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Old 10-14-2009, 12:34 PM   #16
Lornce
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Quote:
Originally Posted by Stagehand
I dream of seibenrocks with the big fat pistons. :swoon

1900 euro's is still big bucks even without the VAT.

Arent the Seiben's only 9.5's?
Maybe, but they'd be approx 12:1 mated to the heads on my PD.

The Venolias I'm running only produce 9:1 mated to a pair of stock heads.

The secret to the big compression numbers are in the head mods.

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Old 10-14-2009, 12:40 PM   #17
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thats pretty neat.

and a piece of 26 gauge sheet copper for a head gasket, eh?
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Old 10-14-2009, 12:50 PM   #18
Lornce
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Quote:
Originally Posted by Stagehand
thats pretty neat.

and a piece of 26 gauge sheet copper for a head gasket, eh?

Not sure what 26 guage translates to, but 0.032" is the thinckness of the copper head gaskets sourced from CC Products.

Ideally, it'd be nice to have 0.040" copper gaskets. But we make do.


Man, I love the way that bike works.

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Old 10-14-2009, 02:36 PM   #19
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lornce- what kind of trouble did the dyna coils ever give you? ive used them for years and have nothing but good to say....curious....
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Old 10-14-2009, 03:33 PM   #20
walkingbear OP
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k bike coils

My mechanic suggested using a K1oo/k1100 coil when you go to duel plugging. Less space taken and would do the job


Quote:
Originally Posted by Lornce
imho, the only con for street use is the Dyna coils: They're not as reliable as the old 6v Bosche coils that came stock on BMW's in the '70's and early '80's.

Having said that, they're probably no more failure prone than the twin tower 12v Bosche coils fitted to BMW's in the late '80's and early '90's.

This is good and useful information.

I'm still really enjoying my modified GSPD.

: Modded '77 RS heads (running 12:1 with Venolias)

: Venolia 1050cc forged pistons

: Andrews high-lift cam


It's faster than an 1150GS in any straight up contest.

This winter I might convert it to dual plug coils. The heads are already machined for dual plugs I've just shied away because of past experience with Dyna coils.

The only concern with my motor is oil consumption that's inherant with the 1050cc Venolia pistons and bored iron barrels. I add a liter to a liter and a half every 1.5k kms. I plan around it and carry oil when travelling. Not a big deal if I'm prepared, but not ideal.

Solution, I believe, might be the Sidenbrock 1070cc nikasil piston/cylinder kits available in Europe. Pics I've seen of those pistons offer hope that they'd work with these heads. ie: flat periphery for effective squish band.

But they're expensive.

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Old 10-14-2009, 03:41 PM   #21
Lornce
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Quote:
Originally Posted by bomberdave
lornce- what kind of trouble did the dyna coils ever give you? ive used them for years and have nothing but good to say....curious....

Hi Dave,

They worked great when they worked but had a much higher rate of failure than the 6v Bosche coils I was using alternately back in the day. Not really fair because the Bosche coils never failed.
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Old 10-14-2009, 03:42 PM   #22
Lornce
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Quote:
Originally Posted by walkingbear
My mechanic suggested using a K1oo/k1100 coil when you go to duel plugging. Less space taken and would do the job

Thanks WB, I'll look into that.



cheers,
Lornce
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Old 11-21-2011, 11:20 AM   #23
Madman1
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It seems like dual-plugging might be worthwile.
Im considering it for my 95RT.

http://www.motoren-israel.com/produc...ng--2St--.html
http://www.motoren-israel.com/produc...TAL------.html

Any experiences with dual-plugging a similar bike? Especially milage before and after.

Sincerely
Hans
Norway
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Old 11-21-2011, 11:28 AM   #24
blaine.hale
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Quote:
Originally Posted by Stagehand View Post
interesting article.

Those prices seem more than 15 years old. My biggest question is: WOULD it be more reliable than stock? I guess some people will balk at the K+N bit. I'm on the fence on that one.
So essentially dual plugging allows leaner mixtures, thereby increasing fuel mileage. Did the three angle valve job really do anything? I thought it was a just a higher quality seal and face, but to actual performance? maybe...

one horsepower on synthetic? oh, man the oil threads will never shut up, now :lol
I have a 3 angle cut on my valves...It seems a tad more powerful but I think I attribute that more so to an entirely rebuilt engine than just my valves :)
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