Ops-Normal.org

Mrs Ex-Ascot wrote: ↑

Sat Apr 04, 2020 12:58 pm

Another clue; it normally withers away in early adulthood so normally speaking none of us have one any more.

I had one of those!

ribrash wrote: ↑

Sat Apr 04, 2020 1:02 pm

Thymus gland.

Ribrash to set the next challenge!

Which vitamin is the only one that you will not find in an egg?

Vitamin C which occurs in fruit and vegetables, whatever they are!

Correct Cape.The baton should reach you any second.

Thanks.
OH.

Next question:-

Explain the ignition system of a hot bulb engine.

John Hill wrote: ↑

Sat Apr 04, 2020 8:12 pm

Next question:-

Explain the ignition system of a hot bulb engine.

I'm more confused by Mazda's new 'spark-controlled compression ignition'.

BTW I dont believe some of the on-line descriptions of the hot bulb engine are correct.

What I meant to say..

BTW I dont believe all of the on-line descriptions of the hot bulb engine are correct.

Not much happening yet.

A hundred and 20 or so years ago big machines, trains and ships used the power of steam while the new-fangled horseless carriages relied on steam, electricity or the temperamental internal combustion engines burning petrol and similar fuels. Diesel was not yet on the scene but Hornsby-Akroyd and others were building hot bulb 'oil' engines which were extremely reliable and burned a variety of fuels including heavy oils and tallow.

These engines were employed on stationery duties driving all manner or machinery, pumps and generators etc. They were also used in a variety of small ships, canal boats and fishing boats. On land early heavy tractors (including the first tracked vehicle) were powered by the hot bulb engine.

Although these original engines were four strokes the famous Lanz Bulldog and Field Marshal tractors were two stroke versions of the same principal.

Starting a hot bulb engine requires the use of a blow lamp or similar to heat the 'hot bulb' to near red heat before turning the engine to start. Many tales have been told of farm boys swinging on the starting handles** of a 10 litre Lanz Bulldog and the excitement that could come with the first ignition.

**Actually the Lanz had a clever system where the steering wheel could be unlatched and moved to the side of the tractor where it engaged a dog on the crankshaft, the wheel gave excellent leverage and was much less likely to cause injury than a regular crank handle.

But how did the ignition system work?

P.S. Very early cars had a 'hot tube' ignition which was not the same as the hot bulb used on oil engines.

There was a Lanz Bulldog club near where I lived in Germany, when they took them out on a sunny Sunday in summer it was like an artillery barrage. Louder than the loudest thing you ever heard, but with the amp turned up to 11!

John, as you probably know they were in common use in dairies (& no doubt many other places)but I'd have to google or look at 50+ year old notes to answer your question.

Sunday night here, and I'm not sure I'ver seen a question in the past few posts, so if I may, from this weekends 'Weekend Australian' quiz -

Name two countries, four letters in length, that also have Capital cities that are four letters long. (There are acually Three, but the original question was for 2, the answers page gave the 3)

Peru & Lima
Fiji & Suva

OH

Correct Ian!, and I'm ashaned to say i got neither....but my somewhat 'blonde' Son did!!

However I did for some unknown reason did get TOGO & (Lome) ! ...... How I cannot tell!

Fliegenmong wrote: ↑

Sun Apr 05, 2020 1:01 pm

Correct Ian!, and I'm ashaned to say i got neither....but my somewhat 'blonde' Son did!!

However I did for some unknown reason did get TOGO & (Lome) ! ...... How I cannot tell!

I just got Google Earth up and eyeball scanned the countries, paused on the 4 letter ones and check the capitals.

Chad failed the test!

ian16th wrote: ↑

Sun Apr 05, 2020 1:18 pm

Fliegenmong wrote: ↑

Sun Apr 05, 2020 1:01 pm

Correct Ian!, and I'm ashaned to say i got neither....but my somewhat 'blonde' Son did!!

However I did for some unknown reason did get TOGO & (Lome) ! ...... How I cannot tell!

I just got Google Earth up and eyeball scanned the countries, paused on the 4 letter ones and check the capitals.

Chad failed the test!

I guess it was just hanging in there.

Ahem! It appears my question re the ignition process in a hot bulb engine has been cast aside unanswered, so here we go.

The hot bulb engine has a secondary chamber which is connected to the cylinder in which the piston moves. The hot bulb is usually(?) made of cast iron and positioned for easy pre-heating with the blow lamp.

The fuel is injected in to the hot bulb and the common misconception is that the fuel ignites when it comes in contact with the hot metal. This is not true and can be readily recognised when one learns the Lanz engines actually injects fuel during the INTAKE stroke. What happens is that the injected oil vaporises in the hot bulb but does not ignite due to there being insufficient oxygen in the bulb to support combustion. Later in the cycle when the piston is approaching top dead centre the level of oxygen in the bulb rises until ignition occurs and vigorous combustion begins.