Making a small fortune from a 2 stroke V8 1

[motorsportsdesign]

Here is my plan....Start with a large fortune, then make a large V-8 2 stroke for sportsman dragster racing.

The basic scheme is a supercharged piston port design with 4.840 bore spacing so I can use big block Chevrolet crank and rods.

The foggy areas for me at this point are port design, since the 2 stroke design software that I have looked into so far is not a good fit for bores in the range of 4.0".

I will also need to find a source for a piston with a ring on the bottom, I wonder, can a ring on the bottom piston be forged? It seems that it would be a big undercut.

Last thought is if the engine would require expansion chambers to make good power as they might be rather bulky I will have to model that to see once I have the approximate dimensions.

Any thoughts would be appriciated.


Jonathan T. Schmidt

http://www.motorsportsdesign.com

 

[malbeare]

Jonathan T. Schmidt
Perhaps you could consider a Beare sixstroke V4
Bore 4.500 stroke 4.250 upper bore 3.200 upper stroke 1.375
and then couple two for a V8 and three for a V12. then you would have a stand alone V4 at low production cost or multiples for larger engines.
malbeare

http://www.jack-brabham-engines.com/

A tidy mind not intelligent as it ignors the random opportunities of total chaos. Thats my excuse anyway
Malbeare

 

[dwedel]

Sorry Malbeare, your opposed piston is not unique. Granted in your case it sounds like it is a modified valve, but there are other engines out there. It seems to me, the crankshafts, pistons, con-rods and the supporting structure are the heaviest part of the engine. Why do you want to double the weight of your engine? In a stationary design, weight is not a problem, but in mobile aplications weight is everything.

Fairbanks Morse

http://www.fairbanksmorse.com/

here is the link to the brochure

http://www.fairbanksmorse.com/engines/literature/Opposed Piston Brochure.pdf

This manufacture has an oppsed piston, 2stk engine that dates back to 1930. I have only heard of some of the engine information and am not an authority. There was one located in the oil field as a generator about 50 miles from here. If you are doing your own overhauls and maintenance on these engine, the double crankshaft design doubles your work. Not to mention that you need to pull the top crankshaft to access the piston and liner, which is a common maintenance area in the stationary engine field. Crankshaft timing is very critical, and they have twice the main and con-rod bearings as a normal engine.

For a link to natural gas fuel, pipeline compression engines, try this link:

http://www.coopercameron.com/cgi-bin/coopercompression/products/products.cfm?pageid=ccsbrands

Ajax and Cooper Bessemer are the 2stk engines for this company.

Dresser-Rand still makes a 2stk integral compressor for pipeline compression.

Ship engine builders use the 2stk design also, but I am not familer with that industry.

While these stationary engines are too big for a mobil aplication, they have been through many different types of designs. Also, the are large enough engines that we can actually watch the combustion event happen with the correct equipment.

Good Luck,
dwedel

 

[motorsportsdesign]

" Why do you want to double the weight of your engine?"

dwedel,

I think you question assumes facts not in evidence.

I remember a former employer that used to (rightly say to me;
"you haven't thought enough about your question to ask it"

I think that applies here.

Consider the weight in proporting to displacment and the mechanics reltive to the cycle changes.



Jonathan T. Schmidt

http://www.schmidtmotorworks.com

 

[malbeare]

"dwedel (Mechanical) Jan 16, 2005
Sorry Malbeare, your opposed piston is not unique."
The engines you refer to are supercharged two strokes not naturally aspirated fourstrokes. The upper crankshaft is more akin to a cam shaft than a crank as it does not have a conrod but a very short stroke scotch yoke. The weight of the head is actually less than a standard fourstroke as there is less steel and more alluminium in the Beare sixstroke head.
We have done conceptual drawings of inline engines and there are at least three different methods of rotating the upper shafts or shaft in coordination with the main crank.We havent as yet done detailed finite analysis of each concept so we dont know wich is most favourable or most acceptable to the market.
From a motorcycle point of view and small car point of view a V4 is the simplest as we still have access to 3 sides of every cylinder with a simple toothed belt or chain drive from the upper, single shaft per bank, to the main crank.
malbeare

http://www.jack-brabham-engines.com/

A tidy mind not intelligent as it ignors the random opportunities of total chaos. Thats my excuse anyway
Malbeare

 

[dwedel]

Motorsportdesign & Malbeare,

By the way, for sake of simplicity, please allow me to abbreviate Fairbanks-Morse as F-M. Thanks.

I have now explored Malbaere’s website. And yes, my assumptions are suspect.

In regards to Motorsportdesign initial specs and comments:

Simple design for racing application
-no valves in head
-pressurized intake manifold
-2stk, v8 configuration
-machining a spherical sealing surface is too complex
-component life is relatively short (no million mile overhauls)

Are you planning on individual heads for each cylinder? Large 2stks use this time saver. Even ones with fuel valves/injectors in the head.

This is a simple supercharged two stroke engine. My thought on your plan Motorsportdesign, is that your 2stk idea/design is sound. People have done the same thing many times over, in many different applications. I would expect that your 4stk design would work also.

