2000 377 Scorpion questions! ASAP
 

hey guys i am new to the forum! I recently picked up a 2000 donzi 28zx with twin 377 scorpion engines. I knew ahead of time one engine had a couple issues which leads to me now. It looks like Mercury used crane cams back in the day but i am looking to get a new cam for the engine to match the factory specs. Can anyone tell me or show me the factory cam specs for this specific motor? Thank you in advance. This is the only part holding me up from boating ! lol

https://cimg2.ibsrv.net/gimg/www.off...3a3411d26e.png
https://cimg3.ibsrv.net/gimg/www.off...9a1ac9f10b.png
Found these

Are there any numbers on the original cam ?? If not it would take less than an hour to bolt it in the engine and put a degree wheel on it and figure out exactly what it is. What is wrong with the original cam ? Wiped lobe ?

Young is certainly more experienced than me. But I was looking over the SBC motors in the OE manual just yesterday. Came to the conclusion that the high HP engines had roller cams and 9.3:1 compression. The highest, a Black Scorpion had those plus it had the highest red line. 5000. The MAG engines mostly were 4800 and they would rate efi 20 hp more than carb.

If you have one good cam send it off to get measured and get a copy ground or have your core fixed. Delta Camshaft in tacoma Washington may help.you out.

Since it is a 2000 Donzi 28zx with twin 377 Scorpions, then I assume we are talking about the blue 377 Scorpion engines from Mercury Racing.

I have the factory service manual for that engine, and it says:

Compression ratio: 9.0:1
Maximum rpm: 4800-5200 RPM
Engine rev limiter: 5400 RPM

Valve system:
Valve lift intake 0.510
Valve lift exhaust 0.530

Camshaft:
Duration at .050" cam lift: Intake 222 degrees and exhaust 230 degrees.

Its a Crane Cam. A buddy rebuilt a pair of his and had to replace a cam. Was able to get one.

Edited: I need more coffee to see the dates clearer. Lol. Thought was old thread. My bad. :)

Gm Performance Parts offered a cam just like that , made by Crane too,, but on a 112LSA. It warns to usemelonized dist gear so may not be cast iron gear, which would be weird because Crane HR cams typically come with a iron gear on them.

Chevrolet Performance 19210723

Perfect! This is exactly what I needed. Thank you. They said the cam isn’t terrible but trying to order a cam right now is gonna take awhile. He said it’s runnable for now. I’ll replace both this winter.