Go Back   Horizons Unlimited - The HUBB > Technical, Bike forums > BMW Tech

BMW Tech BMW Tech Forum - For Questions specific and of interest to BMW riders only. Questions comparing which bike is best etc go in the "Which Bike" forum.
Contact Overland Solutions for all your custom modifications and setup for overland travel.

7 Litre Camel Tank Lets You Explore More, Click to Find out More!

Like Tree1Likes

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 7 Mar 2006
c90 c90 is offline
Registered Users
New on the HUBB
 
Join Date: Mar 2006
Location: nottingham
Posts: 1
twin plugging an air head BMW

Has anyone out there had an air head bm that has been twin plugged, if so, how did it improve the bike from the stock single plug head ???
Reply With Quote
  #2  
Old 8 Mar 2006
Vaufi's Avatar
Contributing Member
Veteran HUBBer
 
Join Date: Jan 2004
Location: Munich, the beer capital
Posts: 814
I was a bit disappointed, after having my R80GS twinplugged. I thought that this would improve (reduce) the fuel consumption, but there was hardly any difference, although I also had the cylinder head smoothed out on the inside, to get the sharp edges away.

It starts better, runs a little smoother. Thats it. Although, for the 100GS it should make more of a difference. The R80 runs smoother than the R100 before any changes done. The effect is said to be much greater on the 1000cc engine.

Hans
__________________
Only when we pause to wonder
do we go beyond the limits of our little lives.
(Rod McKuen)
Reply With Quote
  #3  
Old 8 Mar 2006
Registered Users
Veteran HUBBer
 
Join Date: Aug 2001
Location: Vancouver, BC - now at large in the world
Posts: 405
Tom Cutter has written the book on this topic. Contact him at:
http://www.rubberchickenracinggarage.com/

Also see:
http://www.airheads.org/content/view/281/98/

www.airheads.org is the only resource you need for airhead stuff... Unless you speak German, then there are a few others out there.

Kevin

------------------
Kevin

http://www.nohorizons.net
__________________
http://www.nohorizons.net
Reply With Quote
  #4  
Old 8 Mar 2006
Moderator
Veteran HUBBer
 
Join Date: Mar 2001
Location: British Columbia
Posts: 239
I twin plugged my R100GS (Canadian model, 40mm carbs). I was told to expect an increase to power (5-10%), a reduction in fuel use (5-10%), smoother running, and less or no 'pinging' on <92 octane fuel.

I can say that the pinging on 89/87 octane fuel was reduced to the point where it wasn't a problem. Maybe a slight increase to power, Maybe a slight reduction to fuel economy, but nothing I could clearly measure. I'd do it again, but wouldn't consider it necessary unless you expect a steady diet of <91 octane fuel.
Reply With Quote
  #5  
Old 8 Mar 2006
Mr. Ron's Avatar
Registered Users
Veteran HUBBer
 
Join Date: Oct 2003
Location: Vancouver, BC, for now...
Posts: 798
I had the following mods done on my "89R100: 32mm heads dual plugged, polished intakes. Dyna coils. The result was sharper acceleration, with minor inrease in power and fuel consumption. Motor has to be timed -2 to -3 degrees, i can't remember which. I only burn the cheepest gas, so far i've been happy with the performance, no problems. The bike is also easier to start when cold.
Reply With Quote
  #6  
Old 3 May 2006
Registered Users
Veteran HUBBer
 
Join Date: Sep 2002
Location: london,england
Posts: 158
the main improovement i found with my 100 was it now starts easy peasy on the kick. also added the black box from a kickstart model which also helps.
Reply With Quote
  #7  
Old 25 Sep 2008
Registered Users
Veteran HUBBer
 
Join Date: Oct 2002
Location: Stockholm - Sweden
Posts: 316
Been running twinn plugged since about 1992.
This summer/fall is the first time I ever have had it running well... 16 years of hassle and head-ache!
I've run 800cc 8.2:1, 9.2:1, 10.3:1 32mm carbs, 40mm carbs, different air-intakes, different exhausts, jetting laborations, etc and so on...

