Register

If this is your first visit, please click the Sign Up now button to begin the process of creating your account so you can begin posting on our forums! The Sign Up process will only take up about a minute of two of your time.

Page 4 of 5 FirstFirst ... 2345 LastLast
Results 76 to 100 of 101

  1. #76

    Join Date
    Jun 2003
    Location
    winter park, FL
    Posts
    6,723
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: Need Help with Fox 15 Davis Conversion

    If compression seems low a phone call to Fox may be in order, really think the head is out of the loop martin

  2. #77

    Join Date
    Apr 2007
    Location
    Wollongong, AUSTRALIA
    Posts
    330
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: Need Help with Fox 15 Davis Conversion

    How easily does it start? If it's starting all right then I can't see either ether content or compression being the problem. The figures quoted seem way low, even for a worn-out engine.

    If it can do 15500 in standard glow form, I can't see that Fox would be particularly sympathetic.

    Out of interest, have you tried something like an 8x4, 8x6 or 9x4 with it running as a diesel? 9x6 and 10x6 are both more than I would normally use for a .15 (I fly CL), so I'm wondering how it would go on a smaller prop.

  3. #78

    Join Date
    Oct 2009
    Location
    SydneyNew South wales, AUSTRALIA
    Posts
    1,237
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: Need Help with Fox 15 Davis Conversion


    ORIGINAL: steve111

    How easily does it start? If it's starting all right then I can't see either ether content or compression being the problem. The figures quoted seem way low, even for a worn-out engine.

    If it can do 15500 in standard glow form, I can't see that Fox would be particularly sympathetic.

    Out of interest, have you tried something like an 8x4, 8x6 or 9x4 with it running as a diesel? 9x6 and 10x6 are both more than I would normally use for a .15 (I fly CL), so I'm wondering how it would go on a smaller prop.
    Pretty much my thoughts on the starting Steve, something is being missed here.

    What I want to know is, does it misfire when running as a diesel?


  4. #79
    tweedy's Avatar
    Join Date
    Sep 2004
    Location
    Cedar City , UT
    Posts
    260
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: Need Help with Fox 15 Davis Conversion

    I think the problem may be the Cylinder to piston fit, if you look at the wear pattern on the piston it is wearing at the top on one side of the piston, and at the bottom on the other. I talked to Chris at Fox and he is going to send me a piston and Cylinder Assembly that is on the tight side, and I will spend an evening hand lapping it.

  5. #80

    Join Date
    Jun 2003
    Location
    winter park, FL
    Posts
    6,723
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: Need Help with Fox 15 Davis Conversion

    Nice- hope that fixes it nice to deal with folks that care, did not mention it before but thought that might have been issue, glows can scream on lower compression
    diesel a lost cause martin

  6. #81
    Moderator Hobbsy's Avatar
    Join Date
    Dec 2001
    Location
    Colonial Beach, VA
    Posts
    15,315
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: Need Help with Fox 15 Davis Conversion

    Martin, I'm going to run my Fox .15 conversion tomorrow with a variety of props. One problem though, I need to either make or scrounge up some kind of bushing for the props. Not a single one fits the Fox shaft.
    Farmall 240 the final issue of the Farmall C, Super C, 200, 230 series.
    122 Cu. In. 22 hp. A small tractor that would do big work due to its 10x36 inch rear tires.

    As competition improves products, the differences between them get smaller and smaller

    Club Saito member #5

  7. #82

    Join Date
    Jun 2003
    Location
    winter park, FL
    Posts
    6,723
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: Need Help with Fox 15 Davis Conversion

    Hobbsy I have a variety of K and S thin wall aluminum tubing some even telescopes like a rc transmitter antenna so can fit almost any engine a must in the small ones, you can wrap some tape around the shaft to bring up the diameter so a good fit in I guess 1/4 inch is the standard prop bore I have done it you may have to
    do a re-wrap when you change props martin

    scotch tape to the rescue

    K and S bush for prop
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	Mk27658.jpg 
Views:	2 
Size:	45.7 KB 
ID:	1810656  

  8. #83
    Moderator Hobbsy's Avatar
    Join Date
    Dec 2001
    Location
    Colonial Beach, VA
    Posts
    15,315
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: Need Help with Fox 15 Davis Conversion

    OK, here are the props I ran,

    A MasterAirscrew Scimitar 9x5S rpm====12,100
    A Taipan 10x4 rpm================9,200
    A Graupner 10x5.5 rpm=============9,000
    Idle==========================3,100

    I only got a single outside photo to take, its really difficult to take them in the fall, as you can see. This one about two clicks from the peak. I don't seem to have a 10x6 of any brand. I think you can take a look at the Taipan and see why it made only 9,200 rpm but that dude makes some serious wind.

    The fuel was Davis ABC blend.
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	Ca82732.jpg 
Views:	2 
Size:	103.0 KB 
ID:	1810795   Click image for larger version. 

Name:	Vq52755.jpg 
Views:	3 
Size:	78.2 KB 
ID:	1810796   Click image for larger version. 

