Want a 860cc XS??

[AussieHard]

Want a 860cc XS??
Big bore kit for the 447 motor to 860cc?? Mmm Sounds good. Wonder if this is a good idea though? It is the original cylinders bored out...is there enough metal in it??

760cc is common and often comes with a new casting from Heiden or Mikes XS etc to allow for the bigger internals and keep the wall thickness.

Love to know if anyone has any experience with this???
Is it a off the shelf kit?

 

[XSJoel]

There was a thread around here recently saying once you got past 750ish CC you start to have problems with something. I forgot what exactly.

 

[AussieHard]

There was a thread around here recently saying once you got past 750ish CC you start to have problems with something. I forgot what exactly.

Tried doing a search on it but came up with nothing, maybe I wasn't using the right key words.

Also wondering how much hotter the engine would possibly run?

 

[jay760]

Try here, http://www.oldsidecarcross.com/phomot/pistons.html

 

[gggGary]

It seems the europeans are big on big (860) displacement. In the US about 750 is the usual go to size. I wonder if it has to do with stock larger displacement bikes being less available over there? Don't know that it's displacement related but once the xs engine starts making enough horsepower the crankcase begins to crack? Have I heard 75 or 80HP as the upper limit? I think this was found by flat trackers early on.

 

[XSJoel]

Yeah Gary, that was it.

 

[AussieHard]

Try here, http://www.oldsidecarcross.com/phomot/pistons.html

Over 1000cc



This engine was developed in many displacements ranging from 750 cc to over 1000 cc. Many preparers have worked on this engine, among the best known, GRM, GGC, TGC, Zabel BIGTUNET, BIGELARD. But also by small and talemtueux fans as Jacques Legrand, Jean REIGNIER Yes and many others.

At the end of 85 years remained the only original housings. The cylinder head , camshaft, valves, the cylinder , the piston the crankshaft, clutch, gearbox, ignition carburetion were affected.

Initially shirts and Alfa Romeo pistons were used according to the model, engine size ranged from 750 cc to 820 cc, this change could not be done on the first models XS1 and XS2 to small end 22mm. From the engine models 447 pistons 500 XT-axis of 20 mm which gave a displacement of 880 cc bore 87mm stroke for a 74 mm. This preparation does not require many changes and was affordable for a good price / quality ratio. Only the lower cylinder and crankcase were rectified. Then there was the drivers said "long runs" that is, the crank pins of the connecting rod was off center. It was a big job of machining. The stroke increased from 74mm to 82mm or 90mm 84 see. Which gave a bore of 87 mm and a stroke of a cylinder 84 to 998 cc. Version of "normal" this engine was given to 80 hp, the most powerful side by side the 100 hp. The preparer french VAM ran its own cylinders, clutch housings, Ignition and offered the same kick on the left.

Here is what they offering:
Kit includes bored barrels and new sleeves, new pistons and rings, new piston pins and circlips and offset dowells. To the best of my knowledge its all there except gaskets and the crankcases would need boreing out and perhaps head relieving. Head gasket would need to be cut, probably from copper, or otherwise made.

This kit is being sold for a mate, for who this has become surplus to requirements, never used. (He races XS650 and this would put him over his class capasity for racing). Head gasket would need to be cut, probably from copper, or otherwise made. $800AUD Inc delivery

"crankcases would need boreing out and perhaps head relieving" Not sure what is additionally involved with that.
Then of course do you do the crank, rephase, 6th gear etc while its apart???
What about cooling, would additional be required?

 

[AussieHard]

The Crank.
With a rod of origin the maximum displacement that can be achieved is 880 cc. For more displacement is mecessaire change the crankshaft crank pins in the displaced orbits. The piston stroke from 74 mm to 82 mm 90 84 86 see, with pistons 500 XT 87 mm bore and stroke of 84 mm results in a displacement of 998 cc. There were two ways for displaced orbits the crank pins is it was the original linkage was amended, be it a linkage was made ​​to measure.

 

[member3480]

I wonder if this is the same way that they did the old CB750 to over 1000cc but there was a catch. You had to offset the pistons to meet up with the rods and they did work on many DRAG BIKES in the late 70's and 80's Rods did have to get beefed up because of weight and offset but horepower was there. I just don't know if i would go threw all that labor and maybe get 20 more horse and make the motor run with very thin walls. Drag race yes but for the street i think it will just have way to much heat and not last long. OLD Honda with that and much much motor work ran fast but i know from personal experance that 650 twin may have some limits. I did have a Routts kit on a 650 TRIUMPH 850cc KIT and had many heat problems with bike and xs650 is built the same so i would like to see one done and see how it works out. Most big bore Drag motors have aftermarket cylinders with more meat in them so that would be a must if someone was going to build such a monster. Fastest i ever got my TRIUMPH with the kit in 1/4 mile was 13:10 at around 110mph and it was a bike i used to get to and from work but get caught in traffic and you were pushing it until it cooled down.

