Today's Message Index:
----------------------
1. 12:49 AM - Fw: emailing photo test (Kevin Pilling)
2. 01:31 AM - Fuel and M14P (Richard Goode)
3. 06:49 AM - Re: Fuel and M14P (Roger Kemp)
4. 07:20 AM - Re: Fuel and M14P (MajorGoofinoff@aol.com)
5. 11:14 AM - Re: A couple of things (Brian Lloyd)
6. 11:32 AM - Re: Fuel and M14P (Brian Lloyd)
7. 11:34 AM - Re: Fuel and M14P (Brian Lloyd)
8. 11:36 AM - Re: Fuel and M14P (Brian Lloyd)
9. 03:27 PM - Re: Fuel and M14P (John W. Cox)
10. 05:18 PM - Re: A couple of things (Bitterlich GS11 Mark G)
11. 05:21 PM - Re: Fuel and M14P (Brian Lloyd)
12. 05:28 PM - Re: Fuel and M14P (Bitterlich GS11 Mark G)
13. 05:48 PM - Re: A couple of things (Brian Lloyd)
14. 05:50 PM - Re: Fuel and M14P (Brian Lloyd)
15. 06:12 PM - Re: Fuel and M14P (A. Dennis Savarese)
16. 06:13 PM - Re: Fuel and M14P (Kelley Monroe)
17. 07:24 PM - Re: Fuel and M14P (Roger Kemp)
18. 09:15 PM - Re: Fuel and M14P (cjpilot710@aol.com)
Message 1
| INDEX | Back to Main INDEX |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Fw: emailing photo test |
Do not archive
Test only
Fly safe
kp
Message 2
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
0.15 HTML_TEXT_AFTER_BODY BODY: HTML contains text after BODY close tag
There are three issues for those considering motor fuel in the M14P:
Octane rating - motor fuel and aviation fuel are measured in different ways. 100LL
Avgas is, I believe, equivalent to about 110 octane on the Motor Research
Method.
The M14P is cleared to run down to 92 octane on the Motor Research Method. I would
suggest that 87 octane is too low, and possibly could cause pre-ignition
and detonation. Obviously octane requirements will be higher for 400-hp and above
versions.
Volatility - automotive fuels not only vary in volatility (100LL never changes)
according to seasons, but also according to manufacturers. On a Yak-52 you are
sucking fuel from the tanks up into the engine, and this coupled with a hot
day will exacerbate the problem - i.e. the fuel will literally boil but virtue
of the reduced pressure and, quite simply, your engine won't run on vapour.
High ambient temperature and altitude will of course exacerbate the problem.
Lead content - it way never thought that the M14P would run on unleaded fuel and
the Russians view is that it should always have a reasonable amount of lead
in the fuel - hence a need to use a certain amount of 100LL, otherwise there is
potentially problems of valve-seat erosion etc.
My suggestion is to mix 100LL and a minimum of 95 octane fuel, and experiment be
reducing the proportion of 100LL, being aware that your engine may have a problem
at a stage.
Richard Goode
Richard Goode Aerobatics
Rhodds Farm
Lyonshall
Hereford
HR5 3LW
United Kingdom
Tel: +44 (0) 1544 340120
Fax: +44 (0) 1544 340129
www.russianaeros.com
dangerous content by the http://www.invictawiz.com
MailScanner, and is believed to be clean.
Message 3
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
Thanks for the insight ol'boy. For me, right now I'll stick with 100LL. When the
cost of AV gas goes up more and autogas comes down, I'll make the change. Everybody
is forgetting about thecorrosion on the backflow valves on the fuel lines
coming from the main tanks to the header tank. They can stick or freeze up
with pure auto gas.
Doc
----- Original Message -----
From: Richard Goode
Subject: Yak-List: Fuel and M14P
There are three issues for those considering motor fuel in the M14P:
Octane rating - motor fuel and aviation fuel are measured in different ways. 100LL
Avgas is, I believe, equivalent to about 110 octane on the Motor Research
Method.
The M14P is cleared to run down to 92 octane on the Motor Research Method. I would
suggest that 87 octane is too low, and possibly could cause pre-ignition
and detonation. Obviously octane requirements will be higher for 400-hp and above
versions.
