R.R.merlin,Jumo 210,BMW 139 which was most reliable

It is no accident that the Merlin has been the most successful Liquid cooled inline engine used in post war racing. By the end of its development it was as bullet proof as current technology could make it. Part of how the Merlin got to this position can be explained by the excellent supercharging and associated parts of the intake system that all work together to take advantage of the supercharger. Having provided the means of producing more power the mechanical engineers rigorously strengthened every component. This is the essence of how the engine became so strong. Of course it did not happen all at once.

Much myth surrounds the German fuel injection, but most people don’t understand how it worked or that it bore more relationship to a diesel engine fuel system than any modern type fuel injection system that all inject into the intake of the engine. The system used by Germany during the war on their large aero engines was a metered direct into the cylinder injection system. It suffered at times from poor atomisation and this lead to detonation and lower power levels. As boost pressures rose, these problems became more difficult to resolve.

The humble carburettor on the other hand worked by the low pressure on the intake drawing fuel into the engine. It was soon realised that the traditional float chamber type had some serious drawbacks in combat, but it had better mixture control and atomisation as the supercharger added agitation. The injection carburettor replaced the more traditional type and overcame the operational issues.

Again as boost pressure rose and 2 stage superchargers were used the process of injecting the fuel into the eye of the supercharger could lower the air/fuel change significantly lowering the detonation level and allowing more power to be produced. This was the very effect that MW50 had.

interesting information many thanks for posting it
regards vic

your suggesting that a carburrated engine is more efficient than a fuel injected unit?the intercooled fuel injection units operated very efficiently and had an exellent reliability record, the merlin went through several mods and i agree it was a most potent unit ,however they did suffer in battle and ive seen plenty of battle used examples with blocks destroyed by the shock loading factor whilst most of the german units id examined seemed to fair better absorbing more damage, i dont intend to get into a merlin v the rest scenario but these engines werent blessed by god as it were, nor were the german units:cool: 😎 😎

It is no accident that the Merlin has been the most successful Liquid cooled inline engine used in post war racing. By the end of its development it was as bullet proof as current technology could make it. Part of how the Merlin got to this position can be explained by the excellent supercharging and associated parts of the intake system that all work together to take advantage of the supercharger. Having provided the means of producing more power the mechanical engineers rigorously strengthened every component. This is the essence of how the engine became so strong. Of course it did not happen all at once.

Much myth surrounds the German fuel injection, but most people don’t understand how it worked or that it bore more relationship to a diesel engine fuel system than any modern type fuel injection system that all inject into the intake of the engine. The system used by Germany during the war on their large aero engines was a metered direct into the cylinder injection system. It suffered at times from poor atomisation and this lead to detonation and lower power levels. As boost pressures rose, these problems became more difficult to resolve.

The humble carburettor on the other hand worked by the low pressure on the intake drawing fuel into the engine. It was soon realised that the traditional float chamber type had some serious drawbacks in combat, but it had better mixture control and atomisation as the supercharger added agitation. The injection carburettor replaced the more traditional type and overcame the operational issues.

Again as boost pressure rose and 2 stage superchargers were used the process of injecting the fuel into the eye of the supercharger could lower the air/fuel change significantly lowering the detonation level and allowing more power to be produced. This was the very effect that MW50 had.

your suggesting that a carburrated engine is more efficient than a fuel injected unit?the intercooled fuel injection units operated very efficiently and had an exellent reliability record, the merlin went through several mods and i agree it was a most potent unit ,however they did suffer in battle and ive seen plenty of battle used examples with blocks destroyed by the shock loading factor whilst most of the german units id examined seemed to fair better absorbing more damage, i dont intend to get into a merlin v the rest scenario but these engines werent blessed by god as it were, nor were the german units:cool: 😎 😎

The Merlin was also fitted with an intercooler and an injection carburettor in later marks (60 series onwards)

The Merlin was 27 litres. It was the smallest capacity front line combat engine of the war. It started at 950hp, just, flew the Battle of Britain at 1300hp, by 43 it was at 1600hp and 2000hp reliably by June 44. In 44 it was cleared to 2200hp but not require at this power. These figures alone are not matched by any other engine.