IF you are to go twinn plugged - be prepared to read-up first(!), then be prepared to get a lot of flack.

The difference is 1 gearshift at 2000-2500rpm, better and easier cold starting, better burn, slightly lower mileage (some claim more - I have not experience that on my bikes).
Would I twinn-plugg my next air-head ? YES!

What made my air-head work as it is supposed to after 16 years of testing, reading, etc ?
This did:
Daniel Dicke: Doppelzündung
http://www.derdicke.de/mot/img/doppelzdg.jpg
This German recommendation is strickly contrary to Tom Cutter, Oak Oshlen, SnowBums writings. I have NO explanation for this. I can only say that on my R80 this did the trick.
__________________
Drive Safely,
Albert
Reply With Quote
  #8  
Old 22 Nov 2008
Gold Member
Veteran HUBBer
 
Join Date: Sep 2007
Location: Kamloops, BC Canada
Posts: 108
Mileage increase on R60/6

For what it's worth, I had my 1975 R60/6 dual plugged last winter and put about 13,000 miles on it this summer. My main motivation was to help reduce pinging, particularly as I plan on taking it through central Asia next year. I kept track of mileage both before and after and have had a 3.8 mpg increase on average. I did some other things as well and so admittedly, as an experiment, the variables have not been well controlled. I did reset carb pins to a leaner setting when at higher elevations throughout the summer and switched back from electronic ignition to points at the same time as the dual plugging.

Was it worth it? I think so. It certainly has made a huge difference in the pinging, I think I have more power (hard to say) and there seems to be an overall increase in mileage. It is interesting in that after doing a bit of rough road riding, I notice that it was vibrating and running overall crappy. A little investigation showed that the bottom left wire had been snagged and pulled off the plug. Put the wire back on and back to smooth... so yes, there must be a power difference between single and dual plugging. But maybe not much.

Oh yeah... and be prepared to take crap from those who haven't done it.
__________________
Samuel Longiaru
Kamloops, BC Canada
1975 BMW R60/6
http://thetwilightproject.net
Reply With Quote
  #9  
Old 22 Nov 2008
Registered Users
Veteran HUBBer
 
Join Date: Feb 2006
Posts: 1,515
BMW themselves released the cure for pinging, cylinder base gaskets at about £7 each.
I have asked on the BMW forums, and no one has answered. Why do BMW's need dual plugging? Other air cooled bikes seem to manage fine without. It does allow later ignition timing, but I sometimes wonder if the timing was retarded without dual plugging wouldn't it still allow the engine to run smoother. It seems to me abit like the big bore kits. The extra CC's produce less power than the original cc's.. IE 20% increase in swept volume=15% increase in 'claimed' power. Mostly things claime dby people who do teh conversion come down to it 'feels like' so and so is better. I can positively state here, every time I clean my bike it feels like it is 5mph faster in all gears, and runs smoother. Very rarely do you get a catagoric measured difference. If you dont belive me try for your self. clean your bike , check the oil and air pressures and ride, It will feel better.
As an aside, on top gear they did a test recently and spent £15K adding go faster bits to a car. The road test speed increase was barely measurable. The most effective thing was doing a standard service.
Reply With Quote
  #10  
Old 23 Nov 2008
Registered Users
HUBB regular
 
