Challenge to car manufacturers: Put a second spark plug in each cyliner.

[thunder rising]

I'm not sure why auto engines only have one spark plug, but internal combustion aircraft engines have two.

You might try to make the argument that it's for safety, but you'd be wrong. Every pilot (except military) knows the second cylinder is for fule efficiency.

My guess the additional power per unit of fuel is on the order of 15%; however, there are a lot of varaibles involved. One BIG advantage of the auto industry is that they do not have to worry nearly as much over weight as the aircraft industry.

The challenge is this: be the first manufacturer to create this engine with the accompanying increase in efficiency and you WIN the contest. Everybody else will be force to compete, but will be the "also rans" forever.

[kristopher]

1. They've been doing that for a long time

at least 15 years. Not all engines, but I think it pops up on a fairly routine basis.

[thunder rising]

2. Please name one ... I have never heard of a say NASCAR candidate auto with an engine with 2 spark

plugs per cylinder.

Please make a better argument than that.

[kristopher]

9. Who said anything about nascar?

92 Ranger, 93 mustang.

[thunder rising]

17. the NASCAR ref was to infer commonly available make. I take it Ford produced such an engine

What is the displacement? So, folks could Google it.

[NutmegYankee]

23. 2.3L Ford

[muriel_volestrangler]

14. Mercedes

Like all current Mercedes-Benz engines, the E320's has three valves and twin spark plugs per cylinder, an unusual design chosen for its relatively economical operation and good fuel economy.

http://www.theautochannel.com/vehicles/new/reviews/2001/russ0125.html (2001)

[NutmegYankee]

19. Ford did it with a 4 Cylinder.

It was funny to sell 8 plugs for a 4-banger.

[thunder rising]

20. Was that 1992/3 I mean this is technology that would help the world now.

[NutmegYankee]

22. 1991 to at least 1994

Overall it really didn't help the engine since computer control and chamber redesign increased the efficiency far more than adding a second plug. Airplane engines run at max power most of the time, while a car engine will run at 20-30% of max power something like 80% of the time. The second plug didn't allow for engine designs that could handle the variable power levels more efficiently in a way that pleased the car buyers. Vroom Vroom.

[thunder rising]

28. Cool! However AC engines are rated for fuel efficiency at 75% power. 25-2700 due to propellers

the props tend to do strange stuff at real high RPM.

[sailor65]

33. Actually, both Piper and Cessna

recommend 65%.

Once you really do get that license, go try to rent a wet rate airplane and tell them you're going to keep it at 75%

Let us know what they say, ok?

[thunder rising]

37. 1200 hrs on my plane at 2400 RPM and 7.8 gal / hr (not my plane anymore or I would give

you the tail number)

[argonchloride]

74. If you have a "license", tell us what is printed in microtype around the hologram

in the lower right corner. Use a magnifying glass if you need.

[thunder rising]

134. FAA (all spelled out)

[Name removed]

145. Deleted message

Message removed by moderator. Click here to review the message board rules.

[MajorChode]

53. The reason they recommend 65%...

Is because there's a lot of pilots out there who have no idea how to use that red knob and they want to reduce the number of warranty repairs.

There's nothing wrong with running an engine at 75% provided you know how to lean it properly. I routinely fly my own aircraft at 75% and have for many years.

[sailor65]

67. I didn't say there was anything wrong with it.

The issue was fuel efficiency. There is certainly nothing wrong with flying yours at 75, but even properly leaned, if you are flying one of the aircraft I was referring to, 65% (Properly leaned) inproves the economy. That is why I brought up the rental agencies and the reason why wet rate rentals usually have a 65% placard on the panel. I wasn't suggesting 75% is somehow a problem.

[MajorChode]

80. I would never rent from an outfit that had such a restriction

It makes sense for them financially, especially if they are renting on a wet rate.

I haven't seen any rental outfits that had that requirement, but I haven't rented one in at least 5 years now.

[sailor65]

87. I haven't been able to afford to buy yet.

so it's all rentals, all the time :-( And I almost always have to agree to the 65% even on the rental form.



But I have got a line on a used RV-7, so maybe this year!!!

[MajorChode]

96. There's always partnerships and clubs

They are a great way to get your foot in the ownership door without jumping in feet first. There's a ton of stuff you can learn that way.

[sailor65]

102. I really should consider that, yes.

My wife's father did it, and I actually sailed that way for years, with a club, because of the cost.

[thunder rising]

108. oh yeah .. experimental. Since I lost the 172 I've looked at everything. For hours ...

It's the Affordaplane ... VW powered, cheap, and you can register it.

I started building a Cozy MK IV, but thanks to GWB I'm bankrupt and there is barely enough to keep the house.

