BMW high compression ratio pistons (11.2:1)
 

Hello

I’m planning an expedition with a R100GS. The bike has high compression ratio pistons (11.2:1)

Will I have problems with sahara fuel? The normal pertol is 95 octant or lower?

I normally travel with diesel LRs so this problem never cross my mind

tks

...are you really sure about that?

Do you have 4-valve technique on the airhead?

Above 10.5:1 on an airhead is pushing it... and above 11:1 is adviced against by all sources I have have found...

It is -not- possible to run on poor petrol with that high compression ratio... you should seriously consider changing to stock 9.5:1 or even the 8.2:1 version to minimise overheating risks and allow for usage of low and poor octane petrol... there is a reason for why the Egypt Police ordered a special version of the R80 engines... 44/40 valves with Bing 40... equates about 7:1 allowing for EU 87 octane petrol to be used...

Let us know -exactly- how your engine have been modified. It is possible that my comments above may not apply - it depends on exactly how the conversion to 11.2:1 have been made.

Are you sure 11.2:1 is correct? I would have made a compression-test to check it.

Personally I would never used anything higher then 9.5:1 on bike intended for traveling in areas with poor fuel. It's probably a bit on the safe side but on the other hand you can get a very powerful engine with 9.5:1.



Yes, please tell us!

hello

I have a normal 2 valve airhead and I need barrels (they have some scratches) and pistons + pistons rings

“It is -not- possible to run on poor petrol with that high compression ratio” I full agree with you if you keep the same combustion chamber shape.

http://www.moorespeed.co.uk/bmw-engine

“High compression ratio pistons
Designed by Richard Moore in collaboration with Omega pistons, these high compression pistons offer the most cost-effective (and easiest) way to boost power. The dyno charts show the solid increase in both bhp and torque achieved simply by slipping in these new pistons (use your existing piston rings if in good condition) – an extra 8bhp for a couple of hours work! Combine them with a free-flowing Moorespeed air filter conversion, and gain an extra 2bhp (see also Moorespeed Tuning Kit section).”


I still don’t have the pistons installed but I have the same doubts that you have (that why I have I posted where)

Yesterday I called Richard Moore from moorespeed and I had a long talk with whim. He has a looong experience in motorsport and in BMWs air heads. He seems a very well formed fellow and not just a curious.

We said that his pistons here used in several African races with out problems. He also has some bikes that were used in Africa tours also without problems.

He says that eventually if the fuel is very low in octane level you should delay a bit the timing to avoid some knocking.


“Personally I would never used anything higher then 9.5:1 on bike intended for traveling in areas with poor fuel. It's probably a bit on the safe side but on the other hand you can get a very powerful engine with 9.5:1.”


What solution do you use? Siebenrock replacement Kit?

thanks

I can't see that Richard Moore claims hat the pistons will give you 11.2:1 and I would have expected much better dyno-runs if they did.

There are some discussion about his pistons (and my old setup) here: Power piston kit - ::. UKGSer.com .::

I used a Siebenrock upgrade kit (800cc -> 1000cc) and a few other modifications for 60kkm. The kit worked nice and will probably be re-used on my second R80.
Right now I use a setup based on narrow 1043cc cylinders (from Mahle/HPN). I spend quite some time thinking about what compression-ratio to choose before I ended up at 9.5:1.
The bigger bore increases the risk for pinging so I also installed dual-plugging.

Hello

The compression ratio of Richard M. pistons is not written in his web page but he told me that by email and confirmed that yesterday by phone.

“1043cc cylinders (from Mahle/HPN).”

Can you give me more information about that? Part numbers, piston rings, prices…

If you prefer please send me a PM to:

bernardofeio @ yahoo.com.br

thanks

BTW:

any comments on this kit?

[url=http://www.motoren-israel.com/products/en/Shop/Engine/Cylinderkit/Sportkitt-1000cc-75mm-kuerzer-MADE-IN-GERMANY.html]Sportkitt 1000cc, 7.5mm k

Mr. Moore may be a excellent engineer, or a good con artist...
His site looks so much like the old catalogues from Luftmeister and CC in California... The pistons do look very smart. Keihan carbs - quite interesting. I will study his site later - my curiosity have been awakened :)

What is your budget?
How much may the conversion set you back (cost)?
=> gives us an idea of what to suggest, recommend and advice about.


If you want to play it as safe as possible, I would recommend that you get a set of 8.2:1 BMW original pistons with squissband (those perform just a little bit better than those without, in my opinion).
Perhaps you will have to buy pistons for steel-lined barrels and pistonrings for the nicasil barrels that your model have; that's how I had to solve high-compression on the 800-system. Works nicely - no problem.