Is your proposed market able to support either your 4stk or 2stk engine? Most of the people in the racing circles like to tinker themselves, and making their own engine, allows them to do that. How many people buy factory stock engines and race them? Do the people who have the factory engines prefer the tested designs that Chevy, Ford, et. al. have? Would they be willing to risk running a startup company’s engine. Those are the questions I have, when I hear your proposal. {shrug}

My observation is that most people don't make or lose money on the quality of the design, as much as a lack of marketing and buisness ability. As I am an engineer and not a buisness major, I won't give you advice in this area.

In regards to Malbeare’s engine:

I assumed the bore for the upper cylinder was the same as the bore for the lower cylinder. This is my main mistake. With the upper cylinder roughly half the area of the lower cylinder you have half the force on the upper piston and driving components. Thus you don’t have the weight of the F-M upper drive train.

The F-M upper piston was used to make a small amount of power; which the Beare engine probably doesn’t do. My guess is the peak firing pressure on the upper piston creates more friction on the scotch yoke at that point and the possible power gain is negated. This would be hard to measure, but is probably moot anyway.

How has the loss of work due to the upper piston expanding during the power cycle worked out?
How well has the scotch yoke survived sliding during the peak firing pressure event?
Did you weigh the Ducati Desmo heads, intake runners, and throttle bodies?
How about the Beare head parts, reed valves and throttle bodies that went on the Ducati engine?
How do you maintain an oil film on a scotch yoke bearing?
How do deal with the oil pooling on the top of the upper piston?
From your pictures of the exhaust disk, is that the exhaust port that is shown right below the upper crankshaft?
Why is it so much smaller than your air intake system?
Or is this just perception from the pictures?
Why do you have two intake manifolds, when most ported cylinders only use one?
Can you/have you taken a pressure trace of the engine during operation? How does it compare to your predicted values?
What do you think of the fact that you have 3 seperatly unique sealing surfaces in your process, while the poppet valve has one type of sealing surface? (maybe two if you count the different temperatures of the intake and exhaust valves)

I suppose these questions are considered hijacking this thread.

I don’t know gentlemen, maybe Beare's head is a good alternative to poppet valves. I lean towards the not side, but we’ll see what happens in about 40 years. I read somewhere that Lord Kelvin said that people could never travel faster than 60 miles per hour. If I miss my prediction here, at least others have made inaccurate predictions as well. I certainly don’t place my intellect on the same level as Kelvin’s, so I will probably guess wrong more than he did. Maybe I can do as well as a meteorologist.

Good Luck

 

[yoyo133]

The really hard part is to change the rules so they would let you race something different (god forbid).

 

[motorsportsdesign]

yoyo you are right about racing rules driving out originality. I have nearly lost my interest in racing as it has become more of a celebrity sport than a technology sport.

Jonathan T. Schmidt

http://www.schmidtmotorworks.com

 

[tbuelna]

malbeare,

Race sanctioning bodies can be extremely finicky. Just ask your namesake, Mr. Brabham, how far the Brabham BT46 F1 car got back in 1978(?).

Once it demonstrated it had a significant advantage, even though it qualified within the existing rules, it was quickly "outlawed".

Regards,
Terry

 

[gazza285]

Is that a dustbin lid?

Not a nice car to follow apparently, as it sucked all the debris off the track and threw it out the back.

 

[popwarlick]

scottmc
im needing to find a place that will roll me a pipe
according to my specs.someone to roll the cones or just build the pipe altogether.

popwarlick(mechanical)

 

[malbeare]

popwarlick,
a specialist motorcycle exhaust maker REBAND in Australia
I get work done there
Phone 61 885 645122 ask for Rick.

A tidy mind not intelligent as it ignors the random opportunities of total chaos. Thats my excuse anyway
Malbeare

 

[sledneck]

Motorsportsdesign, concerning the use of the same crank as the chevrolet big block. Going from 4 stroke to 2 stroke is only possible with an odd number cylinder blocks. You could use the same crank but would get nice reciprocating and rotating dynamic moments resulting in vibrations. These moments are also the premice to internal efforts you clearly don't need because you'd have to beef up your block for strenght and since your talking about a racing engine, nothing you want to beef up...

Keep up the 2 stroke! God I love those

 

[DesignOutsourcing]

Jonathan,

I was thinking about building a 2-str from a common small 4-cyl turbo-diesel 4-st when I realised what sledneck just pointed out-- having two combustions at the same time will be a problem which means a custom crank (which suddenly makes things a lot more expensive!)

Check out the 2-str Wilksch aero diesels:

http://www.wilksch.com

cheers, derek

Join us at

http://groups.yahoo.com/group/opensourcecars

 

[Icanfix]

Back in the 70s there was a little Italian furniture manufacture. His dream was to make a competitive motorcycle for road racing. He made two sizes, 50cc and 125cc. If memory serves me the 125 put out 47 hp at 8,000 RPM. A sample bike made it to the states for an evaluation by one of the cycle magazines. Never heard anything more about it.

The name was (Morbidelli) I don't think the spelling is correct. It would seem that if you could approach that output from a ported engine that is naturally asphirated you would do well.