DB vs Merlin vs ?? - Aircraft of World War II

schwarzpanzer · 10-25-2005, 04:20 AM

All the top engines used in WW2.

Which would you have?

What would you change?

BTW: What was the equivalent Russian engine?

Jabberwocky · 10-25-2005, 06:07 AM

The Klimov M-105P/PF and M-107A were the Russian equavilents of the RR and DB liquid cooled engine serise. They were based on the Hispano-Suiza V12 designs from the early 1930s. Also know as the VK-105 and VK-107.

M-105P put out about 13o0 hp at sea level, about 1200 at 2500 and about 1000 at 4000m. It dropped off sharply after that

M-107A put out about 1550-1650 hp at sea level to 2 km, and about 1450 at 3800m.

I am a British aviation fan so I am biased, but I would have to say its really a toss up between the two engines. Each has their own pluses and minuses. I think that the Merlins biggest advantage was in the ability to tailor the supercharger and compression ratios so easily, usually giving them a performance advantage at altitude. The DB family was much larger in cubic engine capacity (36 liters vs 27 litres) and when British engineers got their hands on a few captured DB 601s during the Battle of France they were suprised at how little power the Germans were getting out of engines with 1/3 greater capacity than the Merlin.

It's unfair to compare the whole DB601/605/603 family to the Merlin serise alone. Better to compare the DB engines to the Merlin and the Griffon, which had a similar capacity. The DB 601 is really the counterpart to the single stage Merlins (Merlin 40 family), the DB-605 the counterpart to the two stage Merlins (Merlin 60 family) and Griffon.

Invariably, its probably going to come down to personal preference rather than any shining, clear out winner. The engines see-sawed back and forth so much in terms of power advantage during the war that deciding on a conclusive answer is difficult. Generally speaking the DB-605 was superior to the Merlin 60 family at low altitudes. At medium altitudes they swapped back and forth between powerbands. At high altitudes the Merlin is generally seen as the better engine.

Sal Monella · 10-25-2005, 12:01 PM

Pratt & Whitney R-2800-59 rated at 2,430hp.

Late war models came in at 2,800hp.

Takes a licking and keeps on ticking.

FLYBOYJ · 10-25-2005, 12:09 PM

Quote:

Originally Posted by Sal Monella

Pratt & Whitney R-2800-59 rated at 2,430hp.

Late war models came in at 2,800hp.

Takes a licking and keeps on ticking.

Yep! And no Glycol!

evangilder · 10-25-2005, 12:15 PM

The 2800 rocks!

Gnomey · 10-25-2005, 12:25 PM

Quote:

Originally Posted by evangilder

The 2800 rocks!

Yep it does! I like the Merlin's and Griffons as well though.

evangilder · 10-25-2005, 12:56 PM

Me too. I just see more of the 2800s where I am.

Jabberwocky · 10-25-2005, 07:31 PM

The Packard Merlin V-1650-9 in the P-51H was rated at 2220 hp. Not too shabby for an engine with only 55% of the cubic capacity of the R-2800. At 28 lbs boost the standard Merlin 66 was putting out about 2180 hp with 150 octane avgas ("purple passion"). Rolls Royce even got a Merlin up to 2,310 hp and 30 lbs boost in July 1943 by use of additives in the petrol.

Sal Monella · 10-25-2005, 08:05 PM

Yes but the late war P&W R-2800 that was stuffed into the P-47 M and N models and was rated at 2,800hp could literally generate 2,800hp at 32,000ft though.

cheddar cheese · 10-26-2005, 08:29 AM

Fiat RA 1050 R.C.58

the lancaster kicks ass · 10-26-2005, 08:52 AM

i don't think we shoould compare inlines like the merlin and DB to radials like the R-2800.........

Piaggio108 · 10-26-2005, 09:06 AM

Quote:

Originally Posted by cheddar cheese

Fiat RA 1050 R.C.58

Was there any difference between the RA 1040 R.C.58 and the DB605A-1? I don't have much information on italian engines, but there doesn't seem to be any difference in HP, so it can't have changed much, if any.

cheddar cheese · 10-26-2005, 09:26 AM

I dont think so - The RA.1050 was just the license built DB-605. They probably are almost identical; I'd look up some information on them but I dont have the time right now.

schwarzpanzer · 10-26-2005, 10:06 PM

Well to be honest, I was trying to avoid discussing radials, but what the heck.

I'm confused as the DB605 has advantages/disadvantages that are reversed for modern car engines, e.g:

It was a square engine for WW2 - Good for high RPM's, but never saw above 3000rpm?

Direct Fuel Injection (Kugelfischer?) - bad for high rpm, but reversion is undesirable in plane engines is it?

It has things that are interesting i.e the viscous supercharger Lunatic mentioned.

How does it being inverted help handling?
Surely CG doesn't matter in the air?

- I'm outta my depth here.

Jabberwocky · 10-26-2005, 11:36 PM

Lets discuss the Napier Sabre instead!

The Sabre IIc could put out over 3000 hp at emergency overboost according to Closterman, and was fitted to or swapped into a number of Tempest Vs!

