For those who are interested, I recently saw this video of a 109 recovery on youtube and noticed the large Warning sign painted onto the side of the DB605.
The sign states:
“Achtung Zündfolge”
1-11-2-9-4-7-6-8-5-10-3-12
Which translates as:
“Attention Firing order”
1-11-2-9-4-7-6-8-5-10-3-12
What this shows is that the motor had a non standard firing order as the firing order should be:
1-8-5-10-3-7-6-11-2-9-4-12
After showing the video to my father he noted that the firing order for this engine is the firing order the DB605W,X DB610A,B double engines (from the He177, two DB605s stuck together) which shows this engine used the Crankshaft,Camshafts, fuel injection piping and magneto wiring from the DB605W,X DB610A,B engines instead of standard 605 parts and had to be marked up as such to stop it from being accidentally damaged by mechanics during maintenance in case they thought it was a standard DB605.
He had long since suspected that the germans used up the crankshafts and camshafts from these engines in standard 605’s and so this video appears to prove it!
It would be very interesting to see the data plate for this engine and see what it is designated as, anyone speak polish???
Matt
Photo of the type of engine the Parts for this 605 came out of!
DB610
By: Creaking Door - 9th December 2011 at 18:11
“Attention Firing order”
1-11-2-9-4-7-6-8-5-10-3-12
I can make this non-standard DB605 firing-order work too with the ‘standard’ crankshaft (but not with a mirrored crankshaft); is the crankshaft definitely different or is it just the camshafts, injection pump and so on?
By: Creaking Door - 9th December 2011 at 17:29
Thanks for posting the cylinder numbering for the DB605; I wouldn’t have guessed at that system!
After a few fundamental errors, wrong numbering system, wrong crank-journal numbering (forgot that changed too :rolleyes:) and trying it with a 120° angle between banks (oops! :o) I can now make the standard DB605 firing-order work!
Now for that other order.
By: Augsburgeagle - 9th December 2011 at 14:45
Hi,
The firing order for the 610 was chosen during development to minimise resonance and other undesirable effects in the engine as Merlin3945 states, likewise with the order for the 605. It would appear that the Germans felt that the loss in efficiency and increase in vibration etc. was outweighed by the saving in resources from the use of these parts in the 605.
By: Creaking Door - 9th December 2011 at 14:09
…as the firing order should be:
1-8-5-10-3-7-6-11-2-9-4-12
I can’t even get this to work for a DB605!!! :confused:
How are the cylinders numbered on a DB605; Left-bank-odd-numbers / right-bank-even-numbers, lowest number to front?
By: Creaking Door - 9th December 2011 at 13:08
There are a number of combinations an engine can run with but not all of them would perform well…
I wouldn’t say a vast number for a V-12 engine, or any other engine for that matter; I’d say there were very few viable firing orders for any engine configuration without resorting to an unnecessarily complex crankshaft arrangement. I agree with your other statements.
Logically if the crankshaft is different, as the original post states, and the firing order is different, for a DB605W in a Bf109, and yet the propeller turns the same way as a conventional Bf109 then surely the ‘normal’ DB605 firing-order will run the engine backwards…
…I think? :confused:
I’m going to have to break-out the patent ‘crank-o-meter’ again!!! 😀
By: Merlin3945 - 9th December 2011 at 12:56
As long as the firing order keeps to a resonable opposite effect order (there are a few exceptions) then the engine will run. The firing order is designed to get the smoothest running and optimal performance out of the engine. Basically ballancing the engine so it does not shake itself apart.
There are a number of combinations an engine can run with but not all of them would perform well. There are also other things to consider like cams and valves etc. Changing one aspect of the sequence causes an effect on the rest of the comonents in the chain. Some would either need to be modified and changed entirely.
By: danjama - 9th December 2011 at 02:59
I think the firing order would be decided by what is necessary to keep an even load on the crankshaft/s and other components. (although I could be very wrong).
By: Creaking Door - 9th December 2011 at 02:29
Why does the DB610 engine require a DB605 with a different firing order? Different direction of rotation? I know that the two propellers on an He177 turned in different directions but I understood that the different engines (DB610A and DB610B?) had two similar DB605 components and all four DB605 turned in the same direction; the different propeller rotations being achieved with different gearboxes (with additional idler gears in one gearbox).
Or am I getting confused with the DB606 / DB601 of the earlier He177? :confused:
By: smirky - 9th December 2011 at 00:08
My first BMW car had a similar notice cast into the rocker cover 🙂
By: Creaking Door - 8th December 2011 at 23:32
But the crank still turns the same way in the Bf109 with this engine?
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December 8, 2011 at 8:52 pm