Today's Message Index:
----------------------
1. 02:21 AM - Mags (Mark Jefferies YAK UK)
2. 03:13 AM - plugs (Mark Jefferies YAK UK)
3. 05:17 AM - Re: Mags (cjpilot710@aol.com)
4. 07:39 AM - Spark plugs (Dean Courtney)
5. 08:15 AM - Re: Mags (A. Dennis Savarese)
6. 08:16 AM - Re: Re: Spark Plugs (A. Dennis Savarese)
7. 11:52 AM - Spark Plugs (Walt Lannon)
8. 01:30 PM - Re: Spark Plugs (Jim and Vivian)
9. 03:06 PM - Spark Plug Heat Range (cpayne@joimail.com)
10. 04:41 PM - Re: Spark Plug Heat Range (Frank Haertlein)
11. 05:10 PM - Re: Spark Plugs (A. Dennis Savarese)
12. 05:13 PM - Re: Spark Plugs (A. Dennis Savarese)
13. 07:09 PM - Re: Oil Temperatures (Brian Lloyd)
14. 07:55 PM - Re: Oil Temperatures (Walt Lannon)
Message 1
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--> Yak-List message posted by: Mark Jefferies YAK UK <mark.j@yakuk.com>
Three problems mostly with mags.
1. missfiring after 20-25 mins, (sometimes you wont even notice this.) coil.
2. Condenser failure.
3. cap cracked
Note 1. the miss fire will show after heat soak, the insulation is breaking down
in the coil, this will become more common with time.
Note 2. Burning points.
So what do we do? Rewind the coils but here is a problem, the Russians were very
clever and wound the condenser between the primary and secondary windings, no
company or individual in the UK has access to this procedure or materials. So
we wind the coils in a "standard" way and put a commersial capaciter conveniantly
mounted in the housing. i have seen some externaly mounted but that was
a long time ago (perhaps smaller condensers now)
After the coil is wound in temprature controled conditions it is then gently cooked
for a few days to remove any possible moisture and then it is resin pimreganted
in a vacume.
So now you have a coil but as any wise man will knew thats only part of the electrical
story. You will need to remagnatise the unit, this is done with many 12v
batteries in parrallel to get the required current, I dont know what that is
sorry. bearings, insulaters and contacts make up the full overhaul.
There is only 1 man I know in the UK who works alone doing this work in the UK.
We supply most of his work!! But he does have vintage cars, tracters, and every
other machine to attend to so is very busy.
There are other problems, like the wire for the coils, UK manufactures have stopped
producing, the "wax paper" between the windings again problems in obtaing.
Then there is the disimilare metals used on the contacts, not such a problem but
still one to consider.
So when you find an "OLD TIMER" who has the knowledge and machineray to do this
work feed him as many mags as possible before his skills are lost.
SUGGESTION, when you next fly and on an irregulare basis after 30 mins flight go
to WOT and pull the pitch to full course then try the mags, any missfire and
its teh coil breaking down, get a new mag!!
There are other HT issues, like tracking in the plug cap with mosture or a cracked
cap, tracking along the ceramic cigarette ends, leads cracked on on a humid
day only showing, carbon contact in cap woren out, spring in cap broken, carbon
foiling of plugs due to worn cylinders and lots of oil being burned, I'm
sure there are others also.
good luck. MJ
Alternatives will only be electronic ignition in the fullnes of time.
--> Yak-List message posted by: "Yakjock" <Yakjock@msn.com>
Has anyone found a reliable place for magneto overhauls? Shane Wease (my
mechanic)
and I sent my harness to Savage Magneto and they did a great rebuild. Only
problem is that the rubber wear sleeves have become heavily cracked during
the year the harness has been in my hangar waiting to go back onto the project.
These will have to be replaced before we can use the harness.
