I am looking to have some work done on a set of RZ500 cylinders and heads. The cylinders are all on 1st overbore. The clearances (per my possibly error prone measuring) are generally a little tighter than I would like to run and I'd like to have the piston-cylinder clearances opened up to about .06mm on the fronts and .09mm on the rears. Currently I measure .04mm front and .06mm rear. I'd like to keep the bores as straight, round, and centered as possible. At least one cylinder also needs imperfections in the deck cleaned up.
The heads are a spare set I have that both experienced some sort of failure and have pitted domes. I would like to have the chambers cleaned up and the squish set with the focus on reliably running pump fuel.
Any suggestions on a good machinist for this?
Those clearances sound a bit large , what does the factory specify .
I'll tell you what it says 0.060-0.065 mm or in old money ( thou)0.0024 - 0.0026 "
So your clearances are miles out ! if what you have written is correct , in old money 2 and a half thou, so go back and recheck and read this !
http://www.rz500.net/RZ%20500%20REFERENCE/APPENDICES.pdf
What type of pistons are you running?? Oem cast pistons? If so I would say .0025 for all 4 should be sufficient. If not then I can help you out per your instructions.
Also how are you measuring them? Bore gauge I hope.
Garrett
Quote from: Barrie on April 27, 2019, 12:23:03 PM
Those clearances sound a bit large , what does the factory specify .
I'll tell you what it says 0.060-0.065 mm or in old money ( thou)0.0024 - 0.0026 "
So your clearances are miles out ! if what you have written is correct , in old money 2 and a half thou, so go back and recheck and read this !
http://www.rz500.net/RZ%20500%20REFERENCE/APPENDICES.pdf
Those are the specs I was going by. Notice in the piston clearance section it states a limit of .10mm/.004" ? The idea is to run more clearance on the seizure-prone rear cylinders.
Pistons are oem.
I am measuring with cheap telescoping gages and a Mitutoyo mic.
If the rear cylinders run hot to a point of seize , just up the main jets on the rear cylinders 1 size , simples, don't open up the clearances! I worked on these machines in the '80's,
Once you re machine the bores you can't go back , your going about this the wrong way :umm:
Read your first post you've written your measurements down wrong.
If you run at 0.01mm (4 thou) if will sound like a shite! , a bag of old nails
Just to be clear, I am not asking for advice on what clearances to run.
I'd like to know who is a skilled machinist able to set up a set of cylinders and heads to the specs I've chosen.
Play nice guys C:-)
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Thank you
Quote from: Twidget on April 27, 2019, 02:27:15 PM
Just to be clear, I am not asking for advice on what clearances to run.
I'd like to know who is a skilled machinist able to set up a set of cylinders and heads to the specs I've chosen.
If your set on your clearances I can hone the cylinders to the specified size.
Shoot me an email and I can send examples of work.
Garrett
Gra2strokes@gmail.com
Quote from: Barrie on April 27, 2019, 02:06:28 PM
If the rear cylinders run hot to a point of seize , just up the main jets on the rear cylinders 1 size , simples, don't open up the clearances! I worked on these machines in the '80's,
Once you re machine the bores you can't go back , your going about this the wrong way :umm:
Read your first post you've written your measurements down wrong.
If you run at 0.01mm (4 thou) if will sound like a shite! , a bag of old nails
Barrie,
I think you might have been in a hurry.
.01mm is almost .0004 tenths of a thousandth, not.004 that you implied in your post.
Garrett is a very good machinist, also willing to machine to your needs.
I don't have the CNC machines that I once had due to a bad business partner for 9 years.
I can do cylinders as well, but due to the RZ500 heads are one piece its much harder to machine custom chambers without CNC mill. I have done them before when I had a gap bed lathe...
Chuck
Quote from: SUPERTUNE on April 27, 2019, 09:00:08 PM
Quote from: Barrie on April 27, 2019, 02:06:28 PM
If the rear cylinders run hot to a point of seize , just up the main jets on the rear cylinders 1 size , simples, don't open up the clearances! I worked on these machines in the '80's,
Once you re machine the bores you can't go back , your going about this the wrong way :umm:
Read your first post you've written your measurements down wrong.
If you run at 0.01mm (4 thou) if will sound like a shite! , a bag of old nails
Barrie,
I think you might have been in a hurry.
.01mm is almost .0004 tenths of a thousandth, not.004 that you implied in your post.
Garrett is a very good machinist, also willing to machine to your needs.
I don't have the CNC machines that I once had due to a bad business partner for 9 years.
I can do cylinders as well, but due to the RZ500 heads are one piece its much harder to machine custom chambers without CNC mill. I have done them before when I had a gap bed lathe...
Chuck
I was kinda hoping for a response from you Chuck, since from the examples I've seen, you are very detail-oriented in your work. I appreciate the honest response about the limitations you have for cutting heads.
Quote from: GRA400c on April 27, 2019, 08:13:09 PM
Quote from: Twidget on April 27, 2019, 02:27:15 PM
Just to be clear, I am not asking for advice on what clearances to run.
I'd like to know who is a skilled machinist able to set up a set of cylinders and heads to the specs I've chosen.
If your set on your clearances I can hone the cylinders to the specified size.
Shoot me an email and I can send examples of work.
Garrett
Gra2strokes@gmail.com
Thanks for the response Garrett! I am planning to shoot you an email.
I'm really not 100% set on those exact clearances I mentioned, but it is pretty much where I want to be. They were given to me by Rick L. and I understand the reasoning behind using them. And in my opinion, it is far more important that the bore is straight, round, and centered than worrying about the clearance being toward the upper end of the spec. The cylinders I have don't have perfect bores anyway, and will need to have some material removed regardless.
Look forward to hearing from you.
And every bore I do the piston is measured clearance established and all cylinders are honed then measured with a bore gauge and checked for straightness. I typically end up with around a .0001 of taper.
Garrett