modern 2 strokes

[MTv Dave]

Just read a thread about somebody re-building a classic race car that has a 1l 2-stroke.
I'm not that comfortable with them, but it has got me wondering if there are any new ones made with modern materials that are road legal?
Continuing the theme of super light cars with little engines from Diahatsu, I expect that more modern 2-strokes would produce reasonable power (100bhp/ton) with NA and not too much trouble, but can you get them running with EFI? Are they low mass, or do they need to be strong so made of iron?

I just want to get a feel for them, or if this is a dead end and not worth me pursuing?

[thong]

dead dont bother they have far to much waste in the exhaust,and little torque.

[Pigeon]

You can indeed get them running with EFI, and if you inject direct into the cylinder after the exhaust port has closed you avoid the problems with charge spillage.

[The_Burg]

Pigeon said:

You can indeed get them running with EFI, and if you inject direct into the cylinder after the exhaust port has closed you avoid the problems with charge spillage.

I beleive Aprilla made a direct injection scooter, and Ford with the 'Orbital' engine a few years back. Loads of other refinement Hondas 'Active Radical' for example.
2 strokes are awesome, huge power for tiny capacity, ultra simple and sound amazing.
(Even smell fantastic running Castrol R or similar).

If your talking about the 'Lova' rebuild i for one can't wait hear and smell it running!

[aceparts_com]

I helped rebuild a berkley barkley or barkley berkley some years ago. Powered by a 500CC 2 stink. Tiniest car you ever did see

http://66.102.9.104/search?q=cache:5W

[boosted ls1]

aceparts_com said:

I helped rebuild a berkley barkley or barkley berkley some years ago. Powered by a 500CC 2 stink. Tiniest car you ever did see

http://66.102.9.104/search?q=cache:5W

Reminds me of my first motorbike, powered by a 2T villiers engine. Quite a nice engine but I soon went to the Japanese stuff. They really could do a ton

Boosted.

[chuntington101]

boosted, r anyone else, what do you think a 1000cc 2stroke could do compeared to a 4 stroke????

i know emmsions would be out the door (right???) but would be interesting to see power for power.

thanks Chris.

[MTv Dave]

The_Burg said:

Pigeon said:

You can indeed get them running with EFI, and if you inject direct into the cylinder after the exhaust port has closed you avoid the problems with charge spillage.

I beleive Aprilla made a direct injection scooter, and Ford with the 'Orbital' engine a few years back. Loads of other refinement Hondas 'Active Radical' for example.
2 strokes are awesome, huge power for tiny capacity, ultra simple and sound amazing.
(Even smell fantastic running Castrol R or similar).

If your talking about the 'Lova' rebuild i for one can't wait hear and smell it running!

Yup, Justin's Lova. Looks like an awsome little car

I've never had any dealings with 2's before, hence my worry. I'd also want the finished product to be road legal, so emissions would be an issue for me.

I expect I'd want a relativly large (1l ish) capacity engine, so nicking one off a little modern scooter or somesuch isn't really an option.

My target wet mass is around the 450kg mark, so I was looking at 600-1000cc 3-pot 4-strokes from the GTti et al to get reliable 100-150 bhp (blown). If I can get similar reliable outputs for less money, mass, bloody knuckles or trouble and N-A then I'd be happy to go 2-stroke, but have zero idea on where to even start.


ETA - Alan, I have just visited your website - Are those LED clusters any good? I've been looking for some similar things, but ended up designing my own units, but would rather go with 'off-the-shelf' bits if I can.

Edited by MTv Dave on Wednesday 21st March 12:58

[hugoagogo]

chuntington101 said:

boosted, r anyone else, what do you think a 1000cc 2stroke could do compeared to a 4 stroke????

i know emmsions would be out the door (right???) but would be interesting to see power for power.

thanks Chris.

well 500 strokers weren't far behind 990cc 4-strokes when the rules changed for moto gp - over 200 bhp for both

so a 1000 (v8 maybe - two v4s nailed together) should be over 400 bhp, and very light

narrow power band and it would eat fuel though

for a road bike, a bimota v-due has about 120hp from a 500 twin, 65 lb ft torque - if and when it works
old mid eighties suzuki rg500 square four can be reliably (for a stroker) tuned to 100+bhp


edit: found this site
they make 1000 v4 2-stroke race engines for snowmobiles and stuff
www.aaenperformance.com/V4_racing_engine.asp