Regarding mags, several of us sent about five mags to Al at Savage Magneto
for
overhaul. He kept them for about six months or so and finally sent them
back
without having worked on them. Apparently new jobs kept coming in the door
and
our stuff kept being pushed farther back in his shop. We are still looking
for someone to do an overhaul. Would appreciate any suggestions.
Hal
Best regards, Mark
www.yakuk.com
+44 (0)1767 651156 office +44 (0)7785 538 317 mobile
Message 2
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--> Yak-List message posted by: Mark Jefferies YAK UK <mark.j@yakuk.com>
we find the champion last about 150-200 hrs expencive but can be cheaper in the
long run.
RA plugs about 200- 250 hrs but if you go past 200 your on the down hill to blowing
out!!
Never fit an RA plug if its been dropped, I feel that can lead to a blow out. 9cracked
or loose insulator)
We did have a plug go just before its first 50 hrs check once.
Of about 60 a/c fling on average (loggged time) 30 - 100 hrs per year we find about
2 plugs per year blow, so the average is quite low but still puts the wind
up the pilot!!
cheers, MJ
--> Yak-List message posted by: "A. Dennis Savarese" <DSAVARESE@ELMORE.RR.COM>
Yes Steve, based on what I've seen in other M14's, that's quite unusual.
I
don't know if the heat range is too hot or too cold. But I have been told
by a couple of engine experts these plugs were selected because they were
the only ones that were 14 mm when the westernization began. My guess is
they're too cold. But that's strictly a guess. The most I have seen last
between 100 and 200 hours.
As for the automotive spark plug, they were tested "under fire" (no pun
intended) to determine the best operational heat range. The testing was
done on a Sukhoi. Sukhoi's tend to be operated at the extremes. I've
subjected mine to some really extreme cylinder head temperatures just to
see
what happens and not one single hiccup.
Dennis
Best regards, Mark
www.yakuk.com
+44 (0)1767 651156 office +44 (0)7785 538 317 mobile
Message 3
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--> Yak-List message posted by: cjpilot710@aol.com
I had the original mags that came with my M-14 overhauled by Carl Hays.
After some problems that had nothing to do with Carl's work. They are running fine
with just about 100 hours on them at this point.
Jim "Pappy" Goolsby
Message 4
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--> Yak-List message posted by: "Dean Courtney" <deancourtney696@hotmail.com>
Gents,
Great info on auto plugs, right up to the point where you tell us all what
the heck plug model & manufacturer you are using/recommend.
Cheers,
Dean Courtney
Message 5
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--> Yak-List message posted by: "A. Dennis Savarese" <DSAVARESE@ELMORE.RR.COM>
Isn't it amazing that those of us who have experienced a mag misfiring
problem caused by the coil always have it occur in the 20-30 minutes of
operation. When it does occur, it feels like the engine literally shuts
down for a couple of milliseconds. It DOES get your attention!
Dennis
----- Original Message -----
From: "Mark Jefferies YAK UK" <mark.j@yakuk.com>
Subject: Yak-List: Mags
> --> Yak-List message posted by: Mark Jefferies YAK UK <mark.j@yakuk.com>
>
>
> Three problems mostly with mags.
>
> 1. missfiring after 20-25 mins, (sometimes you wont even notice this.)
coil.
> 2. Condenser failure.
> 3. cap cracked
> Note 1. the miss fire will show after heat soak, the insulation is
breaking down in the coil, this will become more common with time.
> Note 2. Burning points.
> So what do we do? Rewind the coils but here is a problem, the Russians
were very clever and wound the condenser between the primary and secondary
windings, no company or individual in the UK has access to this procedure or
materials. So we wind the coils in a "standard" way and put a commersial
capaciter conveniantly mounted in the housing. i have seen some externaly
mounted but that was a long time ago (perhaps smaller condensers now)
> After the coil is wound in temprature controled conditions it is then
gently cooked for a few days to remove any possible moisture and then it is
resin pimreganted in a vacume.
