Twin Plug Airheads? Any observations/experience?
- Thread starter Merlin999
- Start date
...No.
Rob Farmer said:
Seconded
What they said above.
Geoff Johnson said:
no, stops you getting pregnant.
"YES" .... 
Twin plugged my R100R but had it done by Wunderlich... took the heads across, went down to the Black Forest, and picked 'em up on my return a few days later.
With mods to the air box the bike would easily rev through the gears and run into the red in fifth... upset quite a few folk what with the WP suspension etc.
Have it done in this country no mods to the advance and retard curves done... with Wunderlich they need your electronic gismo to alter said advance curves.... B I G difference!
Great improvement
www.adventure.gs
Twin plugged my R100R but had it done by Wunderlich... took the heads across, went down to the Black Forest, and picked 'em up on my return a few days later.
With mods to the air box the bike would easily rev through the gears and run into the red in fifth... upset quite a few folk what with the WP suspension etc.
Have it done in this country no mods to the advance and retard curves done... with Wunderlich they need your electronic gismo to alter said advance curves.... B I G difference!
Great improvement
www.adventure.gs
Bone Dry
Registered user
Down to the Black Forest and back with no cylinder heads, thats impressive man!
What mods did you make to the engine to compensate??
Has anyone else run an airhead with no cylinder heads??
Would it still be an "airhead"??
What mods did you make to the engine to compensate??
Has anyone else run an airhead with no cylinder heads??
Would it still be an "airhead"??
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No !
Running rich..then call Motorworks and tell them your exact model and they'll tell you what the correct sized jet/needle should be fitted...maybe worth buying there excellant carb overhaul kit ( plus new diaphragm rubbers)
Also, Cookie is right as well
Running rich..then call Motorworks and tell them your exact model and they'll tell you what the correct sized jet/needle should be fitted...maybe worth buying there excellant carb overhaul kit ( plus new diaphragm rubbers)
Also, Cookie is right as well
jimstephenson said:
You get first prize of course for spotting the deliberate mistake, but it wasn't a mistake really... I took 'em across on my other 'bike! It did say... took the heads across!
www.adventure.gs
Bone Dry
Registered user
Cheers Mickey - just a bit of harmless fun.
FWIW I have long thought about twin plugging but have always bottled it, interesting to hear your views - thanks.
FWIW I have long thought about twin plugging but have always bottled it, interesting to hear your views - thanks.
jimstephenson said:
I know dat Jim ....
If I had another airhead I'd certainly twin plug. Once in deep conversation with the top brass at Cosworth... if the spark plug is in the right place to start with then it's no use twin plugging. They were doing experiments for Fiat, if my memory correct, and were trying seven (yes seven) spark plugs in a cylinder head. When the correct spark plug lit up it developed the same power as if all seven had lit up
Perm any of the others and power was down.Twin plug in England and that's all they do. Over at Wüdo and Wunderlich they need the electronics cannister and alter the amount of advance/retard to suit the quicker flame burning path... and it makes a huge difference.
Much smoother and at the same speeds more economical. On a flat road my R100R would rev through the gears so easily and quickly, soon to be in the red in fifth gear and still pulling
If I'd kept the 'bike I would have gone for the taller fifth gear...But that was a few years ago... and now even my F650GS Dakar is of equal performance, better handling and suspension, better braking....
www.adventure.gs
Micky said:
tricky in a hemi head with big valves.
"Twin plug in England and that's all they do. Over at Wüdo and Wunderlich they need the electronics cannister and alter the amount of advance/retard to suit the quicker flame burning path... and it makes a huge difference."
All they do is bend the "ears" back on the advance retard stop. The problem with twin plugging is it improves things at lower revs but at higher revs it is actually detremental to performance. I did it to my last Airhead just to see what the difference was. The only real noticeable difference was an improved tickover and slightly cleaner pickup from low revs.
This is a good article from a well respected source:-
http://www.airheads.org/content/view/228/49/
Spend the money on the chassis. I fitted my 70BHP 1000cc engine in my G/s to see how it went. It was quite obvious, and bloody scary, to see how inadequate the standard chassis was for the extra power..needless to say the original engine is back in until I get better brakes, forks and rear suspension
All they do is bend the "ears" back on the advance retard stop. The problem with twin plugging is it improves things at lower revs but at higher revs it is actually detremental to performance. I did it to my last Airhead just to see what the difference was. The only real noticeable difference was an improved tickover and slightly cleaner pickup from low revs.
This is a good article from a well respected source:-
http://www.airheads.org/content/view/228/49/
Spend the money on the chassis. I fitted my 70BHP 1000cc engine in my G/s to see how it went. It was quite obvious, and bloody scary, to see how inadequate the standard chassis was for the extra power..needless to say the original engine is back in until I get better brakes, forks and rear suspension
Rob Farmer said:"
Spend the money on the chassis. I fitted my 70BHP 1000cc engine in my G/s to see how it went. It was quite obvious, and bloody scary, to see how inadequate the standard chassis was for the extra power..needless to say the original engine is back in until I get better brakes, forks and rear suspension
I agree with Rob ...Put a Siebenrock kit on my G/S went well enough but i recon it was a more balanced better package as a 800 like it is now...Rode a friend of mines that is twin plugged and like Rob says was a bit better on pick up that was it certainly no faster
Sean Kelly
Registered user
Hi
Andrew Sexton does the bean can mod for dual plugged bikes.
Interesting article on dual plugging in this month classic bike guide. Points out that the more advanced, modern twin plug setups vary the time between each of the two sparks. I think it was from fully synched at low rpm to the second spark lagging at high rpm so that it has no effect. Now I think about it, it would be relatively easy to achieve this on an airhead by running two of these fancy mappable igniton modules in parallel with different maps and dispensing with the bean can entirely.
I'm very happy with my twin plug setup on my GS - 100RT bottom end and barrels with Andrew Sexton modded twin plug 800cc heads. I kept the 800 bevel but put a lower 5th in the box. Great economy and easy crusing at 85mph.
Cheers
Sean
Andrew Sexton does the bean can mod for dual plugged bikes.
Interesting article on dual plugging in this month classic bike guide. Points out that the more advanced, modern twin plug setups vary the time between each of the two sparks. I think it was from fully synched at low rpm to the second spark lagging at high rpm so that it has no effect. Now I think about it, it would be relatively easy to achieve this on an airhead by running two of these fancy mappable igniton modules in parallel with different maps and dispensing with the bean can entirely.
I'm very happy with my twin plug setup on my GS - 100RT bottom end and barrels with Andrew Sexton modded twin plug 800cc heads. I kept the 800 bevel but put a lower 5th in the box. Great economy and easy crusing at 85mph.
Cheers
Sean
Paul Rochdale
Registered user
Twin plugging? Certainly. Jim Cray twin plugged my R100/7 about twelve years ago and the bike immediately ran smoother with more mid-range acceleration. The fuel consumption also improved to.
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I have twin plugged my 81-84 R100RS and turning it into a Cafe' Racer. With a 2-1 Armour downpipe, I am thinking of putting on a more up todate Remus type endcam instead of the familiar Keihan exhaust.
What issues does anybody forsee in regards to breathing and/or exhaust flow problems if any.
Also fitting a sportier cam.
What issues does anybody forsee in regards to breathing and/or exhaust flow problems if any.
Also fitting a sportier cam.
