Big Bore B6?

[Swiss Toni]

Anyone know if there’s a kit for the Mk1 B6?

[Duckndive]

23 minutes ago, Swiss Toni said:

Anyone know if there’s a kit for the Mk1 B6?

yes there used to be a few in the 600 class in straightliners had them ... 

easiest way is chuck a 750 motor in it  

[R1guy]

44 minutes ago, Swiss Toni said:

Anyone know if there’s a kit for the Mk1 B6?

1127 or 1157 kit.

 

Usually come with crankcases, gearbox and a head.

Cost between £400-£600

Edited April 18 by R1guy

[DAZ]

There used to be a 884 conversion but if I remember it needed the cases boring to suit the big oversize liners ...... Set of slabby/long stroke 750 barrels pistons maybe ? More practically this

1 hour ago, R1guy said:

1127 or 1157 kit.

 

Usually come with crankcases, gearbox and a head.

Cost between £400-£600

 

[Archie]

I keep looking, but can’t find anything. Always see info on the 884 kit, but seems to be discontinued. Apparently it’s quite a nice upgrade as it gives good power / torque curve. (Apparently)

dunno about 1100 / 1200’s for cheap anymore. All the ones I see are about £800 without carbs

[BillyR]

JE used to do pistons for the 750 to take it out to 884, dont know if they still do.

[Swiss Toni]

I’ve already got a 750J Dot motor, and two 1127 Teapot motors. Just fancied a barrel/piston upgrade for the 600. 

[DAZ]

Well I think the easiest / most cost effective is long stroke 750 barrels and pistons but still got to factor in the seals and gaskets vs a known runner swap. I wonder if there are any differences in the 600/750 long stroke heads e.g. Valve and combustion chamber sizes that may add to the swap ?

[Swiss Toni]

I’ll have to do some swotting up!

[Tony Nitrous]

Even though the 11 and 12’s aren’t dirt cheap, wouldn’t a teapot 750 or GSXR750 motor be a cheaper easier big bore than an aftermarket kit with buying pistons, gaskets, rebore etc ? 

A fire breathing bigbore motor would have some appeal if it was kept stock looking in a stock looking bike though. 

[Swiss Toni]

@Tony NitrousNormally I’d say yes to an engine change, but the way things are with Swansea, I can’t be arsed to jump through the hoops and over the obstacles we know they just love to put in the way. 

[clivegto]

70mm with 18mm pin with 15mm pin height. There not for sale if you were wondering. 

[Dezza]

12 hours ago, Archie said:

I keep looking, but can’t find anything. Always see info on the 884 kit, but seems to be discontinued. Apparently it’s quite a nice upgrade as it gives good power / torque curve. (Apparently)

dunno about 1100 / 1200’s for cheap anymore. All the ones I see are about £800 without carbs

On eb@y maybe but OSS prices tend to be a lot lower. You sell lower; you buy lower

[wraith]

I put a set of long stroke 750 barrels and pistons on a b6 motor (project see how far we go gs550 b6) 

Used the b6 head but had to use two head gaskets so the pistons didn't touch. Apart from that it was a straight swap.

If it came to it again, I'd just put a 750 motor in it and just change the cc on the V5 and leave the engine number as is, because as you say the DVLA just make problems just for a joke 

[DAZ]

The 771 wiseco pistons that Clive has are still listed on us sites and wossner list similar for long stroke motors @£640/650 ish ...... Soon adds up to 11/1200 money 

[DAZ]

4 hours ago, wraith said:

Used the b6 head but had to use two head gaskets so the pistons didn't touch. Apart from that it was a straight swap.

Just out of curiosity did you have a 750 head to compare to the 600?  was it that the head of the b6 had a shallower combustion chamber than the 750 do you think kind of like the dot head vs 11/1200 head different chamber size ? 

Edited April 19 by DAZ

[wraith]

1 hour ago, DAZ said:

Just out of curiosity did you have a 750 head to compare to the 600?  was it that the head of the b6 had a shallower combustion chamber than the 750 do you think kind of like the dot head vs 11/1200 head different chamber size ? 

I didn't, but I would think it's the b6 head that had a shallower combustion chamber. So using the b6 head with the 750 pistons would of bumped the compression up. 

I never even rode the bike before I sold it  as I got it running and the jetting somewhere need but it needed tyres etc but a mate offered me good money for it and I needed the space.

[Bow]

Long stroke 750 barrels, pistons, and head,  bolt on power, whilst keeping the original bottom end.  No messing with DVLA that way.

or, keep the 600 head,  so carbs and airbox all line up.

[gsxwill]

On 4/19/2024 at 4:41 PM, wraith said:

I didn't, but I would think it's the b6 head that had a shallower combustion chamber. So using the b6 head with the 750 pistons would of bumped the compression up. 

I never even rode the bike before I sold it  as I got it running and the jetting somewhere need but it needed tyres etc but a mate offered me good money for it and I needed the space.

@wraithdid your mate ever run it?? Did he ever say what the power delivery was like?? 

[wraith]

18 hours ago, gsxwill said:

@wraithdid your mate ever run it?? Did he ever say what the power delivery was like?? 

He sent me a video with him riding it with a big grin in his face, and said it was great and loads of poke but I didn't ask any further, as was in the middle of packing to move house. 

He has since sold it to a mate he knows for more money but he had finished the bike off with a nice seat cover and paint job. Don't think he would of sold it on, to a mate if he wasn't happy with it himself.