AMB

Being raining in Florida, decided to run the Fox 50 ringed with a 12x8 apc gray prop we finally got it settled at a steady 8500 good transition also whattcha think folks?. comments it is ringed and only about 40 minutes on it martin

Hobbsy

My Feedback: (102)

I say, that's good very, are you going to try a 12x7?

AMB

Hobbsy, YUP most likely Tues or Wed martin

Hobbsy

My Feedback: (102)

I ran my Rebuilt Fox .50 converted back to Diesel today with a ProZinger 12x7 and got 9,076 rpm with the nicest 2,350 rpm idle you ever saw, it was almost silent at idle. I converted it back to glow and put about 2 hours on it at various speeds to make it more Diesel ready.

AMB

Dave sounds great sounds like it needed that re break in now roaring like a lion no purring martin

Hobbsy

My Feedback: (102)

Martin, I had my first ever engine near miss. I pulled the backplate off of the Fox .50 and lower rod bushing had spun and is loose in the rod. It's my fault I heard it sag and richened the mixture instead of reducing the throttle, it may have been too late anyway.

AMB

I do not think it would have made a difference it had most likely spun the insert when it sagged. Strange event how could it have run dry to do that?? At least only a rod 8 or 10 bucks and back in biz. and it could have been a quirk like a loose fit of the insert to start
martin

Change of pace reading my new tower catalog and they have a high a temp cutoff looks like a digital read too to pull the throttle
back at a preset temp this was in the car stuff, might have a application in a cowled glow, diesels of course are out of the loop on this one

Hobbsy

My Feedback: (102)

Martin I found out why, the rod had no oil hole in the bottom end, I had it turning 12,000 plus for extended periods of time as a glow the other day and nothing happened. I have new rod in it now that has two oil holes in it. The crankpin was not hurt.

AMB

THat was a goof should have had oil holes martin

Hobbsy

My Feedback: (102)

Martin, I tried it today on glow with the new rod, at the end of 16oz more fuel it nows turns the 10.5x6 Graupner at 13,110 rpm, its getting stronger. I had to put a different piston in it also, the cold rolled wristpin retaining pin would not budge. Time for Davis head again.

Bodge

Martin, Dave,

Hope you don't mind my gatecrashing your Fox 50 thread, but I would like advice and I think you two guys are the most likely to answer my question. So, while you are both in one place, so to speak...

I have two Jen 56s, one ABC and a new ringed version. I am a glutton for punishment and could never get the ABC to pick up cleanly from idle. The ringed version I bought to have another go is only slightly better, so I've ordered a diesel head - I WILL get the d@mned things running well one way or another.

My question is: which is likely to respond to the diesel conversion the best, the ABC or the ringed version? I have a few years diesel experience from my C/L combat days - Olivers, PAWs, MVVS, Supertigre diesels, but I am wondering if the high diesel compression will rattle that ring around too much...

Cheers,

Hobbsy

My Feedback: (102)

B, if the ringed one flips with about the same amount of compression bounce as the ABC one then its a toss up, I use my Fox .74 ABC as a conversion because when my two .74s were new the ABC one was much easier to start, now that the ringed one has more time it starts easily also. I'd say you can use the ABC one after a 20 minute or so break in. From what I understand the .56s you guys have are nearly the same engine as the Black Lincoln .61 that Fuelman loaned me to wring out.

AMB

Budge I have both the ringed and ABC Jen 56 they both run well The ABC does run about 500 rpm faster this not really an issue\since
I heep them down < 10000 anyhow, as a diesel you only have to run about 75% open for full speed its a big bore carb. A lot of the guys like the ring over the ABC for the fun fly stuff, For some reason there is a rumor that ABCs make better conversions, After
running my Jen 56, Fox 50 (davis head) , ST40 (davis head) do not buy that thinking, you may get a bit more top end out of and ABC
but not needed anyhow as diesel I have no need to fly them at 11K or above martin

Bodge

Great!

It's not out and out performance I'm after - actually I'm using this as a bit of an excuse to justify diesels to myself. So, it seems that as there are no mechanical reasons to choose one over the other, so I will convert the ABC and try an MVVS carb on the ringed version and persevere with it as a glow engine.

I have asked Just Engines for a slightly smaller carb (than the 8mm supplied) with the diesel head so the improved fuel draw should help with any possible pick-up problems that the glow ABC version displayed.

Thanks for your thoughts.

Bodge

Dave,

The "Black Lincoln 61": is that a diesel. I've never heard of it.

DarZeelon

Martin,


After seeing the MVVS .49 doing 10,400 RPM on a Bolly 12.5x6 (load equal to an APC 12x7), I would say 8,500 RPM on the 12x8 is a bit low on power. 9,900 should be a reasonably good number to shoot for on that prop (1 hp, compared to 0.63).