ok when you go direct fire on an fb both leading plugs fire at the same time,
isnt this bad?

or are both rotors perfectly aligned?

i dont know i never opened up a rotary,

i always though one rotor was offset,so when one rotor was being fired on the other was not to keep the engine in balance.

i plan to direct fire on monday,i searched and could not find anybody that has asked this,
its plagueing my ming and i have to know.

thanks

 

FCs run wasted spark on the leading plugs from the factory.

 

that wasnt even close to answering my question.

 

How so? Obiviously theres no ******* problem with it if it left the FACTORY that way! A rotary engine is a rotary engine, generations don't matter with regards to timing issues such as this.

 

omg you have no clue what i am talking about,

a 2nd gen is amde for direct fire,and who here can say the both leading plugs fire at the same time????

ok then,a 1st gen is not made for direct fire,
by changing over to direct fire both leading plugs are now sparking at the same time,

by doing so if the two rotors are not perfectly aligned the one spark is sparking on who knows where?

i know the trailing sparks are wasted,this has nothing to do with them.

draw 2 triangles on a piece of paper,
one on top of the other,
now think what would happen if the 2 triangles werent lined up but both leading plugs sparked at the same time.

i dont know if in fact they are lined up,but i would think they are not to keep the engine balanced.

 

Right. The spark in the non-firing chamber happens near the end of the "exaust stroke". Good for emissions.

-John.

 

if thats the case then only one rotor is working.

im gonna draw some crappy pics to better explain.

 

ok here we go,
the first showes the rotors aligned and spark plugs sparking
the second set showes them unaligned and sparking.




here is the 2 rotors aligned



here is a exploded type of view side by side 1st and 2nd rotor






ok in that scenerio everything is peachy

 

but if the rotors are not perfectly aligned
which i though they were not to keep the engine balanced ,
well look what would happen

again front view of rotor 1 and rotor 2 behind it




and another side by side view

look where the spark is hitting the second rotor???

 

Yes, of course. The benefit of direct fire is getting a stronger spark by bypassing the distributor. A side effect is the wasted spark. As the rotors are 120*(I believe) out of phase with each other, the wasted spark happens at the end of the exhaust cycle. No problem.
Direct fire just refers to firing the coils directly, by not going through the distributor cap. That's it. It does not fire both rotors on the compression stroke at the same time. Better spark, better emissions. That's all.

 

"Direct fire was firing both coils at the same time so I could see the timing mark even when the timing light was on the rear rotor. "


http://www.geocities.com/cd23c/poorman.html


hmmm,now this has really got me thinking,

if the rotors are 120 degrees out of phase then there could be a 50% loss or more of hp.

both front and rear rotors leading plugs do in fact fire at the same time when going direct spark.

the reason for this is from by passing the dizzy,
the dizzy it what would normally decide when the two rotors get there spark.

by bypassing it now it is only being decided by the magnetic pickup,
thus the front and rear rotor are sparking when the front would normally spark,

if the rotors are not aligned then the rear rotor is doing very little in helping the enigne turn,


when people talk about wasted spark on direct fire their talking about the trailing plugs,
this has nothing to do with the trailing plugs

 

V8kilr, if the wasted spark thing was bad for the rotary, then there would be people posting telling everyone not to try Paul's idea. No one has had any problems except with his timing recommendations and even then, we're only talking about a handful of members. It's not dangerous and people are not losing HP as a result of going direct-fire. This is where the benefits of real world experience work in your favor. Finish the direct-fire job and then find the posts on side-cut plugs to really take advantage of the extra fire power!

 

 

I've been running direct fire, both plugs firing at the same time for about 2 1/2 years, no problems, cept for some broken trannies

 

oh ok so the ignitor actually puts out doudle the spraks,
one for the 1st rotor
one for the 2nd rotor

and which ever rotors turn it is get the spark and the other one get a wasted spark,
then when its the other rotors turn it goes vise versa.

why didnt someone just say so.

thanks fj

i though only one rotor was getting one spark and the other getting a wasted
then when its the other rotors turn it gets another wasted and the first still gets its spark.

now i see,both leading plugs just fire twice as much.
to make sure both get their sparks when they need it.

whoohooo im happy i got that off my mind.

 

i kinda want to wait until paul has finished testing the plugs,
if you go to his site he has already tested like 20 diferent plugs,
he has plans to buy a few cases,make the cuts then sell them,
i'll buy his if he ever gets em done,
im trying to contact him now to find out the latest on the situation.

 

By the way, I think the 120 Degree thing is for the 20B.

The 13B has a different one (maybe 180 Degrees?)

 

yea it makes sense to be 180 degrees,
just to keep the engine stable,
could you imagine if both rotors spun at the same angle?
wooble wooble

i keep kickin myself in the *** for not looking when i went to the auto show and the ahd the display up with the rotary engine and the plexiglass panel on the side.

 

I'm back from supper.
Right. It's not 120, it's 60* of rotor rotation between TDC for each rotor. 120 is the rotation of one rotor to fire on it's next face. I did say "I believe". I guessed a bit to have a number for the sake of discription. Here's a good chart showing the details:


-John.

 

presto gono

 

Not to anyone running direct-fire so far...Paul's work on ignition hasn't been updated recently, has it? If I remember right, that stuff was done for a club newsletter last August. We've got a member, puaka, who has been running NGK V-Power plugs side cut for 15,000 miles with no problems! His leading plugs are gapped at 0.085" and his trailing at 0.055". I don't know how he arrived at those arcane numbers, but, again, his real world endurance "testing" is for our benefit, now. I just got my fat IRS refund back and I'm going whole hog on carb mods and the MSD/Direct-fire/side cut plugs ignition set-up...after I finish setting up my garage, that is....

 

Since the rotors are 120 degrees out, you don't loose anything. You simply havewhat the motor was made to do. What you are thinking is you want one rotor firing for every cycle. Need one more rotor to do that. Its called a 20B.

 

how musch will i be looking to benefit for going side cut plugs,
yes i searched,there was nothing.

 

isn't the leading plug the BOTTOM one? The leading plug firing is not a problem, it fires once when its corresponding trailing plug is firing, and also again when the other rotors plugs are firing.

It happens that when the other rotors plugs are firing, the apex hasn't yet passed the leading plug to finish off its current cycle, so it's a waste spark, and doesn't ignite anything besides whatever gas might be left over. However, if the trailing plug were to fire at the same time, it would cause issues igniting a NEW air/fuel mixture too early, because the apex has already passed it.. basically this is the situation, stars indicate a firing:

Rotor 1

\ --- Trailing Plug
\
/
/ *-- Leading Plug
Rotor 2
| *--- Trailing Plug
|
|
| *--- Leading Plug

That is how I understand it to work

 

That diagram doesn't make one bit of sense to me but the explanation was spot on.