Volatility - automotive fuels not only vary in volatility (100LL never changes)
according to seasons, but also according to manufacturers. On a Yak-52 you are
sucking fuel from the tanks up into the engine, and this coupled with a hot
day will exacerbate the problem - i.e. the fuel will literally boil but virtue
of the reduced pressure and, quite simply, your engine won't run on vapour.
High ambient temperature and altitude will of course exacerbate the problem.
Lead content - it way never thought that the M14P would run on unleaded fuel and
the Russians view is that it should always have a reasonable amount of lead
in the fuel - hence a need to use a certain amount of 100LL, otherwise there is
potentially problems of valve-seat erosion etc.
My suggestion is to mix 100LL and a minimum of 95 octane fuel, and experiment be
reducing the proportion of 100LL, being aware that your engine may have a problem
at a stage.
Richard Goode
Richard Goode Aerobatics
Rhodds Farm
Lyonshall
Hereford
HR5 3LW
United Kingdom
Tel: +44 (0) 1544 340120
Fax: +44 (0) 1544 340129
www.russianaeros.com
dangerous content by http://www.invictawiz.com
and is believed to be clean.
Message 4
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Fuel and M14P |
I tried mogas years ago. 50/50 mix worked great. Cheaper than 100LL, but
with a little lead for flavor.
Major Goofinoff.
Yak52
Message 5
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: A couple of things |
--> Yak-List message posted by: Brian Lloyd <brian-yak@lloyd.com>
Cliff Umscheid wrote:
> Mark
> In your use of that 50-50 mixture, are you using full throttle
> position on takeoff? Do you make any effort to limit the percentage of
> T.O. RPM to 100% ,or is your prop set to only allow you to achieve
> 100% at full throttle? Some folks are "tweeking" the gov. adjustment
> to 102% at T.O. throttle to get extra advantage in the vertical . Of
> course, they are using 100LL.
> Does the M 14 P and PF have an "nrichment jet " in the
> carburetor which opens at the full throttle position ?
> How much MMO are you using with a full tank of gasoline?
Detonation is mostly a function of BMEP (a measure of cylinder pressure) which
is proportional to MAP, not to RPM. Bumping up the RPM will not increase the
likelihood of detonation. Pushing the MAP up will.
For that matter, a 20 degree change in OAT is going to have a much greater
effect on detonation margin than is a 2% change in RPM.
--
Brian Lloyd 2243 Cattle Dr.
brian-yak@lloyd.com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
- Antoine de Saint-Exupery
Message 6
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Fuel and M14P |
--> Yak-List message posted by: Brian Lloyd <brian-yak@lloyd.com>
Richard Goode wrote:
> There are three issues for those considering motor fuel in the M14P:
>
> Octane rating - motor fuel and aviation fuel are measured in different
> ways. 100LL Avgas is, I believe, equivalent to about 110 octane on the
> Motor Research Method.
>
> The M14P is cleared to run down to 92 octane on the Motor Research
> Method. I would suggest that 87 octane is too low, and possibly could
> cause pre-ignition and detonation. Obviously octane requirements will
> be higher for 400-hp and above versions.
But that implies that 91 octane mogas is more than adequate as mogas in the US
is the average of the motor and research method (I made a mistake yesterday
when I used the word "radical", having forgotten what the 'R' stood for). As I
understand it, the research method tends to produce an octane number lower
than the motor method therefore mogas with an octane rating of 91 based on
(R+M)/2 has a motor octane rating higher than 91. This implies that the M14P
should run very happily (and safely) on premium auto fuel in the US.
I would not try to run the 400hp M14 on mogas unless I did a test such as that
suggested by Mr. Peterson, i.e. testing at increasing MAP and checking the
tops of the pistons after each run.
> Volatility - automotive fuels not only vary in volatility (100LL never
> changes) according to seasons, but also according to manufacturers. On a
> Yak-52 you are sucking fuel from the tanks up into the engine, and this
> coupled with a hot day will exacerbate the problem - i.e. the fuel will
> literally boil but virtue of the reduced pressure and, quite simply,
> your engine won't run on vapour. High ambient temperature and altitude
> will of course exacerbate the problem.
But that is independent of the engine. I ran my CJ6A almost exclusively on
mogas when at home. The only time it got 100LL was when I was on the road and
mogas was not available. Even on the hottest days I never had a problem with
fuel pressure or vapor lock. Given the similarities in the fuel systems
between the Yak-52 and the CJ6A, I would expect similar results.
