Author Topic: Spit IX in AH has Merlin 61 (Read 785 times)

Dead Man Flying · « **Reply #15 on:** October 03, 2002, 09:14:37 PM »

Man, I hope they correct the Spit V soon! I'm tired of it outaccelerating, outclimbing, outdiving, and outrunning everything -- especially that crappy undermodelled Luftwaffe stuff.

-- Todd/Leviathn

Chanter · « **Reply #16 on:** October 03, 2002, 11:38:16 PM »

"heyya Taur, i was wondering what happend to you

I noticed that 416 attendance wasn't quite what it used to be..

So, when are you joining 308 ? "

Maybe once you guys put arrestor hooks on your planes

(416 is pretty much all here as 880 Fleet Air Arm now)

Squire · « **Reply #17 on:** October 04, 2002, 08:50:21 AM »

Its the Navy life for me now Ski!

Having fun with my new unit (click the link in the signature), and we are doing well in AH events. Im just glad we had a place to go to. As Chanter (Sniper) said we are all pretty much in 880 now from the old 416 crew, although a few have remained in Warbirds.

308 seems like a great bunch, I had the pleasure of flying in some of the TODs with them, most notably Malta. Good to see they have some CMs in the roster too.

Cya up sometime I hope!

Later

Wilbus · « **Reply #18 on:** October 04, 2002, 11:02:32 AM »

With Merlin 61 it means either it accelerates too fast or the 190 too slow. My guess is on the second.

Squire · « **Reply #19 on:** October 04, 2002, 05:35:41 PM »

I did a bit more digging, it seems there were Merlin 61 Spits operational past 1943, which makes sense since the RAF was still using Spitfire LF Vs in 1944. They wouldnt retire them prematurely for no reason.

94 Sqn Operated Spitfire IXs from Cyrenaica (Med Theater) in June 1944. Serial number "MA766" was a Merlin 61 Spitfire, the CO of the unit flew that one.

As for 18 boost, it seems there were times when it operated at that level (from Funkeds link) but I dont have any more data on that. I also dont know enough about engines to speculate.

As for 150 octane, it was available at some point, as to wether any Merlin 61s ever used it operationally, I dont know, but many Allied fighters did use it post 1944. Need more data.

Nashwan · « **Reply #20 on:** October 05, 2002, 06:30:59 AM »

Spitfire: the History has MA766 as a Merlin 63 aircraft.

There's more info on 150 octane usage at http://pub131.ezboard.com/fallboutwarfarefrm31.showMessage?topicID=535.topic

See also the links on page 2 of that thread.

As a sum up, all the Spit IXs in ADGB were using 150 octane from Spring 44, most of the rest of ADGB soon followed (Mossies etc). In July 44, Britain produced 40,000 tons of 150 octane, ADGB used 12,000 tons. ADGB usage fell off as the Germans retreated from France and Belgium.

2nd TAF switched to 150 octane in Jan 45. US 8th AF switched in the summer of 44, for all it's fighters. Mustangs at least switched back to 100/130 towards the end of the war.

In the RR documents on one of the links, it gives details for which engines can and can't benefit from 150 octane. The Merlin 61 isn't listed.

The description for the Merlin 63 (and a few others) is "These engines are a development of the Merlin 61 type, and are essentially high altitude engines. They have a strengthened supercharger drive which was introduced to permit the use of 21lbs boost pressure, and which is likely to be the main limitation to futher increases in boost pressure."

The Merlin 63 is listed as 18lbs on 100/130 ful, 21lbs on 100/150.

I don't think the Merlin 61 ever used more than 15lbs operationally, and that was probably down to the supercharger.

Note, on the link Funked posted, the Spit IX on 150 octane was performing poorly, about 20 mph slower on 18lbs boost than was usual for a Spit IX. Go to the Spit VIII page for a better idea of what a Spit IX on 150 octane should be capable of.

Squire · « **Reply #21 on:** October 05, 2002, 03:22:46 PM »

Cool, I appreciate the info on that! , I was looking everywhere for that kind of info. Yes, I double checked my book, it is a Merlin 63 Spitfire. I guess I was looking for "non Merlin 66s" that were used in 1944 anyways.

So 18lbs boost in a standard F. IX can be correct, for a Merlin 63 powered version.

I understand more Merlin 63/63As were in early F IXs than 61s?

Later.

Nashwan · « **Reply #22 on:** October 05, 2002, 04:25:11 PM »

Going from memory, the first 350 or so Spit IXs used the Merlin 61, then production switched to the 63, 66 and 70, for the F, LF and HF respectively.

Again from memory, I think around 1000 Fs were produced with the Merlin 63 and 63A, with around 3000 LFs, and a fairly small number of HFs.