[sailor65]

The R-7 looked like a good option.

And I know the original owner/builder. It's only a "Line" on it so far because he's not sure he's ready to part with it yet.

As to the Cozy, that's a canard, right? I looked at a Velocity for a while, but pricey!

[thunder rising]

136. That's why you go with the Cozy. The kit includes fiberglass cloth and resin (and plans)

For me if I were ever going to get close to 200MPH I would have to build it.

My dream .... Lancair (now Columbia) ... closest think to a jet.

But in the mean time ... Affordaplane (cheap hrs and recency)

[argonchloride]

100. It wouldn't matter anyway, they would have no way to know how the engine was operated.

It isn't as if a 172 has a FDR in it. My 310 doesn't either. :-)

[sailor65]

105. In my case, they do (Not the FDR)

Both my fields are running 172's with G1000's including the engine unit. Kind of like the Hall Monitor sitting in the backseat! :-(

They always check it.

[thunder rising]

111. G1000's are EXPENSIVE ... you've got a license head to the back woods. Put an add in the paper

to see if a private person wants to start a flying club.

[argonchloride]

113. I thought the GEA was just to drive the display, didn't know it kept a record.

My plane has radios with tubes. :D
Not really, but it's way older than the Garmin glass which I haven't much used.

[MajorChode]

118. Once you go glass, you'll never go back

Actually I went back, but I do love flying the G1000.

[sailor65]

119. It really is a dream to fly,

but I'd like to go back to non-glass rentals because I think the glass is pumping my cost way up.

On edit: Plus, there's no way I could afford one of my own, so I don't want to get spoiled!

[argonchloride]

125. When I learned to fly, anything over and above needle/ball and airspeed

was a luxury. I didn't even see a sensitive altimeter for the first 10 or 15 hours. Not kidding. :-)

[MajorChode]

128. Well there's plenty to be said for flying an old cub

But for long x-countries or for instrument flight, I'll take the G1000 if I can.

[thunder rising]

82. Might also have to do with where you are flying. I live in FL and the highest natural elevation

is 17 ft. So our charts are all green. However, I've made two trips in the 172 over the rockies to Salt Lake City and I know their charts are all brown. The point is that midwest pilots take-off at elevations that 'coasters' don't even normally fly at.

The bottom line to this statement is the max efficiency vs percent of full throttle is inversely proportional. 5000 is max efficiency for 75% (coast) and (about) 7500 for 65%

[thunder rising]

73. My trusted mechanic told me keep the throttle at full power adjust RPM with mixture ... had great

fuel economy and never fouled a plug. The adjustment is touchy as hell. When I got in to a pickle I went back to the regular throttle / mixture relations.

[argonchloride]

78. Adjust RPM with MIXTURE? Jeezuschrist, I wouldn't let you within half a mile of a plane.

:scared:

[MajorChode]

86. You can under certain circumstances

Assuming a normally aspirated aircraft, if you are flying at very high altitudes that preclude anything over 60% power, that's the way you do it. You just set full throttle and lean for max RPM, which puts you pretty close to peak efficiency.

You wouldn't want to try it under any other circumstances, and I suspect the OP meant other circumstances.

[argonchloride]

97. Yes but if you're flying a plane without a constant-speed prop you're not likely to be

that high in the first place, and in that case you can find 2 peak rpm readings...on the lean and the rich side of stochio. It's easy to pick the wrong one and it's bad practice anyway...EGT is the right way to do it.

But you're right, the other poster wasn't talking about this particular flight regime.

[MajorChode]

110. I'm not sure what constant speed prop has to do with it

My aircraft has a constant speed prop and that's the way I do it. In fact, if you want to make it to the service ceiling, it's just about the only way to do it. If all you can get is 60% power or less, there's no way you're going to harm your engine no matter what you lean it to. Peak RPM in that scenario puts you pretty close to peak EGT, so there's no way to be on the wrong side because you're in the middle. By peak RPM I don't mean peaked on the prop knob, just the mixture.

I routinely fly my plane as high as 15,000' if I need to in order to take advantage of favorable tailwinds.

[thunder rising]

137. Exactly the point. I have verified "You cannot voluntarily burn a valve" So I started using the

technique and never stopped.

[MajorChode]

138. Try it at 75% power

Let us know how that one works out, or we can just read about you in the paper.

[thunder rising]

121. I don't know about constant speed ... I fly single pitch...so, HONEST TO GOD I HAVE AT LEAST 500 hrs

flying full throttle with RPM adjusted with mix. When I get into a pickle (or landing) I revert back. But I would do this at 1k ft if I were going to be there for a while.