Of course, if you DO have a problem with vapor lock it can ruin your whole
day! But it should be apparent on the ground by letting the airplane heat soak
on a hot summer day and then perform a full-power ground run. The other place
it will show up is at altitude so take it up to 14,000' and see if you have a
problem there.
Again, I never saw the slightest problem with the CJ6A. YMMV.
> Lead content - it way never thought that the M14P would run on unleaded
> fuel and the Russians view is that it should always have a reasonable
> amount of lead in the fuel - hence a need to use a certain amount of
> 100LL, otherwise there is potentially problems of valve-seat erosion etc.
The lead does not need to be present all the time. Peterson recommends running
about every 10th tank with 100LL to maintain lead on the valves. The rest of
the time you can run on 100% mogas.
As an aside, I never had lead fouling on plugs (no surprise) and plug erosion
was lower. In my Huosai I ran my first set of plugs for 600 hours before
replacing them. The electrodes were still serviceable but I was getting
uncomfortable with plugs being in there that long. Still, that is a long time
for one set of plugs.
> My suggestion is to mix 100LL and a minimum of 95 octane fuel, and
> experiment be reducing the proportion of 100LL, being aware that your
> engine may have a problem at a stage.
We don't get 95 octane fuel here but then, we probably measure the octane
differently here, i.e. (R+M)/2. Our "91" octane may be equivalent to your 95
octane mogas there.
--
Brian Lloyd 2243 Cattle Dr.
brian-yak@lloyd.com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
- Antoine de Saint-Exupery
Message 7
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Fuel and M14P |
--> Yak-List message posted by: Brian Lloyd <brian-yak@lloyd.com>
Roger Kemp wrote:
> Thanks for the insight ol'boy. For me, right now I'll stick with 100LL.
> When the cost of AV gas goes up more and autogas comes down, I'll make
> the change. Everybody is forgetting about thecorrosion on the backflow
> valves on the fuel lines coming from the main tanks to the header tank.
> They can stick or freeze up with pure auto gas.
That is an issue with mogas that sits. If you are not going to fly very often,
use 100LL as it does not gum up the way that mogas does when it sits. If you
are flying all the time and refilling the tank every week or so, it will not
be an issue.
--
Brian Lloyd 2243 Cattle Dr.
brian-yak@lloyd.com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
- Antoine de Saint-Exupery
Message 8
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Fuel and M14P |
--> Yak-List message posted by: Brian Lloyd <brian-yak@lloyd.com>
Richard Goode wrote:
> The M14P is cleared to run down to 92 octane on the Motor Research
> Method.
Is it the motor method or the research method? I thought that most engines
used the motor method.
BTW, a good treatise on this is at:
http://www.prime-mover.org/Engines/GArticles/octane.html
--
Brian Lloyd 2243 Cattle Dr.
brian-yak@lloyd.com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
- Antoine de Saint-Exupery
Message 9
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
--> Yak-List message posted by: "John W. Cox" <johnwcox@pacificnw.com>
With the octane rating, there should be discussion on the different Reid
Index numbers between MOGAS and AVGAS. This discourse is missing one of
the key ingredients, before sacrificing a perfectly good M14P.
John Cox $00.02
-----Original Message-----
From: owner-yak-list-server@matronics.com
[mailto:owner-yak-list-server@matronics.com] On Behalf Of Brian Lloyd
Subject: Re: Yak-List: Fuel and M14P
--> Yak-List message posted by: Brian Lloyd <brian-yak@lloyd.com>
Richard Goode wrote:
> There are three issues for those considering motor fuel in the M14P:
>
> Octane rating - motor fuel and aviation fuel are measured in different
> ways. 100LL Avgas is, I believe, equivalent to about 110 octane on
the
> Motor Research Method.
>
> The M14P is cleared to run down to 92 octane on the Motor Research
> Method. I would suggest that 87 octane is too low, and possibly could
> cause pre-ignition and detonation. Obviously octane requirements will
> be higher for 400-hp and above versions.
