Diesel .50s (mostly)
11-10-2015, 07:11 AM
#253
The GS45 runs 10,680rpm with the 12x7 APC and thin spraybar, and 9,900rpm with round spraybar. I'll have to try it on the 13x6 APC. For my intended purpose of the .51, I'm not sure I'll be able to fit a 13" prop.. I think a 12x6 may be a bit small; and a 12x7 or 12x8 may not put out the thrust I'll need. I do like the 8.5lb thrust of the 13x6 though.
One question comes to mind - if I idled the 51 for say 10-15 seconds, it would have a hard time recovering to run WOT. I tried running it about 1/2 throttle to see if it would heat back up enough to recover to run WOT but it wouldn't. Would I want to run it a tiny bit more advanced (higher compression) to combat this or do I just need to limit idling to just a few seconds?
One question comes to mind - if I idled the 51 for say 10-15 seconds, it would have a hard time recovering to run WOT. I tried running it about 1/2 throttle to see if it would heat back up enough to recover to run WOT but it wouldn't. Would I want to run it a tiny bit more advanced (higher compression) to combat this or do I just need to limit idling to just a few seconds?
Last edited by 1QwkSport2.5r; 11-10-2015 at 07:14 AM.
02-25-2016, 07:43 PM
#254
There's a new Diesel thumper in the drawer... K&B Sportster .45 with a brand new Davis head. The engine has a .024" head shim which I'll need to use with the Davis head, and probably have to make another .002-.004" shim. This Davis head protrudes into the chamber so far (without the shim) that the piston hits the head. Add the shim and it feels like the piston still just barely kisses the head. It has superb fitment, so it should diesel like a dream.
02-28-2016, 07:23 PM
#256
The head for my Sportster .20 wasn't machined to use a shim. There is no mention in the instructions for the .45 head about a shim either. Maybe he forgot to include a memo with this head. The fact that it needs the factory shim plus another shim is puzzling to me, but isn't a big deal.
05-07-2016, 10:16 AM
#257
So for some reason, I decided to procure another Fox .50 to run as a diesel and I'm going to put my current .50 back into "FrankenFox" mode with the MDS piston and liner.. If the new .50 runs good as a diesel, I'll keep it around. If it doesn't, I'll sell it and have my .50 Davis head milled to fit the .46 Fox I have and go from there. Hopefully I'll see the new .50 next week. Might get time to run it next weekend or the week following possibly.
11-08-2022, 03:48 AM
#261
Senior Member
Just for kicks I ran all my .50 sized Diesels today, I may have a SuperTigre .45 conversion somewhere too.
MVVS .49 with Graupner 12x7 DDD ABC mix===9,775 rpm
Fox .50 Graupner 12x7 DDD ABC mix===9,150
Irvine .53 Graupner 12x7 DDD Abc mix===10,121
Webra .50/Bisson Pitts=Gr.12x7 DDD ABC=====9.950
SuperTigre .45 ABC Gr.-12x7 DDD ABC mix===9,800
SuperTigre .51 Graupner 12x7 DDD ABC mix===9,650
OS LA .46 Graupner 12x7 DDD Plane Fuel==9,450
OS LA .65 Bolly 13.5x8 DDD Plane Fuel===9,300
PAW .60 same Bolly 13.5x8 DDD Plane fuel===7,300
There is renewed in the Super Tigre 51 conversion
Super Tigre 51 turning a Grey Graupner 12 x 7.
MVVS .49 with Graupner 12x7 DDD ABC mix===9,775 rpm
Fox .50 Graupner 12x7 DDD ABC mix===9,150
Irvine .53 Graupner 12x7 DDD Abc mix===10,121
Webra .50/Bisson Pitts=Gr.12x7 DDD ABC=====9.950
SuperTigre .45 ABC Gr.-12x7 DDD ABC mix===9,800
SuperTigre .51 Graupner 12x7 DDD ABC mix===9,650
OS LA .46 Graupner 12x7 DDD Plane Fuel==9,450
OS LA .65 Bolly 13.5x8 DDD Plane Fuel===9,300
PAW .60 same Bolly 13.5x8 DDD Plane fuel===7,300
There is renewed in the Super Tigre 51 conversion
Super Tigre 51 turning a Grey Graupner 12 x 7.