>
> So now you have a coil but as any wise man will knew thats only part of
the electrical story. You will need to remagnatise the unit, this is done
with many 12v batteries in parrallel to get the required current, I dont
know what that is sorry. bearings, insulaters and contacts make up the full
overhaul.
>
> There is only 1 man I know in the UK who works alone doing this work in
the UK. We supply most of his work!! But he does have vintage cars,
tracters, and every other machine to attend to so is very busy.
>
> There are other problems, like the wire for the coils, UK manufactures
have stopped producing, the "wax paper" between the windings again problems
in obtaing.
>
> Then there is the disimilare metals used on the contacts, not such a
problem but still one to consider.
>
> So when you find an "OLD TIMER" who has the knowledge and machineray to do
this work feed him as many mags as possible before his skills are lost.
>
> SUGGESTION, when you next fly and on an irregulare basis after 30 mins
flight go to WOT and pull the pitch to full course then try the mags, any
missfire and its teh coil breaking down, get a new mag!!
>
> There are other HT issues, like tracking in the plug cap with mosture or a
cracked cap, tracking along the ceramic cigarette ends, leads cracked on on
a humid day only showing, carbon contact in cap woren out, spring in cap
broken, carbon foiling of plugs due to worn cylinders and lots of oil being
burned, I'm sure there are others also.
>
> good luck. MJ
>
> Alternatives will only be electronic ignition in the fullnes of time.
> --> Yak-List message posted by: "Yakjock" <Yakjock@msn.com>
>
> Has anyone found a reliable place for magneto overhauls? Shane
Wease (my mechanic)
> and I sent my harness to Savage Magneto and they did a great
rebuild. Only
> problem is that the rubber wear sleeves have become heavily cracked
during
> the year the harness has been in my hangar waiting to go back onto
the project.
> These will have to be replaced before we can use the harness.
>
> Regarding mags, several of us sent about five mags to Al at Savage
Magneto for
> overhaul. He kept them for about six months or so and finally sent
them back
> without having worked on them. Apparently new jobs kept coming in
the door and
> our stuff kept being pushed farther back in his shop. We are still
looking
> for someone to do an overhaul. Would appreciate any suggestions.
>
> Hal
>
>
> Best regards, Mark
> www.yakuk.com
> +44 (0)1767 651156 office +44 (0)7785 538 317 mobile
>
>
Message 6
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| Subject: | Re: RE: Spark Plugs |
--> Yak-List message posted by: "A. Dennis Savarese" <DSAVARESE@ELMORE.RR.COM>
Great feedback Jim. Thanks
Dennis
----- Original Message -----
From: "Jim Martyn" <vertigo@whidbey.net>
Subject: Re: Yak-List: RE: Spark Plugs
> --> Yak-List message posted by: "Jim Martyn" <vertigo@whidbey.net>
>
> Steve,
> I'm not Dennis, but I do have some experience with Automotive plugs. In my
> case, we determined the correct heat range by instrumenting the the CHTs
and
> EGTs and (using the Russian plugs as a baseline) then tested at least 15
> different auto plug types, each in various heat ranges. Almost all of them
> produced significantly superior combustion events than did the Russian
> plugs, and did so over the entire power range with far less evidence of
> fouling than those crummy Russky things.
>
> Remember, the heat rating of the plug DOES NOT refer to any ability to
> produce heat - the plug is passive - instead it refers to the plug's
> relative rate of dissipation of combustion heat out to the cylinder head.
> The question to ask is why you would want to increase or decrease the rate
> of heat dissipation to the cylinder head. It is my feeling that this
> question is of secondary importance. The more important question is how a
> more vigorously firing plug may be affecting the combustion event and
> whether the timing should be altered to better harness that event...
>
> Jim
>
> ----- Original Message -----
> From: "Steve Dalton" <sdalton@goeaston.net>
> To: <yak-list@matronics.com>
> Subject: Yak-List: RE: Spark Plugs
>
>
> > Dennis, I'm just curious;
> > --if the heat range of the REL37B is wrong, is it too hot, or too cold?