But that implies that 91 octane mogas is more than adequate as mogas in
the US
is the average of the motor and research method (I made a mistake
yesterday
when I used the word "radical", having forgotten what the 'R' stood
for). As I
understand it, the research method tends to produce an octane number
lower
than the motor method therefore mogas with an octane rating of 91 based
on
(R+M)/2 has a motor octane rating higher than 91. This implies that the
M14P
should run very happily (and safely) on premium auto fuel in the US.
I would not try to run the 400hp M14 on mogas unless I did a test such
as that
suggested by Mr. Peterson, i.e. testing at increasing MAP and checking
the
tops of the pistons after each run.
> Volatility - automotive fuels not only vary in volatility (100LL never
> changes) according to seasons, but also according to manufacturers. On
a
> Yak-52 you are sucking fuel from the tanks up into the engine, and
this
> coupled with a hot day will exacerbate the problem - i.e. the fuel
will
> literally boil but virtue of the reduced pressure and, quite simply,
> your engine won't run on vapour. High ambient temperature and
altitude
> will of course exacerbate the problem.
But that is independent of the engine. I ran my CJ6A almost exclusively
on
mogas when at home. The only time it got 100LL was when I was on the
road and
mogas was not available. Even on the hottest days I never had a problem
with
fuel pressure or vapor lock. Given the similarities in the fuel systems
between the Yak-52 and the CJ6A, I would expect similar results.
Of course, if you DO have a problem with vapor lock it can ruin your
whole
day! But it should be apparent on the ground by letting the airplane
heat soak
on a hot summer day and then perform a full-power ground run. The other
place
it will show up is at altitude so take it up to 14,000' and see if you
have a
problem there.
Again, I never saw the slightest problem with the CJ6A. YMMV.
> Lead content - it way never thought that the M14P would run on
unleaded
> fuel and the Russians view is that it should always have a reasonable
> amount of lead in the fuel - hence a need to use a certain amount of
> 100LL, otherwise there is potentially problems of valve-seat erosion
etc.
The lead does not need to be present all the time. Peterson recommends
running
about every 10th tank with 100LL to maintain lead on the valves. The
rest of
the time you can run on 100% mogas.
As an aside, I never had lead fouling on plugs (no surprise) and plug
erosion
was lower. In my Huosai I ran my first set of plugs for 600 hours before
replacing them. The electrodes were still serviceable but I was getting
uncomfortable with plugs being in there that long. Still, that is a long
time
for one set of plugs.
> My suggestion is to mix 100LL and a minimum of 95 octane fuel, and
> experiment be reducing the proportion of 100LL, being aware that your
> engine may have a problem at a stage.
We don't get 95 octane fuel here but then, we probably measure the
octane
differently here, i.e. (R+M)/2. Our "91" octane may be equivalent to
your 95
octane mogas there.
--
Brian Lloyd 2243 Cattle Dr.
brian-yak@lloyd.com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
- Antoine de Saint-Exupery
Message 10
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | A couple of things |
I never received the message from Cliff, so let me respond to this one if I
may.
Yes, I use full throttle on take-off and not gradually applied either. By
that I mean, the Russian manual on the YAK-50 has you applying partial power
until the tail comes up, etc., etc., and then full power for "x" amount of
time and then power back.
I do not do that.
I apply full power from a dead stop and then either fly it off in a three
point attitude, or on a very narrow runway, I raise the tail a little bit to
see better and then fly it off. Immediate full power just requires a tad
more footwork as the torque comes in, IMHO.
In running with the big boys, I noticed that their M-14PF's were set to a
little over 100% power. I re-adjusted my prop gov. to achieve the same
thing.... a tad over 101%. However, I then talked to Vladimir, and he
mentioned that this was a setting approved for the 400 HP versions and not
the 360 HP model like I am equipped with. So, in the interest of adding a
little bit more time to my "TBO" (per se), I put the prop gov. back to a
maximum of 100% and checked that speed with a strobe-a-scope (old
technology, but hey... it works!)
I ran 101% for about 5 months. During that time I had the opportunity ...
or rather the "requirement" to yank the #2 jug in order to reseat an exhaust
valve that was causing low compression (80/68). I examined the piston
closely and saw no evidence of detonation. I am very familiar with evidence
of that phenomenon having worked on engines running nitrous oxide in drag
car motors... which is why ... by the bye... I will never use that junk in
any engine I run. :=-)
I ran "pure" automobile fuel (93 octane) for several tankfulls with no
apparent ill-effects, but being concerned with valve seat erosion I decided
to not tempt fate and settled for a 50/50 mix as a "more than safe" ratio.
