KZ1000 head rebuild

APE Jay wrote:

Old Man Rock wrote:

Ape Jay... $165 for guides? I'm assuming you meant $65.

Z1 has the exhaust guides (4 each) @ 45.64.
intake guides (4 each) @ 40.72. Add tax and crap around $80-$90. Set of 8 seals @ 12.24 plus tax.

Now for my project, APE heavy duty valve springs @ z1 $61.36.

Now the real killer is the damn CAM bearings @ $111.84, ouch! But it must be done...

Anyway you look at it. For a bare minimum or a basic 3 grind valve job, your speaking anywhere between $300-$500 for parts and labor. With a 3 way grind & port and polish... well the price goes up.

Again, for how crucial the head is in a fine tuned machine, let the professionals handle this part no doubt about it. For those that have the tools and know how, I'm envious.

OMR

I posted a link to our head work page. Guides are about $67.00. Changing them out and honing to size $95.00. So if the head is in the shop and needs guides, it is about $165.00

If the valves are all good, and most are, if the head needs guides, the whole thing is about $375.00, and that is with more flow past the seat.

Jay

There's an old proverb that goes like this....

"The wind blew and the sh*t flew and I couldn't see for a day or two"

A couple things pop straight up in this thread.

First, you can't measure guide to stem clearance with the guide out of the head. That's totally misleading.


How much more flow Jay? How about some actual numbers?

You don't need a mega dollar valve machine to improve on the OEM valve job for crying out loud.

OMR, There's probably a 98% chance you don't need new cam bearings. Post a pic of yours and lets have a look. Don't piss money away on things you don't actually need. In almost every instance, the stock bearings can be touched up and reused. I have a special hone we made just for that purpose and it's worked on dozens of heads.

The stock bearings will often get marked up but rarely do the every wear out. There's a lot of bearing surface area for the cams to ride on. Not at all like some of the modern heads with very narrow journals and run directly in the aluminum w/o bearings.

I've even saved a couple of Suzuki heads that were scored up pretty badly by honing the journals. Absolutely no issues with cam noise or wear problems after the repair.





Larry C

OMR, There's probably a 98% chance you don't need new cam bearings. Post a pic of yours and lets have a look. Don't piss money away on things you don't actually need. In almost every instance, the stock bearings can be touched up and reused. I have a special hone we made just for that purpose and it's worked on dozens of heads.

See there's my point... Let the PROFESSIONALS do what they do...

Larry already knows I'm sending my head to him plus (springs, guides and seals) for we have discussed this over the last couple of months... and he just saved me $111...

Thanks Larry...

OMR

"First, you can't measure guide to stem clearance with the guide out of the head. That's totally misleading."

Who would remove a valve guide, then check it to see if it needs to be replaced? I am missing something here. :dry:

I imagine seat flow could be improved with a Dremel if someone had the time and patience.

I know a guy who can do incredible performance seat work using Neway cutters, by hand. Takes him about four days to do a 16 valve Suzuki.

Jay

Question for Jay... How do you measure valve stem to guide clearance or how do you even measure the diameter of the guide? I have bore gauges but none that small. I wobble the valve in the guide and check for play. I have been doing this for quite a few years and always considered this a fairly accurate way of checking for play. Am I wrong? Really would like to know. Thanks wg

That is how we initially determine if the guides or valve stem is worn. The Serdi pilots are in .0004" increments. If the valve stems are good, we determine which pilot should be used for that size stem. Then if larger pilots will fit the guide, we know they are oversize.

It also works the same way when we install new guides. We figure which pilot is correct for the stem size, and after installation, we hone the guide to that pilot.

APE Jay wrote:

"First, you can't measure guide to stem clearance with the guide out of the head. That's totally misleading."

Who would remove a valve guide, then check it to see if it needs to be replaced? I am missing something here. :dry:

I imagine seat flow could be improved with a Dremel if someone had the time and patience.

I know a guy who can do incredible performance seat work using Neway cutters, by hand. Takes him about four days to do a 16 valve Suzuki.

Jay

Well, I'm still curious Jay. You made the claim of improved airflow with the big dollar valve machine.

How much flow improvements are you getting from .050 -.150 lift with it?

Larry, if hes using a serdi machine, it cuts the seat with a 3 angle cutter, just cleaniong up the back side of the seat with the proper angle will improve the flow, he can also open up the inside of the seat area which will also improve flow, but Jay knows what they do .

BSKZ650 wrote:

Larry, if hes using a serdi machine, it cuts the seat with a 3 angle cutter, just cleaniong up the back side of the seat with the proper angle will improve the flow, he can also open up the inside of the seat area which will also improve flow, but Jay knows what they do .

Larry;
We don't flow std size valve jobs, so have no data, but I will tell you what I will do.

I understand you spend a lot of time doing that kind of stuff, so send me a KZ head ', junk one is fine, with at least two good stock valve seats in it, with original 1970s style cuts.

I will cut one seat with a modern high flow profile and send it back no charge. Then you flow them both and you post on here what you find out.

Jay

That sounds very fair to me and it would give Larry a chance to actually make some good, educated comments on APE's comments. I would be very interested in seeing the results. My next engine build will include some professional work so I am interested in seeing REAL results.

wg there are small split ball ended guages(small hole guages)that you use to measure valve guide inside diameters.
i was one of joe mondellos first class of students at his head porting technical school when it was in paso robles.i had been rebuilding industrial engines for a job and my racing buddies stuff on the side.we had a serdi at joes and we also had sioux valve grinding equipment.i had joe show me how to do the best valve job possible using the grinding equipment.now i have siuox valve equipment and a kwikway valve grinder.i can do just as well of a valve job with my grinders as can be cut with a serdi.30 60 45 are the three angles of a 3 angle valve job.i prefer the grinders and stones as i can manipulate the 30 to run out into the floor without having a special cutter and the sixty goes right down into the bowl.
just bought some neways for a friend and they are really nice for doing your own stuff.

and yes,any modern 3 angle valve job will improve flow over an old single angle(45 degree) valve job.