Anyone know what the primer bulb on a two stroke engine does?

I always thought it pumped fuel into the engine (or carburettor), but after trying to r&r the hoses on one tonight it looks as if it's on the other side of the carburettor and therefore sucks the fuel through the carb and returns it back into the tank.

r&r?

Something plugged in backwards? Primer to send some juice into the carb...

remove and replace.

No it was all hooked up correctly, I just followed the lines.

Weedwhacker btw

Very strange.
Have experience with such machines... Could be the hole from the primer into the carb is blocked or similarly from the fuel tank into the primer. Happened last summer to me (with a weed wacker). Turned it upside down & gave it a good shaking. Then re-primed). Problem solved.

Probably made in England by someone who can't speak English.

If all else fails, take it back to the shop & tell 'em to fix it. Or else they get sued.

If that fails, blame the French. :}

The primer bulb 'fills up' the pump/diaphrgm type carby - and a little goes into the venturi - once it is 'full' further priming causes excess fuel to go back to the tank......

If you are unsure of anything do not muck around with it! Fuel leaking from a running whipper snipper and running down your back..... get the picture......

You've just reminded me - wasn't Jaguar doing R&D on a 2-stroke engine some years back? Seem to remember that they had at least a working prototype, which produced double the power for half the weight of its 4-stroke equivalent.

Yes, were working with or licensing tech from Orbital, somewhere in Australia.

I think Ford fitted some to police cars in Norfolk, which explains the Australian link - Norfolk being the UK's "outback". :E

So, why aren't we seeing 2-stroke engines in cars now? Is it because they are not environmentally friendly, or is there a hidden agenda among car makers and oil producers?

Helluva lot of 2 stroke diesels in trucks though...





After an excellent landing you can use the airplane again!

Have you ever smelt 2 stroke exhaust?:E

Personally I hate 'em because I never really knew what to do with the choke. I just try different positions until the thing starts up. My question was just because I was surprised at what I was seeing from a correctly plumbed motor.


I'm gonna install some new fuel lines as one has sprung a leak

So, why aren't we seeing 2-stroke engines in cars now?


Probably all got haunting memories of thos little 'peds that used to buzz up and down.....nying nying, nyiiiiiing, NYIIIIIIIIIIIING.

Great fun, but killed a few on the way.Ever tried substituting the red oil with vegetable oil? Smelt like a dodgy chippy:)

And don't forget this one: http://www.youtube.com/watch?v=MQwj0EqOQJw

The Luftwaffe used 2-stroke diesel engines on a few planes during WW2, although the engines were super-charged. Now one of those on a fissy...

The Jumo engine:

http://en.wikipedia.org/wiki/Junkers_Jumo_205

How many strokes is this buggah then? :uhoh:
http://i89.photobucket.com/albums/k226/Tony_Draper/Napier_Deltic_-_001s.jpg

I think it's a mere three cylinder two banger (diesel, judging by the pistons), Mr D.

Wossitoff?

The Commer 2 stroke diesel bus engine used a similar system of opposing pistons and no cylinder head - no gasket to blow and the whole engine was lighter than it might have otherwise been. They supercharged it as well!

Fatal flaw preventing wider use of 2-stroke in vehicles is the mixing of oil with fuel - a simplification inherent in 2-cycle that saves weight and complexity by eliminating the oil circulatory system found in most other engine designs.

Because cylinder lubrication is still necessary, oil must go into the fuel, where much of it burns during the normal combustion cycle. This burning is inefficient, at all the wrong temps, and very high in oil component residues that emerge in the exhaust as air pollution -- and water pollution in the case of boat engines.

Places with tight controls on air pollution emissions would like to see an end to 2-cycle jobs altogether. California, for one, has banned 2 cycles on boats and is moving to do so on hand tools and gardening machines. Their problem is that all the simple pollution fixes have long-since been done... so 2-cycle engines are actually a significant percentage of hydrocarbon figures... according to the experts.... (who occasionally are found to be lying gits.)

Solve this one minor problem (2-cycles with no oil emissions) and you will become wealthy beyond imagination.

Perhaps a MAGLEV cylinder design would do it.... anyone care to give it a try?

arcniz,
There is little in engineering that hasn't been tried before!

Norton motorcycles were working on a "stepped piston", twin cylinder, 2 stroke engine in the early 1970s. This type was more like a 4 stroke with regard to lubrication, it had a lubrication system kept under the piston in a sealed crankcase and it ran on neat petrol, rather than on 2T mix so the emissions were relatively low. The stepped pistons were effectively two stage devices, shaped like a top hat, with upper and lower ringed sections.