Also, with older 172's they didn't have the turn-type mix which might make it harder to do. On my BFR's I have shown instructors how to do it.

[MajorChode]

144. What you are describing is the "best power" setting

In your aircraft, essentially peak RPM = peak EGT (close enough). So if you're running at peak RPM, you're running at peak EGT or what the engine manufactures refer to as "best power". In your aircraft, I suspect your prop prevents you from getting into trouble if you truly have been running your engine that way as it probably prevents you from getting to high power configurations for your engine.

[thunder rising]

115. Keep paying for those spark plugs. Also, keep shaking in your boots. After all those hours I know

there are 2 kinds of people around airplanes ... Pilots ... and those that have certificates and love to talk about flying.

[argonchloride]

117. You probably shouldn't smoke that stuff.

...

[sailor65]

81. Come on, you just made that up! n/t

[NutmegYankee]

36. Do they start getting excited vibration modes?

I figured it wasn't 100% power, since that would leave you shit out of luck in an emergency. ;-) I was making a point though that the airplane engine sees less rpm movement than a car engine and spends most of it at a far higher power level. I believe it takes roughly 30HP (depending shape, etc) to keep a car going at highway speed on a highway. If you have a 170 HP engine, you are using only 18% of your power to drive on the highway.

To expand on my earlier comment, car engines have gone to the 4 valve per cylinder arrangement and so on to get the better performance and efficiency.

[Ikonoklast]

30. Those were the DIS motors.

Lima made them. I think. One second.

http://therangerstation.com/tech_library/4cylinders.html

There they are.

Some of those little over head cam four bangers could be made to scream. I knew a guy that had one in a super-modified dirt track bracket racer. Cheap to build, and you could beat the crap out of them before they popped.

Junkyards were full of them, so he always had a couple two or three laying around in various states of re-build.

[NutmegYankee]

44. Ford made some good four cylinder engines

I remember checking them out when I was grubbing for money for college at the auto parts store. I still prefer the 300 Cu In. inline 6. What a long lasting design.

[Ikonoklast]

55. Oh, God, I had one of those in a '65 Mustang convertible.

200 cu. in. only though, but that motor was indestructible and had torque out the ying-yang.

Had a custom-made header for it, and a Holley carburetor. Three on the tree!



Damn, I'm showing my age here.

:cry:

[Gold Metal Flake]

68. Different engine family.

The Mustang six was the 170/200/250 cubic inch family with the integrated intake manifold and cylinder head. The 300 was a larger truck engine with a 240ci sibling. The long rods of the 240 (6.8" c-c) were often used for offset-ground stroker engines such as the 530ci 460. I had a set I collected for a Ford FE build but I abandoned the effort.

You may recall the three-carb conversion kit for the Mustang six. It's still available.

[NutmegYankee]

71. I was talking the F-150 inline 6, but inline 6 is nice period.

Nice balance with good torque and generally easy access for maintenance. I saw those 300's in quite a few Ford tractors too.

[Gold Metal Flake]

88. Yeah, the truck six is the 240/300. Darn good engine. When I was having some work done...

...to some Ford 302 parts I was talking to the head guy at my fav machine shop. He figured out that the cylinder head bolt pattern and the cylinder bore spacing for the 240/300 and the Ford 351 Cleveland V8 were the same. So, he cut a 4V Cleveland head in halve and welded it to another to make a 6 cylinder 4V C head. Crazy. A 300 with that long stroke with those huuuuge 4V Cleveland ports and valves. I never did follow up on that job to find out how it worked. Fun stuff.

[Ikonoklast]

85. That cost money.

I had a single two-barrel Holley, I think I paid $29 for it. Lots of money...back then.

[Gold Metal Flake]

98. Cool. I had a 170 in a Comet wagon.

I'd like to have an early 'Stang with the six. I have some ideas. It would be cheaper to drive than the engine I have now.

[Ikonoklast]

106. Cousin of a kid I went to high school had a '65 Plymouth Barracuda

with a 225 Slant six.

He spent more money on that six cylinder motor than most guys spend on their whole car.

It went like stink down the strip, but over-rev it or miss a shift once and boom.




And just remember, the right foot is the expensive one.

Edit to add: Clean build you got there.

[Gold Metal Flake]

124. Thanks!

Factory iron heads. Very specially prepped factory iron heads.

Funny. Slant six rods are also used in old stroker V8 builds. I had a set of those as well.