Edited by hugoagogo on Wednesday 21st March 13:43

[MTv Dave]

Nice, neat and only 44kg!
No prices for the engines, so I guess they're quite expensive
The road/race version kicking out 200bhp from 850cc @ 9k rpm sounds good. Maybe it would last a little longer than the 275 bhp @10,000 rpm for the 1l drag engines

Edited by MTv Dave on Wednesday 21st March 14:12

[The_Burg]

No obvious signs of power valve or reeds, surely this is not a pure piston ported motor?
As regards a useable engine cheap and powerfull possibly a motor from jetski?
Up to 750 - 800 cc so 150+ bhp should be no problem.

[Mtv Dave]

The_Burg said:

No obvious signs of power valve or reeds, surely this is not a pure piston ported motor?
As regards a useable engine cheap and powerfull possibly a motor from jetski?
Up to 750 - 800 cc so 150+ bhp should be no problem.

See, things like that worry me, I have no idea what you are saying! I'm guessing it's something to do with moving fluids from below to above (or visa versa?) the piston?
Can anybody point me to a web source for more in depth info on 2-strokes and tuning them?

Edited by Mtv Dave on Wednesday 21st March 15:40

[The_Burg]

Reed valve is a one way valve used on the inlet to stop fuel blowing back out of the carb and allows wilder induction timing.

A power valve is bit like VVT on a 4 stroke in what it does. Basically alters when the exhaust valve opens, gives more lower / mid power without losing topend.
Looking at that site some serious outputs on snowmobiles so plenty of potential.

[The_Burg]

Another though if just high power low weight maybe a Wankel from and RX7 or similar?

[Mtv Dave]

Not so much high power with low mass, but "fun" with low mass.
For me, I think this means about 100-150bhp (220-330 bhp/ton) and a reasonable spread of torque.
I'm looking for dyno graphs of tuned 2-strokes just to see how the torque looks across the rev range, if they're spikey then I'll leave them be.

[hugoagogo]

in the 70s Barry Sheene described the engine of his suzuki race bike as having "a powerband as wide as the cock on a chocolate mouse"

maybe the modern ones aren't that bad, but it's all top end

[The_Burg]

Mtv Dave said:

Not so much high power with low mass, but "fun" with low mass.
For me, I think this means about 100-150bhp (220-330 bhp/ton) and a reasonable spread of torque.
I'm looking for dyno graphs of tuned 2-strokes just to see how the torque looks across the rev range, if they're spikey then I'll leave them be.

Fun is the key with a 'stroker', massive hit as it comes on pipe.
Like a turbo but more so and amazing sound.
Forget graphs, just another statistic. If you can ride a bike try a stroker, even a 125cc you will have a huge grin for sure. Anything bigger and you will be hooked!

[MTv Dave]

Can't get onto a bike on a public high way
I did have a little play on an RS 125 Aprilia a few years back. I thought it was mad, but I hadn't really experianced riding anything else or been in any seriously quick cars, so I'm not sure what I'd make of it now.

I'll have a scout around and see if I know anybody that has a bike I can have a go on somewhere private.

[MTv Dave]

Pigeon said:

You can indeed get them running with EFI, and if you inject direct into the cylinder after the exhaust port has closed you avoid the problems with charge spillage.

Just checked out your profile - how's the luck going with the engines? How much do you think you'd have to sell one for to make it worh your while? How long do you think they will last - bwtween needing tuning and between going pop?

[boosted ls1]

The_Burg said:

No obvious signs of power valve or reeds, surely this is not a pure piston ported motor?
As regards a useable engine cheap and powerfull possibly a motor from jetski?
Up to 750 - 800 cc so 150+ bhp should be no problem.

It could be just piston ported or maybe it's got disc valves? I used to love my 2 strokes and still fancy an rg500 but I'd probably kill myself all to quickly.

Boosted.