Turbo 2-stroke nothing to do with toyotas sorry

[Aging Hoon]

Why are diesels so different ? The only real difference is that a petrol uses a sparkplug to ignite the fuel and a diesel uses heat through high compression. I was only trying to point out that you can have oil in a sump in a 2 stroke.

As a matter of interest, does anybody know what has 3 cylinders, 6 pistons, 12 condrods,1 crankshaft, 2 stroke and supercharged??

[fangsport]

Why are diesels so different ? The only real difference is that a petrol uses a sparkplug to ignite the fuel and a diesel uses heat through high compression. I was only trying to point out that you can have oil in a sump in a 2 stroke.

As a matter of interest, does anybody know what has 3 cylinders, 6 pistons, 12 condrods,1 crankshaft, 2 stroke and supercharged??

the motor that Pearse used to build THE first aeroplane?

[Lloyd]

Isn't that in essence a 4 stroke with 2 cycles happening at once in either side of the piston? (assuming I'm thinking of the same engine)

[vvega]

Why are diesels so different ? The only real difference is that a petrol uses a sparkplug to ignite the fuel and a diesel uses heat through high compression. I was only trying to point out that you can have oil in a sump in a 2 stroke.

As a matter of interest, does anybody know what has 3 cylinders, 6 pistons, 12 condrods,1 crankshaft, 2 stroke and supercharged??

THE PETROL 2 STROKE

STROKE 1A: PISTON AT BDC
the piston is at BDC (Bottom Dead Centre - meaning it is at the lowest point of travel within the cylinder). The air, petrol and oil mixture within the crankcase is forced into the cylinder and exhaust gases are driven out.

STROKE 1B: THE INSTROKE
The piston moves upwards and covers the air intake and exhaust ports closing them.

The charge of fresh air is compressed to about 5% of its original volume. The act of compressing the air heats it tremendously.

This happens on every upward stroke of the piston.

STROKE 2A: PISTON AT TDC
Just as the piston reaches the uppermost portion of it's travel at Top Dead Centre (TDC) the spark plug is fired causing combustion of the compressed mixture within the cylinder. At the same time petrol and oil vapour is being drawn into the crank-case in preparation for the next stroke.

STROKE 2B: PISTON NEARING BDC
During the downward stroke the exhaust port opens, and the cylinder is swept clean of burnt fuel by fresh air from the inlet port. The petrol, oil and air charge within the crank-case is compressed during this stroke in preparation for the next stroke.

This entire cycle is repeated for every revolution of the crank shaft.



THE DIESEL 2 STROKE

STROKE 1A: PISTON AT BDC
the piston is at BDC (Bottom Dead Centre - meaning it is at the lowest point of travel within the cylinder). A blower is forcing compressed air into the cylinder, the air flow forces spent gases out through the open exhaust valves in the top of the cylinder.

Not all two-stroke diesels have a blower, some rely on the suction of the piston alone to draw in the necessary air. An air compressor can replace the blower.

The blower could be considered a very early style of super charger (a device which forces air into the cylinder).

STROKE 1B: THE INSTROKE
The piston moves upwards and covers the air intake port.

The exhaust valve closes.

The charge of fresh air is compressed to about 5% of its original volume. The act of compressing the air heats it tremendously.

This happens on every upward stroke of the piston.

STROKE 2A: PISTON AT TDC
Just prior to the piston reaching the uppermost portion of it's travel at Top Dead Centre (TDC) atomised fuel is sprayed into the cylinder by the fuel injector.

The high temperature of the compressed air in the cylinder ignites the fuel vapour, the resulting explosion forces the piston back downwards.

STROKE 2B: PISTON NEARING BDC
During the downward stroke the exhaust port opens, and the cylinder is swept clean of burnt fuel by fresh air from the inlet port.

This entire cycle is repeated for every revolution of the crank shaft.


now after all that
the diffrence is diesel 2 stroke requires a ex valve to run
without this they cannot gain enough compression from stroke to run correctly
blowers and supercharges are used to to bring up the dynamic compression to a more acceptable level
they also do not use the crankcase as a pump or have transfer ports like a petrol
hence why a diesel can have a wet sumb unlike a petrol
they also do not mix fuel with oil like a petrol
they also use shells like a 4 stroke whereaz a petrol uses roller bearings


bar a very few
petrol 2stroke have no valves and rely on "slots" carfuly positioned to give port timing to allow for ex and inlet flow
they also use the crancase positive and negative prssure to suck charge though the carb and pump it up the transferports into the compression chamber

they also use a expansion chamber that uses carfully timmed ex pulses to create a force to stop esessive inlet charge from escapeing and helpping to create more compression
this is pulse timming is only effective over a limited rev rage effectivly giving you your "powerbband "
oil and fuel are mixed togethier to lubricate the mains and big end rollerbearings(not used on diesel) this is to allow easy lubracation of them


hope that helps

v

ps the first half of the explaination of the 2 diffrent engines was borrowed from a site to hopfully allow easyer understanding

v

ref :http://www.steamengine.com.au

[fivebob]

Why are diesels so different ? The only real difference is that a petrol uses a sparkplug to ignite the fuel and a diesel uses heat through high compression. I was only trying to point out that you can have oil in a sump in a 2 stroke.

Diesels are different because they direct inject the fuel at TDC so they do not fill the crankcase with fuel/oil mixture hence the requirement for a sump. They are very far removed from the topic being discussed, but you're right, not all two strokes supply oil with the fuel mix (just as not all four strokes use a sump, some use premix )

BTW you missed a few important configurations in your list of Series 53,71,92 & 149 Detroit Diesels, like the inline 6 that started it all.

As a matter of interest, does anybody know what has 3 cylinders, 6 pistons, 12 condrods,1 crankshaft, 2 stroke and supercharged??

That'd be the Tilling Stevens TS3 made by the Rootes group from 1954 - 1972 used in Commer trucks and as an industrial power unit. Sound different but a PITA to fix, or so I'm told.

[Zak]

Woah.. that motor looks mad

[Aging Hoon]

Hey Five Bob are you an old dude too?. If I mention TS3s to any young guy they think you are dreaming. No I didnt mention all the Jimmys but you got it sorted.

[vvega]

Hey Five Bob are you an old dude too?. If I mention TS3s to any young guy they think you are dreaming. No I didnt mention all the Jimmys but you got it sorted.

guess ill have to help you with that
i used to restore old bikes and engines
ive seen one
herd it runinng and even pulled one done down
cant say i reasembled it though
it was a bit beyond me back then with no spec's to run by

this one was attached to a old saw mill 150" saw used for milling trees


the point was made that 2 stoke diesels are nor comparable mechanically to petrol ones
that was all

and i have yet to see a wet sump 2 strole petrol engine
if you provide one ill happly be corrected

some have direct injection oil feeds but they still dont have a wet sump
it all just gets blown up the transfer ports


they are a massive unit

[Aging Hoon]

Hi VVega only one I can think of off hand is the Rolls Royce Crecy but must be others. Ive had a fair bit to do with 2 stroke motors, used to work on Evinrude/ Johnson outboards after years on cars trucks etc.Also been into motorcycles ,pommy mainly-still have a few. What bikes have you got ??

[vvega]

hehe
thats a sleave valve so it dont really count but do keep tring
shame it was never a production engine

i worked for a ex gp750 rider who has quite the colletion of motor cycles
including a tz750

a lot of the colections were just old jap bikes wit a little class
re-5
gt750
etc
quite few classic race bikes as well
though id have to say most were never a production item

i also helped do restoration for wwwII colector so ive have a intermate play with the likes of v12 merlin powered air raid sirens

both of these are private colections

v