I suspect you could easily go with a 25% 100LL to 75% auto fuel ratio, but I
simply have no long term experience with that ratio. Valve erosion does not
start "right away" when you are running unleaded fuel in an engine without
hardened seats. In truth it will sneak up on you. I have read that it is
in fact possible to run 100% unleaded fuel, and vary that with a tank of
"leaded" once every so often and still avoid seat erosion, but I did not
want to be the one to experiment and prove that statement to be right OR
wrong, given the cost of cylinder replacement!
The carb. on the P and PF model engines are identical. Of course the
jetting is different between the two, and in fact even between the same
models if they are tweaked by an expert... which I am NOT by the way. There
are adjustments in the carb. not only for fuel jetting, but even for "air"
passages. It is a complicated little animal to be sure.
I have seen and studied the accelerator "pump" circuit in the carb. per se,
which is as I understand it, two-fold. There is an imbalance circuit that
adds fuel as a result of the internal pressure imbalance that occurs when
you open the throttle plate. This circuit in fact is there to compensate for
the temporary lean condition that occurs when you push the throttle open,
exactly as say the Power Valve does on a Holley carb. I would call this an
"enrichment circuit". There is also an accelerator pump that works pretty
much exactly as does the one on your car (assuming you have a carburetor in
your car), and is there just to get the engine over the EXTREME lean
condition occuring during the initial PUSH of the throttle and not the
longer term effect of waiting until the engine vacuum "catches up" to the
throttle setting. I believe the latter is one that some of the M-14PF guys
are having trouble with which can cause a "stumble". On my 360 HP model it
works perfectly unless you just JAM the throttle open from idle.
Vladimir once mentioned to me that the M-14 Carb DOES in fact have an
additional "full throttle" enrichment circuit. I have looked for it, but
can not find it in the schematic. Which does not mean it is not there. It
means I still don't fully understand that darn thing. On cross country
flights, Vladimir has recommended that I slowly pull the throttle back (from
full open) until I just start to see movement on the manifold pressure gauge
and stop there. I follow his recommendation on every long distance high
altitude flight that I make, but I do not have accurate enough fuel flow
measurement equipment to tell you the exact impact. However, I do trust
Vladimir completely. He is human. I caught him in a mistake..... once.
I use a little over the recommended amount of MMO per gallon. That amounts
to about 1/3 to at most... 1/2 quart for about 30 gallons. I also use 2
quarts of it on every oil change (in the oil). Lately, I have switched to
adding two quarts of it to the oil a few hours BEFORE every oil change.
I have not run the 50/50 fuel mix at temps at below 10 degrees or above 100
degrees "F". My YAK-50 has no internal heat and below about 20 degrees OAT,
it is not much fun to be in.
To the gent that mentioned problems with mogas being sucked up from the
wings and the problems there-of... sorry, I don't know about that, my fuel
is right in front of my feet in the 50.
Best Regards,
Mark Bitterlich
N50YK
-----Original Message-----
From: Brian Lloyd [mailto:brian-yak@lloyd.com]
Subject: Re: Yak-List: A couple of things
--> Yak-List message posted by: Brian Lloyd <brian-yak@lloyd.com>
Cliff Umscheid wrote:
> Mark
> In your use of that 50-50 mixture, are you using full throttle
> position on takeoff? Do you make any effort to limit the percentage of
> T.O. RPM to 100% ,or is your prop set to only allow you to achieve
> 100% at full throttle? Some folks are "tweeking" the gov. adjustment
> to 102% at T.O. throttle to get extra advantage in the vertical . Of
> course, they are using 100LL.
> Does the M 14 P and PF have an "nrichment jet " in the
> carburetor which opens at the full throttle position ?
> How much MMO are you using with a full tank of gasoline?
Detonation is mostly a function of BMEP (a measure of cylinder pressure)
which
is proportional to MAP, not to RPM. Bumping up the RPM will not increase the
likelihood of detonation. Pushing the MAP up will.
For that matter, a 20 degree change in OAT is going to have a much greater
effect on detonation margin than is a 2% change in RPM.