Currently I am running 1000cc replacement Siebenrock pistons - love them.
But (!) - that is 9.5:1 and as I pointed out above; I would recommend that you do not choose the high-compression solution.
The Siebenrock pistons are about 50gr lighter than my Velonlia 10.5:1 pistons. The Venolia pistons are about 70gr lighter than stock (if I recall correctly) - and runns very smoothly once warm; far nicer than the heavy lumpy unbalanced original pistons.
If you go with 8.2:1 original pistons - balance them (!) and the conrods => the engine runns far better if you do.



Should you want high-compression - study carefully what Alibaba and Mr.MR writes!

My personal experience with high-compression is; good power, good mileage, a ... lot of garage time and heachache figuring out what broke and why. Since I ride in an area where high-octane petrol is available I want the high-compression; but should I ride in areas with questionable petrol, well... I would study closely how the Egyptian Police set up their special R80's!!!

Remeber - as compression raises... so does engine heat... The mileage differens is not -that- great that I would sacrifice/risk durability...


Good - to excellent engine/oil cooling should be your focus as well as looking at the most optimal solutions for keeping the engine running.

The hall-sensor pick-up (ITU) is a source of concern. The braker-point canister used on the late 70:ties models may be an option to consider. Braker points take little room, a spare hallsensor-canister is kind of bulky and difficult to mend on the road. I read here on H.U. about a year ago about this tip on the braker-point option - if I recall correctly VW 1200 (beetle) braker-points fits. You need to check that though - I might remeber it in-correctly.

If you want more power... you could install a turbo or super charger... ;)
Seriosly - keep everything as light as possible and as close to stock as possible, or rather "retro-convert" to more simple and easy solutions for best road-side repairability.
*
Apply KISS strategy; "keep it simple stupid" - That will save you from a lot of trouble and headache :)

Quote:

Originally Posted by dc lindberg (Post 309608) Mr. Moore may be a excellent engineer, or a good con artist...

:)



600 euros?... but I also need some barrels (can be used)

:)

Quote:

Originally Posted by dc lindberg (Post 309608) looking at the most optimal solutions for keeping the engine running.

? I didn't understand you now...

Quote:

Originally Posted by dc lindberg (Post 309608) The hall-sensor pick-up (ITU) is a source of concern. The braker-point canister used on the late 70:ties models may be an option to consider. Braker points take little room, a spare hallsensor-canister is kind of bulky and difficult to mend on the road. I read here on H.U. about a year ago about this tip on the braker-point option - if I recall correctly VW 1200 (beetle) braker-points fits. You need to check that though - I might remeber it in-correctly.

braker-point canister?... what is that? :) I also didn’t understand you on this…:oops2:

Quote:

Originally Posted by dc lindberg (Post 309608) Apply KISS strategy; "keep it simple stupid" - That will save you from a lot of trouble and headache

That I use almost always. If you look to my signature you will notice what kind of vehicles I use in my expeditions.... very simple and basic

thanks for your very interesting answer...

The kit from Motoren Israel will set you back around 950€.
It's 699€ for the kit, 55€ for the pushrod-tubes, 15€ for inserting the pushrod-tubes, 75€ for the pushrods, 45€ for bolts and 35€ for the gaskets.


The kit is from Mahle and usually their products are nice. I have no experience with the kit but I do have some experience with Motoren Israel.
It might be a smart idea to get in touch with them and tell them what you are looking for. Silvia is a friendly guy and he has given me many good advices through the years.

Lindberg mentions heat as a possible problem with a modified engine and he might have a point here. The problem with air-cooled engines is that there is not much cooling when you ride really slow (technical sections or rush-hour). This is not a major concern for equipment used under racing-conditions because they keep the speed up and gets better air-flow.
My bike ran hotter with the modified Siebenrock-setup and an oilcooler then it did as a stock R80 (without a cooler), but it never gave me any kind of problems.

You can ask Silvia at Motoren Israel but I don't think he will know.
Usually people change a lot in their engines when they rebuild it so it's hard to tell..

I just studied Mr Moores homepage/Dyna test.
Technical

THAT I did miss reading from the beginning.
I am NOT one bit impressed!
60bhp and 6kg torque - on a 1000cc engine?!
I do see notions of 66bhp and 7.6(?)kg torque - but it is very hard to read his test papers (too low resolution).

Anyway, you do get FAR more power by simply installing stock 9.5:1 pistons and old 44/40 valve heads with bing 40. That should give you 67-70bhp and about 7.4kg torque.
And he is asking 400 EU for such a "crappy" kit?!

With the low compression pistons: 8.2:1 and bing 40 you should have 60-65bhp, and about 7kg torque.

38mm exhaust. 40mm exhaust does not give you more power, rather you loose a bit of lowend torque.

11:1 would theoretically give you about 80bhp and close to 8kg torque - but to be sure you need to test it.

1100cc kit from 7-stones or the tunings done by Motoren Israel will give you >>80bhp. Those who have that kit describe it as -powerful- and -fun- to drive.

