K4 Camshaft Question

[hadal]

I have a pair of camshafts I hope to use in my ZR hillclimb car, although new I believe they were intended for the MG XPower 1.8 185ps engines designed for the 2003 MG ZR one make series.

There only markings apart from the Powertrain/rover camshaft blank part numbers is MGXP902, from the measurements I can make they appear to have approximatly 10mm of lift and a 280 Degree duration?

Does anyone out there have any more details on these?

[DVandrews]

They are the VHPD profile (Piper 872), they are you say 280 degrees, but with not very aggressive valve accelerationor peak lift. They require solid followers with .008"/.010" follower clearances. They are best timed at 120 thou/100 thou lift at TDC. They give similar charaqcteristics to the Piper BP285H profiles.

Dave

[Mr2Mike]

The VHPD cams also don't work too well with the original intake plenum do they?

[hadal]

Thanks guys, just the info I needed.

Dave are you still doing the shims to convert hydraulic to solid followers?

[DVandrews]

VHPD cams are far too hot for a plenum, maximum duration for a well behaved engine on a plenum would be around 270 degrees with some *very* careful timing. If you are using an Alpha-N based ECU then this is much more tolerant of overlap, an MAP based ECU will struggle with anything greater than 264 degrees.

I still have a number of conversion shims for regular and VVC followers and the VHPD cams arent too agressive so they are ideal for converted followers.

Dave