[Ikonoklast]

139. Here's a pic of the Comet a friend of mine owns. You should like it.

http://www.dragracingonline.com/raceresults/2005/vii_9-superstock-1.html

Kurt and Skip Koester both run Fords in the nostalgia class, Skip runs a Comet Thunderbolt. Both are national record holders.

http://image.mustangmonthly.com/f/9607147/mufp_0702_01z+grand_slam_event+on_track.jpg
Skipper launching the Comet.


Kurt owns the diesel shop that does work for me, behind the entire six-bay shop is his race shop.
I drool every time I go back to shoot the shit with him.

Besides these, he runs a Ford-powered funny car and a pro-stock Mustang.

[Gold Metal Flake]

140. Aw! A/FX!

A cammer with stacks. Love it! All Dyno Don lookin'.

The Thunderbolt is a Fairlane.

Does Kurt know about fordfe.com? That is where the hardcore FE racers and builders hang. Including people making NEW cammer parts.

Thanks for the pix and links. That's what I like!

[conscious evolution]

77. My 1987 Nissan Pick-up

had duel plugs.
The same engine was in some of their other cars also.
I don't know if they or other auto companies still do it though.
It is a good idea to do it though.I once changed only the exhaust side plugs once(for some reason the plugs were different sizes} and there was a noticable difference in fuel milage and engine power.

[CRF450]

83. The Dodge 4.7 Magnum v8 does.

Only the newer ones from 08, not the one in my 04 Dakota. They are a little bit more efficient, but WAY more powerful! 300hp compared to the 235hp 4.7 in mine. Now, if I can swap one of those new motors into my truck, that'd be awesome! But I'm waiting for someone else to try first. I hear it should be a direct bolt on almost, but the dual spark plug and electronic throttle body would a little bit of a problem as far as I know.

The newer HEMI's also use the dual spark plug design I believe.

[ejbrush]

146. 1987 Nissan Pickup, 4cyl, 8 plugs.

33mpg with the tailgate off if I kept my foot out of it. Would be driving it today if the frame hadn't rusted through.

[thunder rising]

5. In fact one of us in incredibly stupid ... prove it's me ... please

[kristopher]

13. Thank you for your effort.

[HysteryDiagnosis]

3. Since the advent of the afterburner added to the rear of Dodge, Ford

and Chevy diesel pickup trucks... the dealers have been swamped with modification after modification after clogged receiver, and the occasional fire coming out of the tailpipe.

Fire ---> http://www.youtube.com/watch?v=v36MCcRPRTc

The afterburner is a soot trap that lights up once in awhile to burn the soot... this is their answer to the pollution problem while this technology sits right there staring them in the face...

http://www.hy-drive.com/main/index.htm

And we cannot leave out the Gorilla....

http://www.gethydropower.com/press.html

Gorilla Development has performed a series of emissions tests with the following results:
Idle Tests
7.2 L Caterpillar 6 cyl Heavy Duty Diesel
CO 100% reduction
CO2 0.88% reduction
NOx 33.93% reduction
Hydrocarbons 100% reduction

7.3 L Ford 8 cyl Heavy Duty Diesel
CO 40% reduction
CO2 7.33% reduction
NOx 5.56% reduction
Hydrocarbons 100% reduction

4.0 L Ford Explorer (Unleaded Gasoline)
CO 100% reduction
CO2 2.38% reduction
NOx 100% reduction
Hydrocarbons 100% reduction

Operations Tests
Fuel Consumption 30% Average Reduction

[thunder rising]

6. Wow 30%, my guess was in the neighborhood, but conservative ... cool!!

[cosmik debris]

4. Are you sure?

The "everybody knows" argument doesn't carry much weight. Have you got a link to prove your point?

[thunder rising]

7. Go get a pilot's license ... mine is reviewable online at the FAA.

[cosmik debris]

8. That doesn't help

If you can't support your point, I'll just figure you are full-o-shit.

[sailor65]

24. You may have a license,

but you obviously got that question wrong on the written. The second spark plug is only there for live redundancy (Read: SAFETY), just like the second magneto that drives it. If it were only for efficiency, the second magneto would not be there. In fact, the spark plug is part of an entirely independent second ignition system.

[thunder rising]

26. You don't know induction coil induced spark, w/o two ingnitions first SP takes the energy .. oops

[cosmik debris]

31. You're making this up as you go along aren't you? n/t

[sailor65]

34. Here's a good piece of advice

when you see you're in a hole, STOP DIGGING!

[MajorChode]

38. Time to raise the flag

The FAA doesn't issue licenses either. If you have anything it is a certificate.

In order to put an engine into a certified aircraft, it must have 2 independent ignition systems all the way to the spark plug. The reason is safety. The FAA could care less about your fuel efficiency. Fuel efficiency is an added bonus, but there are other ways to get it with a single plug.