If you click at the graphs you will get better resolution.
He claims:

Standard R100: 51bhp/ 47Ft/lb (64Nm)
Omega long skirt: 58bhp / 53Ft/lb (72Nm)
Omega long skirt with different filters: 60bhp/ 55Ft/lb (75Nm)
Omega with long rods: 63bhp / 57FT/lb (77Nm)

I think the numbers for a standard R100 looks about right. Like you I'm not impressed by the results for the Omega pistons, with such an increase in compression I would have expected more.

hello

thanks for all the comments.

For now I will put the 11:1 pistons in standby. I'm still not sure if I will have problems with low octane fuel with this solution.

BTW: last May I went to Algeria with my lightweight and with a friend with a modified KTM. The KTM was using an engine with 11.5:1 compression and he didn't have any problems with pinging. Only overheating… J

I will probably go moto Israel solutions but I would like to see some Dyna tests and find more comments about them.

Bernaro Feio

The KTM handles low-octane petrol pretty good, I guess a modern cylinder-head and watercooling helps. Some (all?) have a possibility to alter the ignition.

I was driving with a guy on a 640-adventure in Iceland, it overheated...

Thank you Alibaba.
I am quite illiterat when it comes to brittish measurement - I did interpret Mr Moores test too negatively.
My applogies to all for this misstake.


Bernardo I do stand firm in my primary recommendation - address oil cooling and vehicle durability/simplicity. This tuning will not be expensive if you use 2:nd hand parts.

This is a neat idea on enging cooling (I do not recommend this to you - its just a creative solution):
Photos R90W

Hello

My needs are:

-low end torque
-ability to work with different fuels (I’m available to in some situations retard the timing if necessary)
-reliability
-(no over heating problems at low speed)
-two barrels since mine have flaking Nikasil
-a simple mechanic and simple electronics “electricity” so it can be easily fixable in the road.
-I bought the bike in the Ebay for 1800 euros. (this should be my reference when doing improvements… ) J My budget is around 600euros +/ - 20%

After all your comments I will probably jeopardy my budget in MAHLE Sport kit 1000cc from Moto Israel, for 699,00 €

(but it’s still an open issue)

One fast question: if I need to change the big end shells do I also need to change the bolts?
?c?

Good - now we have something to work with (presenting our ideas, suggestions and recommendations) -:)

Lowend torque:
- best torque will be with 1000cc or larger using "too small" carbs and inlet ducts (stubs).
- I have only tested the "modern" R100 with torqure max at 3000rpm once. It was good but BMW have traded off too much power to my taste. I use the old type of engins with torque max at 5500rpm - I do find that type of engine to be far better.

My personal recommendation to this is:
- dual ignition. In my R80, 800cc system, it gave me one full gearshift more power at 2000rpm, and that is a -lot- of low-end torque enhancement.
- larger, and high-flow valves. It gave me another full gearshift step at 2000rpm.
These two minute tunings/adjustments gave me from 1st to 3rd (at 5-7% up-hill) added torque.
On my R100 it is not as distinct; but it is the same ratio in added power; my R100 have a 32/10 final drive and not a 33/11 which kinds of enhances low-end torque also.
- Swap the 33/11 for a 32/10 and change the 1st and 5th gears inside the gearbox (major investment overhaul though) => 3.0:1 in 5th will be 3.01 or there about in 5th; i.e. one looses a little bit of top-speed potential (a beemer does not handle well at 180km/h and up, "so who cares?").

Wider range of acceptable petrol quallity:
- lower the compression ratio from 9.5:1 to 8.2:1; i.e. change to low-compression pistons. A neat "trick" is to simply install dubble head-gaskets (done that by misstake so I know it can work).
- dual-ignition!!! It is -so- important!
- larger intake-valves, high-flow. I have tested BugPack 45mm; sounds silly changing from 44 to 45, but it does have far more effect than what I anticipated.
- changing from 40mm to 38mm on the exhaust valves.
The change of valves enhances volumetric efficiency which does result in more engine power, but also at the same time a better acceptancy for less good fuels. The dual ignition enhances the burn-rate so radically that you should be able to run on as low as 87-90 octane (EU standard) which is close to karoseen when combined with low-ratio compression and larger inlet-valves (46/38 is what you should aim for).


OBS!
NB!
The piston heads and the combustion side of the heads -must- be grinded to be "smooth as a babys bottom"! ALL edges must be taken/grinded away, and all surfaces must be polished to "super smooth". Hot spots form at edges due to carbon deposits! Hot-spots causes pre-ignition. Pre-ignition is what determins what quallity of petrol that one must use. When these surfaces are -perfect- you can run on very low octane-:)


To lower the risk of overheating at low speeds, you will need to install electical fans. Tube fans or simply computor fans will do nicely. My mechanic have tube-fans on his side-car.
You could use temprature pic-up switch or a simple switch to activate the fans.

