The Triumph Dolomite Club - Discussion Forum

...and as if by magic...



There is another list as well somewhere.

Newman cams will grind pretty much what ever you want.

Updated list over here:

That's perfect.

Thanks again folks.

Tom.

just got a 285 cam from piper ground from a blank , i have measured the base circle which is 1.20 inch's , with the the distance over the lobe 1.590 inch's which gives a lift of 0.390 inches , which is near to there 270 cam

the lift quoted on there website for the 285 is 0.426″

[http://www.pipercams.co.uk/pipercams/ww ... d=TRSBP285

piper cam list for dolomite sprint
http://www.pipercams.co.uk/pipercams/ww ... engine=125

has any one else had problems with piper cams

Depends how you measure the base circle. Putting calipers or micrometer across the cam where it "seems" round is not the base circle typically.
Correct measurement of the BC is to measure the cam bearing surface (I dont know the sprint numbers off hand so lets say 25mm). Then measure the height from the base of the cam (where you put the feeler blade) to the bearing surface. The base circle will be proud of the bearing journal of course so lets say that is 3mm. Now that 3mm is the RADIUS difference of the 2 diameters so in this case the base circle would be 25+ 3+3 = 31mm. Cams never read that number directly when measured across the side of the lobes because the opening/closing ramps are already spreading outwards and this gives the seemingly lower lift than expected. If you know all this I apologise but any one reading that doesnt may find it useful

PS this is assuming inlets are being talked about here as its direct acting. With the exhaust there the rocker ratio to work in too and I dont know what that ratio is off hand

Tony

thank you
mike