Join Date: Jan 2008
Location: colchester uk
Posts: 64
Quote:
Originally Posted by oldbmw View Post
BMW themselves released the cure for pinging, cylinder base gaskets at about £7 each.
I have asked on the BMW forums, and no one has answered. Why do BMW's need dual plugging? Other air cooled bikes seem to manage fine without. It does allow later ignition timing, but I sometimes wonder if the timing was retarded without dual plugging wouldn't it still allow the engine to run smoother. It seems to me abit like the big bore kits. The extra CC's produce less power than the original cc's.. IE 20% increase in swept volume=15% increase in 'claimed' power. Mostly things claime dby people who do teh conversion come down to it 'feels like' so and so is better. I can positively state here, every time I clean my bike it feels like it is 5mph faster in all gears, and runs smoother. Very rarely do you get a catagoric measured difference. If you dont belive me try for your self. clean your bike , check the oil and air pressures and ride, It will feel better.
As an aside, on top gear they did a test recently and spent £15K adding go faster bits to a car. The road test speed increase was barely measurable. The most effective thing was doing a standard service.
excellent couldnt agree more, add in a sunny day and smooth road.............
Reply With Quote
  #11  
Old 26 Nov 2008
Gold Member
Veteran HUBBer
 
Join Date: Sep 2007
Location: Kamloops, BC Canada
Posts: 108
Who need dual plugging?

I guess the general consensus is that not all airheads need dual plugging. Not sure that anyone ever said that they did. Mid-late 70's high-compression models are the only ones I know that really benefit from it. They don't do well on swill, and often ping on even Chevron Superduper when under load. Dual plugging helps there. The thicker base gaskets lower the compression but can also lead to lower combustion temperatures, increased carbon, pre-ignition and eventually higher compression and here we go again.

When looking for a bike for my trip, I was trying to avoid one with a high-compression engine, but got swayed by the other good characteristics of the /6's. I figured that dual-plugging needed to be worked into the cost of the bike. And pinging my way all the way up the hill to my house on it's maiden run was just as expected. Had it dual plugged and now it's quiet even on regular.

That's all I know. Don't know about big bore kits or 15k go-faster kits.
__________________
Samuel Longiaru
Kamloops, BC Canada
1975 BMW R60/6
http://thetwilightproject.net
Reply With Quote
  #12  
Old 26 Nov 2008
Registered Users
Veteran HUBBer
 
Join Date: Oct 2002
Location: Stockholm - Sweden
Posts: 316
The Egyptian Police commissioned a special edition of the R80. 800cc barrels with 1000cc 44/40 heads and 40mm Bing carbs.
This should result in about 7.0:1.
This edition was only made for and sold to the Egytian Police.

To get the best mileage L/dollar one needs to raise the compression ratio.

The plug is places off set in the beemer and VW air-cooled heads. Krauser 4-valve heads have the plug placed at the center which is the best position.

The 1200 oil-heads have 11:1 and dual plugs...

Recomended reading:
* 4-stroke performance tuning, Graham Bell, Haynes Books
* Internal Combustion Engine Fundamental, Prof Heywood, MIT.
* Oak Oshlen - Dual Plugging
* Tom ... ABC home-site - Dual Plugging
* Snowbum - Dual Plugging
* Daniel Derdicke - Dual Plugging
* Technik BMW 2-Ventiler
etc
Then test a dual-plugg vs a single plugged; do not guess - test and try for yourself before you decide what you think about 4 vs 2 plugs on the 2-valves.

As far as I know there are no available Dyno Tests on signle vs dual plugged 2-vales. All I have found is one (1) test, and that was on a Duccati by an American motorcycleshop.
__________________
Drive Safely,
Albert
Reply With Quote
  #13  
Old 20 Dec 2008
Registered Users
Veteran HUBBer
 
Join Date: Apr 2001
Location: Canada and the Alps
Posts: 123
Quote:
Originally Posted by c90 View Post
How did it improve the bike from the stock single plug head ???
A co-worker dual plugged his old R100 RS (maybe he bought it that way). He didn't comment on any power increase, but he was very happy with the extra 10 MPG increase.

You can't just dual plug and ride off. You then need to reset the idle ignition timing and limit the amount of ignition advance.
__________________
All the best,
Alex

Alex's BMW Motorcycle & Global Touring Page
SmugMug Site
Alps Motorcycle Tours - Priced Right


- If motorcyclists claim to be individuals, why then do so many of them ride in packs?
Reply With Quote
  #14  
Old 21 Dec 2008
Registered Users
Veteran HUBBer
 
Join Date: Feb 2006
Posts: 1,515
Quote:
Originally Posted by Global Rider View Post
A co-worker dual plugged his old R100 RS (maybe he bought it that way). He didn't comment on any power increase, but he was very happy with the extra 10 MPG increase.