Name:	Va71552.jpg 
Views:	2 
Size:	47.3 KB 
ID:	1810797  
    Farmall 240 the final issue of the Farmall C, Super C, 200, 230 series.
    122 Cu. In. 22 hp. A small tractor that would do big work due to its 10x36 inch rear tires.

    As competition improves products, the differences between them get smaller and smaller

    Club Saito member #5

  9. #84
    tweedy's Avatar
    Join Date
    Sep 2004
    Location
    Cedar City , UT
    Posts
    260
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: Need Help with Fox 15 Davis Conversion


    ORIGINAL: Hobbsy

    OK, here are the props I ran,

    A MasterAirscrew Scimitar 9x5S rpm====12,100
    A Taipan 10x4 rpm================9,200
    A Graupner 10x5.5 rpm=============9,000
    Idle==========================3,100

    I only got a single outside photo to take, its really difficult to take them in the fall, as you can see. This one about two clicks from the peak. I don't seem to have a 10x6 of any brand. I think you can take a look at the Taipan and see why it made only 9,200 rpm but that dude makes some serious wind.

    The fuel was Davis ABC blend.
    I'f I'm able to sort things out and get those kind of numbers I will be a happy camper

    Tweedy

  10. #85

    Join Date
    Jun 2003
    Location
    winter park, FL
    Posts
    6,723
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: Need Help with Fox 15 Davis Conversion

    Tweedy most likely you will get those numbers everything i fly diesel or 4 strk glow we get 9 to 10K on the revs and sure they unload a bit in the air, an other 300 at least martin

    I should have my digital fish scale early next week so I can see the real numbers on thrust on the planes should be interesting and not "well feels like a lot"

  11. #86
    Moderator Hobbsy's Avatar
    Join Date
    Dec 2001
    Location
    Colonial Beach, VA
    Posts
    15,315
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: Need Help with Fox 15 Davis Conversion

    I finally found a 10x6 that I thought was a 10x8 because it was buried in a stack of props on a peg board hanger. It is a Graupner 10x6 Scimitar.

    Graupner 10x6 Scimitar rpm ====9.250, the idle with this prop is a very steady 2,400. It is about 40 degrees right now and there was no idle cool down at all.
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	Ay73967.jpg 
Views:	2 
Size:	27.0 KB 
ID:	1810872  
    Farmall 240 the final issue of the Farmall C, Super C, 200, 230 series.
    122 Cu. In. 22 hp. A small tractor that would do big work due to its 10x36 inch rear tires.

    As competition improves products, the differences between them get smaller and smaller

    Club Saito member #5

  12. #87

    Join Date
    Jun 2003
    Location
    winter park, FL
    Posts
    6,723
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: Need Help with Fox 15 Davis Conversion


    not bad at alll, but Brrrrrrrrr on the temp high 80s here today MARTIN

    FOOD FOR THOUGHT A 10X6 IS A COMMON FOR A 40 GLOW

  13. #88

    Join Date
    Sep 2005
    Location
    Infront NSW, AUSTRALIA
    Posts
    1,034
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: Need Help with Fox 15 Davis Conversion

    ORIGINAL: AMB
    FOOD FOR THOUGHT A 10X6 IS A COMMON FOR A 40 GLOW
    Too windy to fly yesterday so we ran engines. A bloke ran a c/l unmuffled Norvel 40 BB on an APC 9x7 and I tachoed it at 15200 RPM.

    I ran my Oliver Tiger MOD 2.5cc on a Master 10 x 6 and got 7600 RPM consistently with a maximum of 8200 RPM. However it would

    only hold the latter speed for about a minute before overheating.

    It turned the full RAM 8 x 6 comfortably at 12100 RPM.

    It also turns an APC 7 x 6 at 16500 and an APC 8x4 at 15400 which makes it a goodin!

    Regarding the claimed Davis RPM figures my gut feeling is that they're fantasy and as far as I'm concerned the myth is busted!

    A fair amount of salesmanship in the claims?

    Ray




    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	Tr49300.jpg 
Views:	6 
Size:	91.1 KB 
ID:	1810956   Click image for larger version. 

Name:	Sq48363.jpg 
Views:	2 
Size:	93.2 KB 
ID:	1810957  

  14. #89

    Join Date
    Aug 2010
    Location
    , AUSTRALIA
    Posts
    108
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: Need Help with Fox 15 Davis Conversion

    Should do the quoted rpm on a single blade 10x6 methinks.

  15. #90

    Join Date
    Sep 2005
    Location
    Infront NSW, AUSTRALIA
    Posts
    1,034
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: Need Help with Fox 15 Davis Conversion


    ORIGINAL: Diesel Fan

    *Should do the quoted rpm on a single blade 10x6 methinks.
    ... or the 10 x 6" with an inch and a half off each blade.


  16. #91
    Moderator Hobbsy's Avatar
    Join Date
    Dec 2001
    Location
    Colonial Beach, VA
    Posts
    15,315
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: Need Help with Fox 15 Davis Conversion

    Coming within 750 rpm with a fairly new engine isn't exactly myth busting and comparing a .40 to a .15 isn't what I'd call fair either.
    Farmall 240 the final issue of the Farmall C, Super C, 200, 230 series.
    122 Cu. In. 22 hp. A small tractor that would do big work due to its 10x36 inch rear tires.