The DB605 at 35 litres was the size of the Griffon, yet never matched the Merlin, and was way off what the 36 litre Sabre regularly ran at. The 605 was beset with lubrication issues as well as deficiency’s with its fuel system. Perhaps the Jumo 213 would have been the best German fighter engine but it was originally developed for bombers and the war had ended before its more advanced versions were produced in meaningful numbers.

The BMW 801 was roughly the same size as the R2600 and a bit larger than the Bristol Hercules. Again the 801 was not seen to be racing ahead of the other 14 cylinder radials on the block.

Forget the nonsense spoken about direct fuel injection. You lost as much as you gained and often more. One of the key features lost with the direct into the cylinder injection of the Germans was the important charge cooling they lost.

I don’t mean to burst the bubble but whilst the Germans had no end of good idea’s they did not have a monopoly on good ideas, and nor did they do the best job of getting all these ideas into effective production. War conditions had an obvious detrimental effect, but it doesn’t account for all that could have been done better.

your suggesting that a carburrated engine is more efficient than a fuel injected unit?the intercooled fuel injection units operated very efficiently and had an exellent reliability record, the merlin went through several mods and i agree it was a most potent unit ,however they did suffer in battle and ive seen plenty of battle used examples with blocks destroyed by the shock loading factor whilst most of the german units id examined seemed to fair better absorbing more damage, i dont intend to get into a merlin v the rest scenario but these engines werent blessed by god as it were, nor were the german units:cool: 😎 😎

Push a motor hard….

And from what I,ve read the Merlin would hold together longer.In battle the Radials would be the engine that would get you home with 3 cylinders shot off.Whereas a liquid cooled V12 would fail with a bullet hole through a coolant line.

The Merlin was 27 litres. It was the smallest capacity front line combat engine of the war. It started at 950hp, just, flew the Battle of Britain at 1300hp, by 43 it was at 1600hp and 2000hp reliably by June 44. In 44 it was cleared to 2200hp but not require at this power. These figures alone are not matched by any other engine.

The DB605 at 35 litres was the size of the Griffon, yet never matched the Merlin, and was way off what the 36 litre Sabre regularly ran at. The 605 was beset with lubrication issues as well as deficiency’s with its fuel system. Perhaps the Jumo 213 would have been the best German fighter engine but it was originally developed for bombers and the war had ended before its more advanced versions were produced in meaningful numbers.

The BMW 801 was roughly the same size as the R2600 and a bit larger than the Bristol Hercules. Again the 801 was not seen to be racing ahead of the other 14 cylinder radials on the block.

Forget the nonsense spoken about direct fuel injection. You lost as much as you gained and often more. One of the key features lost with the direct into the cylinder injection of the Germans was the important charge cooling they lost.

I don’t mean to burst the bubble but whilst the Germans had no end of good idea’s they did not have a monopoly on good ideas, and nor did they do the best job of getting all these ideas into effective production. War conditions had an obvious detrimental effect, but it doesn’t account for all that could have been done better.

But hardly a candidate for a ‘reliability’ comparison.

We should also add the Jumo 213 as an engine for the Fw190 if we a making a comparison of these fighters and the success and reliability of their various engines. 🙂

go for it why not

By the way the BMW139 powered the prototype FW190…

But hardly a candidate for a ‘reliability’ comparison.

We should also add the Jumo 213 as an engine for the Fw190 if we a making a comparison of these fighters and the success and reliability of their various engines. 🙂

No matter how partisan you are there is only one answer. RR Merlin. By the way the BMW139 powered the prototype FW190, but was bigger and heavier than the newer 801

didnt the merlin lack fuel injection ? and i know later marques improved performance but all in all i feel the british aero engines fell behind german technology, i appreciate their jet engines were somewhat unreliable ie. 262 /arado but overall their enginerering prowess outshone ours,dont forget their tech boys had day and night bombing to contend with but still produced the goods,i consider the FW 190 the ultimate ww2 fighter plane despite its heavier powerplant,its clean lines and superb handling outclassed the spit/hurricane Galland rated the aircraft and his opinion will certainly “do for me”:cool: 😎

Engines

No matter how partisan you are there is only one answer. RR Merlin. By the way the BMW139 powered the prototype FW190, but was bigger and heavier than the newer 801

Aren’t you getting your engines a bit mixed up?

Surely you mean the Merlin/Griffon, the DB601/DB605 and the BMW801?

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