The Murphy Builders Site

I think you'll have to wait for someone to implement ion spark sensing
to do that. That would protect the engine if you don't mind less power
but also negate some of the advantage of having the 160 hp engine. By
monitoring the spark signal immediately after the plug initially fires,
the electronics can sense impending detonation in each cylinder. A few
cars have done it for several years now so sooner or later someone
should offer it for aero engines. I've never seen a conventional knock
sensor installation that I would even begin to trust on a large
aircooled engine. Too much mechanical noise and too much variablity
between cylinders.
Ken

kpierson@dcsol.com wrote:

Drew: Will the e-mag that you have on your 160hp engine
make it possible to use auto fuel, I have heard that they
will sense an impending knock and adjust the timing accordingly.
However the manufacture will not confirm, or deny this.
Thank you. Keith

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At 08:24 PM 8/23/2007 -0900, you wrote:

Drew: Will the e-mag that you have on your 160hp engine
make it possible to use auto fuel, I have heard that they
will sense an impending knock and adjust the timing accordingly.
However the manufacture will not confirm, or deny this.
Thank you. Keith

Hi Keith The emag doesn't have a knock sensor that I know of but it does
use manifold pressure to adjust the timing. There's two choices of advance
curve or you can program your own. The recommended one has a maximum
advance of 35 degrees and the alternative one has a max of 28. supposedly
if you choose a max of 28 you can burn auto fuel. I had mine at 28 while
breaking in the engine but now I'm running it at 35 degrees and truthfully
I can't tell any difference. If auto fuel without ethanol was widely
available in Ontario I probably would have had my engine built to 150hp but
I've chosen to just burn 100LL and save a lot of worries about fuel quality.
Drew



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I test all mogas now if it is going into gas cans unless the pump is
labelled "non oxygenated" or "alky free". There is no requirement to
label or provide notice that gas contains alky in Ontario.

Outside the big city I find many still have alky free regular gas in
Ontario, especially low volume retailers.
So far I have not found alky in any premium gas in Ontario (I have in
other locations). Some Shell stations actually are labelled as having
no alky in their premium and they have publicly committed to keep it
that way for the time being in Canada. BTW Canadian Tire seems to only
charge about 6 cents extra per liter for premium whereas most are at
least 10 cents. Near the city all regular that I've purchased has 5 to
10% alky now.

If the Lycoming needs higher octane than premium mogas I would hesitate
to put mogas in it period. You would loose power and still be at some
risk of damage even with retarded ignition IMO. OTOH if mogas is
available with acceptable octane I agree with the guys that try hard to
run most of the time on mogas irregardless of the fuel cost!

Ken

Drew Dalgleish wrote:

At 08:24 PM 8/23/2007 -0900, you wrote:

Drew: Will the e-mag that you have on your 160hp engine
make it possible to use auto fuel, I have heard that they
will sense an impending knock and adjust the timing accordingly.
However the manufacture will not confirm, or deny this.
Thank you. Keith

Hi Keith The emag doesn't have a knock sensor that I know of but it does
use manifold pressure to adjust the timing. There's two choices of advance
curve or you can program your own. The recommended one has a maximum
advance of 35 degrees and the alternative one has a max of 28. supposedly
if you choose a max of 28 you can burn auto fuel. I had mine at 28 while
breaking in the engine but now I'm running it at 35 degrees and truthfully
I can't tell any difference. If auto fuel without ethanol was widely
available in Ontario I probably would have had my engine built to 150hp but
I've chosen to just burn 100LL and save a lot of worries about fuel quality.
Drew

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Do you guys have a bulk farm gas dealer that is nearby? I think you can get
premium from them, too, and they may not have alky. Should be a lot cheaper.
I joined our local Otter Coop here in Langley and buy reg gas from them at
.85 a litre, which sure beats paying 1.45 and more for 100LL. Plus they give
you a 5 or 6 % rebate at the end of the year. Fortunately, we don't have
alky in our mogas here in BC.

With the Lyc clones, I thought they were OK with 91 premium mogas for the
8.5 engines, and reg for the 7.0.

Walter

-----Original Message-----
From: mike.davis@dcsol.com [mailto:mike.davis@dcsol.com] On Behalf Of Ken
Sent: Saturday, August 25, 2007 1:04 PM
To: rebel-builders@dcsol.com
Subject: Re: [rebel-builders] e-mag

I test all mogas now if it is going into gas cans unless the pump is
labelled "non oxygenated" or "alky free". There is no requirement to
label or provide notice that gas contains alky in Ontario.

Outside the big city I find many still have alky free regular gas in
Ontario, especially low volume retailers.
So far I have not found alky in any premium gas in Ontario (I have in
other locations). Some Shell stations actually are labelled as having
no alky in their premium and they have publicly committed to keep it
that way for the time being in Canada. BTW Canadian Tire seems to only
charge about 6 cents extra per liter for premium whereas most are at
least 10 cents. Near the city all regular that I've purchased has 5 to
10% alky now.

If the Lycoming needs higher octane than premium mogas I would hesitate
to put mogas in it period. You would loose power and still be at some
risk of damage even with retarded ignition IMO. OTOH if mogas is
available with acceptable octane I agree with the guys that try hard to
run most of the time on mogas irregardless of the fuel cost!

Ken

Drew Dalgleish wrote:

At 08:24 PM 8/23/2007 -0900, you wrote:

Drew: Will the e-mag that you have on your 160hp engine
make it possible to use auto fuel, I have heard that they
will sense an impending knock and adjust the timing accordingly.
However the manufacture will not confirm, or deny this.
Thank you. Keith

Hi Keith The emag doesn't have a knock sensor that I know of but it does
use manifold pressure to adjust the timing. There's two choices of advance
curve or you can program your own. The recommended one has a maximum
advance of 35 degrees and the alternative one has a max of 28. supposedly
if you choose a max of 28 you can burn auto fuel. I had mine at 28 while
breaking in the engine but now I'm running it at 35 degrees and truthfully
I can't tell any difference. If auto fuel without ethanol was widely
available in Ontario I probably would have had my engine built to 150hp but
I've chosen to just burn 100LL and save a lot of worries about fuel

quality.

Drew

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