    As competition improves products, the differences between them get smaller and smaller

    Club Saito member #5

  17. #92

    Join Date
    Jun 2003
    Location
    winter park, FL
    Posts
    6,723
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: Need Help with Fox 15 Davis Conversion

    Hi Hobbsy I just thought it was interesting that a 10x6 prop was listed as a common size for40 size glow engines, a 15 diesel has no issue turning one
    Just checked my factory sheet on PAW and indeed a 10x6 one of the suggested props so I guess in the 9 to 10K rev range on a 10x6
    is the norm for a 15 diesel, the Davis sheet list 9x7 so a 10x6 I think pretty equal to a 10x6 best regards martin

    Post note just became a grandfather yesterday was told about time since just hit the 80 mark in Sept

  18. #93
    Mr Cox's Avatar
    Join Date
    Jul 2007
    Location
    Karlstad, SWEDEN
    Posts
    3,147
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: Need Help with Fox 15 Davis Conversion

    I thought it made 9250rpm on a 10x6?

    That would make it 1250rpm less than the claims, and on pair with other .15 diesels. Perhaps not a myth busted but certainly a marketing bluff being caught. I would prefer to think of it as a missprint though.

  19. #94

    Join Date
    Oct 2002
    Location
    Port Ewen, NY
    Posts
    3,383
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: Need Help with Fox 15 Davis Conversion


    ORIGINAL: AMB
    Post note just became a grandfather yesterday was told about time since just hit the 80 mark in Sept
    Congratulations on both milestones!

    BTW, I turn 71 next month and I have two grandsons...both in college.

    George

  20. #95
    Moderator Hobbsy's Avatar
    Join Date
    Dec 2001
    Location
    Colonial Beach, VA
    Posts
    15,315
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: Need Help with Fox 15 Davis Conversion

    Sorry Mr. Cox, my memory is more flawed than my math, Like George I'm currently 70 and so far that has not been a bad thing. I am still searching for an APC 10x6 although I doubt I'll see that kind of rpm with it either. But as the guy said at the end of that Dirty Harry movie, "I gots to know."

    Congrats on the grandchild Martin, I have 17 of em, I wonder how that happened.
    Farmall 240 the final issue of the Farmall C, Super C, 200, 230 series.
    122 Cu. In. 22 hp. A small tractor that would do big work due to its 10x36 inch rear tires.

    As competition improves products, the differences between them get smaller and smaller

    Club Saito member #5

  21. #96

    Join Date
    Jun 2003
    Location
    winter park, FL
    Posts
    6,723
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: Need Help with Fox 15 Davis Conversion

    Mr Cox think it is a miss-print Mr Davis has very high ethics do does not resort to false claims has no need too martin see my post and replys dated'10/3 and replys of others martin

  22. #97

    Join Date
    Jul 2006
    Location
    Sydney, AUSTRALIA
    Posts
    446
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: Need Help with Fox 15 Davis Conversion


    ORIGINAL: AMB



    Post note just became a grandfather yesterday was told about time since just hit the 80 mark in Sept
    Congrats on both Martin. Are you a grandfather or grandmother....errr is it a boy or girl?

    I've got two granddaughters - they're so great, I sometimes think I should have just gone there first. hahahhaha!



    Greg
    Regards
    Greg

    Elwood: They're not gonna catch us. We're on a mission from God.

  23. #98

    Join Date
    Jun 2003
    Location
    winter park, FL
    Posts
    6,723
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: Need Help with Fox 15 Davis Conversion

    HOBBSY`.. 17?? must be the baby virus, no cure LOL had to say that, family get togethers must really be an event martin

  24. #99

    Join Date
    Sep 2005
    Location
    Infront NSW, AUSTRALIA
    Posts
    1,034
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: Need Help with Fox 15 Davis Conversion


    ORIGINAL: Hobbsy

    Coming within 750 rpm with a fairly new engine isn't exactly myth busting and comparing a .40 to a .15 isn't what I'd call fair either.

    A new engine which is now getting what seems to be a much needed new p/l.

    I'd say it was fair comment.

  25. #100

    Join Date
    Oct 2009
    Location
    SydneyNew South wales, AUSTRALIA
    Posts
    1,237
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: Need Help with Fox 15 Davis Conversion


    ORIGINAL: Hobbsy

    .........and comparing a .40 to a .15 isn't what I'd call fair either.
    Hi Dave,
    that comparison was already done when a .15ci engine was quoted using a 10x6 - the extropolation was linking that prop to what sized engine normaly would use one.

    The unfairness lies in fair placing a 10x6 with any .15ci engine and then saying it does 10500 rpm in any usable form.

    By democratic vote here, it just ain't possible.


Page 4 of 5 FirstFirst ... 2345 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
All times are GMT -6. The time now is 12:49 PM.

SEO by vBSEO 3.6.1 ©2011, Crawlability, Inc.