I am a fan of car alternator conversion with belt pully. Those start at about 40A. A standard Audi 100 or Saab 99/900 55-70A from the 80:ties will do just nicely.
The car alternator have a fan that aids in cooling the engine; more on the side it is mounted of cause. And because one takes out the original generator it opens the front for better air-passage which also enchances engine cooling.
http://www.webstruktur.com/svea/board/artik/bilgen.html
http://www.webstruktur.com/svea/board/artik/mont_bilgen.html

More engine oil does aid in cooling the engine as does lower compression ratio as does larger inlet valves.

I like oil-coolers - but installing an oil-cooler is trading off some of the reliability. Oil-cooler is kind of necessary in really warm areas... Catch 22 situation -:(...

Consider -retro- tuning away from the electronic ingnition trigger unit (ITU) to a braker-point can. Mind you - I drove close to 300 000km before a secondhand ITU broke (hallsensor failiur); so they are -very- reliable. You could consider a dual-hallsensor ITU from Motobins though -:)

A replacement 1000cc siebenrock kit is -very- nice. You will be amazed how nice they are -:)
The light-weight pistons make the engine more rappid/snappy. The engine tends to run a bit cooler - my guess is that the lower piston weight may have this as a nice sideeffect.
However... this is a 9.5:1 kit, i.e. a 70bhp kit, and I have recommended that you drop the top-end power from 70bhp to about 60bhp and then tuning it up by changing the valves and installing dual-ignition which I guess will give you about 65-67bhp on a 60bhp base.

Simplifying electronics really means dropping the poor standard alternator for a pully drive car-alternator. Spare-parts all over. (Riding in west Africa means that you should perhaps look at french alterntors?).
Braker-point canister instead of the electronic ITU. Dual ignition in parallel like Daniel Dicke presentes = if one set of coils break, you simply continue drive (happened to me once in heavy rush-hour traffic jam down-town on a road with no side-lanes).
I.e. "retro" tune the ignitionsystem; or carry one spare ITU and at least one spare ICU (ignition control unit).

Problem:
- 600EU will not cut it -:(...
The suggestions above will set you back about 1500-2000EU in parts...
You need to make compromises -:(...
As a compromise I would strongly recommend 2nd hand 8.2:1 pistons and barrels. This gives you room for head-overhauls (i.e. dual ignition conversion, Derdickes solution, Q-techs is not anywhere within reach).
There is no room for a spare ITU nor a spare ICU.


Now I look forward to read what other riders recommends :)

Hello

Thanks for your very interesting answer.

I rebuilt “my” heads not so long ago so I will not change them now. But a good idea will be to clean them and polish the combustion chamber.

Were can I find “free flow” photos of inlet and exhaust ports? Is it normal to cut part of valve guides?

Since my bike is a R100 I already have 40/42 mm valves. As I wrote I will not change them (at least now) but I will analyse the possibility to install dual plug if I notice some pinging.

The references to improve cooling are quite interesting but as you suggest in the past I will apply where the KISS strategy. If I notice any high temperatures I will analyse the possibility of installing a bigger oil cooler.

Now I’m being a lazy mechanical engineering: did you calculate the compression ratio decrease when using 2 head gaskets? This is a very good idea since it’s a very simple “do it in the field” change if I start to have problems with low octane fuel. Is it possible to put a head gasket in the base of the barrel? This would have the same effect but will not compromise pressure escape…


bernardo feio

Rather than use two head gaskets, why not install a cylinder base spacer. these are made by BMW and cost very little. Originally designed to overcome pinging.

I do recommend the 8.2 :1 pistons, I had these in my stock r80rt and they worked perfectly with all fuels I tried to use.

to get extra power use 'tame' cams and ensure the engine breathing is easy.
That way you have power on hand at normal driving speeds and revolutions, not just at high revs.
remember if your engines natural breathing is poor, increasing the compression >ratio< may not actually increase combustion chamber pressures by much at all.

Having done all this, where do you propose to use the extra 10% of power ??
30hp will easily let you cruise at 85mph.

But is there not a snag with the cylinderbase gaskets from R75-90 when one tried to install them on a o-ring-based cylinder/barell?

The dual-igniton conversion came when BMW started to make the 1L engine with 9.5:1 compression, right?
Was there ever a problem with poor fuel and the 900cc bikes (R90) ?
How bad were these problems with the 8.2:1 R100 steel-lined engines?
Doesn't the post '85 R100 have 60hp, 8.2:1 pistons, torque max at 3000rpm, 32 bing carbs?

The R80, 800cc, 8.2:1 system is reputed to be able to cope with quite poor petrol -right?

How accurate is measured compression as to reflecting the volumetric efficiency?
I have for a very short time had 10.5-10.8kg in my R80, with 800cc, and that was -powerful-; 9.2:1, 44/40 high-flow valves . Compared to the 8.2:1 with 42/38mm standard valves it was simply not the same engine.

