Quaid

Does anyone know the cam spec's for the 502 Magnum MPI and the HP500EFI? If not, where can I find this?

Kanookstr

The year would be helpfull

a 1999 502 efi mag Gen 6 roller I had was 224/224 .483/.483

an earlier flat tappet mag cam on a GEN V (pre gen 6 roller) was .512/.512 but 211/227

Quaid

I didn't realize they changed the cam for the same motor. The year of the 502 MAG is 1995. I'm guessing the cam didn't change for the HP 500 EFI yet. It is still fairly new.

Thanks,
Dave

Ric232

Kanookstr, I take it you were able to confirm the Gen 6 profile? My Merc service manual shows the cam specs for my Gen 6 as the spec you show for the Gen 5. I would not surprise me if the book was wrong. I guess it makes sense that they could reduce the lift when going to the roller cam since the lobe ramps are steeper.

Ric232

The 500EFI cam is Crane part # 169621

Lift .598"/.610"; duration 230/236 LSA 114

Griff

I think your the cams were the same in the 454mag and 502mag for that vintage.
Is your 502 mag the 390hp carbed version???

It should be a flat tappet with 220/220 and .510/.510. on a 115.5 LSA.

Ric232

Quaid, aren't you glad you can come to one place to get the single decisive answer ???

Griff

Really need the Merc engine serial # or some more info to determine exactly what engine he has.
Changes to roller cams happened in 1995-1996.

If its a roller than Kanookster's is the one.

Quaid

The number stamped in the block is "N2507" (seems kinda short to be the serial number). My boat is a 1995, but I bought the motor in 2001. It was fresh out of the crate. I was told it was definitely a roller motor.

Quaid

By the way, it is a EFI 415HP