Z1000J Engine Mods?

[LeeJackson]

Hi All

I have started a thread on my project, in the early stages but looking for some advice on the engine.. Lots of questions sorry.. Plan is to have this as a road bike, I won't use it a lot or do big miles, but want something that won't need constant messing with yo keep it running properly..

I have stripped everything down and sent the crank off to Debbens for rebuild and welding. Now in the mean time I need to decide on what top end to put on it.. I was thinking to get GPz barrels and go to 1200, is this a wise choice or do you think something bigger is worth exploring? I see some feedback on the big blocks overheating, does anyone have any experience with these to share?

If I go for a set of GPz barrels do I need to machine the crankcase openings to accept them?

On the top end, I'll use Debbens as well, is it wise to just start with the Z1000J head or is there and advantage to using the GPZ head as a starting point?

Last question for today (there will be more ) has anyone ever used the high temp ceramic powder coating that some people are offering? I went to get my cases done, but unfortunately a small repair was discovered when they started blasting, so either need new cases or a repair.. But I'm having second thoughts now on the ceramic powder coating, will it work, will it cause any issues by blocking up oil ways etc?

Thanks
Lee

[garyd]

It's only worth changing the head if you can get a unitrak head. But everyone is wise to this and don't come up for sale often.

I'd go for an 1170. Best for power & reliability.

[Coose]

Ring Pete Stansfield of Yorkshire Rally Spares on 07969050019. He recently broke a sorted Unitrak with a 4000-mile old 1170 big bore and a nicely flowed head. He may have sold the top end now as he no-longer has it listed on eSkip, but it's worth a punt?

[Al]

It's only worth changing the head if you can get a unitrak head. But everyone is wise to this and don't come up for sale often.

I'd go for an 1170. Best for power & reliability.

Agree the 1170 is the best of all worlds.
Piston kits gaskets and ring sets are still very much available unlike the 998 and 1100 variants which are pretty much unobtanium.
More than enough engine for occasional road use.
Get the right kit for the 17mm J crank.

Get some GPz 1100 barrels and get them bored. Unitrak barrels same as 1100R even better. But B1 and B2 are fine.
You dont need to open the mouths of the crankcase for 1100 barrels.

If you get a Unitrak / 1100R head / cams, all well and good but with the J crank and high crown Wiseco (10.25 ; 1) pistons you will need to get Ray to machine the exhaust valve reliefs in the pistons or the ex valves will hit on Unitrak / 1100R head only because the exhaust valves are at a different angle.
He has a the jig for doing this.
There is another 1170 kit with lower comp pistons but dont know if its available in 17mm, however you can have the 17mm small ends honed out to 18mm!
Fit an oil cooler.
If youre thinking of revving this set-up past 11,500 rpm,... dont.
The pistons will hit the head.

Great looking bike by the way.
That rear engine mount should be easily repairable, it is structural but because the front of the engine is rubber mounted it needs not to be over-tightened as has happened unfortunately.

AL

[LeeJackson]

Thanks for the advice guys, 1170 sounds like the way forward then.

I will give these guys a shout tomorrow to see if they still have that too end, failing that I need to find some donor gpz barrels and decide what to do with the head..

Cheers
Lee