Engine idle

Forever, Britain's most cherished Crown Jewel
new reply
User avatar
LZ-WIL
Master Sergeant
Posts: 1370
Joined: 23 Jun 2015, 13:59
Location: LBSF

Engine idle

Post by LZ-WIL »

Hello,

In Spitfire Mk.I, it seems engine cannot idle well with fully closed throttle. When I pull back the throttle and close it, engine starts to cough, stutter and puff black smoke from unburnt fuel. I've been left stranded at the end of the runway multiple times after landing, where I left the engine to idle for too long during ground roll. :shock: Is this normal for those early Merlin engines :?:

Cheerz,
Will
Bonanza, Skylane, Skyhawk, Cherokee, Cub, Texan, Mustang, Warhawk, Spitfire, Flying Fortress

User avatar
Piper_EEWL
Chief Master Sergeant
Posts: 4544
Joined: 26 Nov 2014, 14:14
Location: Germany

Re: Engine idle

Post by Piper_EEWL »

Mine has the same behavior and especially with the fixed pitch prop it’s hard to keep the engine running at roll out. But I seem to recall that I either read it in the manual or the forums somewhere that this is absolutely normal an realistic behavior. What I do is raise the rpm ever so slightly that she won’t die on me at the end of the runway :wink:

Happy flying
B377&COTS, J3 Cub, B-17G, Spitfire, P-40, P-51D, C172, C182, Pa28, Pa24, T-6 Texan, L-049&COTS, Bonanza V35B

Tomas Linnet
Senior Master Sergeant
Posts: 2286
Joined: 05 Nov 2013, 10:48
Location: Oksboel, Denmark

Re: Engine idle

Post by Tomas Linnet »

As far as I know this is correct, simply don’t close the throttle completely.
Kind Regards
Tomas

Sim: FSX SE
Accu-Sim aircraft in my hangar:
C172, C182, P51 Civ, P51 Mil, B17, Spitfire, P47, B377 COTS,
J3 Cub, T6, Connie, P-40, V35B
A2A Accu-Sim Avro Lancaster Loading:............0.000003% complete, please wait.

User avatar
Killratio
A2A Spitfire Crew Chief
Posts: 5785
Joined: 29 Jul 2008, 23:41
Location: The South West of the large island off the north coast of Tasmania
Contact:

Re: Engine idle

Post by Killratio »

Hi Guys,

You should be able to close the throttle momentarily, while stationary, without the Merlin stopping but it
will complain horribly and you will oil up the plugs very quickly. This is exactly how the A2A engine behaves.

From the Spitfire I Manual
Clearing engine after prolonged slow running :- If the take-off is delayed for any reason, the engine should not be allowed to idle too slowly, and should be "cleared" by opening up to moderate r.p.m against the brakes, care being taken to hold the stick fully back, and not to raise the tail by opening up to too high a power. Ensure that the maximum temperature limit is not exceeded (120C).

regards

Darryl
Last edited by Killratio on 25 Apr 2018, 07:22, edited 3 times in total.
<Sent from my 1988 Sony Walkman with Dolby Noise Reduction and 24" earphone cord extension>


Image

User avatar
LZ-WIL
Master Sergeant
Posts: 1370
Joined: 23 Jun 2015, 13:59
Location: LBSF

Re: Engine idle

Post by LZ-WIL »

Thanks guys!
This is what I will do - put to full close (the throttle) and then open it a bit. The problem is I got too distracted with the radiator on landing and by the time the speed bleeds off - the engine is dead too. That is a part of piloting skills I guess - not to get distracted and stay focused on your duties as a pilot. 8)

Cheerz,
Will
Bonanza, Skylane, Skyhawk, Cherokee, Cub, Texan, Mustang, Warhawk, Spitfire, Flying Fortress

User avatar
Killratio
A2A Spitfire Crew Chief
Posts: 5785
Joined: 29 Jul 2008, 23:41
Location: The South West of the large island off the north coast of Tasmania
Contact:

Re: Engine idle

Post by Killratio »

Yes, but always remember not to panic too much if you boil for a bit when you do land and taxi back.... even the best do that ... (well, maybe not ME :) :) :) )

I heard a great comment by one of the old ATA female pilots the other day, who described the Spitfire as a "Lady in the air..but a Bitch on the ground"

I nearly wet myself :)

BTW, if you ever get the chance to see the documentary "Secret Spitfires" take it!! It is about the production dispersal after Eastleigh got bombed.
<Sent from my 1988 Sony Walkman with Dolby Noise Reduction and 24" earphone cord extension>


Image

User avatar
LZ-WIL
Master Sergeant
Posts: 1370
Joined: 23 Jun 2015, 13:59
Location: LBSF

