Why no new diesel radials?

"On-Condition" wrote in message
news:MMMUe.167883$wr.92445@clgrps12...

Just wondering, exactly why are radial diesels not part of the
diesel revival? You can't beat radials on airplanes for smooth
reliability. I once saw a cracked-off jug pounding through the
cowling as the engine was still running (the single Otter had
just landed).

Because there are no airframes currently in production that are designed for
radials. With other engine configurations, it is possible that the new
diesel(s) might be fitted to current airframes, either for new production or
for retrofits.

Kyle Boatright wrote:
"On-Condition" wrote in message
news:MMMUe.167883$wr.92445@clgrps12...

Just wondering, exactly why are radial diesels not part of the
diesel revival? You can't beat radials on airplanes for smooth
reliability. I once saw a cracked-off jug pounding through the
cowling as the engine was still running (the single Otter had
just landed).


Because there are no airframes currently in production that are designed for
radials. With other engine configurations, it is possible that the new
diesel(s) might be fitted to current airframes, either for new production or
for retrofits.



Thrush, Air Tractor, Weatherly.

Sokois, Murphy Rebel...

Bryan "The Monk" Chaisone

"Flyingmonk" wrote in message
ups.com...
Sokois, Murphy Rebel...

Bryan "The Monk" Chaisone

And if you add up all the Sukhois, Murphy Mooses (not rebels), Thrushes,
etc. it isn't a drop in the bucket. There isn't nearly enough volume there
to make a radial diesel worthwhile for someone who wants to make money.

KB

"Build it and they will come..." ~ field of dreams.

Bryan "The Monk" Chaisone

"Kyle Boatright" wrote

And if you add up all the Sukhois, Murphy Mooses (not rebels), Thrushes,
etc. it isn't a drop in the bucket. There isn't nearly enough volume there
to make a radial diesel worthwhile for someone who wants to make money.

I would think that the reason is not economics, but the suitability of a
radial for diesel.

You always see diesels using a very stout block, and very stout cranks and
rods. Could a radial diesel be beefed up enough? I don't know, but I think
the answer is no.

GM tried to use a gas engine block converted to diesel, and it was a dismal
failure. That even had a solid cast iron block, and stout crank, and that
wasn't even up to the task.

Individual jugs are weak, since they blow off even with gasoline pressures,
sometimes. How much stronger would they have to be, for diesel? Could it
be done using separate cylinders?

A master rod may be strong enough, but I would think that the slave rods and
pins would not be. They would have to be extremely beefed up to stand the
pressures. I don't know if there would be enough room in the case to do it.

Good questions raised here. Answers?
--
Jim in NC

Morgans wrote:
"Kyle Boatright" wrote

And if you add up all the Sukhois, Murphy Mooses (not rebels), Thrushes,
etc. it isn't a drop in the bucket. There isn't nearly enough volume there
to make a radial diesel worthwhile for someone who wants to make money.

I would think that the reason is not economics, but the suitability of a
radial for diesel.

You always see diesels using a very stout block, and very stout cranks and
rods. Could a radial diesel be beefed up enough? I don't know, but I think
the answer is no.

GM tried to use a gas engine block converted to diesel, and it was a dismal
failure. That even had a solid cast iron block, and stout crank, and that
wasn't even up to the task.

Individual jugs are weak, since they blow off even with gasoline pressures,
sometimes. How much stronger would they have to be, for diesel? Could it
be done using separate cylinders?

Pressures during misfiring/backfiring are considerable also
but don't bust the jugs. I'm no engine expert but think that
jug failures are mostly O/H, fatique or casting related (?)
and they sure do happen on opposed gas engines as well as
radials. The difference is that a radial (at least one I saw)
just kept on going.

Most gas radials I've seen/flown had around 8:1 compression,
that's food for thought. Just wondering though, are the german
aircooled diesel cylinders intergral with the block?


A master rod may be strong enough, but I would think that the slave rods and
pins would not be. They would have to be extremely beefed up to stand the
pressures. I don't know if there would be enough room in the case to do it.

Good questions raised here. Answers?

"On-Condition" wrote

Just wondering though, are the german
aircooled diesel cylinders intergral with the block?

I think they are bolt on, but in a dual assembly. Not positive.
--
Jim in NC

Most gas radials I've seen/flown had around 8:1 compression,
that's food for thought. Just wondering though, are the german
aircooled diesel cylinders intergral with the block?


Nope as far as
I know separate cylinders and heads

On-Condition wrote:

Most gas radials I've seen/flown had around 8:1 compression,
that's food for thought. Just wondering though, are the german
aircooled diesel cylinders intergral with the block?

the WWII era Guiberson and Cat D-200A Radials had 14.3:1 and
15.5:1 respectively. The Guiberson weighed about 1100 pounds
in Tank trim, And that Cat engine started out as an Wright R-1820,
but weighed over 3000 pounds by time Cat beefed it up enough
to be reliable.

**
mike
**