Rebuilding Head

[Wayne]

I got a quote from a shop that does vintage Honda work to overhaul my cyl head, fix the broken fin, remove a broken stud and fix the spark plug hole. Price was scary! lol

I think I'll pull the head apart, check the guide clearance and if all are OK I'll just buy new valves and do the seat work myself. I can probably get the broken exh. stud out and I'll farm out the spark plug hole repair and broken fin repair.

My partner and I used to have a valve grinding set however he says that most of the stuff is worn out or missing so not much good to me. Has anyone ever used cutters like those available from Neway? If I go ahead and do the head myself I thought I would just buy the cutters I need and when finished sell them for a few bucks less to a member that may want them.

http://www.cylinderheadsupply.com/nesmdicubo.html

[Steve Swan]

The motorcycle dealerships i have worked in and currently work in use the Neway cutters.  I have used the Neway cutters.  They work very well, are pretty much the industry standard for cutting three angle faces in cylinder heads.

[UK Pete]

Wayne, i thoroughly recommend the neway valve seat cutters, i invested  a set as i have about 5 heads to do maybe more as the years go on, i have already done my gpz head , its is so easy compared to some of the stuff we do, here are some pictures of my gpz head i did , yes sorry its not 69 Honda but it is on subject, and in a few weeks time i will probably do my 69 k0 head and post up the results,as my new guides have just arrived

Here is a shot of the original Kawasaki 1 angle valve seat the 45 degree one



Here are some after i installed new guides and done a 3 angle job



http://cb750sandcastonly.com/coppermine/albums/userpics/10004/zx550_valve_job_281129.JPG

Here is a link to youtube on how to use them  Honda CB750 cafe SOHC4 Neway Valve Seat cutting.AVI

And finally just incase you would like to see my current Gpz restoration here is the link to the photobucket account showing my progress up to date

http://s924.photobucket.com/albums/ad90/UK-Pete/1986%20GPZ550%20ZX%20A2%20Restoration/

[Wayne]

Thanks Pete. I had watched that video while doing some research on Neway cutters. Boy, I wish they had these 30 years ago!  Your work looks great! Nice job!

[Steve Swan]

The way he's turning that cutter back and forth on the seat is concerning.  My understanding of correct use in making a pass with the cutter is making  one rotation at a time in the same direction; not twist back and forth as in this youtube.  Also, as the rotation comes to an end, gently release pressure.  Making the cutting pass in the same rotation and releasing pressure at the end of the pass assures a smooth face, free of marks from the cutter teeth.

[Wayne]

I read that as well Steve. Also, Neways site says you do not have to lap valves in after using their cutter.

"The finished valve seat will have a machine textured finish
(not highly polished or shiny). This provides a soft surface for
final mating with the valve face in the first seconds of engine
operation. It is not necessary to lap the valve."

I'll have to do some reading on whether a 46 deg seat (interference angle) is recommended on these heads.

[UK Pete]

Yes the video is not a great example , but the only one i could find, as you mentioned one turn in one direction , then check, perhaps using engineers blue to see eveness, you want to be taking off as little as possible, i have to admit i also gave my gpz a quick lap in as well with the fine paste, just to be sure