Hello All.
Tony Leary here, in the USA.
I've recently begun racing (Flat Track) a late friends 350 that was 1st done up as a "Street Tracker" in the early 80's and turned in to a race bike when another friends bike broke they striped off the lights and raced it.
It does seem to run well however at one point i was geared wrong and over rev'ed a race later (after a gear change) snapped the exhaust push rod, bent the intake rocker and push rod. I've since replaced those and it is running better then it ever has.
Looking thought the part bin i found several bent push rods so seems it may have been an issue in the past as well. Sadly I can't ask the build as he passed away 5+ years ago.
I can not find some valve spec info anywhere, someone must know it.
1) Valve spring installed height.
2) Valve spring seat pressure.
3) Max valve lift.
4) Desired coil clearance (space between coils at max lift before coil bind)
The Blue book has none of this information that i could find. I'm trying to make sure I don't hurt it again.
Thank you for your help!
3 1/2 Valve spring specs
Re: 3 1/2 Valve spring specs
The blue book do's not cater for possible race setup as far as i remember. I would look at the valve to piston clearance, with some kind of silver solder or Plasticine in the valve area. If you have a high lift cam and raised compression ratio, you may be running out of clearance. I run a 350/410 in flattrack in the Uk vintage class.
Re: 3 1/2 Valve spring specs
Thank you FastHarry.
I've used a bore scope down the plug hole i did not see any Valve marks on the piston when doing the repairs. Leak down testing showed the front cyl better then the rear by 1 %.
I've not had time due to shutdown week at work to do a post race inspection but it was running good when i pulled off so I think i'm good so far.
I ordered a Performance book off Amazon I'm hoping will have more detailed specs. but no mater what I need to break out the dial indicators and degree wheel and check it all before the Vintage National races in September.
Tony
I've used a bore scope down the plug hole i did not see any Valve marks on the piston when doing the repairs. Leak down testing showed the front cyl better then the rear by 1 %.
I've not had time due to shutdown week at work to do a post race inspection but it was running good when i pulled off so I think i'm good so far.
I ordered a Performance book off Amazon I'm hoping will have more detailed specs. but no mater what I need to break out the dial indicators and degree wheel and check it all before the Vintage National races in September.
Tony