My experience is that larger inlet-valves, hi-flows will result in about 1 gearshift more power at about 2000rpm, and dual ignition will ad yet about one gearshift (measured subjectively in a slop of about 5-7%). Switching from 8.2:1 to 9.2:1 and then lowering the heads by 0.8mm did only raise the power at about 2000rpm with about ½-a-gearshift; but at 5000rpm and up it made a large(!). The difference raising the compression ratio "only" made the bike accellerate much faster, and raised top-speed.

How about the heat-problem when riding in Africa, the out-backs, and other warm places?
Is there any chance that he could get around the oil-cooler issue on a 1L engine???

Unfair comments
 

[quote=dc lindberg;309608]Mr. Moore may be a excellent engineer, or a good con artist...

On what grounds does dc lindberg call Richard Moore a con artist? He makes a claim and then substantiates it. Unlike lindberg who makes outrageous claims with no support to his arguement.

For the record, if you get 60bhp at the back wheel from a Siebenrock 1070cc with no other work done, then you are doing well - and you will be set back atout £2K. A pair of Moorespeed pistons (again with no other work) will give virtually the same result at a quarter of the price. I know where my money would go.

To answer Lindberg's question, Richard is an excellent engineer - but a lousy con artist.

If someone gets 60bhp from a Siebenrock 1070-kit they have a problem. You should get at least 70 bhp and that's not virtually the same as 57bhp.
I think we are comparing apples and bananas here, Moorespeed long-skirt pistons are not close to the 1070-kit, nor in price or in performance.

So you should get 70bhp at the rear wheel from a Siebenrock 1070cc conversion with no other work done? What do you base this information on? Got a dyno chart to show us? Agree the Moorsepeed pistons are not in the same price league as the Siebenrock kit, but the performance is very close...

70+HP engines have been build for decades, BMW won Paris Dakar with a 72HP bike in 1983. HPN, Fallert, GMR, Wudo and Schek all have 70+HP.
The Siebenrock-kit was made to outperform the 1043-kit from HPN (68-75HP). You can find some dynocharts on the 1043-kit here: SR-Racing-Auspuff an BMW G/S

Last year I was in contact with Boxerschmiede regarding a 1070-conversion. They claim 80HP/90Nm if you use 44mm inlet-valves. If you use standard valves they claim 75Hp/87Nm.
When you do the conversion you also change the camshaft (included in the kit).

44mm inlet valves:
http://www.boxerschmiede.de/fotos-le...7701070ccm.jpg

Sadly I don't have any graph from a bike with standard inlet valves, but you don't gain 10HP by using larger valves.

For the record I didn't buy the Siebenrock-kit and I'm not a fan of comparing graphs like this.


If you want to compare the Siebenrock-kit to the Morespeed-solutions it might be more interesting to compare it with the " long con rod/short skirt pistons, sports cam shaft, airfilter and exhaust"-type. Price?



We obviously have different definitions of the word "close".

[quote=PeteMK;313358]Thank you Pete.
You are quite entitled to your reaction. My choice of words may perhaps not have been the most appropriate, I do agree with you there.
Thing is, I've been around long enough to aquire quite a substatial amount of theoretical and practical knowledge though I fear you are right in as much as I do not have enough hard data/evidence to battle claims such as Mr Moors in Court, then again, to what possible benefit would a leagal battle on this issue come to?...

Obviously you either are a close friend of Mr Moore, or have bought stuff from him at his very high costs.
The data provided by Mr Moore on his homesite does not convice, and there is no chance of double checking them. Claims such as the once made does kind of defy the basics of physics, you did take physics at school/college? So, just reading Mr Moores homepage and applying the most rudimentary physics (almost grade school level), one can clearly see that things do not ad up.

As for your kind of more emotional reaction, that was not called for.

Mr Moores skill as a mechanic/engineer is something I have -not- questioned! Just look at the parts presented on his homepage. One needs to know what one is doing to make such products!
What -is- questionable are the presented claims of power, and those either make him a very skilled engineer, or con artist... To prove this is up to Mr Moore, he is the one publishing the claims.

I rarely, hardly ever, make remarks as hars as the once I have made about Mr Moores claims, but when someone makes claims that are silly with the intent to convince someone else to spend money buying these claims... that is connery!

You need to separate the basic concept here which are:
- performance
- claims of power
I do -NOT- question the claimed performance, to do that I would need to test the stuff myself. I -DO- question the ridicules claims of -power- on solid scientific grounds, and personal expericens with "tuning" the beemer engines.

If you want to let yourself be fooled, that is up to you.
Petronius (c. AD 27-66); Talleyrand (1754-1838)
"Mundus vult decipi, ergo decipiatur"

Your argument defies logic. My original response to you was in the interests of fair play: I don’t like to see one individual accused of something by another with no justification - or in your case, explanation.

You stated that you were unimpressed with the LOW performance Moorespeed is achieving, and now say that they are ‘ridiculous claims of power’ (even though they are the result of independent third-party test figures). You can’t have it both ways!

