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Also preferably a motorkannone shaft from the start.
If the evolution of the DB-605 is mimicked, then this Jumo-213 should be quite a lot lighter that the OTL design, maybe around 800 or not much over kg? So it's lower power will in part be compensated by lower weight. Possibly if used on FW-190D it may not need the fuselage extension, thus easing design and production?
It was the 4mm change in bore that 'helped' Screw the DB 605 up for while.
I was going by the example of the planned FW-190C-1 which it seems it didn't have the fuselage extension. Though it may be that they would have found out they need the fuselage extension if the 190C-1 was produced.While lighter than the historical 213, it's still a long engine, so unclear whether the fuselage extension can be omitted. What if the motor cannon is omitted in addition to the cowl MG's, would that allow the engine to be mounted further back, improving balance?
And, if omitting the motor cannon, what about using the motor cannon tube for the engine air intake and filters? That would get rid of the need to have the air intake sticking out in the airflow as in the historical FW190D or Bf 109. Would need to reposition the SC though.
Without the motor cannon nor cowl MG's, only two MG 151/20's in the wing roots is a bit weak. So keep the wing mounted MG-FF's from the FW 190A.
I was going by the example of the planned FW-190C-1 which it seems it didn't have the fuselage extension. Though it may be that they would have found out they need the fuselage extension if the 190C-1 was produced.
Both the OTL Jumo-213 (2,26m) and DB-603 (2,6m) are considerably longer than the Jumo-211 (1,74m), so since this TL supposes relatively few changes to the basic Jumo-211, the length should remain about the same? This coupled with the expected lower weight, say 100kg less than OTL, should alleviate any changes needed to the airframe or altering the armament, other than dropping in the inline power egg. So there will be little disruption to production. That's the idea anyway.
Imo removing the cowl guns is only worth it if a motorkannone can be fitted instead, so the armament will be either 3 x MG-151, or 1x MK-108 and two MG-151s.
They did try the tunnel intake as you suggest on FW-190V13 with the DB-603, it didn't work, reduced the ram and critical altitude way too much. So they got back to the external intake.
I have seen claims of piston failures or burnt pistons, could be wrong. Since one of temporary fixes was to reduce the manifold pressure from 1.42 to 1.30 that may not have been bearing problem. Again I could be wrong but I would think for a bearing problem you would limit the rpm?I thought it was largely the switch from ball bearings to plain bearings, as well as the switch to the 'sparmetall' valves that were the main issues with the initial 605? Both introduced to alleviate material and component shortages, and only incidentally introduced at the same time as the bored out cylinders?
DB messed, and messed big time by not employing the oil de-aerator and by not employing the central lubrication via the crankshaft that starts on the end of a crankshaft. That left the lubrication at higher revs to be insufficient.I have seen claims of piston failures or burnt pistons, could be wrong. Since one of temporary fixes was to reduce the manifold pressure from 1.42 to 1.30 that may not have been bearing problem. Again I could be wrong but I would think for a bearing problem you would limit the rpm?
Both the OTL Jumo-213 (2,26m) and DB-603 (2,6m) are considerably longer than the Jumo-211 (1,74m), so since this TL supposes relatively few changes to the basic Jumo-211, the length should remain about the same? This coupled with the expected lower weight, say 100kg less than OTL, should alleviate any changes needed to the airframe or altering the armament, other than dropping in the inline power egg. So there will be little disruption to production. That's the idea anyway.
I have seen claims of piston failures or burnt pistons, could be wrong. Since one of temporary fixes was to reduce the manifold pressure from 1.42 to 1.30 that may not have been bearing problem. Again I could be wrong but I would think for a bearing problem you would limit the rpm?
Things don't always go according to plan but plain bearings usually stand up to higher impact loads better than roller bearings. Assumes that your plain bearings are good to begin with though.
DB messed, and messed big time by not employing the oil de-aerator and by not employing the central lubrication via the crankshaft that starts on the end of a crankshaft. That left the lubrication at higher revs to be insufficient.
Corroding valves, again at high settings, were a cause of premature detonations, that were wrecking the pistons. Valves were corroding since they were not coated by some resistant material, like stellite (needs cobalt) or nickel.
It took retrofit of the oil system with a better one (basically a copy of what Junkers was doing several years prior?), and introduction of chrome-plated valves in order for the DB engines work reliably on the 'book' settings from 1942 (but now we're in late 1943, and air war is as good as lost).
DB was proudly noting the presence of the oil de-aerator on the data sheets of their engines in 1944-45.
DB 605A was not the only DB engine that was bad when run at 'book' settings, the DB 603A was also unreliable in 1943.
About the DB-601E as i understand it was cleared for full power as of spring 1942, so presumably it didn't have the kind of issues the 605 had, but did it have valve problems as well? If not, why not, were it's valves made with better materials?
PS: were the DB-603 reliability issues the same as for the 605, ie with oil system, valves, spark plugs etc.?
They did try the tunnel intake as you suggest on FW-190V13 with the DB-603, it didn't work, reduced the ram and critical altitude way too much. So they got back to the external intake.
As for the tunnel intake, that's interesting they tested it and it didn't work for them. Seems there's no fundamental issue with the approach, as long intakes going from the nose to behind the engine were successfully used e.g. on the P-40 and P-51?
Fair enough.I've took a peek on the actual and relative dimensions of the ram air intake. Already eyeballing it here shows that the tunnel for the motor cannon was of a too small cross section, especially when aimed for the high-altitude engines where any restriction of the airflow is not wanted, period.
IIRC the pre-set internal diameter of the tunnel for motor-cannon installation was 70mm, while the diameter inducer of the impeller on the DB 601E was some 150 mm (the widest, outer diameter was 260mm) - that is less than more than 4 times the cross section required. Basically, even the modest engine, like the 601E, will be starved for air if the fresh air is to be routed via the tunnel, let alone some more capable engine like the Jumo 213, where the 213A was with roughly 150 x 250 mm cross section at the ram air intake.
Correct me if i'm wrong, but my understand is the V13 intake was an aperture in the oil cooler then running on the side of the engine under the cowling to the impeller. sort of like on Ju-88? Nothing to do with the motorkannone tunnel.I've took a peek on the actual and relative dimensions of the ram air intake. Already eyeballing it here shows that the tunnel for the motor cannon was of a too small cross section, especially when aimed for the high-altitude engines where any restriction of the airflow is not wanted, period.
IIRC the pre-set internal diameter of the tunnel for motor-cannon installation was 70mm, while the diameter inducer of the impeller on the DB 601E was some 150 mm (the widest, outer diameter was 260mm) - that is less than more than 4 times the cross section required. Basically, even the modest engine, like the 601E, will be starved for air if the fresh air is to be routed via the tunnel, let alone some more capable engine like the Jumo 213, where the 213A was with roughly 150 x 250 mm cross section at the ram air intake.