Today's Message Index:
----------------------
1. 07:41 AM - Spark plugs and heat range (rvdave)
2. 08:28 AM - Re: Spark plugs and heat range (Tim Olson)
3. 09:22 AM - Re: Spark plugs and heat range (rvdave)
4. 02:47 PM - Re: Re: Spark plugs and heat range (Kelly McMullen)
5. 03:09 PM - Re: Re: Spark plugs and heat range (Tim Olson)
6. 03:21 PM - Re: Re: Spark plugs and heat range (Kelly McMullen)
Message 1
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| Subject: | Spark plugs and heat range |
Is there a relationship between heat range of plugs and running lop and what would
be the science behind that either way? I mean lop operation usually means
throttling back(?) which reduces map which changes timing on most ei systems,
does a colder or hotter plug make any difference to get to lower fuel burns lop?
--------
Dave Ford
RV6 for sale
RV10 building
Cadillac, MI
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=496465#496465
Message 2
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| Subject: | Re: Spark plugs and heat range |
I can't answer the spark plug heat range part of the question other than
to say that if you use fine wire plugs, you don't have a huge selection
of heat ranges, and I haven't found that I've needed anything different
than the normal plug I'd use anyway.
But, running LOP doesn't *usually* mean throttling back. It certainly
can, if you're trying to run LOP at low altitudes and want to honor
the 65%/75% power levels. However, I usually cruise at altitudes
over 8,000' when possible, preferring 9000-10,500 whenever it's
practical. Much of the time I'm not needing to power back at all
because the altitude took care of that MP reduction for me.
I'm sure that in an ideal world, a person would have a multi-heat-range
spark plug, because ideally you'd have a different one for takeoff
power at sea level, and cruising in the mid-teens. But in the real
world, you'd pick one that can handle the high power level of takeoff
in all situations, and compromise when it comes to cruise flight.
I just had all my plugs out this week and they're mostly clean, as
usual. The bottoms sometime get a little gunk in the bottom that needs
to be cleaned out, but the insulators generally are tan/faint grey
and never black, so they always look good to me. That's fine wire
though. I haven't run massive electrode plugs in years.
Tim
On 5/23/20 9:41 AM, rvdave wrote:
>
> Is there a relationship between heat range of plugs and running lop and what
would be the science behind that either way? I mean lop operation usually means
throttling back(?) which reduces map which changes timing on most ei systems,
does a colder or hotter plug make any difference to get to lower fuel burns
lop?
>
> --------
> Dave Ford
> RV6 for sale
> RV10 building
> Cadillac, MI
>
>
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=496465#496465
>
>
Message 3
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| Subject: | Re: Spark plugs and heat range |
Im running iridium plugs with dual ei and should have mentioned flying lower altitudes
also. My light speed ei came with denso slant ground, have tried some
different plugs but seem to get best performance with these, only problem is
leaning to get best economy cant get down to where Id like to be and wondering
if a different heat range would make a difference there?
--------
Dave Ford
RV6 for sale
RV10 building
Cadillac, MI
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=496468#496468
Message 4
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| Subject: | Re: Spark plugs and heat range |
1. Leaning has very little to do with plug heat range. Primarily plug heat
range is determined by compression ratio, and to lesser degree the amount
of oil burned.
2. Once you get fully LOP, going further lean just reduces your power, does
little to improve efficiency, which is why for normally aspirated engines
LOP with 8.5-9.0 ratio; 14.95 times fuel flow in gph equals horsepower. So
11 gph is 165 hp, 12 is 180 and 13 is 195 or 75% in round numbers. If you
have higher compression the multiplier goes up. For turboed engines the
multiplier goes down as compression goes down....typically in the 13.7
range.
3. While iridium plugs of the auto variety are fine for electronic systems
built for them, in the aviation plug variety they are mostly a waste of
money, unless you can guarantee that no plug will ever be dropped, that the
resistance will never change, so you can use them for a full engine TBO. Do
you really want to invest over $1000 in a set of plugs? I had 8 used
Champion fine wires that I put in my engine early on. More than half have
gone way above the suggested 5K ohm value and had to be pitched. Of the new
massive Champions that came with the engine, another 1/3 rd developed high
resistance in under 200 hours. So when my supply of good used plugs is
exhausted, it will be Tempest massives for me.
