1262CC big bore, to boldly go or not?

In the process of rebuilding my A2 KZ1100 motor, I had this fantastic idea to go big bore. There once was a 1262cc kit available from Wiseco, but has been discontinued and cannot find the complete kit anywhere, however I have found all the parts individually.
Has anyone here done this big of a conversion?
Should I get the .435 cams to help the motor breath better?
Will the BS34 Mikunis be able to handle the extra few CCs?
My friend also suggested a turbo. I told him no, but it's itching in the back of my head....

The parts:
78mm sleeves
www.summitracing.com/parts/wis-ka750sl/overview/

78mm head gasket
www.summitracing.com/parts/wis-w3920/overview/

base gasket
www.summitracing.com/parts/wis-w5496/overview/

78mm pistons w/rings, wrist pin and clips
mxpartsonline.com/Merchant5/merchant.mvc...0&Category_Code=WPKS

Better budget for a welded crank to go with those paint can sized jugs.

Good call, I'll have the shop do that as well. Thanks

You will have to bore the case out also to take the larger liner spigots.
A stock block is very prone to overheating when going 1260 and the process of boring out the block for those liners leaves the casting very thin and can break through to the outside which also makes oil leaks common.
1200 is the now the more popular size as the liners are not as large a diameter which reduces the rick of breaking through.
Ideally you should use a big block if going over 1200 on the early motors.

$ounds expensive :pinch:

Zed as usual is right on the money.
If you are going to pursue a big block e mail Joe at Pitstop in Florida.
Best prices on MTC Big Blocks. It will come to you ready to install ( other than boring the top case )
What compression are you thinking of using ???
A Big Block in the heat of Mesa will be a concern
How are you planning on using the bike ?? Racing only ? Cruising ?
Oil Cooler will also be on your short list of must haves
Dave

1200 would be the 76mm pistons right?
I'm fine with that. Although I don't necessarily want to drop an extra $500-$900 on a new block.
Joe's website is down, do you have his e-mail somewhere?
Thinking 10.5/1 compression.
Yeah, the lovely desert heat sucks with air cooled bikes. I'll definately add the oil cooler.
This is a daily street bike, with the occasional drag day.

Yes! 76mm for 1200 but why not just go for 1170cc (75mm) which will go in your stock 1100 liners and save a bunch of $$$.
No need for case boring or new liners etc and it's a proven upgrade.

A little off subject, but would an 1170 kit cooperate with a 84 GPZ 1100 head and cams? What should be considered the maximum-safe RPM's with such a configuration?

daveo wrote: A little off subject, but would an 1170 kit cooperate with a 84 GPZ 1100 head and cams? What should be considered the maximum-safe RPM's with such a configuration?

If it's for a hybrid J/GPZ motor then you can specify the pistons for that application or cut the piston valve pockets to the GPZ valve angle.
11k is really the safe max for the roller bearing crank.
The rollers start to skid instead of rolling at much over that although I've hit 12k on one or two occasions but I don't recommend it.

zed1015 wrote: Yes! 76mm for 1200 but why not just go for 1170cc (75mm) which will go in your stock 1100 liners and save a bunch of $$$.
No need for case boring or new liners etc and it's a proven upgrade.

Yeah I think I'll just do that. It's not like I have a ton of cash floating around to blow on the bike anyway, $340 for boring and another $340 for the head work, plus new pistons and overbore gasket, is a reasonable amount.

Should I do cams with the 1170? .410?

Check APE for the boring and pistons..... thinking you could save a little there.... at least on the bore and hone.