camshaft selection

[Rif Raf Racing]

I got a gs1100 head with a fresh valve job,APE springs,mild port job,stock valve guides.What cams are the best choice for power output? This will be a 1327 /10.5 comp,34-36mm carbs,street and drag bike. thanks, Steve

[lhanscom]

I really like the G4 cams in mine. Just a note on your carb selection, if you're going with a 1327 you should really consider the Mikuni RS38 carbs, 34s will be too small, 36s are nice, and give good midrange, but the 38s will rock your world on top, and I have no problems with them down low.

[Rif Raf Racing]

camshaft selection

Thanks Luke,cam motion g4.Are they a .345 lift cam.I know there is a limit to what will work without shorter guides. Steve

[lhanscom]

355 lift, 256 duration @ .050. They work fine without doing anything funky.

Here's a page with all the profiles, do a search for 'G4' to get to the list of cams that will work. I think you would have issues running pump gas with much bigger then the G4.

http://www.cammotion.com/Portals/fee9d5f1-aae3-4978-9a04-5af3bfd13a1a/Binder.pdf

[SqDancerLynn1]

Get hardened rockers if you are running NON stock springs. Spring pressure IS CRITICAL to long life

[Rif Raf Racing]

camshaft selection

That was another concern I had,who does the rocker hardfacing? Steve

[oldschoolGS]

APE and Megacycle does them for about $50 a rocker. 16 valve motor=8 rockers=$400. Quite pricey. If you do run .350 lift Cam Motion regrinds, I believe you will also need longer adjuster screws. Cam Motion sells them- if I remember right about $100. By reducing the base circle of the cam lobe, as they do on a regrind, the stock adjuster screws become too short to hold proper valve clearance. good Luck, Ed.

1983 GS750ED

[Rif Raf Racing]

thanks ed,everything seems pricey on these heads.You can get a pair of aluminum heads with the best valve components for a chevy,for less than setting up one GS/KZ head.Doesn't seem right. Steve

[morthrane]

Guess that's what happens with volume sales-- everything is cheaper. Motorcycles to start with are piecemeal and only go downhill from there... small market, high prices.

[Rif Raf Racing]

right,thanks for that insight.

[Richie]

G 4's will work good...you wont need to harden the rockers...hardneing the rockers helps them last longer...we have not done it to any of our bikes we have 430-390 lift cams in the big bike and have stock rockers, but they last a season or so usually with no problems, Richie

[Rif Raf Racing]

Thanks Richie,To bad a roller tip style rocker isn't available,seems it would make sense to me. Steve