[thunder rising]

43. PPL ... Private Pilots License (google)

[MajorChode]

49. Why don't you just look on your "license"

And tell me where it says "license". Assuming you have one, which at this point seems to be a bit far fetched.

[thunder rising]

56. How about a photo blog .. just me, airplane (Obama wing), HRC, and a couple of SS guys

http://good-times.webshots.com/album/563170025QwUraP

[MajorChode]

62. Here's my picture too!

I'm still waiting for you to tell me where it says, "license" on your ticket.

I'd be interested to know since I've never seen one. Mine says certificate.

http://www.faa.gov/licenses_certificates/airmen_certification/

[sailor65]

70. Hey, you'll appreciate this!

http://www.amazon.com/s/ref=nb_ss_gw_1_15?url=search-alias%3Daps&field-keywords=royal+guardsmen+snoopy+vs.+the+red+baron+snoopy+%26+his+friends+cd&sprefix=royal+guardsmen

Been listening to it since I was a kid.

[MajorChode]

89. I already have some of the mp3s

I love those tunes.

[sailor65]

91. I should have known!

Great stuff.

The version they do of "The Battle of New Orleans" is quite good too.

[thunder rising]

92. Well how about that ... the new ones don't say either cert or license ... It says Thunder Rising

has been properly qualified to exercise the privilege of ...

[MajorChode]

99. And under that it says....

Certificate number XXXXXXX

If yours doesn't, I suspect you got it on ebay from a Chinese distributor.

[thunder rising]

103. Sorry a certificate number makes it a LICENSE!!

[MajorChode]

112. Non sequitur

It makes it a certificate (duh). Geez son, are you posting from a paint booth?

[cosmik debris]

126. Just how deep are you gonna dig this hole?

It has already been shown that you are full-o-shit.

And now yo arrogantly defy reason as well.

You have lost all credibility.

It's time for you to go to your corner and lick your wounds.

[argonchloride]

123. He won't answer my question - what is printed around the hologram seal.

(What's that about Malaysia pilot in XIII? Mine just says English Proficient.)
(I can't resist mentioning it says "license" twice on the back) :rofl:

[MajorChode]

131. I just found it with a quick google search.

I suspect the cert holder just transferred his Malaysian "license" for a PPL cert in the US per some type of ICAO agreement.

[thunder rising]

133. Accompanied by a Malaysia pilot? I am a pilot, no accompaniment need.

WTF ...

[MajorChode]

141. You'd better check to see if you can get your money back...

on that ebay pilot's "license" from Malaysia.

[thunder rising]

46. Got a FAR number for me? (Just asking) I'll bet it has more to do with the MEL

Minimum Equipment List published by the Manufacturer of the Aircraft.

A Cessna 172 cannot have it's engine change on a whim ... but it's a requirement of the AIRCRAFT certification.

[MajorChode]

50. It's actually a requirement of the engine certification

And you can't put a non-certified engine in a certified aircraft.

[thunder rising]

52. Still looking for that FAR ... you know that Federal Aviation Regulation.

[MajorChode]

54. Good for you

When you find ANYTHING that says 2 plugs are primarily for efficiency, you will let us know, right?

Don't worry, I won't stay up.

[MajorChode]

57. It took me all of about 30 seconds to find it...

Enjoy.

Title 14: Aeronautics and Space
PART 33—AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES
Subpart C—Design and Construction; Reciprocating Aircraft Engines

Browse Previous | Browse Next
§ 33.37 Ignition system.

Each spark ignition engine must have a dual ignition system with at least two spark plugs for each cylinder and two separate electric circuits with separate sources of electrical energy, or have an ignition system of equivalent in-flight reliability.

[cosmik debris]

63. Don't confuse him with the facts,

He's in love with his myth.

[MajorChode]

64. All the more fun to see it go down in flames

[cosmik debris]

66. I knew he was wrong when I started this sub thread

But I wanted to watch him struggle to prove his point.

Apparently even he knew that he was full-o-shit because he didn't even try to back up his bogus claim.

(and thanks for setting the record straight)

:)

[thunder rising]

69. Hmmmm .. .weellll it has been about 7 years since I took that test ... thank God I don't have to

take it again. It's BFRs forever for me.

[sailor65]

75. You're better than I am....

all my searches kept landing me on the Theilert conversion and not the original directive.

[MajorChode]

90. I already knew that engine cert falls under part 33

[flvegan]

10. You mean like the new Hemi has?

Toyota did it in their race cars. I think BMW tried this once a while ago.

[Ikonoklast]

11. You can gain more with variable intake timing

that changes with engine fuel/air demands. There are some four-stroke systems that use a dual plug arrangement, but they are usually higher performance large displacement engines. Fuel economy isn't easily attainable in those instances.

