Dimensions NEEDED

Anybody know how the cylinder studs/ thru-bolts are located on the old

E-185-225 series Cont. Engines ?? Usually one of 2 ways, either a bolt
circle diameter with so many degrees offset from a horiz or vert C/L of
the bore of the cylinder-----Or, rectangular measurements from a horiz.
and /or vert. line .

Thanx ahead 'o time,

muddled motor man

I have a pusher airplane with a nose oil cooler.

I am replacing the existing heavy hydraulic type(rubber/braided steel)
oil cooler lines with lighter metal lines. Either soft Aluminum or soft
copper 1/2 lines.

First question. I would like to use the lines as my ground return and
remove the 2 AWG wire I have now. Good idea?

Second question. Which would be better, or possibly which would be
worse and why? Copper or Aluminum.. Aluminum would be lighter but
copper offers a better ground return(less resistance). I have a big
engine and the starter needs all the current I can muster.

Scott

Think about replacing your 2 AWG with 1AWG aluminum instead.

Aluminum wire has a bad habit of forming an insulative oxidation layer.
But you could use the anti oxidant paste they sell for that problem.

"bashir salamti" wrote in message
...
On Sat, 03 Sep 2005 21:19:03 -0600, Scott Derrick
wrote:
:
:First question. I would like to use the lines as my ground return and
:remove the 2 AWG wire I have now. Good idea?

Strikes me as a Bad idea.

Strikes me as a double unplus BAD idea.



The problem, as I see it, is the posibility of a small short creating
an ark,

I'm sure Noah could use the ark.



(Most engine fires are fueled by oil, not by gas.)

How much weight are you going to save going this route? Think about
replacing your 2 AWG with 1AWG aluminum instead.

And I'd also do the calculation to see just how much weight loss there is
between #2 copper and #1 aluminum. I'd bet you aren't saving a hell of a
lot and getting the aluminum oxidation problem on top of it.

Jim

also look at early o-470s. Share the same cylinders.

jerry wass wrote:
Anybody know how the cylinder studs/ thru-bolts are located on the old

E-185-225 series Cont. Engines ?? Usually one of 2 ways, either a bolt
circle diameter with so many degrees offset from a horiz or vert C/L of
the bore of the cylinder-----Or, rectangular measurements from a horiz.
and /or vert. line .

Thanx ahead 'o time,

muddled motor man

jerry wass wrote:
Anybody know how the cylinder studs/ thru-bolts are located on the old

E-185-225 series Cont. Engines ?? Usually one of 2 ways, either a bolt
circle diameter with so many degrees offset from a horiz or vert C/L of
the bore of the cylinder-----Or, rectangular measurements from a horiz.
and /or vert. line .

Thanx ahead 'o time,

muddled motor man

Well it is on a bolt circle, 6.375 " to be exact---NOW if I just knew
the degrees of separation, I could make me some shims..

In article ,
Scott Derrick wrote:
I have a pusher airplane with a nose oil cooler.

I am replacing the existing heavy hydraulic type(rubber/braided steel)
oil cooler lines with lighter metal lines. Either soft Aluminum or soft
copper 1/2 lines.

First question. I would like to use the lines as my ground return and
remove the 2 AWG wire I have now. Good idea?

*DAMN*STUPID* one!

Consider the cross-section area of #2 wire,
then compare with the cross-section area of the walls of the tubing.

Without considering what happens if/when a line _breaks_.

"Instant" spark across the gap, With a ready supply of fuel being delivered
to the scene.

Second question. Which would be better, or possibly which would be
worse and why? Copper or Aluminum.. Aluminum would be lighter but
copper offers a better ground return(less resistance). I have a big
engine and the starter needs all the current I can muster.

For the same current load, you need (minimum) 1 gauge larger wire, if AL,
vs what you need for Cu. That equates to circa 30% more material, by
volume. Which negates a fair bit of weight difference.

Your last statement *should* answer your question. for max current
transfer efficiency, use the best conductor you can, at the largest size
you can justify.



Scott

In article ,
karel wrote:

"Robert Bonomi" wrote in message
...
In article ,
Scott Derrick wrote:
I have a pusher airplane with a nose oil cooler.

I am replacing the existing heavy hydraulic type(rubber/braided steel)
oil cooler lines with lighter metal lines. Either soft Aluminum or soft
copper 1/2 lines.

First question. I would like to use the lines as my ground return and
remove the 2 AWG wire I have now. Good idea?

*DAMN*STUPID* one!

