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Part of a series on a two stroke engine

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Windy11/03/2021 01:27:37
865 forum posts
185 photos

Part of a series on another website

That Nitro EFI setup - Most Powerful Two Stroke Ever. - YouTube

Howard Lewis11/03/2021 15:29:15
5036 forum posts
13 photos


Glad that he made clear that it was the highest specific out put.

Nitro can be quite dangerous stuff.

Just hope that the moped chassis can withstand the power from the engine, and brakes to match!

The most powerful two strokes to my knowledge are the Wartsila turbo charged two strokes for the "Emma Maersk" and her sister ship.

102,000 bhp at 102 rpm! Everything is massive. The six wheel Scania truck pulling the engine out of the erecting shop looks like a dinky toy in comparison.

The cylinder head studs are 14 feet (4.125 Metres ) long,. The crankshaft weighs 300 tons, and the bed plate is

9 feet deep, complete with ladder rungs in the main bearing saddles!

On board, there are magnets set around the propellor shaft, so that if more power is needed! a set of coils can be energised to provide an additional 4.5 Mw. Or the engine can use this set up to generate 4.5Mw for on board use.

Unless anyone knows of an even more powerful unit?


Lee Rogers11/03/2021 18:24:27
133 forum posts

Howard Lewis. It's a long running tube channel , the ''moped'' is in fact a Bonneville type speed record machine. Some very interesting stuff like 2 stroke theory and home plating of aluminium cylinders.

JasonB11/03/2021 20:02:13
20880 forum posts
2318 photos
1 articles

Did I miss him mention what power he was aiming for?

Old School11/03/2021 22:20:32
390 forum posts
39 photos

I didn’t hear an output figure mentioned, would be interested to compare it against our tether car engines. No nitro just methanol and castor.

JasonB12/03/2021 06:57:17
20880 forum posts
2318 photos
1 articles

That's why I was asking, the model boat guys can get 7.6BHP out of a 2-stroke which it just over 500bhp/Ltr

Kiwi Bloke12/03/2021 08:34:07
573 forum posts
1 photos

Weren't the F1 'grenade engines' used for qualifying in the 'turbo years' of the 1980s capable of > 1,000bhp, from a capacity of 1.5 litres? OK, four-strokes, not 2-stokes...

Edited By Kiwi Bloke on 12/03/2021 08:39:34

Andy_G12/03/2021 08:48:35
125 forum posts

I think he has previously mentioned 20HP - as above, I don’t think he’s factored in the racing model engines, but good luck to him anyway.

Niels Abildgaard12/03/2021 09:03:01
395 forum posts
148 photos

Power per litre is an armchair unit.

For two strokes on unpressurised air and no liquid oxygen(nitro) the ultimate limit is the blowdown time area.

If you double all dimensions we get eigth times the volume but the exhaust area gets only four times bigger and air does not want to go faster than mach one in such situations.

If we considder Aprilia 125 ,54 times 54 mm, and 53 horsepower as the ultimate two stroke ,we can say that is 424 horsepower per litre and look very smart.

The engine mentioned above of 14.74 ccm that is 8.5 times smaller volume and should thus give 53 divided by 8.5 equals 6.2 horsepower if as well dimensioned as the Aprilia thing.

The port area ratio is not 8.5 but 4.1 and if the boat people were as good as Aprilistas they should get around 13 bhp.

JasonB12/03/2021 10:24:53
20880 forum posts
2318 photos
1 articles

I did see the one where he mentioned 20bhp out of a 50cc engine and in this video he mentions possibly reaching 25bhp at some time so assume similar engine capacity that's what the boat boys have been doing for several years.

If anyone wants to look at what goes into building and testing these boat engines including the above mentioned home chroming then have a look at this long running thread by the late Jim Allen on MEM forum, you will need to register to see the photos as they are posted as attachments.
Windy12/03/2021 13:07:08
865 forum posts
185 photos

Very interesting reading the posts when you think an engine is going to be the most powerful or claim unofficial speeds you can walk into a minefield.

Have heard so many times riders of super sport road bikes claim they have done 200mph plus on the road ha, ha what a surprise when timed with Tag Heuer certified timing equipment.

There are so many high power engines to look at some of the model record speed attempt IC engines develop high power then you go to full scale ones.

Am now mainly playing watching big boys toys a motor cycle that comes to mind is Phil Wood on a detuned Hayabusa 271.821mph over flying start 1/4 mile.

If I remember correctly he was on a low boost setting about another 4 to go highest gives about 1000bhp reliability then becomes an issue.

There are 3 contenders to break the UK motorcycle 300mph barrier they are Phil Wood, Guy Martin and good friend Becci Ellis (Fastest Granny).

Beccy and husband Mike have supplied me with an electric wheeled machine for my exploits round the pits at Elvington and Melbourne Drag strip..

Would have been at Elvington Top Speed at the end of March but because of the Virus the ruling body will only allow pre-booked competitors and one helper.

Pete Rimmer13/03/2021 21:30:45
1004 forum posts
57 photos

Good luck to Mike and Becci I only met them once briefly at Woodbridge but they seemed like lovely people.

Windy13/03/2021 22:56:36
865 forum posts
185 photos
Posted by Pete Rimmer on 13/03/2021 21:30:45:

Good luck to Mike and Becci I only met them once briefly at Woodbridge but they seemed like lovely people.

There great like all the motorcycle and car speed attempt enthusiasts if they can will help each other.

Must admit I have been spoilt by them all looks like Andy who had your bike will be dropping off some bottles of vaccine soon'.

Helen is going into a York hospital next week so Andy is calling round.

Edited By Windy on 13/03/2021 22:58:00

mgnbuk14/03/2021 11:18:09
1001 forum posts
69 photos

I think he has previously mentioned 20HP

Late '70s Kreidler 50cc GP bikes made around 19hp between 14 - 16,000 rpm, so not advancing on older technology by much with that goal ?

Pity the smaller GP classes were dropped IMO. Small bikes with small riders, but fast & competitive racing.

Nigel B.

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