Life Changing in a Moment

[gsd4me]

Ontic: PM sent.

[Beemerguru]

Siebenrock makes a great upgrade...for the dual plugging I always go with the smaller lower plug option. Leaves more metal between the holes which reduces the tendency to split. Short reach Japanese bike plugs work great.

[ontic]

Not arguing here, just enquiring.
I thought the location of the plugs was generally the same but the option was to build up some metal first, then drill and tap the hole to allow the same depth plug to be used on the bottom? Giving advantage of same plugs used and deeper threaded hole (less chance of stripping)? Giving negatives of having to weld on head to build up metal and potentially screwing things up?

[Airhead Wrangler]

Originally Posted by ontic

Not arguing here, just enquiring.
I thought the location of the plugs was generally the same but the option was to build up some metal first, then drill and tap the hole to allow the same depth plug to be used on the bottom? Giving advantage of same plugs used and deeper threaded hole (less chance of stripping)? Giving negatives of having to weld on head to build up metal and potentially screwing things up?

The bigger choice is plug diameter. A lot of people go with a smaller 12mm diameter plug on the bottom which also has a shorter reach. It leaves more metal intact on the head and if in the event it ever does strip you can always go up to the larger plug.

[chasbmw]

Jim Cray uses standard sized plugs on the lowers.........I asked him about using smaller diameter plugs and he said that he had never had a problem with a customers bike and his the main dual plug man in the UK.

I always use a hotter running plu in the lower position, it helps reduce fouling. My faster bike has the full Seibenrock 1070 kit, it works very well with various other mods

The Sachse ignition will give you a good choice of ignition maps for dual plug use......remember to deduct the 19% tax.

I like the lighting....

[RGregor]

Originally Posted by chasbmw

I always use a hotter running plu in the lower position, it helps reduce fouling.

Udo Gietl told me he used a 2° offset between upper and lower plug (lower firing 2° later) for better burning.
I will test that with the ignitech as it allows to define that offset.

[adrenal]

Originally Posted by chasbmw

Jim Cray uses standard sized plugs on the lowers.........I asked him about using smaller diameter plugs and he said that he had never had a problem with a customers bike and his the main dual plug man in the UK.

I always use a hotter running plu in the lower position, it helps reduce fouling. My faster bike has the full Seibenrock 1070 kit, it works very well with various other mods

The Sachse ignition will give you a good choice of ignition maps for dual plug use......remember to deduct the 19% tax.

I like the lighting....

That might be the case but does Jim C TIG up metal thickness before machining for standard M14 plug?
Give away here is if you have to use a 5mm thick (approx) washer under the lower plugs. If so then he doesn't build thickness first.
Would be really interested to know what he does here..

[R100LT]

So just a little update.

Last couple of months enjoying the 2 hour ride up to the airport on the RS for work each week ... but with the colder & wetter conditions coming on it is time to get my LT ( RT ) back together.

Nice little package from Motorbins arrived today . Opted for the Omega Pistons to go with the 336 cam ... New values kit ... keeping that all standard ... and some nice new SS push rod tubes and new timing chain whilst I am it.

Not going to do any head work or carbs swap ... see how it all runs when its together ... and hopefully no pinging coz I really don't want to dual plug it yet.

All I am looking for is a bit more bite around the 120 km mark ... which is the speed that I need to pass the road trains .

[chasbmw]

Originally Posted by adrenal

That might be the case but does Jim C TIG up metal thickness before machining for standard M14 plug?
Give away here is if you have to use a 5mm thick (approx) washer under the lower plugs. If so then he doesn't build thickness first.
Would be really interested to know what he does here..

Adrenal,

Jim just uses short reach plugs, no need for welding. You just have to make sure that you don't fit a long reach into the lower positions, if you do when you get to remove the plug you may strip the thread as the exposed threads will have got a layer of carbon.

[chasbmw]

LT

Have you seen the threads on 336 cams and how to check that you have a good one?

[supershaft]

If I raised the compression at all I would dual plug.

I have seen a couple of heads crack between the bottom 14mm plug and the exhaust seat. I haven't been around many dual plugged heads with the bottom built up for a long reach plug. I have filled in a couple of spark plug holes for re-tapping and for some reason it would leave the head pretty warped and needing milled on both sides. I have had friends that have raised port floors by filling them in and and they said that would warp them a lot too. I use 12mm plugs short on the bottom. IMO, remapping the ignition curve is an important part of dual plugging. I would not simply retard the entire curve. It kills right off idle performance.

I have no experience with removing material from the cylinders for compression. Which end? If it's the top, does it cause the nikisil to flake? Starting with 8.5:1 CR pistons, I would think you would need to shorten the push rod tubes a bit?

[chasbmw]

Originally Posted by supershaft

If I raised the compression at all I would dual plug.

I have seen a couple of heads crack between the bottom 14mm plug and the exhaust seat. I haven't been around many dual plugged heads with the bottom built up for a long reach plug. I have filled in a couple of spark plug holes for re-tapping and for some reason it would leave the head pretty warped and needing milled on both sides. I have had friends that have raised port floors by filling them in and and they said that would warp them a lot too. I use 12mm plugs short on the bottom. IMO, remapping the ignition curve is an important part of dual plugging. I would not simply retard the entire curve. It kills right off idle performance.

