1980 GS550 with GS650 Head Swap Question

[Neveragain55]

I’ve already read all the threads on this topic and it’s the route I’ve decided to go with my new café build project.

I see that many are calling for the Katana 650 cylinder head (to be graphed onto the GS550 block) over a non-Katana 650 cylinder head. 

My question/comment is, nobody really goes into explaining why, and also does it matter if the donor Katana 650 head comes from a shaft driven bike or a chain driven bike? (which was apparently very rare for the Katana 650)

I ask that question because my builder told me that we can absolutely do it, but that I have to make sure that all the parts I source are from the “chain driven” motors. Does it make a difference if the 650 cylinder head comes from a shaft driven bike?

Also, it’s really hard getting any info on the year range that the Katana 650 engines were built. Is there a preferable year over another for the 650, and did Suzuki only make Katana 650 (chain driven engines) within a specific year range?

                                                                                            Details folks, drown me with the details…….thanks…

 

 

 

[gs7_11]

Really?

[Neveragain55]

53 minutes ago, gs7_11 said:

Really?

Was it a bad question, or was it my delivery?

Uh, yeah.......really.

It's simple, does it make a difference, if the cylinder section of a 650 comes from a chain drive or shaft drive bike, and which years of the Katana 650's should I be searching for?

My logical side tells me it shouldn't make a difference, but I'm not one to ever assume, and maybe there's somethin inherently different about the two that would make a difference.

 

 

[PaintItBlack]

I’ve never seen or even heard of a chain drive gs650, not convinced there is such a thing,

mate of mine built a 550/650 30+ years back, the 650 barrels pistons and head were definitely off a shafty

[Neveragain55]

13 minutes ago, PaintItBlack said:

I’ve never seen or even heard of a chain drive gs650, not convinced there is such a thing,

mate of mine built a 550/650 30+ years back, the 650 barrels pistons and head were definitely off a shafty

I'm in the US, and they do exist my friend, take a look:

https://www.motorcyclespecs.co.za/model/suzu/suzuki_gs650e 81.htm

There aren't a ton of them, but they do exist.

I still don't have an answer though, would the cylinder chamber section of a shaft driven 650 wok in terms of graphing it onto the 550??????

 

 

[PaintItBlack]

2 minutes ago, Neveragain55 said:

I'm in the US, and they do exist my friend, take a look:

https://www.motorcyclespecs.co.za/model/suzu/suzuki_gs650e 81.htm

There aren't a ton of them, but they do exist.

I still don't have an answer though, would the cylinder chamber section of a shaft driven 650 wok in terms of graphing it onto the 550??????

 

 

Well you live and learn,

the one my mate put together used the barrels from a 650 katana shafty and a 550 bottom end, bolted straight up

[Neveragain55]

1 hour ago, PaintItBlack said:

Well you live and learn,

the one my mate put together used the barrels from a 650 katana shafty and a 550 bottom end, bolted straight up

Perfect, thanks.

I found a really good one for sale in really good condition and of course it's from a shaft driven bike, that's why I was asking.

One last question (promise) and even I admit that this is a stupid question but I have to ask....

Do I also have to use the cylinder head came with the 650 center, cylinder section, or can I reuse the cylinder head from the 550 block?

 

 

[PaintItBlack]

10 hours ago, Neveragain55 said:

Perfect, thanks.

I found a really good one for sale in really good condition and of course it's from a shaft driven bike, that's why I was asking.

One last question (promise) and even I admit that this is a stupid question but I have to ask....

Do I also have to use the cylinder head came with the 650 center, cylinder section, or can I reuse the cylinder head from the 550 block?

 

 

When my mate put his 550/650 together he used the 650 head, don’t know if it was a case of the 550 head wouldn’t work, but he went for the 650 head,

was a long time ago now so details are a quite foggy, was a great little bike though,

 

[Neveragain55]

2 hours ago, PaintItBlack said:

When my mate put his 550/650 together he used the 650 head, don’t know if it was a case of the 550 head wouldn’t work, but he went for the 650 head,

was a long time ago now so details are a quite foggy, was a great little bike though,

 

Thanks...

[Poldark]

Different combustion chamber design between the 550 and 650.   Best for the conversion is the chain drive (81-82 GS650e), it has more aggressive cams.  Shaft drive 650 head and cylinder block can work, but you can't use the cam sprockets from a shaft drive engine (different tooth count).  81-82 550 engine should take the cylinder block just fine; earlier 550 engine cases will require boring out to clear the cylinder liners.