--
Brian Lloyd 2243 Cattle Dr.
brian-yak@lloyd.com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
- Antoine de Saint-Exupery
Message 11
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Fuel and M14P |
--> Yak-List message posted by: Brian Lloyd <brian-yak@lloyd.com>
John W. Cox wrote:
> --> Yak-List message posted by: "John W. Cox" <johnwcox@pacificnw.com>
>
> With the octane rating, there should be discussion on the different Reid
> Index numbers between MOGAS and AVGAS. This discourse is missing one of
> the key ingredients, before sacrificing a perfectly good M14P.
Actually we did comment on vapor pressure. Reid vapor pressure just describes
the likelihood that the liquid fuel will vaporize in the fuel system prior to
reaching the engine. The engine doesn't care so long as liquid fuel reaches
the carb. Symptoms of high vapor pressure are low fuel pressure and/or vapor
lock hence my comment about a full-power run-up with a heat-soaked airplane.
Worst case would be a heat-soaked airplane at a high-altitude airport.
FWIW, I *never* had any problems with mogas vaporizing in the CJ6A fuel system
all the way up to 18,000'. I can't speak for the Yak-52 but since it has a
similar fuel system I would expect similar results.
YMMV
--
Brian Lloyd 2243 Cattle Dr.
brian-yak@lloyd.com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
- Antoine de Saint-Exupery
Message 12
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
I'm just curious. How many people on this list have run ... or have M-14 or
Housai model engines that are running... over 1000 hours? The last thing I
want to sacrifice is MY M-14P !!!! Mine currently is up around 650 hours.
My curiosity is: How many people have higher than that, and have flown all
of those hours themselves? What's the record... from personal experience?
When did compression become an issue? What finally made the owner decide...
"enough is enough, time to replace this baby!" ??? What is the lowest
compression ratio you would consider "acceptable"... as in 80 over "what"?
Mark
N50YK
-----Original Message-----
From: John W. Cox [mailto:johnwcox@pacificnw.com]
Subject: RE: Yak-List: Fuel and M14P
--> Yak-List message posted by: "John W. Cox" <johnwcox@pacificnw.com>
With the octane rating, there should be discussion on the different Reid
Index numbers between MOGAS and AVGAS. This discourse is missing one of
the key ingredients, before sacrificing a perfectly good M14P.
John Cox $00.02
Message 13
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: A couple of things |
--> Yak-List message posted by: Brian Lloyd <brian-yak@lloyd.com>
Bitterlich GS11 Mark G wrote:
> Valve erosion does not start "right away" when you are running unleaded
> fuel in an engine without hardened seats. In truth it will sneak up on
> you. I have read that it is in fact possible to run 100% unleaded fuel,
> and vary that with a tank of "leaded" once every so often and still
> avoid seat erosion, but I did not want to be the one to experiment and
> prove that statement to be right OR wrong, given the cost of cylinder
> replacement!
Go read the Peterson web site. He talks about this. Given that they run
engines hard on mogas for many hundreds of hours they have the best data.
(Each engine target for a mogas STC is run for something like 400 hours to
test the effects.) He discusses the requirement for lead and how to achieve
it. it is worthwhile reading.
From http://www.webworksltd.com/autofuelstc/pa/LeadD-4814.html
========
LEAD CONTENT
Lead content in grams of lead per gallon:
* 100LL = 2
* 80/87 = 0.5
* Regular Auto Fuel = 0.1
* Unleaded (Premium or Regular) = .001
Until January 1986, regular auto fuel contained a maximum of 1 gram of lead
per gallon. It now contains a maximum of 0.1 of a gram per gallon. No minimums
were established under the new lead content regulations so it is possible to
obtain regular with the same lead content as unleaded, or .001 of a gram per
gallon.
In view of this, we recommend that you use one tank full of 100LL every 75
hours to replace lead on the valve seats. Lead builds up on these parts and
will not be "washed off" the first time you use an unleaded fuel. By using
100LL only every 75 hours, you will be supplying adequate lead for these
parts. Also, during break-in following an overhaul or replacement of a
cylinder, you should use 100LL for 25 hours in order to supply lead during the
break-in process. A mixture of 75% unleaded and 25% 100LL yields a lead
content equivalent to 80/87 octane avgas (0.5 gram per gallon). Radial and
Franklin engines should use this mixture at all times because they are much
more dependent on lead for lubrication.