Perhaps, yes.
Careful consideration is required, at least.
Which is exactly what O/P is doing.

Consider the cross-section area of #2 wire,
then compare with the cross-section area of the walls of the tubing.

Without considering what happens if/when a line _breaks_.

Agreed.
But is this any worse than a dedicated electrical ground cable breaking
loose?

HELL YES it is!!

The difference being the proximity of flammable materials to the point
where the sparks are being generated.

The point might be that oil lines are more prone to vibration
than a length of cable of whatever gauge.

"Instant" spark across the gap, With a ready supply of fuel being
delivered
to the scene.

The fuel being lubricating oil, I fancy a tremendous lot of sparks
would be required to actually make it fire.

You, sir, "don't know what you DON'T KNOW" about the size of the sparks
that get generated when a conductor carrying multiple tens of amps
is unexpectedly severed. (#2AWG copper is rated for in excess of 125 Amps.)

OR how easily 'lubricating oils' can be "convinced" to combust. No, they
are not very 'volatile' -- so they don't vaporize by themselves -- but
they 'atomize' fairly easily, which can, and often does, make for an explosive
mixture.


Second question. Which would be better, or possibly which would be
worse and why? Copper or Aluminum.. Aluminum would be lighter but
copper offers a better ground return(less resistance). I have a big
engine and the starter needs all the current I can muster.

Like all other respondents, I feel copper must be preferred.
No arguments to add, though, just agree with all given.

On Mon, 5 Sep 2005 19:46:37 -0000, "karel"
wrote:


"Robert Bonomi" wrote in message
...
In article ,
karel wrote:

"Robert Bonomi" wrote in message
...
In article ,
Scott Derrick wrote:
I have a pusher airplane with a nose oil cooler.

I am replacing the existing heavy hydraulic type(rubber/braided steel)
oil cooler lines with lighter metal lines. Either soft Aluminum or soft
copper 1/2 lines.

First question. I would like to use the lines as my ground return and
remove the 2 AWG wire I have now. Good idea?

*DAMN*STUPID* one!

Perhaps, yes.
Careful consideration is required, at least.
Which is exactly what O/P is doing.

Consider the cross-section area of #2 wire,
then compare with the cross-section area of the walls of the tubing.

Without considering what happens if/when a line _breaks_.

Agreed.
But is this any worse than a dedicated electrical ground cable breaking
loose?

HELL YES it is!!

The difference being the proximity of flammable materials to the point
where the sparks are being generated.

The point might be that oil lines are more prone to vibration
than a length of cable of whatever gauge.

"Instant" spark across the gap, With a ready supply of fuel being
delivered
to the scene.

The fuel being lubricating oil, I fancy a tremendous lot of sparks
would be required to actually make it fire.

You, sir, "don't know what you DON'T KNOW" about the size of the sparks
that get generated when a conductor carrying multiple tens of amps
is unexpectedly severed. (#2AWG copper is rated for in excess of 125
Amps.)

I'll gladly allow I've much to learn,
that's why I'm hanging around here.

Yet it seems clear to me that, in the average GA aircraft,
tens of amps will only be drawn during starting
(which admittedly is a strong moment for vibration)

Actually make that HUNDREDS of amps.

OR how easily 'lubricating oils' can be "convinced" to combust. No, they
are not very 'volatile' -- so they don't vaporize by themselves -- but
they 'atomize' fairly easily, which can, and often does, make for an
explosive
mixture.

On this point I'm grateful to learn from you.
KA

In article ,
Bashir Salamti wrote:

On Mon, 5 Sep 2005 19:01:47 -0000, "karel"
wrote:
:
:The fuel being lubricating oil, I fancy a tremendous lot of sparks
:would be required to actually make it fire.

Actually, no.

It is not just lubricating oil, it is hot - around the temperature of
boiling water. And it is under 50 PSI, or so. So a small leak may
not be a drip, it is rather an atomizing spray. If there is a small
arc present at the same time it will certainly catch fire. Because it
is heavy bodied, there will be a percentage that adheres to the
surrounding surfaces, like napalm, rather than vaporizing and blowing
away - although in side the cabin the wind will be rather less than in
an engine compartment.

The same is true with cooling lines for a liquid cooled engine.
Glycol will burn nicely if you give it half a chance.

I'm not disagreeing with anything that you or anyone else has said on
this topic, but I will point out what appears to me to be a small hole
in your logic. If the oil line were to develop a pin-hole -- as opposed
to severing -- there might well be an "atomizing spray," but there won't
be an arc, because, obviously, the electrical path would still be
continuous.