> > --the REL37B plugs in my M14PF have 400 hours on them, with no
> > problems...is that unusual?
> > --how long should one expect them to last?
> > --if someone converts to automotive plugs, how do they determine the
> > correct heat range plug?
> >
> > Thanks,
> > Steve Dalton
> >
> >
> >
>
>
Message 7
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--> Yak-List message posted by: "Walt Lannon" <wlannon@cablerocket.com>
----- Original Message -----
From: Walt Lannon
Subject: Spark Plugs
Lots of interesting posts on this lately. A few comments and questions of my own
for anyone.
Automotive spark plugs - What about avionics interference due to lack of shielding,
has someone found a way to shield them. Standard auto plug wire connector
does not inspire a lot of confidence for an aircraft installation.
Russian plug failures - No experience with the Russian spark plug but whenever
I hear of a blow out I wonder about installation torque. The M14 manual allows
29 lb/ft. That may be too high.
A 14mm spark plug has thinner walls and much lower strength than the 18mm. All
it takes to cause this type of failure is a small stretching of the case. This
will break the gas seal and crack the porcelain.
Recommended torque varies with engine manufacturers, In the case of 18mm 30 lb/ft
would be about average but could be as high as 40 lb/ft (Curtis Wright). Plug
manufacturers would ensure their product is compatible.
I seem to recall (from the distant past) a torque limit for 14mm plugs of 15 to
20 lb/ft.
Does anyone have a torque specification from Champion for their 14mm product? That
would be of interest but not necessarily applicable to the Russian or Chinese
plug. Maybe different steel grades and thicknesses.
I have not yet seen any failure with the Chinese plug but I tighten those with
the about 7" Chinese wrench. Very subjective but, for me, gives about 18 to 20
lb/ft.
Some spark plug rules -----
1. If you drop it SCRAP it - whether it is Russian, American, Chinese or Tibetan
2. NEVER install a plug in a hot engine
3. Always use new or freshly annealed washers (replace if too thin, damaged or
distorted in any way)
Walt
Message 8
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--> Yak-List message posted by: "Jim and Vivian" <jimscjs@mbay.net>
Yes 15-20 ft.lbs is right for the Chinese and Russian Plugs. I agree maybe
there being over torqued, it's easy to do, 15-20 lbs dosen't seem like much
torque.
Jim
----- Original Message -----
From: "Walt Lannon" <wlannon@cablerocket.com>
Subject: Yak-List: Spark Plugs
> --> Yak-List message posted by: "Walt Lannon" <wlannon@cablerocket.com>
>
>
> ----- Original Message -----
> From: Walt Lannon
> To: yak-list@matronics.com
> Subject: Spark Plugs
>
>
> Lots of interesting posts on this lately. A few comments and questions of
my own for anyone.
>
> Automotive spark plugs - What about avionics interference due to lack of
shielding, has someone found a way to shield them. Standard auto plug wire
connector does not inspire a lot of confidence for an aircraft installation.
>
> Russian plug failures - No experience with the Russian spark plug but
whenever I hear of a blow out I wonder about installation torque. The M14
manual allows 29 lb/ft. That may be too high.
> A 14mm spark plug has thinner walls and much lower strength than the 18mm.
All it takes to cause this type of failure is a small stretching of the
case. This will break the gas seal and crack the porcelain.
> Recommended torque varies with engine manufacturers, In the case of 18mm
30 lb/ft would be about average but could be as high as 40 lb/ft (Curtis
Wright). Plug manufacturers would ensure their product is compatible.
> I seem to recall (from the distant past) a torque limit for 14mm plugs of
15 to 20 lb/ft.
> Does anyone have a torque specification from Champion for their 14mm
product? That would be of interest but not necessarily applicable to the
Russian or Chinese plug. Maybe different steel grades and thicknesses.
> I have not yet seen any failure with the Chinese plug but I tighten those
with the about 7" Chinese wrench. Very subjective but, for me, gives about
18 to 20 lb/ft.