There is some extra expense involved as you get into valve and piston clearance problems, complexity of ignition timing, more expensive head casting, etc.

With modern computer controlled electronically fired ignition systems, generating a hot enough spark to fully combust the fuel/air mixture is seldom a real problem, as far as fuel economy goes.

When you get into larger displacement four-stroke motors, it is difficult to generate a spark large enough to burn the mixture completely, quickly enough. That is one reason a two-plug system is used.

[thunder rising]

15. I agree it's a challenge, but we have much better design tools now. And, intake would have

to correspond to variable exhaust timing; variable tuned exhausts with tuned intakes is probably more of a challenge.

[Ikonoklast]

21. Cost/benefit. Too little a gain for too big an outlay.

You would get a greater gain with a programmable ignition, changing the curve to match demands, with a much cheaper price tag.

Many of the higher-end vehicles already have this, as well as after-market high performance ignitions available for a wide range of motor manufacturers.

Don't forget the difference in how an aircraft motor and auto motor meets power demands. Aircraft run and produce peak power at a lower, constant RPM that is easier to program ignition timing/fuel demands for peak efficiency.

A car motor, on the other hand, has a wider range of power demands over a wider range of RPMs, and it used to be a challenge getting the smaller displacement/horsepower motors to function economically when maximum output is required.

Computer controlled and timed ignition, staged fuel injection along with better transmission design has come a long way to improve that.

Not saying it can't be done, but the gains in fuel economy would be minimal for the amount of money involved.

Sometimes the simpler the design, the better quality product you produce.

[thunder rising]

25. Maitaining usable RPM is what a transmission is for. Also it seems at one Ford and Mercedes

engines have 2 spark plugs/cyl.

[Fumesucker]

29. Variable valve timing has been around for quite a while..

I built my first engine with variable valve timing, a 400 small block Chevy, in 1980, the technology was not new then.

http://www.rhoadsproducts.com/

Over 100,000 satisfied customers, including big name engine builders like Gale Banks, will tell you...With Rhoads lifters you can run more cam and still have great low-end torque, engine vacuum and idle quality. The secret? Variable Valve Timing! Rhoads' exclusive patented design reduces lift and duration on the low-end and restores it on the top. This lets you run more camshaft while retaining great low-end streetability, fuel efficiency and better emissions.

[Ikonoklast]

42. Never said it was new.

Variable timing has been around in one form or another in four-stroke internal combustion motors for fifty years.

Or so.

I built water-cooled two-stroke power valve road-race motors, which were variable-timed, thirty years ago.

The V-TEC system Honda uses is pretty elegant; the motors my son has built are a nice design and have a nice output/displacement ratio.

:hi:


And that early Chevy valve design was a pile of poop. They did it for the emissions.


:P

[Fumesucker]

61. Not the variable setup I linked to

[argonchloride]

12. In common piston powered a/c engines, it is mostly for redundancy.

And of course jet engines which are internal combustion have none and many small piston airplane engines have just one...but also there have been many auto engines with 2 plugs per cylinder. They aren't really any more efficient. Look up 'stochiometric"

[thunder rising]

16. Please delete your comment ... you're embarrassing yourself

[argonchloride]

32. LOL! Yeah, right...

You're a funny little guy.
By the way, that "pilot license" you got from Flight Simulator isn't valid outside the basement. Or maybe you actually don't even know what "internal combustion" means...
:eyes:

[Gold Metal Flake]

18. You really don't know what you are talking about, do you?

[madokie]

27. The purpose of the second ignition system on small airplane engines

is for safety and not for added power. If it was only for added power and not for safety they would be using some of the same parts such as distributor, points and condenser. They don't they use two totally independent ignition systems. If an internal combustion gasoline engine quits running the reason is about 90 some odd percent that it is ignition problems and not gas delivery problems. Thats why they only have one intake system. If a gas engines design has pockets that trap fuel/air in the combustion chamber then it is sometimes necessary to use another spark plug to ignite those small pockets of air/fuel. In an ideal designed combustion chamber there is no need for a second spark and in some cases it can be detrimental. Some two cycle motorcycle and snowmobile engines have two spark plugs because the oil in the fuel mixture fouls sparkplugs so you switch the wire to the other plug thats been just going along for the ride up to that point doing nothing.

