Engines with odd number cylinders

[Beelzebubba]

Originally Posted by Muscle Master

What if I was 2 line to cylinders on each side and one in the upper middle

Like a W8?

[baileyrx]

volvo has used turbo 5 cylinders for a while, not sur if they still do though

[Angrybird 12]

Originally Posted by Muscle Master

Hmm..... I had a dream last night, it was a X-ray view of a 4 banger but it was odd, I notice there was another cylinder and it was a little bigger than the other 4

Maybe this is a sign that I should build an engine like this

Is it possible to build an ( example of what I am talking about) 5 cylinder engine, but have a the 5th cylinder larger than the other 4 and it is only activated when the engine needs more power, kind of like AFM but....not

And here another question, how come automakers don't use cylinders with an odd number, like V3, V7, V9, V11, etc

Chevy/GMC has a straight 5 cyl in the Colorado/Canyon.

[rmyers]

Originally Posted by Wm Holden

they make 5 cyls too......"radial" is the term not rotory

Actually I think he was referring to the Mazda "rotary" engine. Radial engines were used in aircrafts. Still the same piston, connecting rod design. Rotary engine is entirely different than a Radial engine.


Ron

[headpunter]

Originally Posted by Skyman 08

Chevy/GMC has a straight 5 cyl in the Colorado/cCanyon.

great engine i have one in my colorado pickup that i drive everyday

[DGthe3]

I didn't know that anyone had made a 7 cylinder engine. Typically they like to be able to divide 720 by the number of cylinders and get a whole number out of it. this is how far apart the cylinders need to fire in the cycle. 720/7=102.85714. . .
For 1,2,3,4,5,6,8,9,10,12,16,18,20,24 everything works out cleanly.

As for having a larger cylinder, would it be setup with a sort of AFM type deal where it only comes on occasionally? Otherwise why not go with 5 equal cylinders?

[Beelzebubba]

Originally Posted by DGthe3

I didn't know that anyone had made a 7 cylinder engine. Typically they like to be able to divide 720 by the number of cylinders and get a whole number out of it. this is how far apart the cylinders need to fire in the cycle. 720/7=102.85714. . .
For 1,2,3,4,5,6,8,9,10,12,16,18,20,24 everything works out cleanly.

7 cylinders are typically radial engines.

Saab made an inline 7 cylinder but it was a military application.

I don't think Honda's V-7 (4 cyls in front, 3 in back, 90° V) ever made it past prototype. I don't remember why. I would imagine that quelling the primary imbalance ate up more horsepower than having an extra cylinder created.

[DGthe3]

well, I suppose its just as hard to get it to eactly 90.000 degrees apart as it is to get it to 102.857 . . .

And I can't imagine any sort of V configuration working with an odd number of cylinders. Inline makes sense, and I remeber hearing about 7 and 9 cylinder radials from 1930's era aircraft

[Beelzebubba]

this thread makes me think of:

can make money open up a thrift store
I can make a living off a magazine
I can design an engine
Sixty four miles to a gallon of gasoline
I can make new antibiotics
I can make computers survive aquatic conditions
I know how to run a business
I can make you wanna buy a product

[MerF]

That song is my new Myspace song...cracks me up and my wife says it reminds her of me. :shrug:

[Angrybird 12]

Originally Posted by Beelzebubba

7 cylinders are typically radial engines.

Saab made an inline 7 cylinder but it was a military application.

I don't think Honda's V-7 (4 cyls in front, 3 in back, 90° V) ever made it past prototype. I don't remember why. I would imagine that quelling the primary imbalance ate up more horsepower than having an extra cylinder created.

I guess they could make 3 on each side in the V and then one go in a vertical like an inline would, could even have a short 3rd camshaft to work the valves... now wouldn't that look odd???

[Beelzebubba]

All we have to do is make these hybrid battery packs a lot lighter.

Then you would have a power source for an e-charger...a turbocharger driven by an electric motor.

Some guy actually got it to work on an Altima and actually shows a substantial power increase. But his car is a dyno-queen because it's got to haul around a rack of deep cycle batteries.

An extra 160lbs all the time for a short 20 hp boost? Not worth it. Not now. If they can pare that down to maybe 25-40lbs? Maybe.

But then again you could probably just use those ultralight battery packs to drive electric motors on normally undriven wheels or something.:what:


or perhaps with VVT we could make an engine switch back and forth from Miller cycle to supercharged otto cycle :what:

Someone will figure something out.