The strange thing about the engine was that the carburettors were "wrong-handed". Adjusting number 1 carb affected only number 2 cylinder, and vice versa. The reason for this is that the lower part of the stepped piston pumped air/fuel mixture across into the opposite cylinder. The crankcase was not used as a pump chamber, unlike a conventional 2 stroke. The lubricating oil stayed down below and the air/fuel mixture stayed up top.

It was known as the Norton Wulf engine; I remember thinking at the time as a teenager that it was a strange thing for a company making 4 stroke stump-pulling engines to be doing. Looking back, someone at Norton was actually being very far-sighted. Unfortunately, lack of cash for development due to the impending downfall of Norton Villiers Triumph caused it to founder.

There doesn't seem to be much information on this available online but a company called Hooper engineering have been doing some further research on this type of engine. (Bernard Hooper was heavily involved in the Norton project, I see there is a diagram on their website showing how the concept works).

How many strokes is this buggah then


Ah a Napier Deltic opposed piston 2 stroke, first designed as a lightweigh engine for boats Captain. Produced by English Electric and also used in the Deltic class of main line diesel locos to improve the service twix London & Edinburgh via Newcastle.

:)Two connections to your goodself in one question:)

The latest classes of heavy freight locos in use in the UK built in USA/Canada use 2 stroke diesels, the only other loco with a 2 stroke used a Crossley 2 stroke built a Vickers shipyard in Barrow

Is that 3 Capt?

The Chieftain Battle Tank was powered by a 6 cylinder 12 piston opposed diesel engine. (L60). It stood vertically in the rear with another smaller aux engine of only 3 cylinders and 6 pistons for starting and driving the generator. The L 60 made between 600, and 750 bhp depending on how many lobes the roots blower had , 3 lobes = 600 bhp, 2 lobes = 750 bhp. It smoked like WWI destroyer.:= :eek:

Lots of work has been done on 2 stroke petrol engines using fuel infection and supercharging instead of a carburetor and crankcase compression, and therefore no need for a petroil mix. Never the less, emissions have always been the hurdle. :ok:
Regards,
White Bear

fuel infection
Sounds awful, what was it infected with? Mad car disease? :}
:E

The deltics
Basically 2 x 18 cylinder engines in loco rated at 1650bhp at 1,500 rpm each awsome to see but boy are they noisey.

The other was eventually Class 28 nicknamed "Wonderloafs" with a V8 giving 1200bhp at 625rpm

Anyone know what the primer bulb on a two stroke engine does?It's a clever diversion designed to make you think it has some relation to why your two-stroke weed whacker refuses to start.

In truth, it refuses to start because two-stroke weed whackers are CRAP! :ugh:

Toss it in the bin and buy a four-stroke weed whacker, on which the primer bulb actually does supply petrol to the carburetor. You'll thank me later. :p

Bah! proper engines had boilers and burned Shillbottle coal.:rolleyes:

Plenty of two strokes in the marine industry that went to direct injection.

The reason the orbital engine did not take off is that someone applied direct injection to a 4 stroke and got benefits that outweighed whatever gains were noticed on the 2 stroke.

I work on direct injected lexus cars.

Personally, I love the smell of two-stroke in the morning, especially as building work on the garage means my LC is living in the kitchen right now.:)

Personally, I love the smell of two-stroke in the morning


Even better if you try Castrol R as used by 2 stoke racing karts

One used to add a generous splash of Castrol R to the petrol-tank of my modified road car. It was simpler than running the engine using 'R' (which required regular strip-downs to clean out the passages) but gave that distinctive smell from the exhaust.

Engage Homer Simpson mode:

TWO-STROKE??? mmmmmmmm, twooo stroke.

Buzz bombs. Fantastic. My left hand still twitches involuntarily after years of riding bikes that had a tendancy to grenade themselves at every opportunity.

Wasn't there an engine called the Orbital, which is a "modern" two stroke with low emissions and high power to weight ratio. I believe it was just the lack of a manufacturer willing to develop it further.

http://en.wikipedia.org/wiki/Orbital_engine

I don't think it was that one. I may have the wrong name, but I remember Lotus doing some development on it just a few years ago and some of the Italian manufaturers had shown interest in the concept.