[thunder rising]

35. So I googled it ... bingo New York Preview: 2008 Jeep Grand Cherokee revealed

http://www.autoblog.com/2007/04/01/new-york-preview-2008-jeep-grand-cherokee-revealed/2

The new 4.7-liter V-8 incorporates two spark plugs per cylinder (the only Chrysler Group engine to do so, other than the 5.7-liter HEMI), increased compression ratio, improved cylinder-head port flow and a new combustion system. The result is 291 horsepower (217kW), a 24 percent increase, and 322 lb.-ft. of torque (437 N•m), a 6 percent increase over the previous 4.7-liter V-8 engine. And, like the engine it replaces, the new 4.7-liter V-8 engine is flex-fuel capable, which gives customers the ability to use up to an 85 percent concentration of ethanol (E85) to fuel their vehicles.

[cosmik debris]

39. That doesn't support your point about aircraft engines.

You just made that up.

[flvegan]

41. I told you that in post #10.

:eyes:

[thunder rising]

51. This isn't the HEMI .. I'm not sure if it's in the quote, but the article states it's a different

engine line

[CRF450]

93. Actually the 4.7 is a "semi" HEMI.

The cylinder heads have an almost similar design to that of the real HEMI.

[Fumesucker]

40. It's a lot more simple to just fire the spark plug multiple times for each firing stroke..

Multiple Spark Discharge or MSD ignitions work well, increase efficiency and horsepower.

http://www.msdignition.com/default.aspx

Multiple sparks work because the fuel/air charge in the cylinder is very turbulent and each spark ignites a different portion of the f/a mix as it moves rapidly past the spark gap.

Combine that with Singh grooves for even more turbulence in the chamber and better combustion becomes relatively easy to achieve.

http://www.somender-singh.com/

There are a lot of other tricks that can be done also, ceramic coating the combustion chamber and textured intake ports among the most obvious.

It's interesting that the BMEP of pushrod NASCAR engines is within a single percent of the BMEP of Formula One engines, the pushrod engine has been very highly developed in that form.

http://www.epi-eng.com/piston_engine_technology/comparison_of_cup_to_f1.htm

The BMEP of the Formula One engine at peak torque (table line 13) is 15.17 bar while the Cup engine produces a peak torque BMEP of 15.12 bar (0.3 % difference).

[Ikonoklast]

48. I would love to see what a NASCAR motor could do with twin-cam heads.

The exhaust would sound like ripping a sheet of T8 aluminum.

[thunder rising]

58. Thanks!! Somehow I think the racing technology has not been filtering down to the common car.

[Fumesucker]

72. It's a question of costs, racing engines are hand built to extremely high tolerances..

Production engines, not so much.

One interesting thing that can be done is to optimize flow in the intake and exhaust ports at low valve lifts, this gives all of the benefits of a longer duration, higher lift cam without the drawbacks.

In fact a great deal of racing technology makes it to production cars, it just takes a good while for the transfer to take place and of course it's never in as sophisticated form for a production engine.

[thunder rising]

101. Exactly. However, better metalurgy

Exactly. However, better metallurgy, ceramics (higher heat tolerances), machining would make this "trickle down" possible. Since the average driver does not keep is engine at 11000 RPM (whatever) the engines would last.

However, a second spark plug was the first thing that the aviation industry settled on and the last thing that the auto industry is willing to consider.

[Gold Metal Flake]

109. Bullshit.

You are just typing here.

You can not grasp the obvious difference between the average race engine vs. the average passenger car engine. The most basic, obvious difference.

You do not understand what you are typing about when you type "better machining". Metallurgy? Wanna try to explain that in this context?

You also have no basis for your insistance that a second spark plug is "the last thing that the auto industry is willing to consider."

[Fumesucker]

116. The aviation engines that have dual spark plugs have completely separate dual ignitions..

Usually magnetos.

In fact one of the tests you run is to switch ignition systems from dual to each of the singles, there is a slight drop in rpms which confirms the ignitions are both working.

Most aviation engines are very old basic designs that were originally made for highest reliability, not specific output or efficiency, a lot of these engines haven't changed in any major particular in sixty years or more. Detail refinements and better metallurgy true, but not major redesigns.

A buddy of mine switched from a Vertex mag on a 427 supercharged Chevy big block to an MSD system and picked up quite a bit of power. Also the Vertex had a fixed spark advance while the MSD was variable.

Edited for speling.

[Spider Jerusalem]

45. Challenge to Americans: Buy smaller cars.

[thunder rising]

60. Let's make that better smaller cars ... the Pinto was small too.

[NutmegYankee]

65. Aww come on - The Pinto was a great advance in highway safety!

It was it's own road flare in case of an accident. Everyone down the road could tell there was an accident ahead :evilgrin:



While I'm at it - What was the best feature of a Yugo?
Answer - The heated rear window! Your hands could stay warm while you pushed it in the winter.