You can't just dual plug and ride off. You then need to reset the idle ignition timing and limit the amount of ignition advance.
I am curious, How did he know he had a 10 mpg improvement if he bought the bike dual plugged?

If you spend the same amount of time doing a normal service ( include diaphragms, needles and needle jets I believe you will get the same or better results. Running a low compression will reduce the mpg slightly, but early post war 1945-50 Triumphs had 7:1 and would run happily on 'pool pertrol' ( 65 octane). One of the reasons I chose my BMW was because that model was designed fo modern fuel and has an 8,2 CR. It runs absolutely fine on 3 star. It has been stated that the pre monolever bikes with high compression engines are the ones with the problem. To fix the compression ratio ( poor modern fuel) problem lower the compression ratio with BMW's own fix at £7 a go. Spend the rest on petrol and . Only BMW's seem to suffer, no other biking forum I am on mentions it. I think in part it is caused bytheir use of a wasted spark which heats up the plugs more than a non wasted spark system.

Last edited by oldbmw; 21 Dec 2008 at 20:51. Reason: double plugged tripewriter
Reply With Quote
  #15  
Old 21 Dec 2008
Registered Users
Veteran HUBBer
 
Join Date: Oct 2002
Location: Stockholm - Sweden
Posts: 316
Quote:
Originally Posted by oldbmw View Post
I am curious, How did he know he had a 10 mpg improvement if he bought the bike dual plugged?
You are so right in posing this question. I have been looking into dual plugging since about 1992. I have still to find even one correctly done "study"...

When I changed from Bing 40 (worn) to dell'orto PHM 40 (new) mileage dropped from about 6.5L/100km to about 5.6L/100km. The dell'ortos are tuned for 8.2:1 single plugged heads and were used with dual-plugged heads with 10.5:1 (venolia pistons) 45/40 highflow valves... my plugs were quite black... so mileage will be much better when the carbs are properly tuned.
BUT - as you point out; not even I have tested to run my engines with single properly tuned and then retuned to the dual-plugged heads.
The only "testing" I have done was back in 1992/93 when I did not have the dual-pluggin set-up - my bike consumed about 6.7-7.0L/100km and dropped to about 6.5-6.3L/100km when the second plug was activated. Coincidens ?... The bike have been running really hot causing lots of overhauls and repairs since 1992 - up till this very summer, 2008, when I fiddled with the ITU in accordance to Derdickes homesite/tips - now it is running well, but mileage is still at 6.4L/100km or so (and topping 6.7 or there about now at winter with the studded tires).

Summation:
- I agree. On what does these milage claims rest ? Service, wishfull thinking or facts ?
- If there are solid facts; please do present them -
- My view on dual-pluggin does however remain as solid as ever; I'm for it -
__________________
Drive Safely,
Albert
Reply With Quote
Reply


LinkBacks (?)
LinkBack to this Thread: http://www.horizonsunlimited.com/hubb/bmw-tech/twin-plugging-air-head-bmw-8348
Posted By For Type Date
BMW Tech - The HUBB This thread Refback 27 Sep 2008 17:55

Currently Active Users Viewing This Thread: 3 (0 Registered Users and/or Members and 3 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


 
 
 

NEW! HU 2015 Motorcycle Adventure Travel Calendar is now available! Get your copy now for some terrific travel inspiration!

HUGE, 11.5 x 16.5 inches, beautifully printed in Germany on top quality stock! Photos are the winning images from over 600 entries in the 9th Annual HU Photo Contest!

Horizons Unlimited 2015 Motorcycle Adventure Travel Calendar.

"The calendar is magnificent!"

"I just wanted to say how much I'm loving the new, larger calendar!"

We share the profit with the winning photographers. YOU could be in the HU Calendar too - enter here!