Re: Engine idle

Post by LZ-WIL »

I am reading the Spit manual for the second time as I saw your post Daryl. I guess one needs to refresh their knowledge after GA flying. :mrgreen:
From the Spitfire I Manual
Clearing engine after prolonged slow running :- If the take-off is delayed for any reason, the engine should not be allowed to idle too slowly, and should be "cleared" by opening up to moderate r.p.m against the brakes, care being taken to hold the stick fully back, and not to raise the tail by opening up to too high a power. Ensure that the maximum temperature limit is not exceeded (120C).
:wink:

Cheerz,
Will
Bonanza, Skylane, Skyhawk, Cherokee, Cub, Texan, Mustang, Warhawk, Spitfire, Flying Fortress

User avatar
Oracle427
Chief Master Sergeant
Posts: 3916
Joined: 02 Sep 2013, 19:30
Location: 3N6
Contact:

Re: Engine idle

Post by Oracle427 »

The exact same procedures apply to any piston powered aircraft. Idling at minimum rpm is going to cause lots of troubles, and idling in general can result in overheating, fouling, electrical discharge. One had to shift gears mentally and pay attention. Prior to flight, it is best to check everything to ensure that the engine is ready for flight.
Flight Simmer since 1983. PP ASEL IR Tailwheel
N28021 1979 Super Viking 17-30A

User avatar
LZ-WIL
Master Sergeant
Posts: 1370
Joined: 23 Jun 2015, 13:59
Location: LBSF

Re: Engine idle

Post by LZ-WIL »

Oracle427 wrote:The exact same procedures apply to any piston powered aircraft. Idling at minimum rpm is going to cause lots of troubles, and idling in general can result in overheating, fouling, electrical discharge. One had to shift gears mentally and pay attention. Prior to flight, it is best to check everything to ensure that the engine is ready for flight.
Hi,

I was mentioning this since after run up, some checklists suggest to idle the throttle and see how engine behaves. In example the Mustang, the Cessnas and the Cherokee along with the Cub and the T-6 do not tend to quit while in idle for several seconds, but hold steady low rpm.
On the other hand the Spit's Merlin engine doesn't seem to like throttle idle even for the shortest time. :)

Cheerz,
Will
Bonanza, Skylane, Skyhawk, Cherokee, Cub, Texan, Mustang, Warhawk, Spitfire, Flying Fortress

User avatar
bladerunner900
Senior Master Sergeant
Posts: 1991
Joined: 17 Aug 2008, 14:59
Location: South Wales

Re: Engine idle

Post by bladerunner900 »

Had a motorcycle in the 80s that refused to idle. Very cammy engine. It needed constant blipping to keep her going when at a standstill. I use a similar but slower technique with the Spitfire. Easy when you get to know her. :wink:

Steve.

User avatar
Piper_EEWL
Chief Master Sergeant
Posts: 4544
Joined: 26 Nov 2014, 14:14
Location: Germany

Re: Engine idle

Post by Piper_EEWL »

LZ-WIL wrote:
Oracle427 wrote:The exact same procedures apply to any piston powered aircraft. Idling at minimum rpm is going to cause lots of troubles, and idling in general can result in overheating, fouling, electrical discharge. One had to shift gears mentally and pay attention. Prior to flight, it is best to check everything to ensure that the engine is ready for flight.
Hi,

I was mentioning this since after run up, some checklists suggest to idle the throttle and see how engine behaves. In example the Mustang, the Cessnas and the Cherokee along with the Cub and the T-6 do not tend to quit while in idle for several seconds, but hold steady low rpm.
On the other hand the Spit's Merlin engine doesn't seem to like throttle idle even for the shortest time. :)

Cheerz,
Will
Yes this is done to check if the engine has a proper idle rpm. If the idle is too high with the throttle pulled all the way out you’ll have trouble getting a short flare sinc ethe engine will provide some power. But you only check and then raise the rpm back to 800-1000pm on most GA aircraft. It’s different than in cars since in a car you’ll have a clutch to disconnect the drive train from the engine.

Happy flying
B377&COTS, J3 Cub, B-17G, Spitfire, P-40, P-51D, C172, C182, Pa28, Pa24, T-6 Texan, L-049&COTS, Bonanza V35B

User avatar
ratty
Technical Sergeant
Posts: 896
Joined: 29 Oct 2013, 21:08
Location: KPMP

Re: Engine idle

Post by ratty »

The lowest throttle setting a car needs is "Idle". The lowest throttle setting an aeroplane needs is "Minimum Thrust", which is lower than idle.
Image

new reply

Return to “Spitfire MkI/II”

Who is online

Users browsing this forum: No registered users and 7 guests