[Gold Metal Flake]

76. Last summer when I was in the junkyard I pulled off one of the Pinto protection shields.

The part that was added to protect the gas tank from the differential cover in a rear end accident. I bought it. One day I may own a Pinto wagon, so I figured i might as well have the important part.

[WI Independent]

114. I remember hearing the 1st generation Mustangs had

the same basic design... they just had enough power to not get rear-ended so often that everyone noticed. :)

[Gold Metal Flake]

122. Yes and no.

Many cars from that era had a fuel tank that was also the bottom of the trunk. This created a couple of issues.







One, a severe rear end the trunk collapses and the tank, being screwed into the trunk floor by the flange can rip open.

Two, and the real issue with the Pinto, is that in cars with a "rear loading" differential design that has a cover on the back, the tank can be driven against the pointy and angilar rear cover and rip open.

I have a 1968 Cougar and have thought about this a lot.

[WI Independent]

127. I had a 66 Mustang in the mid 70s

when I was in high school. Of all the accidents I could have been in, I think being hit from behind was about the least likely. LOL

[Gold Metal Flake]

130. I started driving in the latter 70's.

I made a mess of it at first. :o

I'm feeling a "first car picture thread" opportunity for the Lounge!

[Ikonoklast]

95. Hah! How little you know!

That rear window defroster would NEVER work more than one time.
What did they use for the element in that thing anyway, used foil gum wrappers?

And the Pinto was a fabulous vehicle. They kept the Ford mechanics current on their boat payments.




But you know how to double the value of your Yugo?

Fill up the gas tank.

[Spider Jerusalem]

79. And auto construction and safety, not to mention fuel efficiency, have come a long way in 30 years

Mentioning the Pinto in this context is about as relevant as mentioning the Apple II in a discussion about computers.

[XOKCowboy]

47. Japanese motorcycle mfgrs have been doing it for years

For a more complete burn of cylinder gases. They've also been using variable intake timing as well. As you said it's all about power to weight. It's the little things that boost power and decrease weight and thereby provide a car that is energy efficient and powerful as well.

There is a lot of innovation out there. The Japanese have used their motorcycle division innovations to upgrade their cars. US car manufacturers should take apart a Honda CBR900RR sometime and see how to put together a high horsepower, low mpg engine.

[thunder rising]

59. Good Post ... thanks.

[WI Independent]

94. High RPM

It's harder to get complete burn at the high RPMs a lot of Japanese bikes run... thus the need to start 2 explosions. Normal cars can burn everything just fine with the right head/piston design.

[Gold Metal Flake]

104. Of course, this is the correct answer. I've been watching for it.

Multiple plugs in automotive engines are for more complete burn with less ignition advance, but they don't "create" more power. Also, it is difficult to package multiple spark plugs in anything but a pent-roof chamber design. Wedge heads are designed to either tumble or swirl and there is no room for a second plug. The thing that would prompt a manufacturer to invest in the added expense of a second spark plug is a slight edge in emissions compliance across all vehicle sold to help make fleet emissions limits. More tricks such as this will be seen now that they are selling fewer trucks. Truck must conform to less stringent emissions regs.

[cloudbase]

84. My '92 Mustang had two plugs per cylinder.

My Moto Guzzi ('07 Breva) also has two per cylinder.

[CRF450]

107. As far as airplanes go, isn't it because they run on leaded high ocane fuel?

I know the engines they use have a very high compression ratio. And you seen the turbo diesel in the new Cessna 172?

[madville]

120. Nissan compact trucks in the late 80's had two plugs per cylinder

I think they stopped around 1990.

[Gold Metal Flake]

129. Funny. OPer claims dual plugs "the last thing that the auto industry is willing to consider."

Last Thing! He knows this because of much exhaustive research in the bowels of the engineering departments of the world's leading auto manufacturers, to be sure. They just stamp their wittle feet and scream NO!

Whata wanker.

[Synicus Maximus]

132. The 1936 thru 1942 Lincoln Zephyr's had dual spark plugs

in their V12s.

[Gold Metal Flake]

135. I've not seen dual plug V12 flatties.

http://www.35pickup.com/LincolnZephyrV12.html

[Mugu]

142. My 1998 Ford Ranger 4-cylinder has 8 plugs.

Once in 10 years it failed to bring me home, when a 10 year old factory battery failed all at once. Other than that it has started every time, but gets awful gas mileage and has no power. If I burn more gasoline to move the same distance that means that I'm contributing more to global warming than necessary which I'm unwilling to do.

I used to give American companies extra credit. No more. I'm not an abused spouse an won't behave like one.

Regards, Mugu

[Greyhound]

143. Ford Merkur through the 80s. n/t