1.What is the shelf life of Dunlop 207 GP tires? 2. My friend who has been racing for over 10 years says I should adjust my valves on the loose side, I say to the tight side. What do you think? Thanks, Kevin
i would set the valves to the book ., and definatley not tight ., you will get blow by the valves and burn them out ., and loose is something done with performance cars., not really for bikes...
What I mean by tight is at the minimum listed measurment. IE:GSXR600 intakes; .004 to .008. I set them at .004.
set them closer to .008. Shim under bucket will tighten up with time. So yes your friend is right loose side but with in spec is better.
My thinking on this is the closer the clearance, the bigger the cam. I realize I'll have to keep a closer watch on the top end running them this way. I just figure it'll make more power. ???
your thinking is correct....a tighter clearance will give you more valve opening and more high rpm power....
looser clearance will tend to give you faster air flow and more low rpm torque.
if you will actually notice any difference though is debateable
QuoteMy thinking on this is the closer the clearance, the bigger the cam. I realize I'll have to keep a closer watch on the top end running them this way. I just figure it'll make more power. ???
What up Kev,
As long as you are keeping that close watch, I'd say you are right on. Tighter is more precise and there is less flappin' around to wear things out, as long as your still keeping that close watch! :o :o See ya soon, dude.
Matt
QuoteWhat up Kev,
As long as you are keeping that close watch, I'd say you are right on. Tighter is more precise and there is less flappin' around to wear things out, as long as your still keeping that close watch! :o :o See ya soon, dude.
Matt
If you've seen me ride, you know I shift at 6500rpm. ::)
Typically, valve clearances are set looser for racing, as it's assumed that race engines are run harder and therefore hotter (thus more thermal expansion and less hot valve clearance) than street engines. For example, HRC issues official racing power-up manuals for 600's and 900's that include revised valve clearance specifications that are a lot looser than what the Honda factory service manual recommends.
What about the tire question? Anyone? :'(
Well about the vaule question unles you are using 100% of the power the 600 has right now as a AM i would not mess with them. i mean someone once said if you are only using 95HP on a bike that has 100HP why try and get it to 110HP. Not that you are not fast...just something to think about. As for the dunlop question that will all depend on what kind of condition them have been in.
Didn't they stop makinng 207's when they went to 208's? I lost confidence in them or maybe I got a bad set of 208's. Either way I went to michelin's and have been quite pleased not to mention my new tire guy Walt Shafer has been awesome to me .All his knowledge and support made the switch logical (it works for me) Walt's # is(256) 538-5906. Hope this helps. Motard11 ;)
QuoteDidn't they stop makinng 207's when they went to 208's? I lost confidence in them or maybe I got a bad set of 208's. Either way I went to michelin's and have been quite pleased not to mention my new tire guy Walt Shafer has been awesome to me .All his knowledge and support made the switch logical (it works for me) Walt's # is(256) 538-5906. Hope this helps. Motard11 ;)
Shamless plug...lol...and walt is a great guy
Tire shelf life - From what I've been told it depends heavily upon storage conditions. Exposure to sunlight, temperature, etc.
I ran 207's all last season and they were 2 years old according to the manufacture date on the sidewall. I never had an issue with tire failure and they didn't show any cracking or splitting. However, a friend had a couple sets of 207's that were actually manufactured several months after mine (so they were newer) but had severe sidewall cracking and splitting after sitting around for about a year. Also, he discovered you might not be able to see that the tire sidewall is split until it is mounted and inflated.
:-/
Just my $0.02
Take care,
QuoteIf you've seen me ride, you know I shift at 6500rpm. ::)
I thought you meant you were going to check the valves frequently. But, by all means, please contiinue to shift at 6500. ;D It'll make my bike look good and justify spending all my money last year to now be broke. Those HRC facts above are interesting about the loose valves. Kevin, please let me know what you find out about the clearance issue.
As far as 207's, that is a really good question. The first few years I raced, several vet racers told me that if they freeze they are done. But Andy's truck had been subject to freezing tire temps last year and the 207's I subsequently bought were great. Tom Mason says he has taken tires off of a freezing pile up there in MN and riders said they worked fine. If they don't freeze, I think the shelf life is approx. 2 years. This whole issue became so convoluted to me that I just always bought new tires. Didn't want to think about it anymore.
Matt
I think that clearance issues are related to the specific motorcycle. The exhaust sides do tend to get hot (exhaust gas) so the clearance that you set up when cold has a tendancy to shrink with the expansion of everything because of heat. So, those end up a bit looser on the intial clearance. Set up a Kawi with tight exhaust clearances and they don't run well.
Intake temperature is cooler. So, sometimes you can get away running a tight clearance for just a bit more lift and duration.
FWIW, they DO make 207s in a 160 still According to race tire service, it's just a 207 mold, but they use a 208 compound. My 207 rear was from November of 02, and I think my 208 front is a bit older. So, I know they're still making them in a 160 at least.
Tire story: I've been offered some new, never used, 207s. The problem is they are 4 years old. Been stored on a mezanine at a bike shop. No sunlight but temps in the 90's. I have spare wheels, so I might just mount them up and try them. Anyone want to ride beside me when I do? :o