Mr Lindberg, you have shot yourself in the foot with both barrels. Or perhaps I am missing something? Can you please enlighten me as to what exactly ‘just doesn’t add up’?

Quite agree with you – 70+HP engines have been around for a long while, but (a) that is when measured at the engine’s crankshaft NOT the rear wheel. Apply the adjustment figure to allow for driveline losses, and that 70HP equates to around 59hp. And (b) those were quite highly modified engines running on non-standard exhausts. Secondly, that graph you have supplied confirms that the power is being measured at the crankshaft: look at the baseline graph for a stock BMW engine peaking at 62.5PS. Now that works out to 61.2bhp – very close to the handbook for my R100GS which states 60bhp. Apply the correction factor again and that means 51.06bhp at the rear wheel – just slightly more than the TTS dyno shows for the standard beemer (which of course was a ‘used’ model, not factory fresh).

Thanks for proving my point for me, AliBaba! Couldn’t have expressed it better myself.

Helllo


Let’s maintain this topic technical and not personal…. :) beerchug

I will probably use the bike in the hot north of Africa. Did any one use moorespeed pistons in with African temperatures and fuel? (not in a racing scenario)

Did you have pinging and overheating problems?

And with the 1070cc kit? what to expect?

thanks

ISO = crankshaft measured power. Predominantly used in Asia.
Horsepower - Wikipedia, the free encyclopedia

DIN = rearwheel measured power. Predominantly used in Europe.
Deutsches Institut für Normung - Wikipedia, the free encyclopedia

E.g.
BMW K100 90hp (DIN) = ca 120hp (ISO).

Hello

I found this numbers:

Does any one want to comment?

1070CC (+dual plugging)
61.69 BHP @ 7002 RPM
53.89 FT/LB @ 4932 RPM

(why is the max torque at 4932 RPM? Should be much lower…)

Original engine:
51.06 BHP @ 6943 RPM
47.26 FT/LB @ 3619 RPM

Omega Long Skirt:
58.14 BHP @ 7003 RPM
52.96 FT/LB @ 3484 RPM

I’m still looking for more information about the Sport kit 1000cc, 7.5mm shorter from Moto Israel.

(I still have some doubts about pinging with the 11.2:1 compression ratio…)


thanks

It's not easy to compare numbers from different dynos, but it's a rough guideline.

First off all there are two different 1070-kits from Siebenrock. The first was Italian-made and the one they are selling today is Mahle. I would guess they have different performance.

I tried to gain as much information as possible about the 1070-kit last year but couldn't find much so I went for another option. Later I talked to a guy who installed the kit on a friends bike and he was pleased with the quality of the parts and how well it ran. Hopefully we will se a dyno-graph next year, but this bike will probably not be used outside Europe.

When it comes to the numbers it (62BHP/73Nm) I think they are low. I had 55BHP/80Nm with a 1000cc upgrade-kit and a few other modifications. The engine is much stronger now, I expect 65-70 hp (rear wheel) but it will not be tested before next year.



The camshaft is probably replaced, but it looks a bit odd.


Looks okay to mee.

my r80gs has the following engine mods along with many other mods
siebenrock 1000cc upgrade, polished balanced conrods,high torque cam, twin plugging, lightly ported and improved inlet and exhaust tracks, twin plug electronic ignition (motoeuroelectrics), two twin tower dyna coils. (several other mods that would not improve power output).the bike is also fitted with Siebenrock sbs exhaust (excellent) and K&N air filter. The gearbox has lower first and higher top gears, I have not had the bike dyno tested but comparing it to other bikes I have ridden and owned over the past 35 years, I would suggest the power would be closer to 65 + bhp maybe even 70 and the torque is flat in its delivery curve and strong from little over 1800 revs, in comparison to modern bikes claiming 75 /80 nm it feels as though it has better spread of torque its really hard to put a figure on it the torque is at its strongest between 2500 and 4250 but then there is a good kick of power above 5000revs. Power tails off from about 6250 revs The engine however is very smooth and returns an average now of around 54(uk)mpg , that includes all kinds of riding (motorways, A and B roads fast country riding and slow touring) the consumption has improved with the bedding in and getting the carbs running as right as they do now, it is more economic at a steady 55/60 on a long run. The siebenrock exhaust really made a notable difference as did the twin plug electronic ignition, which really smoothed out the power delivery and delivered a huge hit of torque in the low to mid range. Cant say what the power figures really are - but does not really matter to me so much because it is a really really nice machine for an old BMW and certainly comparable if not better than most modern machines in the 195 kg /800 to 1000 capacity class.