Kelly
Sent from my TRS-80 Model 100
On Sat, May 23, 2020 at 9:26 AM rvdave <rv610dave@gmail.com> wrote:
>
> I=99m running iridium plugs with dual ei and should have mentioned
flying
> lower altitudes also. My light speed ei came with denso slant ground,
> have tried some different plugs but seem to get best performance with
> these, only problem is leaning to get best economy can=99t get down
to where
> I=99d like to be and wondering if a different heat range would make
a
> difference there?
>
> --------
> Dave Ford
> RV6 for sale
> RV10 building
> Cadillac, MI
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=496468#496468
>
>
===========
===========
===========
===========
===========
>
>
Message 5
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| Subject: | Re: Spark plugs and heat range |
Good info Kelly, but I would like to point out that you said champion find w
ire plugs. Those haven=99t had a good history from what I=99ve h
eard. If you use Tempest fine wire, you may have better luck. I=99ve u
sed them over 1000 hours and they test out great every time. And, since I on
ly need six of them, even at $85 apiece it isn=99t really that big of a
deal over the life of an engine, or even over 1/2 of the life of an engine.
I do know that they are far easier to clean than the massive electrode plug
s, and they seem to stay cleaner than those plugs did, don=99t wear, a
nd really have never required gapping. So lots of benefits. But again, the
se were autolite, now tempest. Less resistor issues with these plugs.
Tim
> On May 23, 2020, at 4:53 PM, Kelly McMullen <apilot2@gmail.com> wrote:
>
> =EF=BB
> 1. Leaning has very little to do with plug heat range. Primarily plug heat
range is determined by compression ratio, and to lesser degree the amount o
f oil burned.
> 2. Once you get fully LOP, going further lean just reduces your power, doe
s little to improve efficiency, which is why for normally aspirated engines L
OP with 8.5-9.0 ratio; 14.95 times fuel flow in gph equals horsepower. So 1
1 gph is 165 hp, 12 is 180 and 13 is 195 or 75% in round numbers. If you ha
ve higher compression the multiplier goes up. For turboed engines the multip
lier goes down as compression goes down....typically in the 13.7 range.
>
> 3. While iridium plugs of the auto variety are fine for electronic systems
built for them, in the aviation plug variety they are mostly a waste of mon
ey, unless you can guarantee that no plug will ever be dropped, that the res
istance will never change, so you can use them for a full engine TBO. Do you
really want to invest over $1000 in a set of plugs? I had 8 used Champion f
ine wires that I put in my engine early on. More than half have gone way abo
ve the suggested 5K ohm value and had to be pitched. Of the new massive Cham
pions that came with the engine, another 1/3 rd developed high resistance in
under 200 hours. So when my supply of good used plugs is exhausted, it will
be Tempest massives for me.
> Kelly
> Sent from my TRS-80 Model 100
>
>
>> On Sat, May 23, 2020 at 9:26 AM rvdave <rv610dave@gmail.com> wrote:
>>
>> I=99m running iridium plugs with dual ei and should have mentioned f
lying lower altitudes also. My light speed ei came with denso slant ground
, have tried some different plugs but seem to get best performance with thes
e, only problem is leaning to get best economy can=99t get down to whe
re I=99d like to be and wondering if a different heat range would make
a difference there?
>>
>> --------
>> Dave Ford
>> RV6 for sale
>> RV10 building
>> Cadillac, MI
>>
>>
>>
>>
>> Read this topic online here:
>>
>> http://forums.matronics.com/viewtopic.php?p=496468#496468
>>
>>
>>
>>
>>
>>
>> ==========
>> -List" rel="noreferrer" target="_blank">http://www.matronics.com/Navi
gator?RV10-List
>> ==========
>> FORUMS -
>> eferrer" target="_blank">http://forums.matronics.com
>> ==========
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>> ==========
>> b Site -
>> -Matt Dralle, List Admin.