Two strokes are very efficient and needent stink from smoke if they use proper injection systems- I run a Suzuki T500 titan motorcycle.
it has no visible smoke and I use a synthetic injection oil
Someone has invented an system to inject oxygen at the proper time in he firing sequence so that it burns clean and not a polluter a few years ago but no one has picked up on it
I like 2 strokes [ have three power saws and a wacker] and drove a 3 cyl 2stroke DKW car across canada many years ago.
I was pulled over on the 401 Toronto by an intrigued motorcycle cop for smoke but was using poor oil.
If I had the machine today it would not smoke.
My bike sounds like a cherry bomb ringa ding ding :) and the power band is exciting
2strokes are used in massive marine engines to good purpose
y

Read this recently on the www.britishseagull.co.uk (http://www.britishseagull.co.uk) website

On the 1 January 2007 it became illegal to manufacture new two-stroke outboard engines but it did not become illegal to use existing two-stroke outboard engines. It is still possible to use them and repair them until the end of their natural life. In some cases this will be longer than others!


I haven't been able to find out any more about it...anyone know anything more? I don't know if this applies just in the UK, or EU generally. I assume this is because of pollution....

Dredging in my memory ... I remember the Orbital engine as investigated by Ford etc. It was supposed to be a clever 2-stroke that could achieve emissions performance better then a 4-stroke. I don't think it was ever proved to do so, but I don't what's happened in the last few years.

Combustion technology to meet emissions regulations has become very sophisticated. Common-rail Diesels, with piezo-electric injectors are achieving impressive performance - probably leaving 2-stroke far behind. But I've been out of that world for over ten years, so would be interested to hear what's new.

Make sure your speakers are on and the volume turned up!

http://www.youtube.com/watch?v=dXVRdSbKDT8

:ok:

http://www.youtube.com/watch?v=fFPjY_shAUU

Found this interesting "new" concept. As I said earlier, there's little in engineering that hasn't been tried before.

What would they call an aircraft powered by this engine? The "Commert" ? :)

Sadly, it was whilst watching the video of a fatal accident that I found it. The engine video is off to the right of the screen; I can't link directly to it.

http://www.aero-tv.net/index.cfm?videoid=00b0d640-e714-4b79-b17b-6f3b0f149c4d

So, why aren't we seeing 2-stroke engines in cars now
the original SAABs were 2 stroke ... and The Jowett Javelin ISTR?
There is a bloke in NZ who rebuilds/repairs Seagull outboards - people send them to him from all over the world apparently....

Don't forget the Wartburg and the Trabi, either!

Or the Trojan.

Don't forget the Wartburg


Ahh remember going to watch the RAC ralley when these "cars"? used to enter, the sound of them struggling up a forest track had most of the spectators rolling around.
Revs up to max with a high frequecy zing, change up, lose revs, nearly stall, change down, revs to max, change up etc.

ShyTorque, if you are talking about the one with chain drive, you are really showing your age.

ShyTorque, if you are talking about the one with chain drive, you are really showing your age.

I'm afraid I probably am. Three litre, three cylinder, 2 stroke engine pulling a chain driven, solid rear axle. They will climb just about any slippery hill as they don't lose traction on one side!

http://i7.photobucket.com/albums/y290/shytorque/Trojancar.jpg

I hadn't seen one in action until the year 2003, though, when I competed in the same MCC classic car trial as two of them, when this photo was taken. :ok:

I have a british seagull - works great! on my boat
had to clean tank and carb but it has a ton of torque pushing my old davis sailboat
biggest prob is whitworth threads
y

I think the Saabs got their engine from the defunct DKW [ I used to have two of them in the 60's]
y

Whilst at Uni I became acquainted with a guy using the dynos to develop his DKW 'junior' racing engine. No doubt his efforts were increasing the output, but regular seizures seemed to outweigh the advantages . . .

Try the Field Marshall tractor; available in 3 or 3.5 litres, a SINGLE cylinder 2 -stroke diesel maximum rpm about 500!! Not very fast or powerful but torque like a steam engine! I've seen them pulling three or four trailers ie corn cutting machine, threshing machine, grain wagon; sometimes adding a baler for good luck.

I still use castrol R on mazda rotaries for race usage.

Some info on current 2 stroke engines.

http://www.dieselduck.ca/machinery_page/diesel_engine/diesel_engine.01.htm
http://www.manbw.com/engines/TwoStrokeLowSpeedPropMEEnginesProgram.asp

:ok:

biggest prob is whitworth threads


Really? I don't recall any whitworth threads! What were they about?

They're suits worn by boaties - I think Burton's used to sell them...

Ah, Field Marshall tractors; traditionally painted orange, as I remember. Wasn't that a single, longitudinally horizontal cylinder? Left parked and running, they would gently bounce up and down on their suspension. I often wondered ......

The problem that you refer to is only relevant to engines that are lubricated by fuel /oil mix, ie crank bearings /piston,etc, in the case of diesels this does not apply! in the Deltic, oil was sprayed onto the lower side of the piston to cool it,

On the Rotax 582, a primer-pump bulb is useful for filling the carby float-bowls with fuel to assist easy starting, especially if the engine hasn't been started for a few days.