 

[Cornish Pixie]

Heiden tuning 880 kit

http://www.xs650.biz/p/28/2736/mo74-cg|22=5/#05-0881-880cc-big-bore-kit-533-type-105:1-compression

Heidens do a number of variations on big bore kits, most of which can be found here http://www.xs650.biz/p/36/1424/mo74-cg|22=5/pistons-rings-pins-&-clips-cylinders

 

[jay760]

Heidens 880 kits are for 533 rods, Australia is one of the country's supplied with 447 motors, could always get a 533 crank and 880 kit from Heiden

 

[oldbiker]

hi david rayner started those 860 kits a few years ago ,,, he did have a few dramas ,,,but i think he soughted them out ,,,, he is expensive,,, regards oldbiker

 

[AussieHard]

It sounds like it is expensive and potentially problematic.

I may give it a miss.

 

[Cornish Pixie]

Only secondhand views (from a couple of guys who have run both 750 and 840's) but the general consensus seemed to be that a well sorted 750 would be as good as an 840 and a lot less expense putting the motor together.

 

[AussieHard]

Only secondhand views (from a couple of guys who have run both 750 and 840's) but the general consensus seemed to be that a well sorted 750 would be as good as an 840 and a lot less expense putting the motor together.

What do people mean by that?

What is a well sort 750? Surely if you did all the same mods to get a 750, or an 850 the larger capacity should be better performance.

So if you stroke the 750, & stroke the 850, put a performance cam in both, rephase, etc. Do all the same work.

Not knocking what your saying as you are not the first to say it. Just trying to understand.

 

[Cornish Pixie]

What do people mean by that?

What is a well sort 750? Surely if you did all the same mods to get a 750, or an 850 the larger capacity should be better performance.

So if you stroke the 750, & stroke the 850, put a performance cam in both, rephase, etc. Do all the same work.

Not knocking what your saying as you are not the first to say it. Just trying to understand.

No worries with what you are saying, I started looking into the various options and I think the more research you do (especially on the internet) the more you find that their are people who love the 800cc plus motors and their are as many people who love the 750's.

The following is an extract from an e mail conversation I had with XS1961 on the subject not to many weeks ago

"Ive owned/built a few 840's & a couplve Wiseco 750's,I always found the 840 to be a very torquey motor,loads of grunt ,mine would outdrag most 4-cylinder bikes over the first 100 yds and sit on the motorway at 80-90mph all day(up to the Isle of Man two-up ,loaded with our luggage)!

As for which is best?;The Wiseco kit is made for the shorter 447 rods,that combined with the lightweight pistons allows the engine to rev higher.

The 840 kit uses heavier 81mm Suzuki SP370 pistons on our longer UK 533 rods . I wouldnt bother with an 840 again, the hassle & expense involved isnt worth it considering the 750 kit is a straight bolt on with no machining of c/cases or special parts. "

All the advice I've had from Lee (XS1961) has been spot on and to be honest I think the above quote sums up the pro's and con's of each option and for me, the 750 is likely to offer the most cost effective performance increase for the bikes intended use (limited road use and some classic tarmac track and hill climb use) The extra torque of the larger capacity probably isn't worth the hassle of the extra machining costs.

Hope this helps, and hopefully Lee waon't mind me sharing the advice he gave me.

 

[jay760]

Look at class 13d on this results sheet http://sprinting.org.uk/results2011/WZ 021011.pdf

This is what a well sorted 750 is capable of, 11.4 second quarter at 111 mph, whith what looks like lowered xs, I've spoken to the guy who runs it, all he says is it's mildly ported, with a sports cam, ( not racing ) with 36mm mikunis, and an electronic ignition system that I can never remember the name of.

 

[Cornish Pixie]

Respectable times when you start comparing his times with the machines competing in the 750 racing class.

Some quick times in the super street class

 

[member3480]

Done a bunch of street Wiseco 750 and some from MIKES here in the US but never took one to the track to see what times it would pull. 11.4 is a good time for a two cylinder that matches up very close to a stock GS1100 which i have run on the track here. I would like to see a picture of one if anyone has it to see if it is stretched and lowered and in a stock frame or a Drag Frame big difference. I am playing with a couple small turbos to go on a xs 650 to see if i can pull some good horsepower before it lets loose and this got me thinking of what this guy did to this motor to go that fast. I been at a lot of tracks all over the USA and can really say i never seen a XS650 run down a 1/4 mile. MANY TRIUMPH'S BSA'S NORTON'S but not any XS 650. Coming over that way next year for a vacation and want to go to a track. Raced here for a long time and seeing racing in another country is on my bucket list. Heiden Racing i think is the company that is making the CARBS for MIKES and i will email and see if they have any info. Anybody DYNO one of these kits???

 

[jayel]

there is a old saying about hopped up motors, "a dog that $hits fast don't $hit long" is it possible to make a monster motor XS? Yes, all it takes is time and money, is it worth it? that's up to you to decide