Honda-SOHC

SOHC.co.uk Forums => CB350/400 => Topic started by: billdn on January 03, 2022, 04:44:57 PM

Title: Can existing valves be reused with new guides, if lapped in to existing head?
Post by: billdn on January 03, 2022, 04:44:57 PM

I've cleaned up the valves very carefully with oven cleaner and a brass brush in a dremel,  if I replace the guides with new can I reuse old valves if lapped in properly on the head.

Title: Re: Can existing valves be reused with new guides, if lapped in to existing head?
Post by: Nurse Julie on January 03, 2022, 04:50:32 PM

Quote from: billdn on January 03, 2022, 04:44:57 PM

I've cleaned up the valves very carefully with oven cleaner and a brass brush in a dremel,  if I replace the guides with new can I reuse old valves if lapped in properly on the head.

Yes, you can, as long as the valves are straight. Changing valve guides is not the sort of job you do yourself at home. Many tears have been shed by owners who have attempted it themselves. Also, when the new ones have been inserted, they still need reaming to spec as all the valve stems will be a different measurement. Get a profession engineering company to do it. The valve seats will also need recutting.

Title: Re: Can existing valves be reused with new guides, if lapped in to existing head?
Post by: mickwinf on January 03, 2022, 04:52:25 PM

As i understand it you would need to re-cut the seats to suit, that is what Graham (trigger) did on my 550 head. You would be best asking an expert like Trigger to do it as he has the correct gear.