looks like the higher the numbers merc can post,,the more they will chrge for the engine:rolleyes:

If it's clear that the advertised hp is at the crank then they are underrated!

Old thread, I know, but good winter reading.

Must be really bored to revive this thread. But I do have some more data I can share. Most dyno shops including myself use a "standard" correction factor for testing. OEM use an "SAE" correction factor which is a couple of percent more conservative. So the HP comparisons everyone sees is more a difference of testing methods than of actual power produced. I recently rebuilt a couple of 525's. I dyno'd them before tear down and made 556 hp running all accessories and wet exhaust, using the Standard correction factor. I rebuilt them, did a mild bowl blend and used the small dome 502 pistons which added a couple of tenths more compression. With a recal of the ECU we made 581 HP. We also replaced the cam (because of damage) with Comps 525 replacement version. It appears to be a tiny bit milder than the Crane OEM cam.

Bob

Glad you did

still 87 octane or?

The compression is about 9.2:1 ....


I DO fill up with premium on land but would top off with mid grade on the water if I had to ...


Doug