10-25-2005, 04:20 AM	#1
schwarzpanzer Senior Member Join Date: Aug 2005 Posts: 580	DB vs Merlin vs ?? All the top engines used in WW2. Which would you have? What would you change? BTW: What was the equivalent Russian engine? __________________ Like WW2 tanks? Then please visit the Panzer Front: http://p208.ezboard.com/bthepanzerfront

10-25-2005, 12:15 PM	#5
evangilder "Shooter" Join Date: Sep 2004 Location: Moorpark, CA Posts: 14,809	The 2800 rocks! __________________ http://www.vg-photo.com For once you have tasted flight you will walk the earth with your eyes turned skywards, for there you have been and there you will long to return. Leonardo Da Vinci

10-25-2005, 12:56 PM	#7
evangilder "Shooter" Join Date: Sep 2004 Location: Moorpark, CA Posts: 14,809	Me too. I just see more of the 2800s where I am. __________________ http://www.vg-photo.com For once you have tasted flight you will walk the earth with your eyes turned skywards, for there you have been and there you will long to return. Leonardo Da Vinci

10-26-2005, 08:52 AM	#11
the lancaster kicks ass Senior Member Join Date: Dec 2003 Posts: 19,945	i don't think we shoould compare inlines like the merlin and DB to radials like the R-2800......... __________________ "Reminds me of the time I sank the Tirpitz" comments a Spitfire pilot, "One pass of course, old boy."

10-26-2005, 10:06 PM	#14
schwarzpanzer Senior Member Join Date: Aug 2005 Posts: 580	Well to be honest, I was trying to avoid discussing radials, but what the heck. I'm confused as the DB605 has advantages/disadvantages that are reversed for modern car engines, e.g: It was a square engine for WW2 - Good for high RPM's, but never saw above 3000rpm? Direct Fuel Injection (Kugelfischer?) - bad for high rpm, but reversion is undesirable in plane engines is it? It has things that are interesting i.e the viscous supercharger Lunatic mentioned. How does it being inverted help handling? Surely CG doesn't matter in the air? - I'm outta my depth here. __________________ Like WW2 tanks? Then please visit the Panzer Front: http://p208.ezboard.com/bthepanzerfront

10-25-2005, 06:07 AM	#2
Jabberwocky Senior Member Join Date: Jul 2005 Location: Japan Posts: 494	The Klimov M-105P/PF and M-107A were the Russian equavilents of the RR and DB liquid cooled engine serise. They were based on the Hispano-Suiza V12 designs from the early 1930s. Also know as the VK-105 and VK-107. M-105P put out about 13o0 hp at sea level, about 1200 at 2500 and about 1000 at 4000m. It dropped off sharply after that M-107A put out about 1550-1650 hp at sea level to 2 km, and about 1450 at 3800m. I am a British aviation fan so I am biased, but I would have to say its really a toss up between the two engines. Each has their own pluses and minuses. I think that the Merlins biggest advantage was in the ability to tailor the supercharger and compression ratios so easily, usually giving them a performance advantage at altitude. The DB family was much larger in cubic engine capacity (36 liters vs 27 litres) and when British engineers got their hands on a few captured DB 601s during the Battle of France they were suprised at how little power the Germans were getting out of engines with 1/3 greater capacity than the Merlin. It's unfair to compare the whole DB601/605/603 family to the Merlin serise alone. Better to compare the DB engines to the Merlin and the Griffon, which had a similar capacity. The DB 601 is really the counterpart to the single stage Merlins (Merlin 40 family), the DB-605 the counterpart to the two stage Merlins (Merlin 60 family) and Griffon. Invariably, its probably going to come down to personal preference rather than any shining, clear out winner. The engines see-sawed back and forth so much in terms of power advantage during the war that deciding on a conclusive answer is difficult. Generally speaking the DB-605 was superior to the Merlin 60 family at low altitudes. At medium altitudes they swapped back and forth between powerbands. At high altitudes the Merlin is generally seen as the better engine.

10-25-2005, 12:01 PM	#3
Sal Monella Senior Member Join Date: Apr 2005 Location: Redwood City Posts: 223	Pratt & Whitney R-2800-59 rated at 2,430hp. Late war models came in at 2,800hp. Takes a licking and keeps on ticking.

10-25-2005, 07:31 PM	#8
Jabberwocky Senior Member Join Date: Jul 2005 Location: Japan Posts: 494	The Packard Merlin V-1650-9 in the P-51H was rated at 2220 hp. Not too shabby for an engine with only 55% of the cubic capacity of the R-2800. At 28 lbs boost the standard Merlin 66 was putting out about 2180 hp with 150 octane avgas ("purple passion"). Rolls Royce even got a Merlin up to 2,310 hp and 30 lbs boost in July 1943 by use of additives in the petrol.

10-25-2005, 08:05 PM	#9
Sal Monella Senior Member Join Date: Apr 2005 Location: Redwood City Posts: 223	Yes but the late war P&W R-2800 that was stuffed into the P-47 M and N models and was rated at 2,800hp could literally generate 2,800hp at 32,000ft though.

10-26-2005, 08:29 AM	#10
cheddar cheese Senior Member Join Date: Jan 2004 Location: WSM, England Posts: 20,387	Fiat RA 1050 R.C.58

10-26-2005, 09:26 AM	#13
cheddar cheese Senior Member Join Date: Jan 2004 Location: WSM, England Posts: 20,387	I dont think so - The RA.1050 was just the license built DB-605. They probably are almost identical; I'd look up some information on them but I dont have the time right now.

10-26-2005, 11:36 PM	#15
Jabberwocky Senior Member Join Date: Jul 2005 Location: Japan Posts: 494	Lets discuss the Napier Sabre instead! The Sabre IIc could put out over 3000 hp at emergency overboost according to Closterman, and was fitted to or swapped into a number of Tempest Vs!

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