650 '700' kit do it yourself thread....

[bushmechanic]

ah ok jason perhaps boring out the cases a little to allow for a thicker 105mm ID liner would be worth doing if using aluminum

yes good ride.. same again this morning its tough living in paradise

Awesome spanner! pictures please!

 

[spanner]

It is on its way ex USA.

Like I say it is only an experiment, the cylinder may not remain round enough once machined or work out to be to thin.

The weight saving would be nice.

Cheers spanner

 

[bushmechanic]

if it goes out of round maybe could then make it real thin and press it inside something that is round probably preferably more aluminium

ally sleeves inside iron liners are used sometimes but i never read anything good about them

 

[spanner]

You can also get these but they are also thin, dry liners Nikasil coated.

items - Get great deals on items on eBay Stores!

 

[bushmechanic]

Hey guys, what price range would expect on each of these items? Rough numbers? Just curious to put it all into context and understand. Thanks!!

sorry Kris I missed your question

very roughly speaking in USD about 200 for a liner that fits from westwood inc ships

pistons vary but a quality one off is usually 400-500usd also inc ship

stud kit about 55

headgasket should cost about 40

I paid over a $1000 for my jbs kit

 

[tourist]

thanks!

another thing I'm curious about ... what's the minimum stroke you'd put a 105mm cylinder and piston on? speculatively?

naively guesstimating from bore/stroke ratio then a [email protected] is 1:1.49, which is less than both 450's and the 390 ... a classic 450 at 104.5 is pretty out there in terms of bore/stroke, at least in dirt bikes - 1:1.83

at some point does the head become a limiting factor?

 

[spanner]

Hi tourist, this is interesting me very much also.
JBS tried a 108mm bore as you may have seen in his auction recently.
I think it would have been difficult to seal the head gasket the way he did it
but I do not know. I have figured another way of doing that though which I
think would work better.
I have a 108mm piston in mind that may work and two options for sleeves.
The stroke would be around 70mm and would depend on the the compression height of the piston.
I am looking for a 550 motor as the basis of this motor. The 550 crank has a 32mm BE pin
which could be offset bored to 35mm, the amount of offset necessary would be determined by the compression height of the piston coming flush with deck height.
I would be using a rod from the 570 i.e. 120.5mm long.
I have already fitted 38mm inlet valves to the std head but these would be to small
for such a motor I am thinking 42mm would be better but perhaps not a possibility
with this head. There is also the problem of carb etc....

Cheers spanner

 

[Dr_C]

Hi fellows!
The positioning of the inlet valves in the combustion chamber is also critical for the max obtainable flow/degree of filling. You will not get the full benefit of the size of the valve if they are too close together, or too close to the cylinder wall. The design of the Husaberg head derives originally from the 500cc 96mm (?) bore engine, so the valves are close to each other. IMHO the head cannot successfully take more than 38-39mm valves with OEM positioning of the valves. BUT, there is a way around the little obstacle...

 

[spanner]

Need to get one of these 3D printers and print a head...

 

[bushmechanic]

or take a 9" to the frame backbone so you can use a ducati head

although not very nice flow wise you could make a new inlet tract to weld onto the duc head and use the OEM frame

 

[spanner]

although not very nice flow wise you could make a new inlet tract to weld onto the duc head and use the OEM frame

Yes was thinking of making a silicon casting of the original Ducati inlet and bending it to make a core.

 

[bushmechanic]

great idea Spanner then send it to me and ill draw it up and destroy some 6061 in the pentasaurus for the cause

found Bergsmlergs 570 rod under a rusty bean tin

its 340gm

 

[Taffy]

Hi fellows!
The positioning of the inlet valves in the combustion chamber is also critical for the max obtainable flow/degree of filling. You will not get the full benefit of the size of the valve if they are too close together, or too close to the cylinder wall. The design of the Husaberg head derives originally from the 500cc 96mm (?) bore engine, so the valves are close to each other. IMHO the head cannot successfully take more than 38-39mm valves with OEM positioning of the valves. BUT, there is a way around the little obstacle...

that's interesting Mats, where did you learn that from? great info!

so do you think that the Husaberg valves are too close together?

regards

Taffy

 

[Dr_C]

that's interesting Mats, where did you learn that from? great info!

