greetings, neil here. been a lurker for a while as i read (tried to) all the old posts. then signed up yesterday. i noticed on another forum, mention that there was some discussion of increasing the i.d. of the oil feed tube to the top end as a cure for cam/rocker wear/failures. i don't see it being ness if your pump is in good shape and the hard line isn't pinched or plugged in some way. i didn't see anything in the archives either. anyone care to comment?? i am reassembling my XR600R with a new jug, valves, hotcam stage1, port and polish, oil cooler and could easily fab a new hard line.

also, i understand that the HotCams stage1 cam is designed to work with stock rockers and springs. i asked hotcams about using Kibblewhite springs with their stage1 cam and here is there answer:

"We designed that cam to work with stock valve springs. If you have other engine mods done and are needing to use aftermarket/stiffer springs that is fine, just be sure to check and adjust the valve lash accordingly. Also this may cause premature wear on the cam, I can not confirm this since we did not do any testing with aftermarket springs with the cam."

so i guess running non stock springs would be detrimental to cam life... anyone have any success using aftermarket springs with the stage1 hotcams? i know there have been posts indicating early failure.

thanx
neil

I think the "right" oil line size is up for debate, especially since there isn't a lot of evidence to indicate that a larger line is necessary. So far, I have yet to see even one instance of a roasted top end that could have been saved with one. I also don't like the idea of cutting tapered pipe threads into the thin clutch and head cover castings when there are banjo-to-AN fittings available.

Regarding the cam, rockers, and heavy springs, that's something I have been wondering about myself. I don't think you would need anything heavier than new stock springs with the HC cam, though. Power is still going to peak below 6500rpm. That said, my father's XL600 has a stock cam, stock rockers, and KW springs and retainers that were in it for no telling how long before he got it. I had it apart earlier this year and the valvetrain was still holding up. :excuseme:

i agree, that line has been there for 50million miles of these bikes, its engineered for the flow n pressure that its got now and just fine how it is.

The banjo bolts themselves are the major restriction. I just drill the side hole to match the center hole and rechamfer. Using Kibblewhite or RD springs shouldn't be any problem since the rates are not vastly different from Hondas. Remember these springs are checked for spring rate a a higher lift than any Honda cam ever had so they will give a lower than advertized number even with the lift a Hotcam has. The major difference between the aftermarket springs and Honda is the maximum lift before coil bind. Stock Honda parts may actually last longer with aftermarket springs because the springs aren't being compressed almost to their limit.