>
> Some spark plug rules -----
> 1. If you drop it SCRAP it - whether it is Russian, American, Chinese or
Tibetan
> 2. NEVER install a plug in a hot engine
> 3. Always use new or freshly annealed washers (replace if too thin,
damaged or distorted in any way)
>
> Walt
>
>
Message 9
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| Subject: | Spark Plug Heat Range |
--> Yak-List message posted by: "cpayne@joimail.com" <cpayne@joimail.com>
Speaking of Automotive plugs...the latest "fine wire"
precious metal plugs offer a much greater heat range than
conventional tip plugs. The flame front is spread over a
greater area and not as much heat is conducted by the plug
itself as the plug stays cooler, yet the spark is hotter.
BTW, this type of plug exploits the high energy spark
systems to a greater degree than conventional "hook" tips.
So what does this mean for an M-14 type engine?? It means
little-to-no fouling and a more efficient burn, hence better
economy and smoothness, also more power. By less fouling I
mean that the plugs will actually fire in oil, but not in
severe carbon-lead byproducts from maladjusted carbs and
improper operation, such as running too cold a CHT and Oil
Temp and too rich.
Craig Payne
Message 10
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| Subject: | Spark Plug Heat Range |
--> Yak-List message posted by: "Frank Haertlein" <yak52driver@earthlink.net>
Craig, Yakkers
When we talk about automotive type "fine wire" plugs we need to consider
practical experience. A good example is the BOSCH platinum plugs. Many,
including myself, have learned firsthand that the needle thin precious
metal comprising the center electrode wears at a rate higher than even
the normal steel center electrode of a garden variety plug. Every spark
erodes the metal imperceptibly and with the high energy ignition systems
on most modern cars that wear rate is increased. A platinum center
electrode measuring .015 isn't going to last as long as a steel center
electrode measuring .20 despite the fact that platinum is more resistant
to spark erosion. I can attest to this firsthand. I put the most
expensive platinum electrode plugs in my car and they wore out sooner
than the cheapest plug you could buy. The thin "fine wire" technology
gives a very short plug life (especially with the high energy ignition
systems of today). Spark plug designers have done extensive testing on
their automotive plugs to determine the maximum life of a fine wire plug
and then manufactured them to "decrease their life span" (Planned
obsolescence). Fine wire plug technology is a load of cra&!
Stick to the original Russian or Chinese plugs and you won't have a
problem.
Frank
N9110M
YAK-52
L71
-----Original Message-----
From: owner-yak-list-server@matronics.com
[mailto:owner-yak-list-server@matronics.com] On Behalf Of
cpayne@joimail.com
Subject: Yak-List: Spark Plug Heat Range
--> Yak-List message posted by: "cpayne@joimail.com"
--> <cpayne@joimail.com>
Speaking of Automotive plugs...the latest "fine wire"
precious metal plugs offer a much greater heat range than conventional
tip plugs. The flame front is spread over a greater area and not as much
heat is conducted by the plug itself as the plug stays cooler, yet the
spark is hotter. BTW, this type of plug exploits the high energy spark
systems to a greater degree than conventional "hook" tips.
So what does this mean for an M-14 type engine?? It means little-to-no
fouling and a more efficient burn, hence better economy and smoothness,
also more power. By less fouling I mean that the plugs will actually
fire in oil, but not in severe carbon-lead byproducts from maladjusted
carbs and improper operation, such as running too cold a CHT and Oil
Temp and too rich.
Craig Payne
Message 11
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--> Yak-List message posted by: "A. Dennis Savarese" <DSAVARESE@ELMORE.RR.COM>
Walt,
The Taylor 8 mm Racing wires are Spiro-wrapped and eliminate all avionics
interference.
