Any info on lean burn & swirl (in combustion)?

[JamesMcD]

I'm interested in finding more info on these concepts. I know about Larry Widmer and read everything he says on his Endyn board, but I'm wondering if there are any books or other experts in this area I might be directed to...

thanks

 

[franzh]

Hmmm, I read it on-line, and I think it the author was either Japanese or Chinese. I will try to do a search and dig it up, but I remember that the author was VERY emphatic about it! I think it MIGHT have an SAE number too, it was about a year ago. I was doing some intake manifold research profiles at the time (still) and it turned up during a search.

Coriolis intake? Sounds like a brand of diet food!

I have heard the looniest reasons for toilet swirl and hurricanes, but still has me baffled. Something with the earth rotation, equator position, moon juxtaposition, and who is in office at the time.

This is the subject of one of the greatest threads yet! ! !

Best regards,
Franz

 

[MaxRaceSoftware]

i didn't want to mention it to MazdaJim , but how much
"in cylinder" swirl can you be getting in that Honda chamber with 4 valves (2 Intakes) ???

Nothing really significant under full load tests
..maybe some "tumble" ...but hardly swirl !!

i think too many head shops make swirl a tremendous deal
because just about everyone has some kind of flowbench,
....so to be competitive ...you push the swirl and tumble
to make the customers come to you ???

swirl and tumble are good for some HP and letyou do things to make more HP...but like i said..how much HP was just the swirl part worth of of say..Warren Johnson's
1260 HP 500 cid ???????? maybe max 25 HP maybe less??
that still leaves 1235 HP being made by something else
puts swirl and tumble into perspective ??????

waste too much time playing with this ..unless you have exhausted every other possible gains for HP Larry Meaux (meauxrace2@aol.com)
Meaux Racing Heads
MaxRace Software
ET_Analyst for DragRacers

 

[franzh]

Larry:
Here the two references to “clockwise swirl”. Strangely enough, it came from Mitsubishi Direct Injection (GDI).

http://www.bath.ac.uk/~en7jsg/lburn.htm

http://www.mitsubishi-motors.co.jp/inter/technology/GDIEC/gdi_ti/05_1.html

More controversy!

Regards
Franz

 

[ivymike]

From reading those articles, it sounds like they're just saying that clockwise tumble is important in their particular engine, because of the relative positions of the spark plug, injectors, and valves.

To make their statement more generally applicable, perhaps they should have said something like "If the air tumbles towards the spark plug, it will carry a directly injected fuel spray into the spark plug, creating a soot buildup that leads to misfires."

It's silly, to me, that they're even calling the tumble "clockwise" as it's only clockwise in the particular view they're showing. If one were to look at the cyl from the other side, it'd be a CCW tumble, and (presumably) nothing would change.

 

[evelrod]

Once, a long time back, I tried to emulate Suzuki and build "swirl" into my combustion chamber/piston design (hemi, two valve straight in and out porting). The odd thing about all this is that the smaller the cumbustion chamber and the closer to flat top I made the pistons ,ie, more'squish' & less swirl, etc, THE MORE POWER IT MADE!!! I am not an advocate of spending too much time on swirl and tumble any longer, not enough time for me, but if someone else gets it nailed down, I'll listen.


Rod

 

[cycle]

Suzuki later on changed from 2 valve to 4. Intrestingly enough this engine was called TSCC. Twin Swirl Combustion Chamber . What they did to induce this was make one floor of the intake port higher than the other (up close to the valve,where the port split to feed both intakes.This caused a downward swirl,towards the piston top,towards the exhaust side. This made great power and a very efficient engine.In many drag race versions they are on the order of 300 H.P.for a 86 cu.in. engine. Now with the advent of aftermarket M/C race heads the 2 valve design has made a great return. Huge ports , very high flow. Versions in Prostock on the order of 325 H.P. with a 92 cu.in. engine. Craig

 

[MaxRaceSoftware]

Interesting Craig..thats basically the same HP
my program calculates

15.4 HP gain from Ram-Air Scoop
Peak HP=319.3 Torque=140.6 (600 RPM/SEC -Acceleration)

Peak HP=335.3 Torque=147.7 (Steady-State non-Acceleration)
Carb CFM=418 to 492 at 1.5 inches Hg.
60= 1.090 63.103 0 to 30 mph=0.362
330= 3.024 122.873 0 to 60 mph=1.008
660= 4.620 154.682 to 155.364 0 to 80 mph=1.551
1000= 5.990 180.131 0 to 100 mph=2.183
1320= 7.150 193.878 to 193.027 0 to 120 mph=2.909

Ft ET MPH
-1 - .155 0.000 = Rollout ET @ 12 inches
0 .000 8.822 = Rollout MPH @ 12 inches
1 0.096 11.655
2 0.145 15.775
3 0.184 18.672
4 0.219 21.018
5 0.250 23.029
6 0.278 24.811
7 0.305 26.422
8 0.330 27.900
9 0.354 29.271
10 0.376 30.554