Question for the boffins here if any can help please. As my bike is modified as above what heat range plugs should be used - As usually higher compression bmw engines (r100rs etc) use a cooler plug than the standard bikes, would twin plugging negate a need for heat range change (if its needed) or not. I find using a cooler plug the bike runs well but gets a little bit carbon on the plugs at lower speeds (suggesting they are too cool around town at low revs) I am currently trying standard heat grade plugs for the Gs but with platinum tips to see what these do but if anyone has any suggestions what would be right please advise me.
Also I am trial running a K&N filter since October - K&N say it allows 40% more air to flow - not that I am so bothered just thought I would give it a go, the bike seems to run very well with it with the exception of starting in the colder conditions - it cranks longer sometimes starts to struggle in minus 10 conditions, (Battery is Oddessy and in very good nick so good power) before firing and is impossible to kick start from cold. I will be reverting to standard filter if I cant sort it - but just for knowledge would I be right in thinking the cold start system is getting too much air and as such running too lean to get the initial fire up (obviously this is more so with the kickstart as its not cranking as quickly and as long on each stroke of the kicker compared to whizzing up on the starter.)Or am i way off the mark and its going to be something else and I am just associating the filter to the starting)I Have just ordered a new paper filter to try - and see if it fixes the problem.

Hi Adventure950,

Twinn-plugging and sideeffects.

Plugs:
- You present what I have experienced. The solution I stumbled up-on is multi-electrode sparkplugs, Busch Super 4 and NGK BUR. I am running Bosch Super 4, 78 (upper, long) and 56 (short lower) plugs. Perfect combination on my present/current engine - all my engines have had their own preferences... "personalities"!
78 = 7 and 8
56 = 5 and 6
=> wider heatrange.
NGK seems to have their temperature steps midway between that of Bosch. BP6ES does not act as Bosch WD7, but they are listed as the same heatrange...
I.e. - you will have to test a few different marks and heatranges.

K&N:
- You will have to re-jet the carbs... Motorworks - BMW Motorcycle Spares - home can assist with jettings; they've helped me with some odd sizes. Look at Bing USA, Throttle Body Rebuild Kit - they have all parts and a tuningmanual that you will need.
After you get the engine running well using dual-plugging and K&N it will not start using a standard air-filter made of paper... well, at least I found myself in that postition with a R100RT... That bike refused to start untill I pulled the paper filter. With no filter it started easilly. When I put the filter back... choked bike.

Thanks Albert I am trying out NGK bp6evx platinum plugs at the moment and the bike feels quite good riding it yesterday, so maybe the heat range difference you mention might sit broader between the bosch heat range w7dc. I have not pulled it out yet but will see later today if there is any fouling.
Re jet the carbs - just what I did not want to hear but suspected the bike runs really well its smooth, power is good but the cold start not so good, I will speak to Motorworks see what they have to say - Thanks for the advice. Jake.

hello

Has you know I’ve been looking for a solution that will give me more torque at low speed.

I look for several solutions including displacement increase, compression increase but with a tight budget

If I didn’t need barrels Richard Moore would be the best price/power solution (eventually some ping problems)

Since I need the barrels Moto Israel 10.5:1 and Richard Moore were very similar price solutions.

I decided that I would go to Richard M but he was out of barrels so after more then one month I when to Motor Israel Kit

First comments: This is a MAHLE motorsport engineering design but nowadays is being sold with MAHLE barrels and Wossner pistons and pistons rings. The barrels are very good but the pistons are not up to Mahle standards. I’m only referring to end product finish look. Most probably the performance will be similar (I would like very much to compare the pistons with the ones from Richard M.)

Installation remarks:
The kit should came with installing instructions since I lost to much time with small details like wrong push rod pipes installation (I will give details if any one is interested)
To avoid more costs I decided to modify myself the barrel bolts and push rods. Easy job but will had a couple of hours to the total installation time.

Since I work in the piston ring area I also lost some time with unnecessary measurements.

After two working evenings I started the engine. The lightness of the engine is instantly noticeable as the engine reacts mush faster. Will see about power/torque and fuel consumption…

I only did one km so no more results for now.

For now I will not touch the carbs to avoid miss results

:)

Think you will find the kit to be quite pleasing.

As you seem to have your engine apart at the moment why not play safe, fit secondhand standard barrels and pistons then after you trip modify your engine in whatever way you want and sell the standard parts. I would also keep the engine standard in other ways, carbs, air filter etc, they might not give the most exciting performance but reliability is more important where you are headed.
I have never had much problem with standard parts on my R80GS despite having run it on 80 octane in Egypt and something equally awfull in Iran, although the latter was only 1.5 pence per litre.

Did the tube between the air-filter and carb fit? Problems with the exhaust?

Nice job, congratulation!
Yes, please keep us informed.

hello

I had some fears with those items but those were the easiest assemble. To be honest the tubes between the inlet and the air filter fit better now and were easier to assemble the with the standard cylinders…

Concerning the exhaust you only have to unbolt the connection pipe between the two main pipes and you will have no problem.

