dual plugging

dual plugging

Once again considering dual plugging my '88
BMW airhead. Supposedly, this strengthens
the low end and allows better running on regular
or 89 octane fuel. Also supposed to allow a
bump in compression.

Job would require a new coil setup and a
small diameter plug hole tapped into each
cylinder.

Any thoughts on this mod ? Good idea ?
Not so good ? Downside ?

Re: dual plugging

Rob Kleinschmidt <Rkleinsch1216128@aol,com > wrote:

> Once again considering dual plugging my '88
> BMW airhead. Supposedly, this strengthens
> the low end and allows better running on regular
> or 89 octane fuel. Also supposed to allow a
> bump in compression.
>
> Job would require a new coil setup and a
> small diameter plug hole tapped into each
> cylinder.
>
> Any thoughts on this mod ? Good idea ?
> Not so good ? Downside ?

All reports I've read say it's a mod well worth doing, especially when
you consider the antique combustion chambers and gas flow that the
standard single plug has to cope with.


--
BMW K1100LT Ducati 750SS Honda CB400F, SL125 & SH50 Yamaha XT600E
chateau dot murray at idnet dot com
"What you're proposing to do will involve a lot of time
and hassle for no tangible benefit."

Re: dual plugging

totallydeadmailbox@yahoo.co.uk (The Older Gentleman) writes:

> Rob Kleinschmidt <Rkleinsch1216128@aol,com > wrote:
>
>> Once again considering dual plugging my '88
>> BMW airhead. Supposedly, this strengthens
>> the low end and allows better running on regular
>> or 89 octane fuel. Also supposed to allow a
>> bump in compression.
>>
>> Job would require a new coil setup and a
>> small diameter plug hole tapped into each
>> cylinder.
>>
>> Any thoughts on this mod ? Good idea ?
>> Not so good ? Downside ?
>
> All reports I've read say it's a mod well worth doing, especially when
> you consider the antique combustion chambers and gas flow that the
> standard single plug has to cope with.

Combustion chamber shape isn't actually that bad, the trouble is that
BMW increased the capacity by increasing the bore, so the flame front
has to travel considerably further on bigger engines, with all the
assorted ill effects of that.

It's a worthwhile modification, but I'd be tempted to go the whole hog
and also use an ignition system that was designed for dual plugged
heads. A German company called Q-Tech does make complete systems for
this using R1100 coils - I've used their parts before and they "just
work". Only problem is that I don't know if the guy speaks any
English...

--
Morini Corsaro 125 | CB450K4 | XL250 Motosport | 900SSD | R1150RT
Laverda SF2 | Harley FXD BOTAFOF #33 TWA#10
The UKRM FAQ: http :// www .ukrm,net /faq/index.html
"Je profite du paysage" - Joe Bar

Re: dual plugging

On 5 Jun, 07:41, Timo Geusch <tnewsSPAMME...@unixconsult.co.uk> wrote:
> totallydeadmail...@yahoo.co.uk (The Older Gentleman) writes:
>
>
>
> > Rob Kleinschmidt <Rkleinsch1216...@aol,com > wrote:
>
> >> Once again considering dual plugging my '88
> >> BMW airhead. Supposedly, this strengthens
> >> the low end and allows better running on regular
> >> or 89 octane fuel. Also supposed to allow a
> >> bump in compression.
>
> >> Job would require a new coil setup and a
> >> small diameter plug hole tapped into each
> >> cylinder.
>
> >> Any thoughts on this mod ? Good idea ?
> >> Not so good ? Downside ?
>
> > All reports I've read say it's a mod well worth doing, especially when
> > you consider the antique combustion chambers and gas flow that the
> > standard single plug has to cope with.
>
> Combustion chamber shape isn't actually that bad, the trouble is that
> BMW increased the capacity by increasing the bore, so the flame front
> has to travel considerably further on bigger engines, with all the
> assorted ill effects of that.
>
> It's a worthwhile modification, but I'd be tempted to go the whole hog
> and also use an ignition system that was designed for dual plugged
> heads. A German company called Q-Tech does make complete systems for
> this using R1100 coils - I've used their parts before and they "just
> work". Only problem is that I don't know if the guy speaks any
> English...
>

Try:

"Vas ist der price of der duppel schparken-lichten zystem, mein herr?"

Re: dual plugging


"Timo Geusch" <tnewsSPAMMENOT@unixconsult.co.uk> wrote in message
news:m2od6gjsdj.fsf@unixconsult.co.uk...
> totallydeadmailbox@yahoo.co.uk (The Older Gentleman) writes:
>
>> Rob Kleinschmidt <Rkleinsch1216128@aol,com > wrote:
>>
>>> Once again considering dual plugging my '88
>>> BMW airhead. Supposedly, this strengthens
>>> the low end and allows better running on regular
>>> or 89 octane fuel. Also supposed to allow a
>>> bump in compression.
>>>
>>> Job would require a new coil setup and a
>>> small diameter plug hole tapped into each
>>> cylinder.
>>>
>>> Any thoughts on this mod ? Good idea ?
>>> Not so good ? Downside ?
>>
>> All reports I've read say it's a mod well worth doing, especially when
>> you consider the antique combustion chambers and gas flow that the
>> standard single plug has to cope with.
>
> Combustion chamber shape isn't actually that bad, the trouble is that
> BMW increased the capacity by increasing the bore, so the flame front
> has to travel considerably further on bigger engines, with all the
> assorted ill effects of that.
>
> It's a worthwhile modification, but I'd be tempted to go the whole hog
> and also use an ignition system that was designed for dual plugged
> heads. A German company called Q-Tech does make complete systems for
> this using R1100 coils - I've used their parts before and they "just
> work". Only problem is that I don't know if the guy speaks any
> English...


The cheap dodge is go to the breakers yard and get the twin lead coils off a
Jap-4.

Re: dual plugging

On Jun 5, 6:29 am, "ian field" <dai....@ntlworld,com > wrote:

> The cheap dodge is go to the breakers yard and get the twin lead coils off a
> Jap-4.-

The trick seems to be matching resistance on the
dual plug coil to resistance the single plug one.