Dennis
----- Original Message -----
From: "Walt Lannon" <wlannon@cablerocket.com>
Subject: Yak-List: Spark Plugs
> --> Yak-List message posted by: "Walt Lannon" <wlannon@cablerocket.com>
>
>
> ----- Original Message -----
> From: Walt Lannon
> To: yak-list@matronics.com
> Subject: Spark Plugs
>
>
> Lots of interesting posts on this lately. A few comments and questions of
my own for anyone.
>
> Automotive spark plugs - What about avionics interference due to lack of
shielding, has someone found a way to shield them. Standard auto plug wire
connector does not inspire a lot of confidence for an aircraft installation.
>
> Russian plug failures - No experience with the Russian spark plug but
whenever I hear of a blow out I wonder about installation torque. The M14
manual allows 29 lb/ft. That may be too high.
> A 14mm spark plug has thinner walls and much lower strength than the 18mm.
All it takes to cause this type of failure is a small stretching of the
case. This will break the gas seal and crack the porcelain.
> Recommended torque varies with engine manufacturers, In the case of 18mm
30 lb/ft would be about average but could be as high as 40 lb/ft (Curtis
Wright). Plug manufacturers would ensure their product is compatible.
> I seem to recall (from the distant past) a torque limit for 14mm plugs of
15 to 20 lb/ft.
> Does anyone have a torque specification from Champion for their 14mm
product? That would be of interest but not necessarily applicable to the
Russian or Chinese plug. Maybe different steel grades and thicknesses.
> I have not yet seen any failure with the Chinese plug but I tighten those
with the about 7" Chinese wrench. Very subjective but, for me, gives about
18 to 20 lb/ft.
>
> Some spark plug rules -----
> 1. If you drop it SCRAP it - whether it is Russian, American, Chinese or
Tibetan
> 2. NEVER install a plug in a hot engine
> 3. Always use new or freshly annealed washers (replace if too thin,
damaged or distorted in any way)
>
> Walt
>
>
Message 12
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--> Yak-List message posted by: "A. Dennis Savarese" <DSAVARESE@ELMORE.RR.COM>
I'm sure that 15-20 ft. lbs is ok, but that is not the spec on the Russian
plugs. The spec is 22-28 ft. lbs. per the M14 manual. This has been
cussed and discussed many times on the list.
Dennis
.
----- Original Message -----
From: "Jim and Vivian" <jimscjs@mbay.net>
Subject: Re: Yak-List: Spark Plugs
> --> Yak-List message posted by: "Jim and Vivian" <jimscjs@mbay.net>
>
> Yes 15-20 ft.lbs is right for the Chinese and Russian Plugs. I agree maybe
> there being over torqued, it's easy to do, 15-20 lbs dosen't seem like
much
> torque.
> Jim
> ----- Original Message -----
> From: "Walt Lannon" <wlannon@cablerocket.com>
> To: <yak-list@matronics.com>
> Subject: Yak-List: Spark Plugs
>
>
> > --> Yak-List message posted by: "Walt Lannon" <wlannon@cablerocket.com>
> >
> >
> > ----- Original Message -----
> > From: Walt Lannon
> > To: yak-list@matronics.com
> > Subject: Spark Plugs
> >
> >
> > Lots of interesting posts on this lately. A few comments and questions
of
> my own for anyone.
> >
> > Automotive spark plugs - What about avionics interference due to lack of
> shielding, has someone found a way to shield them. Standard auto plug wire
> connector does not inspire a lot of confidence for an aircraft
installation.
> >
> > Russian plug failures - No experience with the Russian spark plug but
> whenever I hear of a blow out I wonder about installation torque. The M14
> manual allows 29 lb/ft. That may be too high.
> > A 14mm spark plug has thinner walls and much lower strength than the
18mm.
> All it takes to cause this type of failure is a small stretching of the
> case. This will break the gas seal and crack the porcelain.
> > Recommended torque varies with engine manufacturers, In the case of 18mm
> 30 lb/ft would be about average but could be as high as 40 lb/ft (Curtis
> Wright). Plug manufacturers would ensure their product is compatible.
