Why no 2 stroke performance cars?

[thinfourth2]

a 2 stroke racing engine

44Kgs, 1025cc, 275Bhp, no valve train

http://www.aaenperformance.com/V4_racing_engine.as...

Why is there no performance 2 stroke cars?


Don't forget the most powerful piston engine in the world is a 2 stroke

[kambites]

Economy and the fact you can't run them on just petrol, I'd imagine.

[odyssey2200]

the eco mentalists would have a hissy fit.

[thinfourth2]

kambites said:

Economy and the fact you can't run them on just petrol, I'd imagine.

odyssey2200 said:

the eco mentalists would have a hissy fit.

And so what?

[Boosted LS1]

I used to love my two stroke yamaha's but I think emmissions legislation is killing them off because of the way oil is mixed with the petrol for cylinder lubrication. A big engined two stroke would be mental!

[kambites]

thinfourth2 said:

And so what?

So why would anyone do it? What's the advantage?

[Ozzie Osmond]

Torque - or lack of it.

2-stroke has high horsepower for its weight. Crucial on a motorcycle; less so in a relatively heavier car.

The amount of power needed from a 2-stroke to move a heavy car will result in substantial exhaust emissions compared with a 4-stroke. Although direct injection etc is narrowing the gap.

[Randy Winkman]

I seem to remember Ford developing 2 stroke engines for the Fiesta in the 90s.

[Efbe]

just think of the ears... your ears, my ears, everyone's ears!

[Perd Hapley]

Randy Winkman said:

I seem to remember Ford developing 2 stroke engines for the Fiesta in the 90s.

IIRC the Ka was conceived with this modern two stroke in mind, but emissions killed it.

[anonymous-user]

[Megaflow]

Boosted LS1 said:

I used to love my two stroke yamaha's but I think emmissions legislation is killing them off because of the way oil is mixed with the petrol for cylinder lubrication. A big engined two stroke would be mental!

The oil doesn't have to be mixed with the fuel. You can either have a seperate tank, with a metering pump, which is still total loss system. Or, if you replace the compression in the lower half of the crankcase with a supercharger, it is possible to run a conventional wet sump.

Two strokes have to be warmed up very carefully to avoid the dreaded cold seize, which is not practical for the way we use modern cars.

[kik1.6se]

Randy Winkman said:

I seem to remember Ford developing 2 stroke engines for the Fiesta in the 90s.

One of the development cars is in the Haynes motor museum, a white mk3 fiesta. Was wondering what it was doing there until I looked under the bonnet.

Would superchargeing or turbocharging help? Am I correct in saying it would do away with the two stroke oil problem as scavenging wouldn't be a problem? The big two stroke diesels, such as the Deltic, are supercharged or turbocharged. Would there be down sides to a direct injection turbocharged two stroke?

Kirk

Edited by kik1.6se on Monday 20th June 21:25

Edited by kik1.6se on Monday 20th June 21:26

[B'stard Child]

Ozzie Osmond said:

Torque - or lack of it.

2-stroke has high horsepower for its weight. Crucial on a motorcycle; less so in a relatively heavier car.

The amount of power needed from a 2-stroke to move a heavy car will result in substantial exhaust emissions compared with a 4-stroke. Although direct injection etc is narrowing the gap.

Increased capacity brings greater torque

I've ridden a GT750 Suzuki and it had loads of it

Efbe said:

just think of the ears... your ears, my ears, everyone's ears!

They don't have to sound like a swarm of hornets......

[thinfourth2]

kambites said:

thinfourth2 said:

And so what?

So why would anyone do it? What's the advantage?

With a 4 stroke you get 2 rotations of the crank to get 1 power stroke per piston

A 2 stroke you get a power stroke every rotation of the crank and no valve train to drive so less parasitic loses

We are talking about pure performance not efficiency

[thinfourth2]

kik1.6se said:

Randy Winkman said:

I seem to remember Ford developing 2 stroke engines for the Fiesta in the 90s.

One of the development cars is in the Haynes motor museum, a white mk3 fiesta. Was wondering what it was doing there until I looked under the bonnet.

Would superchargeing or turbocharging help? Am I correct in saying it would do away with the two stroke oil problem as scavenging wouldn't be a problem? The big two stroke diesels, such as the Deltic, are supercharged or turbocharged. Would there be down sides to a direct injection turbocharged two stroke?

Kirk

All 2 strokes must have a force fed induction you cannot run a 2 stroke without some sort of pressure charging in the inlet to the piston.

Large 2 strokes have a wet sump which never sees charge pressure as it i separated by a set of seals. Smaller 2 strokes must run with a pressurised crankcase as there is no room for a piston rod and stuffing box.

[Caruso]

The Saab 96 had a 2 stroke engine and some rally successes.

[odyssey2200]

thinfourth2 said:

With a 4 stroke you get 2 rotations of the crank to get 1 power stroke per piston

A 2 stroke you get a power stroke every rotation of the crank and no valve train to drive so less parasitic loses

We are talking about pure performance not efficiency

With a Rotary you get 3 combustions per rotation and no valve gear and no reciprocating mass to cause vibrations.

i nearly said wankel

[B'stard Child]

Caruso said:

The Saab 96 had a 2 stroke engine and some rally successes.

Got fond memories listening to one of one of those running at the le man classic - one gear change all the way up the main straight

[kambites]

thinfourth2 said:

With a 4 stroke you get 2 rotations of the crank to get 1 power stroke per piston

A 2 stroke you get a power stroke every rotation of the crank and no valve train to drive so less parasitic loses

I know how a two-stroke works, I just don't see a benefit in a car over, say, a turbocharged wankel engine?