New engine build, accepting suggestions!

1982 GPZ 750 Head+Cams
4-1 Exhaust
Carburetors - Have Modern Keihen CV38mm's on
Oil Cooler - From Bandit 1200
hand (can trade/sell these though)
Wiseco 810cc pistons
Pods


Shave head 0.20-0.25
Degree Cams - anyone got a good source of information for this?

The items in bold I already have possession of.

So... I'm accepting suggestions for more H.P., info on degreeing cams, carb selection, as well as anything else.

Post edited by: newbikekiller, at: 2007/07/09 14:01

Oh yes, 93 octane gas 10% ethanol content (i.e. premium gas) will be ran.

I've got some kz750 cams, 750 jugs, Wiseco 810 big bore kit on hand. This winter I'm planing on doing this. I haven't decided on the carbs yet? I'm thinking of using the 650 head, but I haven't decided on larger valves. I'll probably get heavier springs and GPZcams if I can find them.

Please post all info you find. I'll do the same.

see reborn650's build.
he is done now and it sounds killer!
might consider different carbs.
i think it will be soggy at low rpm's with them.
look for 28's or 29's.
he has been a valueable source of info on a "smaller" bike build.
plus his bike looks damm nice!

LAST I HEARD FROM COLIN

For my bike this past season I went with an 810 Wiseco kit. Here is what I did.

1980 Kz 750/4 cylinders bored to handle the bigger pistons. The750/4 blocks were basically 650 cylinders resleaved by Kawasaki.

I stuck with my Kz650 head which is apparently better than the 750 head because the of the combustion chamber design. The intake runners on the 650 also give better throttle response and low end power. I like bottom end grunt for acceleration off the line, that is why I also went with a 14 front tooth sprocket instead of the stock 16 tooth drive sprocket.

I put in 1980 Kz 750 cams. I swapped the sprockets from my '77 650 cams onto the 750 cams. This allowed me to use the stock roller cam chain assembly.

I put in Gpz750 intake valves. They had to be trimmed 15 thou of an inch by the machine shop to fit as they are slightly longer than the 650 intake valve. This gives better breathing and involved putting in new intake valve seats to handle the bigger valve face.

I milled the head about 10 thou to clean up the head's mating surface where it sits onto thI am just in the process of picking up some Mikuni 29 smoothbores from Wired George as I had an irritating flat spot at wide open throttle, around 7,000 rpm. He is going to take my Mikuni 28's on a trade and will be selling my 28's. The carbs were excellent but it seems with my mods I might have wanted to have a slightly larger main jet. We'll see how the smoothbores work, anyhow it just seems way cooler to say smoothbores:_

The performance of the 810 vs the 700 was like night and day, but it was probably a combo of the 750 cams, bigger valves, bigger bore and carbs. Definitely worth the upgrade if you desire more punch for the 650. If you have any questions give me a shout.
Cheers-Colin_________

As a side note:
I like the GPZ750 head+cams is a better option simply because this setup, trim the head, 4-1 ex, and "good" carbs, 810cc pretty much gaureentees good reliable high output H.P. like 90+HP (see GPZ750 FAQ on google).

This is not to say Colin is wrong, he just has different goals (like keeping midrange power) whereas all I care about is top-drag power and fuel economy.

I guess those are two things that don't go well together but oh well!

Also, A 82 GPZ750 Head is supposedly just a ported and polished KZ750 Head

I also forgot,

The GPZ750 camshafts do not have a provision for our RPM gauges - if you want to keep a tach you either have to go electronic or do some other changes.

No problem for me I'm going all electronic.

he has now installed gpz750 cams and 29's.

Why not opt for a stock 1000 ? You'll have all the power and the ride will be great.

kawsakiman wrote:

he has now installed gpz750 cams and 29's.

Yep - Steve is right. I've put on the 29 smoothbores from George and now the GPz 750 cams in my 810. I blocked off the tach drive outlet on the head and don't have a tach. I shift by feel and sound.

I retained the 650 head, milled it 10 thou to clean up the surface and did a porting job on both the intake and exhaust runners. On the exhaust side I really put a nice polish after the porting but on the intake side I left a rough surface.

Since I have never read about anyone comparing the three head combos, the Kz 650, Kz750 or the Gpz750 on a dyno the differences would only be a guess as far as power output. I can only tell you that I have found that the powerband has been moved up higher in the rpm range. With this combo you won't be disappointed.

As the old saying in racing goes...Build what you got and run what you brung.

Cheers-Colin Firth-Ontario Canada

It's curious that none of you guys use a dyno, why is that? Too far away? Too much money?