The problem with the push rod tubes is that you should only push them into the cylinders till they reach the top surface of the cylinder. They are machined to go more then that but after you can not install the head and you can not pull them back…
(if you put them in the freezer they are easy to install)

Just one more detail concerning the piston rings.

The second groove ring gap should always be similar or superior then the gap of the first groove to avoid “fluctuation” problems. If the gap is too small in the second groove some pressure will be created between the two grooves and the fist (top) one will not seal properly.

With Wosner piston rings this was the case. To solve this the gap in the second groove should be increased or you should assemble a top ring with smaller gap… (ideally something like top=0.15(+0.10)mm and second=0.30(+0.20)mm)

Back in the day I used compression plates on my R75/6 and R80 so that the bikes would not ping too much on the fairly poor quality fuel available in india and afganistan. This seemed to work, except in India whenever petrol was adulturated with kerosene.

Modern engines (such as KTMs) can run highcompression ratios because they have better cylinder head shapes and better electronics, not a good idea to compare their compression ratios with our old airheads.

When travelling (rather than racing) power is not an issue, reliability, fuel efficiency and tractability are much more important, so i would go with a standard low compression ratio engine, I might go to twin plugging as well, but not much else.

On the power discussion my 1070 kitted bike develops 72 BHP at the rear wheel with just over 60ft lbs of torque, with a flattish torque curve from around 3000 rpm. It is gas flowed, twin plugged with 38mm dells and 40mm pipes and a jim Cray conti type silencer. It runs well! This compares to around 52BHP at the rear wheel for a standard 82 RS/RT engine. The standard later bikes are less powerfull, mainly due to lowering of compression ratios.

Charles

well thought i would let you know the results of the changes I have made on my bike in measured terms ie on a dyno, The bike is a r80gs 1991 model,to save you checking backover to previous stuff i wrote - it has the following engine mods, siebenrock 1000 upgrade,K&N air filter, twin plugged heads, lightly gas flowed, standard 32 mm carbs and valves, 1 piece rocker guides (really quieten down rocker gear noise and save adjusting for rocker shaft play - nice kit), balanced conrods, (balanced over entire length to match each other),matched pistons, balanced crankshaft, heavy duty clutch, siebenrock sgs2 high torque exhaust, 296 enduro camshaft, bronze bush cam bearing, endurolast alternator and twin plug ignition system, gearbox 1st gear 5%lower, top gear 5% higher, Now she is running near perfect with electrics for the spark from the endurolast ignition ,NGK bp6 iex plugs, ngk plug caps copper core race HT leads, twin tower Dyna coils. After all that work Phew! the figures on paper are not spectacular but riding the bike is very much a different story to a standard 800gs or 100gs.

Dyno measured power at the back wheel, 52.76 hp at 6000 revs (65.95 at the crank - approx calculation some internet guides would have calculate it to be 72.01hp),
Back wheel measured Torque 72.08nm (53.16ft/lb)at 3400 revs However Torque reaches 66.44nm (49 ft/lb) at 2400revs reaches oits peak at 3400 where it continues pulling at 72.8nm through to 5800revs when it tails off slightly to 44nm by 7000 revs - but then the max hp kick is taking over pulling the bike forward with a descent surge.
In rideable terms the engine is very quiet (i mean as quite as I have ever heard an airhead), very smooth all through the rev range and so tractable and usable at all road speeds and will happily cruise at 90mph and pull top gear cleanly from 1800 revs without protest on a level tarmac road and about 2400 when under more load or on an uphill gradient.

Fuel mix ratio stays fairly steady throughout the entire rev range at about 14.6 with only slight variation at the bottom end where it dips to around 13 for the transition at 2,500/3000 revs maybe the next size idle jet would smooth that out but I dont think its worth changing for the tiny difference it would make.

Fuel consumption appears to be steady around the 50 /52 mpg (5.6 litre per 100km) in normal riding.

Bye the way kept the K&N air filter - bike kickstarts again from cold - turned out I had the idle circuit a touch to lean originally and more so after putting in the K&N so now its just fine.

Adventure 950, I have always used slightly hotter running plugs on the lower position, as otherwise they tend to oil up a bit.
Charles

Sounds like a nice bike, congratulations bier

Hi Chas not a problem on mine at the moment now everything else is running right - I run standard size plugs 14mm as I had the lower head face built up before drilling the new plug face, I also think the endurolast ignition which is crank driven and programmed for twin plug advance helps, I had this checked also by a specialist after I set everything up he said the timing and advance was spot on at every point through the ignition cycle and rev range - I had different ranges of plugs but find the ones I am currently running work well. However I note your comments and have heard it mentioned before about the lower plug heat range if there is any oiling shows up then I will follow your advice. Cheeers Jake.

thanks alibaba, Thanks for that - I am happy with her would still like to HPN the chassis thought long and hard and am torn between p/dakar model and rallyesport. Need to speak to Klaus to sort out a ride on both. Jake.