Need to use stock cylinders on bored-out cases

I have a bored-out for drag racing engine I'm putting back to stock, I'm returning an old Kz1000 race bike back to a daily rider. The engine was bored out so those really large piston sleeves would fit into the block.

So I have on this 1980 MkII set of stock cylinders to put on the bored-out 1980 block.
For the purpose of not having to go through the hassle of having a non-matching engine in the bike, on the title, etc. I want to use this bored-out but original-to-the-bike engine block so I can keep its engine number that goes with the frame.

Will it work? I have zero experience with bored-out 1980 Kz1000 cases. I'm pretty sure the stock cylinders will bolt up fine because (of course) the cylinder studs positions are unchanged, a stock cylinder will drop right on to the bored-out cases. I believe he told me he bored the cases out "for 88mm" whatever that means.

Should I be concerned about oil flow with the stock cylinders, crankshaft and pistons?

Or anything else?

There shouldn't be a problem.
The only thing to watch ( And this also applies if fitting the big block ) is if the case boring comes very close to the pry point on the cases as this results in a much reduced base gasket seating area and an increased chance of oil seepage from that region.
A light application of rtv sealant might be needed there.

in most cases bored cases will leak oil with stock blocks. If its over bored for more then a 1200 you will have problems. Its not the sealing area or gaskets, its the bottom of the stock block. Flip it over and look at all the cutouts and oversized holes, that where oil will come out. If the bottom of the block was completely flat, like the big blocks are, you would not have a problem.

He said 'bored to 88mm' which I believe is over 1400cc.

Hence the cases are toast if I wanted to put a stock block on?

Dang, it's hassle to go through the DMV and get a new title when you change the engine number.
I would like to figure out a way to stay with the stock cases but install a new stock cylinder block, and head, etc.

Here in Nebraska, the engine serial number isn't checked. Only the frame serial number is used, and that's the VIN for purposes of registration almost everywhere. There is almost 0% chance of your engine serial number matching your frame number on these old bikes, so most jurisdictions don't even check. Any good "J" motor should bolt in.

In California here (surprise surprise) the DMV is like a military base. They do freaking cavity searches on you.

One time I had a bike in the back of my truck -- just bought the bike, it needed a seat and that was all.

It had not been registered in so long they said 'it's out of the system, we only keep records for a number of years' and then -- even if you have the dang TITLE and a bill of sale from the seller -- you have to get in line and have the bike checked from head to toe.

- they check the frame number against the title
- they check the engine number
- they freaking check the smog advisory sticker (to see if you're trying to sneak in a 2-stroke? who knows).

They refused to pass my bike because THE SEAT WAS MISSING.

I couldn't freaking believe it. I got pissed and went in to get the supervisor.
The supervisor came outside, initially the DMV inspector refused to follow her instructions to go ahead and pass the bike. The inspector kept arguing "I can't pass a vehicle that isn't road-worthy'

It took 5 minutes of the supervisor trying to get her employee to pass the freaking bike.

And I had a TITLE for the bike.

If your engine number differs from the title, stand by, you are about to jump through some hoops.

California sucks in these kind of regulations things, it's bad.

I hear in some states YOU DON'T EVEN NEED A TITLE if the bike is like this one, from 1980, a 34-year-old machine.
Must be nice.

newOld_kz1000 wrote: In California here (surprise surprise) the DMV is like a military base. They do freaking cavity searches on you.

One time I had a bike in the back of my truck -- just bought the bike, it needed a seat and that was all.

It had not been registered in so long they said 'it's out of the system, we only keep records for a number of years' and then -- even if you have the dang TITLE and a bill of sale from the seller -- you have to get in line and have the bike checked from head to toe.

- they check the frame number against the title
- they check the engine number
- they freaking check the smog advisory sticker (to see if you're trying to sneak in a 2-stroke? who knows).

They refused to pass my bike because THE SEAT WAS MISSING.

I couldn't freaking believe it. I got pissed and went in to get the supervisor.
The supervisor came outside, initially the DMV inspector refused to follow her instructions to go ahead and pass the bike. The inspector kept arguing "I can't pass a vehicle that isn't road-worthy'

It took 5 minutes of the supervisor trying to get her employee to pass the freaking bike.

And I had a TITLE for the bike.

If your engine number differs from the title, stand by, you are about to jump through some hoops.

California sucks in these kind of regulations things, it's bad.

I hear in some states YOU DON'T EVEN NEED A TITLE if the bike is like this one, from 1980, a 34-year-old machine.
Must be nice.

In Tennessee....numbers must match title,which shows both frame and engine numbers and yes even Hillbillys want the engine number to match the title. If I were buying the bike and the engine number didnt match the title....I wouldnt buy it....of course thats me and so each to his own I guess!...Just my .02
Regards
Ed

I left Kalifornia in 1985 and have no desire to return. And now I'll have to add TN to my list of not now, not ever.

So, do they check engine serial numbers in cars and trucks also?

Can you slap it together for inspection, then tear it down and do what you like? Also wonder if you could get sleeves to dummy down the big block to stock disp.

Tomolu5 wrote: Can you slap it together for inspection, then tear it down and do what you like? Also wonder if you could get sleeves to dummy down the big block to stock disp.

A stock cylinder block and head will drop right on, the stud positions are not modified from stock.

Could he have machined out the crankshaft journals to accommodate a racing crank?

Back in my days, I bought my first Kz1000 age 17 in 1977, the race guys simply pulled out the cranks and welded them and that was it.

That was a long time ago -- is it possible to buy a race crank setup that would require machining for a bigger shaft/bearings/something else in the bottom end? Do racers these days or in the 80s/90s do that?

I'm trying to give this former race bike a 2nd life here.

What I mean to say is, could the big block jug(assuming you have it) be sleeved down to stock or near stock displacement. This would give you the nice flat gasket mating surface, and the streetablity you are looking for. I would think the stock jugs could be sealed up fine, but I cannot say that I have ever tried.

steell wrote: I left Kalifornia in 1985 and have no desire to return. And now I'll have to add TN to my list of not now, not ever.

So, do they check engine serial numbers in cars and trucks also?

Just saying they are both ( Chassis and engine ) shown on the title, so everyone I know ( Myself included ) checks the info if buying a vehicle, as far as the State checking/verifying the engine number , nope,I dont think so UNLESS, its a "Builders" or "Salvage" Title someone is applying for in which case , yes they do as they inspect those..
'Regards to ya Steell
Ed