Quote:
Just a quicky. Is the L1 equivalent (or near enough) to the STR139 or STR91? I can't remember
Hi Mart, the L1 cam was originally designed for the twin-cam Lotus/Ford/Cosworth engine, so the cam lobe design may not be optimized for the SOHC Dolomite Sprint engine.
These are the figures (as found on a Lotus Elan website):
L1 Camshaft
Valve timing 46/78 - 70/50. Duration 304 deg. Lift @ valve .410" (10.41mm)
Installation data:
Valve clearances (Cold) inlet .007" (0.18 mm)
Ex .008" (0.20mm)
Inlet valve fully open 106 deg. ATDC
These figures come very, very close to the Kent DMS2 cam
Timing is in-between the STR91 and STR139, but that doesn’t mean the performance will be better than STR91, due to design. If it’s for your trackday Sprint, I think STR91 would be your best bet.
Some (unorthodox?) info on Triumph cams and (de-)tuning in general:
Cylinder head work
Camshaft technology
Triumph modified head’s
Happy reading