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n
>> ==========
>>
>>
>>
Message 6
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| Subject: | Re: Spark plugs and heat range |
Oh, I agree that the Tempest are a better plug, although Champion claims to
have fixed their resistor issue, I don't see the benefit of paying 30 bucks
more a plug for a name that no longer means quality.
I don't find massives hard to clean with a dental pick for lead balls. Fine
wires are less work, for sure. I have seen the results of a dropped plug,
and dropping one is kind of like dropping your wife's fine china.
Sent from my TRS-80 Model 100
On Sat, May 23, 2020 at 3:13 PM Tim Olson <Tim@myrv10.com> wrote:
> Good info Kelly, but I would like to point out that you said champion fin
d
> wire plugs. Those haven=99t had a good history from what I=99
ve heard. If you
> use Tempest fine wire, you may have better luck. I=99ve used them o
ver 1000
> hours and they test out great every time. And, since I only need six of
> them, even at $85 apiece it isn=99t really that big of a deal over
the life
> of an engine, or even over 1/2 of the life of an engine. I do know that
> they are far easier to clean than the massive electrode plugs, and they
> seem to stay cleaner than those plugs did, don=99t wear, and really
have
> never required gapping. So lots of benefits. But again, these were
> autolite, now tempest. Less resistor issues with these plugs.
> Tim
>
> On May 23, 2020, at 4:53 PM, Kelly McMullen <apilot2@gmail.com> wrote:
>
> =EF=BB
> 1. Leaning has very little to do with plug heat range. Primarily plug hea
t
> range is determined by compression ratio, and to lesser degree the amount
> of oil burned.
> 2. Once you get fully LOP, going further lean just reduces your power,
> does little to improve efficiency, which is why for normally aspirated
> engines LOP with 8.5-9.0 ratio; 14.95 times fuel flow in gph equals
> horsepower. So 11 gph is 165 hp, 12 is 180 and 13 is 195 or 75% in round
> numbers. If you have higher compression the multiplier goes up. For
> turboed engines the multiplier goes down as compression goes
> down....typically in the 13.7 range.
>
> 3. While iridium plugs of the auto variety are fine for electronic system
s
> built for them, in the aviation plug variety they are mostly a waste of
> money, unless you can guarantee that no plug will ever be dropped, that t
he
> resistance will never change, so you can use them for a full engine TBO.
Do
> you really want to invest over $1000 in a set of plugs? I had 8 used
> Champion fine wires that I put in my engine early on. More than half have
> gone way above the suggested 5K ohm value and had to be pitched. Of the n
ew
> massive Champions that came with the engine, another 1/3 rd developed hig
h
> resistance in under 200 hours. So when my supply of good used plugs is
> exhausted, it will be Tempest massives for me.
> Kelly
>
> Sent from my TRS-80 Model 100
>
>
> On Sat, May 23, 2020 at 9:26 AM rvdave <rv610dave@gmail.com> wrote:
>
>>
>> I=99m running iridium plugs with dual ei and should have mentioned
flying
>> lower altitudes also. My light speed ei came with denso slant ground,
>> have tried some different plugs but seem to get best performance with
>> these, only problem is leaning to get best economy can=99t get dow
n to where
>> I=99d like to be and wondering if a different heat range would mak
e a
>> difference there?
>>
>> --------
>> Dave Ford
>> RV6 for sale
>> RV10 building
>> Cadillac, MI
>>
>>
>>
>>
>> Read this topic online here:
>>
>> http://forums.matronics.com/viewtopic.php?p=496468#496468
>>
>>
>>
>>
>>
>>
>> ==========
>> -List" rel="noreferrer" target="_blank">
>> http://www.matronics.com/Navigator?RV10-List
>> ==========
>> FORUMS -
>> eferrer" target="_blank">http://forums.matronics.com
>> ==========
>> WIKI -
>> errer" target="_blank">http://wiki.matronics.com
>> ==========
>> b Site -
>> -Matt Dralle, List Admin.
>> rel="noreferrer" target="_blank">http://www.matronics.com/contributi
on
>> ==========
>>
>>
>>
>>
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