World War II and the V-1710

Discussion in 'Aviation' started by Milosh, Sep 15, 2014.

Tags:
  1. Milosh

    Milosh Well-Known Member

    Joined:
    Aug 10, 2009
    Messages:
    1,919
    Likes Received:
    96
    Trophy Points:
    48
  2. KiwiBiggles

    KiwiBiggles Member

    Joined:
    Aug 3, 2008
    Messages:
    140
    Likes Received:
    15
    Trophy Points:
    18
    Gender:
    Male
    Occupation:
    Engineer
    Location:
    Grey Lynn
    Interesting. The photo of the B-42 installation is extraordinary. I hate to think how many harmonics you would have to deal with in a drive shaft that long.
     
  3. Stephan Wilkinson

    Stephan Wilkinson New Member

    Joined:
    Oct 20, 2007
    Messages:
    27
    Likes Received:
    1
    Trophy Points:
    3
    The artist's rendering under "P-38 With Radials Is a Bad Idea" is pretty amusing. The artist seems to have used mid-1930s DC-2 Wrights and cowlings as his radial ideals, while properly nacelled R-2800s were in fact very compact, small in diameter and of course powerful. "P-38 With R-2800s Is a Good Idea"?
     
  4. wuzak

    wuzak Well-Known Member

    Joined:
    Jun 5, 2011
    Messages:
    4,185
    Likes Received:
    167
    Trophy Points:
    63
    Location:
    Hobart Tasmania
    R-2800s weren't small in diameter. 52.5" over the engine.
     
  5. rogerwilko

    rogerwilko Member

    Joined:
    Mar 5, 2009
    Messages:
    102
    Likes Received:
    12
    Trophy Points:
    18
    I don't understand how the spark plug cooling arrangement works??
     
  6. Stephan Wilkinson

    Stephan Wilkinson New Member

    Joined:
    Oct 20, 2007
    Messages:
    27
    Likes Received:
    1
    Trophy Points:
    3
    They were a lot smaller than that single-bank radial in the artist's P-38 rendering.
     
  7. Shortround6

    Shortround6 Well-Known Member

    Joined:
    Jun 29, 2009
    Messages:
    9,780
    Likes Received:
    802
    Trophy Points:
    113
    Occupation:
    retired Firefighter
    Location:
    Central Florida Highlands
    HOW CAN YOU SAY THAT!!!!!

    Just look at the accuracy of the P-39 drawing with the V-3420 stuffed in it :) :)

    BTW there were just under 4 inches difference in diameter between an R-2800 and a R-1820. the P&W was about 7% smaller.
     
  8. GregP

    GregP Well-Known Member

    Joined:
    Jul 28, 2003
    Messages:
    5,906
    Likes Received:
    853
    Trophy Points:
    113
    Occupation:
    Electrical Engineer, Aircraft Restoration
    Location:
    Rancho Cucamonga, California, U.S.A.
    #8 GregP, Sep 15, 2014
    Last edited: Sep 21, 2014
    The spark plug coolers are simple. There are two aluminum tubes that stick out of the lower cowling going forward. The back end of the tube is plugged. The tubes go back along the row of exhaust plugs (the outside plugs near the exhaust outlets) and have holes in them that direct the airflow onto the spark plugs.

    Works very well and costs very little in drag.

    Hey Milosh,

    Thanks for this post. Although I worked on Allisons for about 2 years at Joe Yancey's shop, I never saw that particular presentation before. Good find!
     
  9. BiffF15

    BiffF15 Well-Known Member

    Joined:
    Aug 15, 2010
    Messages:
    543
    Likes Received:
    316
    Trophy Points:
    63
    Occupation:
    USAF / Commercial Pilot
    Location:
    Florida
    The Allison powered B-17 looks pretty cool! For a bomber...
     
  10. GregP

    GregP Well-Known Member

    Joined:
    Jul 28, 2003
    Messages:
    5,906
    Likes Received:
    853
    Trophy Points:
    113
    Occupation:
    Electrical Engineer, Aircraft Restoration
    Location:
    Rancho Cucamonga, California, U.S.A.
    It was very good-looking and significantly outperformed the B-17, but the B-17 was doing the job. Ergo, no change. While I love the Allison, there was nothing wrong with the B-17 "as is" and the change to the V-1710 would have resulted in better speed, but not by too much. If you don;t get significant changes in performance ... in a bomber ... then why change? In a fighter, a 25 mph increase might have been worthwhile. In a bomber, especially when the defending fighters can catch either one easily, what is the gain?

    I agree with the decision to stick with the Wrights.

    The driveshatfs in the XB-42 weren't all that long and were supported by bearings at suitable intervals.

    I decry that the V-3420 wasn't really used. It did NOT have the tendency for oil leaks inboard (betweeen the two block) that caused the German He-177 to catch fire so frequently and could have been a very good engine for the U.S.A. .
     
  11. Koopernic

    Koopernic Active Member

    Joined:
    Dec 27, 2013
    Messages:
    638
    Likes Received:
    74
    Trophy Points:
    28
    One thing the Allison Powered B-17 would have achieved is the faster B-17 which might have then matched B-24 speed and simplified mission planning and simplified the escorting of the bombers.

    The Allison also had much more power, it seems to have developed further than the R-1820 and allowed grater take-off weights and even greater speed.
     
  12. wuzak

    wuzak Well-Known Member

    Joined:
    Jun 5, 2011
    Messages:
    4,185
    Likes Received:
    167
    Trophy Points:
    63
    Location:
    Hobart Tasmania
    The greater take-off weight with the Allisons was offset, I would guess, by the extra installation weight.

    The V-1710 weighed 150-200lbs more than the R-1820. The cooling system weighed 430-500lb per engine (from America's Hundred-Thousand, the latter figure for the P-38J, the former for the prototype).

    The problem with the XB-38 was that airframe modifications were required, in that the leading edge between the nacelles was removed and a radiator group put in its stead. Had a QEC module been developed with radiators included, the project may have stood a better chance of going into production.

    But it was still unlikely. The XB-39 was developed from the B-29 with a QEC module for the V-3420, but it wasn't proceeded with even though it showed a greater performance improvement than did the XB-38.
     
Loading...

Share This Page