so do you think that the Husaberg valves are too close together?

regards

Taffy

The valves are as close as they need to be for a smaller bore. When Husaberg increased the bore to 100mm, they didn't have money to make new casting molds for the cylinder head, and they didn't see the need for larger valves. So for the 100mm bore, yes, the valves are too close together, restricting the max valve diameter you can fit. If the valves on the other hand are too close to the cylinder wall, the flow around appr. a quarter of the circumference of the valve, will be obstructed by the cylinder wall. 2-3mm clearance to the wall is desirable. A "tumble" inlet design is less sensitive to these phenomenons, as a larger portion of the flow goes to the front direction, against the exhaust valves. A "dump" design (OEM) uses more flow around a larger part of the circumference of the valve, which makes it more sensitive to the location of the inlet valves. Anyways, I scratched my head more than once, figuring out where I wanted to locate the inlet valves in my DOHC-head...:happy:

 

[spanner]

Motors of all sorts generally evolve like that, start out small then they try to
make them larger using the same tooling, it ends up being a compromise.
Anyway if I could get my hands on a cheap damaged cylinder head or two
I could make a start....

 

[Dr_C]

Motors of all sorts generally evolve like that, start out small then they try to
make them larger using the same tooling, it ends up being a compromise.
Anyway if I could get my hands on a cheap damaged cylinder head or two
I could make a start....

I have a carton box of heads but handing any of them to you, dear Spanner, is not a good deed. I'll take some pictures of my old billet head and send it to you
tomorrow. You'll be better off, trust me!

March 15: You've got mail, Spanner!

 

[spanner]

Dr C,

A "tumble" inlet design is less sensitive to these phenomenons, as a larger portion of the flow goes to the front direction, against the exhaust valves. A "dump" design (OEM) uses more flow around a larger part of the circumference of the valve, which makes it more sensitive to the location of the inlet valves. Anyways, I scratched my head more than once, figuring out where I wanted to locate the inlet valves in my DOHC-head...

The black art of port design:unsure:

The KTM 690 is said to have a very good inlet port.
Would be interesting to compare the angle between the valves on the 690? to Husaberg.
Unfortunately such a downdraft inlet will not fit the OEM frame.

The Raptor 700 inlet port is also talked about as being very good and looks as if it would suit the Husaberg lay out nicely, even having two separate
exhaust ports.
Seen modified here,
CNC Megalodon is done


Good read here,
Login ? Speed Talk

And thanks for the pictures Matts very

 

[Dr_C]

The KTM 690 is said to have a very good inlet port.

Good read here,
Login ? Speed Talk

And thanks for the pictures Matts very

You're very welcome, Spanner!
Yes the 690 head is not bad at all, but the Y-shape (one into two) is a little too "steep" or short, causing turbulence on the "outside" to left and right. Difficult to explain, but Erland Cox (see also the SpeedTalk-thread you linked to) adds plastic in those areas to improve the flow in 690's. Erland Cox has btw ported all my cylinder heads, from OEM to billet SOHC and DOHC. He is very experienced and continues to strive for more knowledge, allways challenging himself!

 

[spanner]

I am wondering how the Raptor port design ("tumble"?) would compare
to the Husaberg`s. ("dump"?)

Probably not as good as the 690 but
at least it will fit in the frame

They claim high horsepower from the Raptor.

 

[Dr_C]

I am wondering how the Raptor port design ("tumble"?) would compare
to the Husaberg`s. ("dump"?)

Probably not as good as the 690 but
at least it will fit in the frame

They claim high horsepower from the Raptor.

As far as I can see and tell, the Raptor is also a "dump" design. But isn't necessarily a bad thing! The later years the design has tended to go towards larger bores, shorter strokes, higher revs and tumble inlet ports. Look at 250cc dirtbikes, Ducati Hypersports or screaming BMW 1000! But it's all depending on where you need the power delivery?

The larger teams in Supermono (2004-2008) used the Yamaha 660 as a base. The went up to 720-780cc, claimed very high power numbers and threw most of the engine in the bin after each race weekend.

I guess trail riding in a humpty-dumpty-tempo and giving it full throttle on rare occasions, will not result in an engine life length comparable to an infantry soldier on Omaha beach...