Is there anywhere that I could find the specs for a hp500? I'm looking for things like cam specs, C/R, piston dome (or dish) CC's, valve sizes, head specs, ect.
Thanks

TTT

Anyone?

Scott B

Cam Card

Compression = 8.5

Two things to cross off your list

I changed cams

My Choice

BTW these are carb Specs.

call mercury racing and speak with a tech.

Thanks for the cam specs. On your new cam, hows the idle? I am building a carbed HP500 clone, and want a (relatively ) smooth idle..

Scott B

HP500 EFI -

Camshaft - Crane 169621 - 230/236 duration @ .050, .598/.610 lift, 114° LC

Pistons - JE700 +1 cc (carb should be the same)

Compression Ratio - Static 8.7:1 - Dynamic 6.2:1

Heads - GM14097088 - Open Chamber (118cc), 325cc Intake Runner, 2.19 Intake, 1.88 Exhaust

Idles great only difference I noticed is that it sounds better I have never stalled it around the docks I have one carb that is starting to get grumpy but it has nothing to do with the cam.
If I am right? One of the weak designs on that motor is the heads there are a lot of better choices. They have the large intakes and the Inconel exhaust valves but they need help with the flow. I had my exhaust side relieved and some mild porting. I also had a tad bit removed to bump up the compression or keep it close after some of the chamber work that was done on the heads. All of this woke it up quite a bit