In a 2-cylinder 2-stroke (such as the Rotax 582) one exhaust-port is always at least partially open, the fuel in that cylinder's carby will tend to evaporate from the float-bowl (via the crankcase porting). Unless the bowls are topped-up prior to starting, a lot of cranking (or pulling the hand-starter) is needed because initially all you're doing is filling the bowls until the level is sufficient for normal carby operation to occur.

The alternative is to physically remove each float-bowl, top them up, then re-attach them to trhe carbys. Works a treat.

How many strokes is this buggah then



Ah a Napier Deltic opposed piston 2 stroke, first designed as a lightweigh engine for boats Captain. Produced by English Electric and also used in the Deltic class of main line diesel locos to improve the service twix London & Edinburgh via Newcastle.



Originally fitted in RN fast patrol boats.

This (http://rowla.dyndns.org/justin/img/piston_deltic320.mpg) animation with sound will explain everything. It looks like a prototype monster from a horror movie.

The main problem with petrol two stokes is the unburnt fuel that escapes from the exhaust port when the piston is at the bottom of its stroke. This is the cause of high emissions. It can be minimised by careful design of the exhaust system. I believe some outboard motors are now using direct fuel injection which solves this by waiting till the piston has covered the exhaust port before delivering the fuel charge. They will still suffer from lubricating oil being burnt, but with modern synthetic oils very small amounts are required.

The situation with diesels is completely different since these either use mechanical exhaust valves (GM "Detroit" series), or asymmetric port timing (Napier Deltic, Rootes / Commer TS3). In any case since the fuel is injected only after ports and valves are closed there is no problem with unburnt fuel.

With twice as many power strokes compared to four stroke engines these can give extremely high power to weight ratios. IIRC the six cylinder Foden was giving 175hp from about 6 litres over 40 years ago and if you've ever heard one working hard you will never forget the sound!

Really? I don't recall any whitworth threads! What were they about?

My guess is that they were a thread, but I am not an engineer.

It is odd how one remembers things, for I can recall exactly who casually asked for a Whitworth spanner or screwdriver or whatever, and where, of a size he prescribed, to be used on a Vampire 5, in about 1956. The requestor was a pilot and the requestee was an airframes LAC or thereby, and I can still see the astonishment on the latter's face at such a request with such informed precision from such a source. I knew, which the airman did not, that the pilot was a graduate of the de Havilland Technical School.

Quote:
Really? I don't recall any whitworth threads! What were they about?

My guess is that they were a thread, but I am not an engineer.


Davaar, I think Mr. S Torque is referring to some ficticious postings or other. Your guess was quite right, btw.

It was his little joke - and a jolly good one too I say.

TRC

TRC and S Torque,

Thank you and my apologies for being dim. It is just so pleasant once in a while for a non-tecchie to have even a glimmering of what the big boys are talking about.

2 Stroke diesels working hard

YouTube - class 66 coal train being banked up Lickey Incline (http://www.youtube.com/watch?v=_R0CJOjdWLs)

this is the engine all 140 litres of it!

EMD 710 - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/EMD_710)

They use the 12 cylinder version set to 3000 BHP

Oh and Mr D's Deltic from earlier in the thread

YouTube - 55022: Climb from Dalmally (http://www.youtube.com/watch?v=JF_69KD2CCM&feature=related)

But not a patch on these

YouTube - 2968-7325 on the Lickey Incline (http://www.youtube.com/watch?v=QpQSFMK3F80&feature=related)

West Lakes.

Love it.

AND, you saved the best for last.

Of course, a steam engine, like the ones in WL's last clip were two-stroke (well, double acting really, I suppose.... :8)

TRC

Ah two strokes! Try this one for size!

http://images.dmldirect.com/bookstore/i/8729.jpg

My wife bought one of these little gems new in 1976 and she drove it every day for more than 20 years! She kept it in perfect condition and it went to a good home. It had the big 358 engine (thats 'cc' not cu in!) and would cruise comfortably at 120 kilometres per hour and would go around corners like they were not even there!

A slight drift those fond of the smell of R 40 should head for Aberdare park road races this weekend the sight and sound of Classic bikes being thrashed around the flower beds and the smell of Castrol in the air you can't beat it.

Back to thread the Science museum at Wroughton has a good collection of Aero engines including some Junkers Jumo's which were IIRC two stroke diesels.

In the strange but true department, a while ago I loaned some kit to a University department who were experimenting with spark ignition diesel engines and compression ignition petrol engines. :uhoh:

Davaar, yes it was my little joke. ;)

Like the one about the chap who went to buy an adjustable spanner.