> > I seem to recall (from the distant past) a torque limit for 14mm plugs
of
> 15 to 20 lb/ft.
> > Does anyone have a torque specification from Champion for their 14mm
> product? That would be of interest but not necessarily applicable to the
> Russian or Chinese plug. Maybe different steel grades and thicknesses.
> > I have not yet seen any failure with the Chinese plug but I tighten
those
> with the about 7" Chinese wrench. Very subjective but, for me, gives about
> 18 to 20 lb/ft.
> >
> > Some spark plug rules -----
> > 1. If you drop it SCRAP it - whether it is Russian, American, Chinese
or
> Tibetan
> > 2. NEVER install a plug in a hot engine
> > 3. Always use new or freshly annealed washers (replace if too thin,
> damaged or distorted in any way)
> >
> > Walt
> >
> >
>
>
Message 13
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| Subject: | Re: Oil Temperatures |
--> Yak-List message posted by: Brian Lloyd <brianl@lloyd.com>
On Jan 8, 2005, at 12:01 AM, Walt Lannon wrote:
> least 30 degs. is specified in the CJ manual and you should NEVER
> apply full
> power below that.
I was under the impression that this was because the oil pressure could
rise too high if the oil was too "thick" and therefore this was not a
problem with multi-vis oils.
> Maximum continuous is 75 degs with an allowance of 85 degs. for not
> over 15
> minutes.
>
> The maximum oil OUT (oil just leaving the engine) temperature is 125
> degs.C.
>
> I would normally expect about a 30 degs. difference between in and out
> temps. If you are operating in a cold area you need to control the
> airflow
> through the cooler by restricting the entrance area and make sure the
> exit
> is almost, but not quite, fully closed when the control is in that
> position.
> The temps. you describe indicate excessive cooling is taking place
> which
> would of course increase the differential between in and out
> temperatures.
>
> As noted temps. are measured at the engine, not the oil cooler. In the
> CJ
> the oil travels a long way to and from the cooler and cooling is taking
> place while it's doing that.
>
> Monitoring of oil out temperature has never been a requirement in
> Western
> aircraft. It is monitored during test and break-in running of new or
> overhauled engines.
And I never understood that because seeing the difference between inlet
oil temp and outlet oil temp tells you something about what is going on
inside the engine. OTOH, the mass of the engine is so much greater
than the mass of the oil that you could get a big rise if you
overcooled the oil going into the engine.
Brian Lloyd 6501 Red Hook Plaza
brianl@lloyd.com Suite 201
+1.340.998.9447 St. Thomas, VI 00802
I fly because it releases my mind from the tyranny of petty things . . .
Antoine de Saint-Exupry
Message 14
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| Subject: | Re: Oil Temperatures |
--> Yak-List message posted by: "Walt Lannon" <wlannon@cablerocket.com>
----- Original Message -----
From: "Brian Lloyd" <brianl@lloyd.com>
Subject: Re: Yak-List: Oil Temperatures
> --> Yak-List message posted by: Brian Lloyd <brianl@lloyd.com>
>
> On Jan 8, 2005, at 12:01 AM, Walt Lannon wrote:
> > least 30 degs. is specified in the CJ manual and you should NEVER
> > apply full
> > power below that.
>
> I was under the impression that this was because the oil pressure could
> rise too high if the oil was too "thick" and therefore this was not a
> problem with multi-vis oils.
Rather than being a problem of excess pressure I think the concern is the
oil is too "thick" to flow and lubricate properly at cold temperatures. Most
certainly the multi grades improve that situation but whether it eliminates
the problem I think is questionable.
I have been using 25W60 in the R1340 ever since it became available. I still
follow P&W recommendations and do not exceed 1000 RPM until the oil temp.
reaches 40 degs.C. P&W did not change that with their acceptance of
multi-grades.
No question the multi-grade is an improvement, the oil will reach 40 degs
much quicker than straight weight 100 or 120.
Walt
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