Year 2001 Typical HorsePower ranges= 290 to 320 Peak HP
Year 2001 Typical ET= 7.15 to 7.25 MPH= 185 to 193+

Engine size= Suzuki 1500cc 92 cubic inches InLine 4 cyl.
Bore= 3.300 in. Stroke= 2.600 in.
16:1 Compression Ratio (Typical) 114+ octane gasoline
315 Peak HP at 13,000 RPM

5-Speed manual transmission and Maximum of 6-Speeds
Drive-Gear ratio= 5.88:1

Weight=550 to 600 Lbs. including Driver depending on engine
WheelBase= 70 inches Width= 26 inches
Overall length= 140.0 inches including wheelie bars

Slicks= M/T ET Drag 26 in. diameter x 10.0 in. wide - 15 rim
Larry Meaux (meauxrace2@aol.com)
Meaux Racing Heads
MaxRace Software
ET_Analyst for DragRacers

 

[MaxRaceSoftware]

just to clarify a little...
when i say "swirl" i'm always referring to
"horizontal" mixture motion/direction ..or
horizontally spiraling downward in either clockwise or counterclockwise direction

you could look at a "side-view" at tumble and call it "swirl" , but i name "tumble" as almost purely
"vertical-swirl" motion in either direction.

maybe that clarifies what i mean ?? Larry Meaux (meauxrace2@aol.com)
Meaux Racing Heads
MaxRace Software
ET_Analyst for DragRacers

 

[MaxRaceSoftware]

Craig...Email me a .JPG picture of your bike and/or shop
and i'll send you a Windows ET_Analyst for DragRacers
HorsePower prediction program

i'll put the picture inside the program to give a personal look !

No strings attached..completely free....offer expires
December 23,2001

it will calculate ET MPH GForces Aero & Rolling Resistance
HP losses each foot down 1/4 mile
and generate all your
1/4 mile progressive time increments
Larry Meaux (meauxrace2@aol.com)
Meaux Racing Heads
MaxRace Software
ET_Analyst for DragRacers

 

[ivymike]

re: when i say "swirl" i'm always referring to
"horizontal" mixture motion/direction ..or
horizontally spiraling downward in either clockwise or counterclockwise direction you could look at a "side-view" at tumble and call it "swirl" , but i name "tumble" as almost purely "vertical-swirl" motion in either direction

I think the pics in that article that Franzh linked to get the point across pretty well, but I'll take a stab at putting into words what may be better represented graphically (perhaps because I like to hear myself type):

* swirl motion is rotation of the in-cylinder fluid about an axis nearly parallel to the cylinder axis.

* tumbling motion is ... about an axis nearly perpendicular to the cylinder axis.

 

[cycle]

Larry, You hit the nail on the head with your program. Thank you very much for your offer,I do not as of yet have a scanner.Maybe soon. The very latest Pro Stock version is now 1640 cc , 89MM PISTON , instead of 85mm. So they drop E.T. down into the 7.0 range. If you would like to see the current cylinder head used go to

http://www.wardperformance.com

This is a new head that has 160 cfm as cast!! Remember we are only "feeding" a 23 cu.in. cylinder... Check it out. What have I built in the past? My true speciality. Hilborn injected / alky / Turbo.. 86 cu.in./ 485 H.P... 10:5.1 comp / with 38p.s.i. boost.. Talk about cylinder pressure. To MazdaJim, sorry for getting off subject here.. Larry,just some info , I work at Rockdale Cycles Racing in Georgia and we specialize in Dragbike Engines And Chassis,Electronics,etc. Craig

 

i m interested to make the project about mpfi engine.

 

[stroker]

What is "LEAN"? Does anybody really know? I've got gasoline engines happy at 30:1! As for swirl and tumble..they WILL make you stumble!

 

[stroker]

HEY!!!....Isn't Larry Widmer the guy with the SOFT HEAD?

 

[JamesMcD]

Yes, he's the soft head guy. Are you familiar?

 

[cycle]

Stroker, "Swirl and tumble will make you stumble"???? Could you elaborate on this ? I am not clear as to what you are saying... Appreciate your reply.. Craig

 

[stroker]

Mazdajim...I recall the Pat Ganal,Jimmy MacFarland stories heralding the "revolutionary new technology" in cylinder head design..and then there's the Coates Spherical rotary valve head and the Crower "STEAMOLINE" engine!

 

[stroker]

Craig..Actually the "stumble" quote belongs to Steve Bozso(I wish I had said it first).I believe swirl,tumble/Piatti effect etc. are weak band-aids that attempt to treat a symptom..not cure the problem. Sorta like putting pre-cats on top of main cats ..more money,more weight,more BAND-AIDS!