you admit that it has all 4 cycles though?

doesn't it suck in air?
doesn't it them compression air?
then it ignites air causing power?
then it gets rid of all the exhuast?

4 seperate cycles

gotdatfiyah

rxspeed87

hey our motor can be called a wankel

Icemark

No, it doesn't, since the intake event is part of the compression event (as in all two strokes). Again, If this was not the case the DEI wouldn't work. There also would not be left over (burned and un burned) mixture, if there was a event purgeing the exhaust (as found on a 4 stroke).

In fact the only 4 stroke that is even mildly close to this is the Miller Cycle engine and even then it is really only a valve timing issue in a 4 stroke configuration.

And again you are confusing cycles (which indicate a complete circle) with events during the cycle. Cycles are not strokes, and cycles are not events.

a two stroke also has your 4 events (what you call cycles in your post), yet you don't call a two stroke a 4 cycle/stroke engine. Why??? because there is only one complete travel on the combustion chamber per combustion event.

Again a 4 stroke, there are two complete travels of combustion face (or chamber in our case) per combustion event.
again:
Now does the combustion face travel twice for every fire or once? Again in our motors (as beautify outlined in your post on Kenichi Yamamoto and his diagrams) combustion happens only once.

I don't know how much clearer it can be.
So if you still chose to believe that because there are 4 events, that makes for a 4 stroke engine, then you need to start calling gas lawn mowers or snow mobiles or gas chain saws also 4 stroke engines.

But I am done argueing this. It is what it is.

rxspeed87

first
you on aim or not?



also look at that post I made that you can find on paul yaws website even

he list all 4 strokes/cycles himself
and I think paul yaw knows the motors fairly well


1. 45° ATDC The intake stroke is just beginning.

9. TDC of the compression stroke

11. 135° ATDC The expansion stroke

14. BDC of the exhaust stroke

the intake is not part of the compression stroke
the intake starts to happen WELL BEFORE compression even starts
and ends not long after compression starts
sure you have some overlap but that happens in piston motors also. inertial ram charging is the reason behind that.

intake the rotary motors is a little weird being it starts a little after TDC but still it is a cycle all in it's own

intake happens from TDC to BDC
compression goes from BDC to TDC
power/exansion cycle goes from TDC to BDC
exhuast goes from BDC to TDC
4 seperate strokes

there is
here take a look at this

how many times does the rotor face go from TDC to BDC
now lets not think as BDC and TDC the top of the motor and bottom of the motor
but rather
TDC equals smallest volume. or everything being compressed
BDC equals largest volume, expanded at maximum capacity

so basicly the motor is at TDC at two points going around the whole motor
same with BDC.


in a 2 stroke motor
you might have 4 events but they are not seperate events
the events aren't even going on with a little overlap (as you would find in most ANY motor) instead the events are happening at the same exact time through most of the stroke.

a 4 stroke has each event happening in it's own time
seperate from one another
a 4 stroke motor also hits TDC twice per combustion event
and BDC twice per combustion event

a rotary does so twice each per combustion event as I hope the next picture will show a little better

granted it might see BDC in two different places
but it does see BDC TWICE. per combustion event
same with TDC

so to asnwer this
it does travel twice to BDC and TDC twice
does it change the fact that it seems TDC and BDC twice at at two different spots??
would that make it a 2 stroke even though the fact does travelt to both BDC and TDC twice?

and I'm not saying just because it has 4 events makes it a 4 stroke
what I am saying makes it a 4 stroke is that the events are SEPERATE

they don't happen at the same time
and the motor does see BDC twice and TDC twice

Icemark

The only way that that concept even starts to work is if you decide that the rotor face does not have to make a complete cycle of the housing to make a complete combustion cycle.

Which it does, so again that doesn't follow through with a definition of a 4 stroke motor. A 4 event motor, yes, but not a 4 stroke.

and I have a much better picture of the rotary engine operation on my web page

rxspeed87

don't follow. how does that concept only work when the rotor face doesn't follow a complete cycle around the housing?

take a look at the picture on the bottom
the blue dot is the housing face that we are going to look at

it goes around the whole housing
yet it seems BDC and TDC twice
just like a 4 stroke piston motor would

what IU am trying to say with the 4 events is unlike a 2 stroke the events are done at the same time
not seperate
on a 4 cycle the events might have overlap ( and most ANY motor does) but the events are still SEPERATE


and once again is paul yaw wrong?
1. 45° ATDC The intake stroke is just beginning.

9. TDC of the compression stroke

11. 135° ATDC The expansion stroke

14. BDC of the exhaust stroke

rxspeed87

don't follow. how does that concept only work when the rotor face doesn't follow a complete cycle around the housing?

take a look at the picture on the bottom
the blue dot is the housing face that we are going to look at

it goes around the whole housing
yet it seems BDC and TDC twice
just like a 4 stroke piston motor would

what IU am trying to say with the 4 events is unlike a 2 stroke the events are done at the same time
not seperate
on a 4 cycle the events might have overlap ( and most ANY motor does) but the events are still SEPERATE


and once again is paul yaw wrong?
1. 45° ATDC The intake stroke is just beginning.

9. TDC of the compression stroke

11. 135° ATDC The expansion stroke

14. BDC of the exhaust stroke

'and I have better pictures also

but it was quick and easy to grab so eh

Icemark

your pic:


Yes, he is wrong if he is saying what you are. He is using a 4 stroke piston engine anology for a 2 stroke operation.

The blue dot in your picture proves my point. a single revolution, per combustion event.

Again, I am done arguing this. Just further study how a two stroke motor works and you'll see that I am correct. Until then we will have to just agree to disagree.

rxspeed87

ok

one revolution yes


but doesn't it hit TDC twice
and BDC twice?

that would be equive to a 4 stroke by doing so

tDC->bDC first stroke for the intake
BDC->TDC second stroke compression
TDC->BDC third stroke for power
BDC->TDC fourth stroke exhuast

that is what I am getting at

each one of those is considered a stroke
and if were where to follow your idea even you would be wrong
it at this point wouldn't even be a two stroke but a single stroke being it rotates once for every combustion event

and to bring it back on topic
it still follows the rules of backpressure for a 4 stroke motor

not a two stroke

backpressure is bad evil and will harm power unless you need it to open the 6pi induction system like my car

rxspeed87

I guess that is my thing

I see a stroke as going from TDC to BDC or BDC to TDC
this on a rotary happens twice for each of them so to me that means 4 strokes


it doesn't matter that the motion is circular

but also in a way if you want to get really techincal here

the rotor face does move

if you take one spot on the rotor
move it around the on the shaft it's distance from the very center of the e-shaft does change

try it sometime if you have a spare motor

if I had calipers I would do so on mine

eh might just take a ruler and try it though to get a rought idea

rxspeed87

ok just made a rough mesurement
seems the DC of the rotor face can be anywhere from 3 1/2 inches down to roughly 2 inches from DC of the E-shaft

it moes in that motion 4 times

another reasson why I was thinking 4 stroke

jester1341

i was thinking about doing a "custom job" i would probably use a pair of N1 mufflers but other than that....

-what size piping should i use 2.5"
-should i run one cat and then split or split and do two cats
-should i try to keep as much stock or get rid of all those resinators/cats/precats under my FC
-and what about headers?

;86 NA stock so far;

thanks in advance for any help on this