Burning an occasional tank of 100LL should not be necessary if the valve's,
guides and seats were constructed in accordance with the latest
specifications. In view of the fact that 100LL is eventually slated to be
replaced with an unleaded high octane fuel, anyone facing an engine overhaul
would be well advised to seek out hardened, newer spec parts. These parts are
not available for radial engines as far as I know. However, most horizontally
opposed engines can be rebuilt with hardened parts if you seek them out.
=======
The Huosai engine is designed for 70 octane fuel. As I recall, 70 octane fuel
has no lead so that implies that the Huosai never needs to ever run on leaded
fuel.
--
Brian Lloyd 2243 Cattle Dr.
brian-yak@lloyd.com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
- Antoine de Saint-Exupery
Message 14
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Fuel and M14P |
--> Yak-List message posted by: Brian Lloyd <brian-yak@lloyd.com>
Bitterlich GS11 Mark G wrote:
> I'm just curious. How many people on this list have run ... or have
> M-14 or Housai model engines that are running... over 1000 hours? The
> last thing I want to sacrifice is MY M-14P !!!! Mine currently is up
> around 650 hours. My curiosity is: How many people have higher than
> that, and have flown all of those hours themselves? What's the record...
> from personal experience? When did compression become an issue? What
> finally made the owner decide... "enough is enough, time to replace this
> baby!" ??? What is the lowest compression ratio you would consider
> "acceptable"... as in 80 over "what"?
When I sold "Betty" she had about 700 hours on the Huosai engine, most of that
running mogas. She is still flying with the same engine but I don't know how
many hours are on that engine now.
--
Brian Lloyd 2243 Cattle Dr.
brian-yak@lloyd.com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
- Antoine de Saint-Exupery
Message 15
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Fuel and M14P |
RE: Yak-List: Fuel and M14PMark,
I am sending you a document titled "Putting Compression In Context". I found it
valuable reading being that it also discusses the benefits of using a differential
compression tester with a master orifice.
Dennis
----- Original Message -----
From: Bitterlich GS11 Mark G
To: 'yak-list@matronics.com'
Sent: Wednesday, October 12, 2005 7:29 PM
Subject: RE: Yak-List: Fuel and M14P
I'm just curious. How many people on this list have run ... or have M-14 or
Housai model engines that are running... over 1000 hours? The last thing I want
to sacrifice is MY M-14P !!!! Mine currently is up around 650 hours. My curiosity
is: How many people have higher than that, and have flown all of those
hours themselves? What's the record... from personal experience? When did compression
become an issue? What finally made the owner decide... "enough is enough,
time to replace this baby!" ??? What is the lowest compression ratio you
would consider "acceptable"... as in 80 over "what"?
Mark
N50YK
-----Original Message-----
From: John W. Cox [mailto:johnwcox@pacificnw.com]
Sent: Wednesday, October 12, 2005 6:27 PM
To: yak-list@matronics.com
Subject: RE: Yak-List: Fuel and M14P
--> Yak-List message posted by: "John W. Cox" <johnwcox@pacificnw.com>
With the octane rating, there should be discussion on the different Reid
Index numbers between MOGAS and AVGAS. This discourse is missing one of
the key ingredients, before sacrificing a perfectly good M14P.
John Cox $00.02
Message 16
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Fuel and M14P |
RE: Yak-List: Fuel and M14PMy CJ 285HP has over 1300 hours and runs great. Mid
70 over 80 in all cylinders. Total time since new is over 2100 hours. I am look
for a replacement if anyone has a spare.
----- Original Message -----
From: Bitterlich GS11 Mark G
To: 'yak-list@matronics.com'
Sent: Wednesday, October 12, 2005 7:29 PM
Subject: RE: Yak-List: Fuel and M14P
I'm just curious. How many people on this list have run ... or have M-14 or
Housai model engines that are running... over 1000 hours? The last thing I want
to sacrifice is MY M-14P !!!! Mine currently is up around 650 hours. My curiosity
is: How many people have higher than that, and have flown all of those
hours themselves? What's the record... from personal experience? When did compression
become an issue? What finally made the owner decide... "enough is enough,
time to replace this baby!" ??? What is the lowest compression ratio you
would consider "acceptable"... as in 80 over "what"?