HU DVD Autumn Special!

Take 40% off Road Heroes Part 1 until October 31 only!

Road Heroes features tales of adventure, joy and sheer terror by veteran travellers Peter and Kay Forwood (193 countries two-up on a Harley); Dr. Greg Frazier (5 times RTW); Tiffany Coates (RTW solo female); and Rene Cormier (University of Gravel Roads).

The first in an exciting new series, Road Heroes features tales of adventure, joy and sheer terror by veteran travellers."Inspiring and hilarious!"

"I loved watching this DVD!"

"Lots of amazing stories and even more amazing photographs, it's great fun and very inspirational."

"Wonderful entertainment!"

Check it out at the HU Store! Remember to use Coupon Code 'HEROES' on your order when you checkout.



Scottoiler automatic chain oilers. The most important accessory for your next motorcycle adventure!


Renedian Adventures


Renedian Adventures

What others say about HU...

"I just wanted to say thanks for doing this and sharing so much with the rest of us." Dave, USA

"Your website is a mecca of valuable information and the DVD series is informative, entertaining, and inspiring! The new look of the website is very impressive, updated and catchy. Thank you so very much!" Jennifer, Canada

"...Great site. Keep up the good work." Murray and Carmen, Australia

"We just finished a 7 month 22,000+ mile scouting trip from Alaska to the bottom of Chile and I can't tell you how many times we referred to your site for help. From how to adjust your valves, to where to stay in the back country of Peru. Horizons Unlimited was a key player in our success. Motorcycle enthusiasts from around the world are in debt to your services." Alaska Riders

contest pic

10th Annual HU Travellers Photo Contest is on now! This is an opportunity for YOU to show us your best photos and win prizes!

NEW! HU 2014 Adventure Travel T-shirts! are now available in several colors! Be the first kid on your block to have them! New lower prices on synths!

HU 2014 T-shirts now in!

Check out the new Gildan Performance cotton-feel t-shirt - 100% poly, feels like soft cotton!


What turns you on to motorcycle travel?


Global Rescue, WORLDwide evacuation services for EVERYONE

Global Rescue is the premier provider of medical, security and evacuation services worldwide and is the only company that will come to you, wherever you are, and evacuate you to your home hospital of choice. Additionally, Global Rescue places no restrictions on country of citizenship - all nationalities are eligible to sign-up!


New to Horizons Unlimited?

New to motorcycle travelling? New to the HU site? Confused? Too many options? It's really very simple - just 4 easy steps!

Horizons Unlimited was founded in 1997 by Grant and Susan Johnson following their journey around the world on a BMW R80 G/S motorcycle.

Susan and Grant Johnson Read more about Grant & Susan's story

Membership - help keep us going!

Horizons Unlimited is not a big multi-national company, just two people who love motorcycle travel and have grown what started as a hobby in 1997 into a full time job (usually 8-10 hours per day and 7 days a week) and a labour of love. To keep it going and a roof over our heads, we run events (22 this year!); we sell inspirational and informative DVDs; we have a few selected advertisers; and we make a small amount from memberships.

You don't have to be a Member to come to an HU meeting, access the website, the HUBB or to receive the e-zine. What you get for your membership contribution is our sincere gratitude, good karma and knowing that you're helping to keep the motorcycle travel dream alive. Contributing Members and Gold Members do get additional features on the HUBB. Here's a list of all the Member benefits on the HUBB.


Books & DVDs

amazon

All the best travel books and videos listed and often reviewed on HU's famous Books page. Check it out and get great travel books from all over the world.


Motorcycle Express for shipping and insurance!

Motorcycle Express

MC Air Shipping, (uncrated) USA / Canada / Europe and other areas. Be sure to say "Horizons Unlimited" to get your $25 discount on Shipping!
Insurance - see: For foreigners traveling in US and Canada and for Americans and Canadians traveling in other countries, then mail it to MC Express and get your HU $15 discount!




All times are GMT +1. The time now is 14:23.