GS550T, new cams?

[Buffalo Bill]

I see webcamshafts.com offers bolt-in .325-270º/234º camshaft for the old GS550 (E, T, L) engine. Has anyone put them in their bike?
Thanks.

[Nessism]

Whole lot of money for a 550. I have no experience but I do know the early 550 cams have a smig more lift than your '81 cams. I have a set if you want to play around.

[Buffalo Bill]

Thanks.

Whole lot of money for a 550. I have no experience but I do know the early 550 cams have a smig more lift than your '81 cams. I have a set if you want to play around.

Playing around is what I'm doing, but $400 is too much to play away, too bad they don't match their Chevy V8 cam prices.
If I take your signature at face value, you may have measured the profile of your cams, can you give me their lift and duration?
Thanks. Bill

[first timer]

it's not worth doing cams on a 550 unless you have pistons to match. most of the cams requires biger pockets in the pistons for valve clearance.

[Nessism]

If I take your signature at face value, you may have measured the profile of your cams, can you give me their lift and duration?
Thanks. Bill

I need to verify yet again but I seem to remember that these cams have something like .020" more lift than the later cams. Not sure about the cam timing. Most likely not worth the effort to swap them unless you want to squeeze out every last bit of power and don't want to spend a lot of money.

Edit: just went though the service manual and can't notice any difference in the cams after checking the specs. Guess I need to do more research before posting.

[skreemer]

it's not worth doing cams on a 550 unless you have pistons to match. most of the cams requires biger pockets in the pistons for valve clearance.

have anymore info on that? I threw in a set of "stage1" yoshimura cams on my '83 550 and haven't had any issues in the year I've had them in place and I am wondering if I'm doing damage that I can't see.

[hampshirehog]

I need to verify yet again but I seem to remember that these cams have something like .020" more lift than the later cams. Not sure about the cam timing. Most likely not worth the effort to swap them unless you want to squeeze out every last bit of power and don't want to spend a lot of money.

Edit: just went though the service manual and can't notice any difference in the cams after checking the specs. Guess I need to do more research before posting.

Confirmed - both inlet and exhaust cams have around 0.5mm extra lift on the early models (at least in Euro spec but I guess US would be the same). Sorry, I can't remember the exact figures and I haven't got it written down anywhere, neither can I remember if there are differences in timing. I've swapped stuff around on the 550s but never in isolation (ie I've changed the exhaust / intake set up at the same time) so I'm not qualified to say what gains you could expect. There are no clearance issues.

[Buffalo Bill]

Peek down there…

I am wondering if I'm doing damage that I can't see.

Look down the spark plug hole for crescent marks on the piston top from the valves.
When the RPMs get very high, the springs can't push the valves back up before the piston touches them. That's why new or high performance springs are recommended for performance cams.
Bill