Which cams are that ?Markings 12048 ?

[FJD]

Digged through some parts, and came up with a set of reground GSXR-Cams i do not have any info on.

Maybe someone here knows what they are, and has a spec sheet.

They have the usual 27A IN and EX markings on them, but are stamped on the side with the following: 12048  2 95

cam base circle is 26.80mm on both IN and Ex, 

Base circle and lobe lift are 32.80 IN and 32.90 EX, so that comes to a lobe lift of 6.00 (.236 inch) and 6.10 mm (.240 inch)

 

Is there any formula to calculate from cam lift to valve lift ?

Because all info on the web i find is based on valve lifts, not cam lift.

[FJD]

[Oilyspanner]

The only sure way of calculating valve lift is with a dial gauge FJD - there's tolerances/slop between the cam and valve, this would make any lobe and follower ratio type calculation inaccurate. I don't know which cams you've got, but the inlet lobes especially are very low, the GSXR's are all 33.5 to 33.9mm range ?? (even GSX-F are much bigger) The inlet lobes should be larger than the exhaust's. They could be Japanese market cams, or some low power market ones, but the inlets should still be larger than the exhaust lobes..... I expect someone on here has come across something similar - I wouldn't want to fit those into one of my motors though Bud ! - maybe in 30 years.....

ps - the cams aren't the normal colour either are they, very silver looking.

[FJD]

yes, looks brownish, but this is due old oil for conservation.

i also thought that these were quite tame....will have to check them against some yosh cams.

[FJD]

Seems we were wrong - they seem to be quite hot cams, i compared them to standard, and they have a decent increase in lift.

Also compared to yosh stg II gsxr1100 they are pretty interesting cams.

Just would like to know who made them ?

[FJD]

No one knows what manufacturer they might be ?

[Lachie04]

APE welded and reground?? could give them a try