I have no experience with removing material from the cylinders for compression. Which end? If it's the top, does it cause the nikisil to flake? Starting with 8.5:1 CR pistons, I would think you would need to shorten the push rod tubes a bit?

Easy to get the dual plugged ignition correct nowadays, if you are adapting heads and cylinders to increase CR, you might have to reduce pushrod length a tad to keep the original geometry.

[supershaft]

Originally Posted by chasbmw

Easy to get the dual plugged ignition correct nowadays, if you are adapting heads and cylinders to increase CR, you might have to reduce pushrod length a tad to keep the original geometry.

From what I can tell it isn't so easy to get dual plugged ignition curves correct these days. If I understand them correctly, a lot of digital advance curves are not what I want to run. Without changing the RPM parameters, it is very easy to change the curve in a bean can. Most electronic curves I have seen have a lot of options that are out of our ballpark and/or not what I would run and the RPM parameters are for the most part not an option at all.

If you shorten the cylinders, the geometry of the pushrod tubes is going to change regardless of their length as far as how they mate up to the case but not by very much at all as far as shortening them for compression is concerned. My concern is keeping them out of the head gasket and the right tension on the pushrod tube seals at the same time.

I would hope the nikisil doesn't flake if they are shortened from the top. That is real close to the most stressed area of the bore!

[R100LT]

Thanks Chas

After reading the 8 odd pages of the 336 Cam thread I am really non the wiser. Not sure exactly what a " good " or " bad " cam should be . I am guessing that both left are right lobes should have the exact tapper . Is this correct ???

Also I just got off the phone to Ray Peake . He is suggesting that I go the dual plug path . He has given me a reasonable quote on the head work but the thing that concerns me is that he is saying that my new values should be " polished " before I install them ... or they will be toast after 8000 km's.

Also not exactly sure on which method to go on the dual plugging . I have the Euromoto charging system ... but there dual plugging system seems to be out of stock ... Any thoughts of best track to take.

Again Ray warned me off installing the 336 cam . Makes me think that I might let it sit on the shelf for the RS . He says great for a road racer ... not so much for a long distance touring .. enough thou I tend to sit on 5000 rpm's from the moment I leave my drive way until I get up to the big smoke ( 200 km's )

[supershaft]

Originally Posted by R100LT

Thanks Chas

After reading the 8 odd pages of the 336 Cam thread I am really non the wiser. Not sure exactly what a " good " or " bad " cam should be . I am guessing that both left are right lobes should have the exact tapper . Is this correct ???

Also I just got off the phone to Ray Peake . He is suggesting that I go the dual plug path . He has given me a reasonable quote on the head work but the thing that concerns me is that he is saying that my new values should be " polished " before I install them ... or they will be toast after 8000 km's.

Also not exactly sure on which method to go on the dual plugging . I have the Euromoto charging system ... but there dual plugging system seems to be out of stock ... Any thoughts of best track to take.

Again Ray warned me off installing the 336 cam . Makes me think that I might let it sit on the shelf for the RS . He says great for a road racer ... not so much for a long distance touring .. enough thou I tend to sit on 5000 rpm's from the moment I leave my drive way until I get up to the big smoke ( 200 km's )

Checking a 336: You can do it with calipers. The two lobes for the left cylinder are a little higher on one side than the other by a couple of thou if I remember correctly. The two lobes for the right cylinder SHOULD be. Hopefully they are!

I would definitely use a 12mm plug below. I just dual plugged my bike (robtg did the machine work!) but I have the stock bean can. Two .7 ohm Dyna coils. BMW /2 wire. 5k ohm NGK caps. I pushed in the two very malleable weight stops inside the can until I got my ignition timed from 6 degrees at idle to 28 degrees at full advance.

If I was road racing I might want more cam than a 336 but they are a great do everything cam with awesome midrange. Not too much lift makes them great for the street. Long lobe ramps makes them not need any more than stock spring pressures. Their narrow degree lobe center to lobe center gives them tons of midrange. IMO, awesome cams for everything but parade duty and they can do that if need be. Sure, I have heard the stories of them making less power than a 308 under 6k rpm and the like but in my bike, friends bikes, and customers bikes? Less power than a 308? I would say under 2000rpm and then it isn't much. I had numerous people warn me not to install a 336. The owner of the dealership I was then working at and three of his mechanics told me he had one in a race bike and they couldn't get it to idle under 2000 rpm and it made no power under 6000. Just like tuners here have warned. I am glad I tried one for myself. From the get go my experience has been just the opposite but that really didn't surprise me after working with some of those guys.

IMO, if you are one of those guys that never revs their bike above 5k rpm, you might not like a 336 although one of my customers claims he is one of those and he loves his. If you are like me and ride from 3k to 8k all the time while rarely dipping below 4k, you will love one. 5K? You'll like 5k SO much better with a 336!