Firewall-forward package weights

Discussion in 'Firewall Forward / Props / Fuel system' started by cluttonfred, Jun 1, 2019.

Help Support HomeBuiltAirplanes Forum by donating:

  1. Jun 1, 2019 #1

    cluttonfred

    cluttonfred

    cluttonfred

    Well-Known Member

    Joined:
    Feb 13, 2010
    Messages:
    6,350
    Likes Received:
    2,220
    Location:
    World traveler
    Does anyone have any accurate numbers for the firewall-forward package weights of various engine options? By firewall forward package weight I mean everything including the engine, mount, exhaust, full fluids, and any external oil/water tanks or coolers/radiators or PSRUs (when applicable), and a typical prop.
    • VW
    • Subaru
    • Suzuki
    • Lycoming (various 4-cylinder models)
    • Continental (various 4-cylinder models)
    • Rotax 912/914
    If not a table of data, then a few examples of actual, measured engine dry weight vs. total firewall-forward package weight would help a lot.
     
  2. Jun 1, 2019 #2

    BJC

    BJC

    BJC

    Well-Known Member

    Joined:
    Oct 7, 2013
    Messages:
    9,307
    Likes Received:
    6,083
    Location:
    97FL, Florida, USA
    blane.c likes this.
  3. Jun 1, 2019 #3

    cluttonfred

    cluttonfred

    cluttonfred

    Well-Known Member

    Joined:
    Feb 13, 2010
    Messages:
    6,350
    Likes Received:
    2,220
    Location:
    World traveler
    Yes, that's a fantastic start. Lycoming O-360 and 3.0 Subaru conversion with PSRU both came in at about 475 lb firewall forward, so a far cry from the much lower published engine dry weights.
     
  4. Jun 1, 2019 #4

    BJC

    BJC

    BJC

    Well-Known Member

    Joined:
    Oct 7, 2013
    Messages:
    9,307
    Likes Received:
    6,083
    Location:
    97FL, Florida, USA
    People tend to underestimate the cumulative weight of all the stuff other than the bare engine.


    BJC
     
    blane.c likes this.
  5. Jun 1, 2019 #5

    blane.c

    blane.c

    blane.c

    Well-Known Member HBA Supporter

    Joined:
    Jun 27, 2015
    Messages:
    3,045
    Likes Received:
    533
    Location:
    capital district NY
    VW engine weights typically published are just under 150lbs (somewhere in the 140 odd lbs weight bracket) recently on this forum I saw a 2180cc VW picture posted with a firewall forward weight advertised as 210lbs. So from that it could be surmised that all the goodies to make it work on an airplane are about 60lbs +.
     
  6. Jun 1, 2019 #6

    blane.c

    blane.c

    blane.c

    Well-Known Member HBA Supporter

    Joined:
    Jun 27, 2015
    Messages:
    3,045
    Likes Received:
    533
    Location:
    capital district NY
    You really have to assume a lot as well, like motor mount included in that weight? Cowling? I mean it is not spelled out, you have to guess or already know what someone else's interpretation of firewall forward really means.
     
  7. Jun 1, 2019 #7

    blane.c

    blane.c

    blane.c

    Well-Known Member HBA Supporter

    Joined:
    Jun 27, 2015
    Messages:
    3,045
    Likes Received:
    533
    Location:
    capital district NY
    I think if you start with a barren firewall, nothing but a space to put things, then every single little thing, washer, cotter key and safety wire included, that is firewall forward.
     
    Pops likes this.
  8. Jun 1, 2019 #8

    blane.c

    blane.c

    blane.c

    Well-Known Member HBA Supporter

    Joined:
    Jun 27, 2015
    Messages:
    3,045
    Likes Received:
    533
    Location:
    capital district NY
    And add Industrial engines to the engine list too. They are coming like it or not.
     
  9. Jun 1, 2019 #9

    ScaleBirdsScott

    ScaleBirdsScott

    ScaleBirdsScott

    Well-Known Member

    Joined:
    Feb 10, 2015
    Messages:
    944
    Likes Received:
    604
    Location:
    Uncasville, CT
    We're trying to get a few data points for Verner 3VW installs. I know we're planning to get one for our 5Si when we pull it, so that may be of use as well, though I'd look for other data points.

    But each engine+aircraft combo will definitely have a big impact on the total weight of any engine, plus if you need to consider the distribution of that weight, it starts getting into the weeds if the overall weight of two packages is the same but the CGs are spread far differently due to cowls, spinners, etc.
     
    GeeZee likes this.
  10. Jun 2, 2019 #10

    blane.c

    blane.c

    blane.c

    Well-Known Member HBA Supporter

    Joined:
    Jun 27, 2015
    Messages:
    3,045
    Likes Received:
    533
    Location:
    capital district NY
    Verners need definitely be added to the engine list.
     
    GeeZee likes this.
  11. Jun 2, 2019 #11

    Mark Schoening

    Mark Schoening

    Mark Schoening

    Well-Known Member HBA Supporter

    Joined:
    Aug 2, 2012
    Messages:
    97
    Likes Received:
    88
    Location:
    KRHI
    For a Cruzer, I roughly computed this:

    250#...Lyc 0-320 E2D..150 hp...….. (with slicks and carb + airbox.)
    12#.....Vetterman 1-1/2 " exhaust
    6 #..B&C alternator
    11#...B&C starter
    6#...Oil cooler and Hoses
    5# ….baffle material
    15#...wood prop, bolts & spinner
    10# for misc....nuts bolts, senders, etc. etc.
    315# total less cowling and mount. Zenith allows 350# FWF.....Hope this proves fairly accurate.....
    Battery and relays to be behind the seat
     
    cluttonfred likes this.
  12. Jun 2, 2019 #12

    Pops

    Pops

    Pops

    Well-Known Member

    Joined:
    Jan 1, 2013
    Messages:
    6,919
    Likes Received:
    5,833
    Location:
    USA.
    1835 cc, 60 HP, VW engine-- Land the SSSC airplane , unbolt the 4130 steel tube engine mount from the firewall and weigh. 141 lbs.
    Single port heads , Single Slick mag and mag drive, Slick shielded wires and aircraft spark plugs , Sunk fit prop hub on stock crank, Culver 60"x 26" wood prop & bolts, Zenith carb with airbox and 1 1/4" dia SS intake tubes with hot oil box, 1 1/2" SS exhaust stacks with a carb heat box, Oil cooler with alum box with 2-- 2" scat hoses, Aluminum bottom oil cover plate for case. Aluminum air scoops over heads and cylinders.
    Forgot to add, no oil.
     
    Last edited: Jun 2, 2019
    cluttonfred, Vigilant1 and blane.c like this.
  13. Jun 2, 2019 #13

    Pops

    Pops

    Pops

    Well-Known Member

    Joined:
    Jan 1, 2013
    Messages:
    6,919
    Likes Received:
    5,833
    Location:
    USA.
    My Cont C-85-12F engine. Starter and ratchet gear removed. Generator removed. 3/16" thick aluminum cover made for the starter and generator openings.
    Slick mags and harness and Stromberg carb and airbox. Heavy brass case vent elbow removed and replace with an aluminum elbow. No exhaust system or prop.
    Weight-- 187 lbs.
    Same weight for the C-85 that Bob Barrows uses on the LSA Bearhawk.
     
    blane.c likes this.

Share This Page

arrow_white