Cannondaleriders

WHAT ARE WE USING FOR CLEARANCES THESE DAYS? I REMEMBER READING THAT SOMEONE WAS USING TIGHTER CLEARANCES THAN STOCK BUT THAT WAS A LONG TIME AGO AND I HAVEN'T KEPT CURRENT. ARE FACTORY CLEARANCES STILL THE BEST?

I believe 7-9 intake and 12-14 exhaust (rather than 14-16 exhaust per factory)

I have been running mine at about .008

Stock specs for me. Never proven to help anything running tighter.

Stock clearances here too. If valves tighten up not fun to drop and reset clearances.

On my personal and race engines I run .005 intake and .010 exhaust. On customer engines I run .002 looser on both due to not knowing if they will ever be checked again. This was done after many hours of internet browsing and local builders study . This is and old builders trick for max cam life and power. The drawback is clearances must be check more frequently. We have not done a study on the effect on horsepower and I have never had a cam lobe wear out on any stock or rehardened cam regardless of clearance so there is no data there. I dont run extra stiff springs or exotic coatings on buckets just stock parts shimmed to 40 pounds and make sure buckets dont stick. I generally run mobil one or whatever the synthetic oil is available in the lightest weight possible.0w40 5w30 . I have been using the stock rev limiters as well . The one nice thing about the engines Ive taken apart years later is the valves dont seem to wear much more than .001 from original setting.
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When testing the high lift cams I had a test set made that were not hardended or coated with a rough surface finish. They would scratch the bucket just setting the valves and took out the buckets after the first dyno test. The cams did not wear though and were used again after being melanited and finish ground. I still have the CWR cams that had a 100% failure rate before being malanited and no wear after. That engine had a 11,800 rev limter for the first 2 years and then a 12,500 rev limiter for the last year.
Thats about all the info I have on this matter. Like said there is no conclusive data on why so many have problems with cams wearing out and an extremly low hours . it has been blamed on to soft/hard cams,buckets ,oils,surface finish ,dry starts,sticky buckets ect. Its most likely a combination of several factors.
As far as valve lash comprehensive testing will never be done as it would take an absurd amount of engine R&R and dyno runs to prove exactly what clearances provide the most power.
If any of you are having issues with cam wear I recommend using valve covers with windows in them so you can keep an eye on your cams without pulling the cover. That way you might just save your engine from a dropped valve by catching a lobe before it wears down to far.

4000 posts

And a good one!Congrats.