[CamaroSpike23]

Originally Posted by Muscle Master

Hmm..... I had a dream last night, it was a X-ray view of a 4 banger but it was odd, I notice there was another cylinder and it was a little bigger than the other 4

Maybe this is a sign that I should build an engine like this

Is it possible to build an ( example of what I am talking about) 5 cylinder engine, but have a the 5th cylinder larger than the other 4 and it is only activated when the engine needs more power, kind of like AFM but....not

And here another question, how come automakers don't use cylinders with an odd number, like V3, V7, V9, V11, etc

ooooooooooooooooooooh, this is a good one. believe it or not ive thought about this before. and discussed it seriously with a couple engineers i work with.

Originally Posted by Shadowsong

Could always go with an inline, or a flat, or a straight 3/5/7/9

inline would be the best bet to deal with the balance issue

Originally Posted by Wm Holden

I think the real revolution could be in "5" strokes instead of 4..
inject water into the cyl on the 5th stroke and utilize the energy that is usually wasted as heat in the radiator....it's been done by a guy who build cams for hi po engines...and it works and the engine never gets to hot to lay your hand on it.

6 stroke motors are in work as well: http://en.wikipedia.org/wiki/Six_stroke_engine

and flat engines are also a good viable option for this setup:
http://en.wikipedia.org/wiki/Flat_engine

Originally Posted by DGthe3

well, I suppose its just as hard to get it to eactly 90.000 degrees apart as it is to get it to 102.857 . . .

And I can't imagine any sort of V configuration working with an odd number of cylinders. Inline makes sense, and I remeber hearing about 7 and 9 cylinder radials from 1930's era aircraft

you could do it, but you'd have to cheat using the design from the pic in post 14. you would technically only have 3 pistons, but one would be oval and would offset the balance.

Originally Posted by Muscle Master

Thoses are good canidates but been done before, I also want this 5 cylinder to get 30+ MPG with a kick

the only hard part about making this engine, that is the engine architect it self, this is going to get complicated my brain hurts

its not difficult to imagine it to look at, but the inner workings are crazy to think about. the problem of balancing is not that difficult to overcome with weights on the crankshaft. and even the power that is given by that particular piston during the combustion cycle would not be too hard to overcome. the real problem would be driveability in a motor. everytime that larger cylinder fires, you are going to get a surge in torque. for those of you out there who have a car with a large cam and an auto without a stall converter can attest to the surging you get when you are at a stop. however, this could be overcome by limiting the length of the stroke that the larger piston has.

by limiting the stroke, you are also limiting the power you are wanting to gain by doing this type of setup but it wont be a large loss. however, you will still get a lot more down-low torque. which if you work in AFM with this, and have that cyl deactivated during idle and during cruising, it could be a phenomenal motor. you would get your down-low torque to get the vehicle moving from a stop (which is beneficial to fuel economy, being able to keep the rpms low while still being in your powerband) then deactivate it when cruising with AFM to keep fuel down again, however, it would be the opposite of AFM at idle, as you would more than likely not want the large cyl firing at idle causing surging. however, it is possible... im adding a quick illustration that i made in MSpaint for everyone to imagine this.

[CamaroSpike23]

Originally Posted by Beelzebubba

All we have to do is make these hybrid battery packs a lot lighter.
Then you would have a power source for an e-charger...a turbocharger driven by an electric motor.
Some guy actually got it to work on an Altima and actually shows a substantial power increase. But his car is a dyno-queen because it's got to haul around a rack of deep cycle batteries.
An extra 160lbs all the time for a short 20 hp boost? Not worth it. Not now. If they can pare that down to maybe 25-40lbs? Maybe.
But then again you could probably just use those ultralight battery packs to drive electric motors on normally undriven wheels or something.:what:
or perhaps with VVT we could make an engine switch back and forth from Miller cycle to supercharged otto cycle :what:
Someone will figure something out.

or i could take a power inverter and plug it into my cigarette lighter to power my electric leaf blower to my intake.
the problem with e-chargers is that, yes in 1 instance there is a significant increase. but how much of an increase was it? 10%? 20%? 30%? 40%?

its comparing apples to oranges. take a 100hp motor and a 300hp motor. 40% of 100 is 40hp, 40% of 300 is 120hp
100->140hp
300->420hp

not going to happen.


what really needs to happen is a change in drivers. i demonstrated to a buddy of mine just yesterday that a change in his driving habits could net him nearly double his gas mileage. we were driving in his Cobalt LS at 70 mph (in a 60...lol) and he was getting 19-20mpg. i told him to slow to 55-60 and check it again. he slowed down, and it measured out to 43 on a flat road.

i myself have been on a pursuit to get better gas mileage, but thats mainly cus i get a bout 10 mpg right now.

electric cars isnt totally out the door, but its kinda like this

powerful
light
long lasting (between charge ups)

pick two