"Metric, or AF, sir?" was always the question asked.

(They don't understand that joke in B&Q these days, they go and look for a grown-up who might know).

But I'm with you, Shy, I'm with you, and I can work out a square root with no aids beyond a pencil and piece of paper. No log tables or wee computers for me.

I had a 1937 MG VA tourer in the 1960s.
I decided to replace the clutch (and fit new bolts holding the pressure-plate to the flywheel).
None of my considerable selection of bolts fitted.
I took a sample bolt to a specialist supplier of 'fixings' (We R Nutz).
I took along my micrometer and my vernier caliper.
Several different standard bolts (BSF, BSW, BA, ANF, UNF and UNC) were tried but none of them matched. Thread tables were consulted, but none of the expected standards offered 25½ threads per inch. The closest was 25.4 TPI, but the head-size didn't match the sample, however it seemed the only option.
The 'Morris' engine (modified by Morris Garages - or MG) transpired to be a Hotchkiss design (which used metric threads, but BSF heads on the fixings) :ugh:
The Hotchkiss factory was equipped with French machinery using metric units and so the Morris engine and gearbox was built with all measurements in metric. The only concession was that the spanner sizes for nuts and bolts would be BSF/BSW, no doubt so as not to upset the motor mechanics who would be servicing the cars!.

Whitworth threads differ from all others in the shape of the thread (rounded ridge and valley IIRC) so even if you have a bolt, or nut, of the same diameter and pitch it wont 'fit'.

BTW, 'mongrel' bolts with metric threads and imperial heads are still being made in distant outposts of the former British Empire.

[QUOTE][the smell of Castrol in the air you can't beat it. /QUOTE]
... same goes for speedway tracks (that's dirt track motosickles for our US cousins) ....

That's just evoked memories of an AVRO 504K being started!

The main difference between Whitworth and other thread forms is the flank angle. Whitworth threads are 55°, Unified and ISO threads are 60°.
There are also pitch differences. However there are certain sizes which are close enough to allow cheaper low tolerance items to be gashed together. Somewhere I have a bodgers get you home list that gives a cross index of thread and spanner sizes which are a near enough in an emergency to get you out of a hole. :}

Although it's absolutley no use at all on an Auster which has the worlds supply of 64th AF nut sizes. :ugh:

A fairly large two-stroke diesel engine :

YouTube - 2 stroke container ship engine (http://www.youtube.com/watch?v=7JpIdkehdD0)

(It probably produces 20-30 times more power than a deltic engine)

PPR D:
It probably produces 20-30 times more power than a deltic engine

A Deltic engine does not produce power, it produces frustrated ship engineers and an abundance of broken parts.
I was offered a free Deltic training course while doing my compulsary military service in the Norwegian Navy way back in the dark ages. I was at the time thankfully already an engineer in the Merchant Navy and knew enough to politely decline. Others didn't and suffered the consequences. :eek:
Per

V4X Stirling Autmotive Engine (http://www.vok.lth.se/~ce/Research/stirling/papers/ST_TA2_1.pdf) :cool::cool:

As an off thread bit of trivia, I believe that the Whitworth form was designed to be disassembled and reassembled a number of times whereas the NC and NF forms were not. Good thing too, given the reliability of Brit machinery.

After an excellent landing you can use the airplane again.

Part of the standard(s) for fixing bolts, apart from details of the thread form, are dimensions of the head (imagine not having any standards for spanner sizes).
A (motor industry) work colleague sat on an industry committee where such things were discussed, decided and fixed. The members had proposed a form for bolt heads and nuts when one of the previously silent participants announced that the proposals 'were not acceptable'. When asked to explain his objections, he replied that such dimensions 'were not climbable'. This stumped the other members (from various branches of manufacturing from electronics through automotive to 'heavy' engineering), so further clarification was demanded. He explained that his business was the construction of very large structures, and the riggers and maintenance crews relied upon standing on the heads of the bolts and nuts for access rather than having to provide permanent climbing facilities.
He got his way . . .

A (motor industry) work colleague sat on an industry committee where such things were discussed Is that what they call a talk torque shop? Sorry, went off thread there for a second, I hope I haven't wound anybody up....

Part of the standard(s) for fixing bolts...


Ah, yes - standards.

They're great, you can have SO many of them - AND - they can all be totally different from each other.

TRC

Gotta say I'm disappointed in you lot. Aviation web site an all and no body mentioned the Rolls Royce Crecy. 90° sleeve valve V-12 displacing 1593 cubic inches (26.1 Litres) 5.1 inch bore 6.5 inch stroke direct fuel injection.