Mark
N50YK
-----Original Message-----
From: John W. Cox [mailto:johnwcox@pacificnw.com]
Sent: Wednesday, October 12, 2005 6:27 PM
To: yak-list@matronics.com
Subject: RE: Yak-List: Fuel and M14P
--> Yak-List message posted by: "John W. Cox" <johnwcox@pacificnw.com>
With the octane rating, there should be discussion on the different Reid
Index numbers between MOGAS and AVGAS. This discourse is missing one of
the key ingredients, before sacrificing a perfectly good M14P.
John Cox $00.02
Message 17
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Fuel and M14P |
Ah, Dennis...Mark...just remember, no man is the master of his orafice!
Doc
----- Original Message -----
From: A. Dennis Savarese
Subject: Re: Yak-List: Fuel and M14P
Mark,
I am sending you a document titled "Putting Compression In Context". I found it
valuable reading being that it also discusses the benefits of using a differential
compression tester with a master orifice.
Dennis
----- Original Message -----
From: Bitterlich GS11 Mark G
Subject: RE: Yak-List: Fuel and M14P
I'm just curious. How many people on this list have run ... or have M-14 or Housai
model engines that are running... over 1000 hours? The last thing I want
to sacrifice is MY M-14P !!!! Mine currently is up around 650 hours. My curiosity
is: How many people have higher than that, and have flown all of those hours
themselves? What's the record... from personal experience? When did compression
become an issue? What finally made the owner decide... "enough is enough,
time to replace this baby!" ??? What is the lowest compression ratio you would
consider "acceptable"... as in 80 over "what"?
Mark
N50YK
-----Original Message-----
From: John W. Cox [mailto:johnwcox@pacificnw.com]
Subject: RE: Yak-List: Fuel and M14P
--> Yak-List message posted by: "John W. Cox" <johnwcox@pacificnw.com>
With the octane rating, there should be discussion on the different Reid
Index numbers between MOGAS and AVGAS. This discourse is missing one of
the key ingredients, before sacrificing a perfectly good M14P.
John Cox $00.02
Message 18
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Fuel and M14P |
In a message dated 10/12/2005 8:29:21 P.M. Eastern Daylight Time,
BitterlichMG@cherrypoint.usmc.mil writes:
I have 1,190 hours on my M-14p since new in Nov 1997. The generator has
1,440 hours and I HAVE NEVER HAD TO CHANGE THE BRUSHES IN IT. My cylinder
pressure average low to mid 70s over 80.
My biggest problem was it started making metal at 430 hours. I found the
factory had put in a scraper ring in the oil land on #3 piston. I basically
did a ring job at that point checking the other pistons.
I've had problems with the ignition harness. The factory one lasted a
little over 1,000 hours (finally changed to the one Dennis sells) and mag coils.
I ran the engine on Chinese mags for about 100 hours (no problems UNTIL one
failed (at about 400 hours mag time) because the Chinese forgot to put a key
in one of the gears and shaft, then the nut that was holding it finally
loosened)
I use straight 120 Mobil oil most of the time otherwise 100. I change my
oil at 50 hours. I have a 10 micron oil filter. Every couple of tanks of fuel
I put in MMO. I have use mogas in a pinch both straight and mixed but I
don't make it a habit.
Jim "Pappy" Goolsby
I'm just curious. How many people on this list have run ... or have M-14 or
Housai model engines that are running... over 1000 hours? The last thing I
want to sacrifice is MY M-14P !!!! Mine currently is up around 650 hours. My
curiosity is: How many people have higher than that, and have flown all of
those hours themselves? What's the record... from personal experience? When did
compression become an issue? What finally made the owner decide... "enough
is enough, time to replace this baby!" ??? What is the lowest compression
ratio you would consider "acceptable"... as in 80 over "what"?
Mark
N50YK
-----Original Message-----
From: John W. Cox [_mailto:johnwcox@pacificnw.com_
(mailto:johnwcox@pacificnw.com) ]
Subject: RE: Yak-List: Fuel and M14P
--> Yak-List message posted by: "John W. Cox" <johnwcox@pacificnw.com>
With the octane rating, there should be discussion on the different Reid
Index numbers between MOGAS and AVGAS. This discourse is missing one of
the key ingredients, before sacrificing a perfectly good M14P.
John Cox $00.02
Other Matronics Email List Services
These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.
-- Please support this service by making your Contribution today! --
|