holygoat
Site Supporter
- Location
- Indiana, USA
Afternoon all,
I recently picked up my first standup, a 1980 JS440. My parents had these back in the day so it's cool to be riding the same skis as them. The ski came in boxes and we put it together on the night I got it and had it on the lake that weekend. It's a nice ski with a westcoast pipe, a bunch of Ocean Pro parts, solas prop, OP ride plate, intake grate etc.
The ski came with another motor. This motor had some light scoring (piston clearance only around 1-2thou) and some decent porting. It also came with a skimmed head.
I'm looking to clean this engine up and drop it into my ski for a bit of a power increase. I've heard good things about these ported and skimmed 440s so I'm eager to try.
I was planning to have a local shop put .004 of piston clearance in the jugs, and take .020 off the top of the jugs. I was then going to run a .020 copper gasket to get my quench down to .040. As it stands it is at .080.
My question is, does this sound like too much? From what I know proper quench actually reduces the chance of predetonation by sending vapours towards the plug, resulting in complete compression. I haven't heard much about people taking anything off of the cylinders when I was reading about these motors, just skimming the heads. I know these are older but this engine is 90% of the way there so I might as well try it out.
Thanks all
I recently picked up my first standup, a 1980 JS440. My parents had these back in the day so it's cool to be riding the same skis as them. The ski came in boxes and we put it together on the night I got it and had it on the lake that weekend. It's a nice ski with a westcoast pipe, a bunch of Ocean Pro parts, solas prop, OP ride plate, intake grate etc.
The ski came with another motor. This motor had some light scoring (piston clearance only around 1-2thou) and some decent porting. It also came with a skimmed head.
I'm looking to clean this engine up and drop it into my ski for a bit of a power increase. I've heard good things about these ported and skimmed 440s so I'm eager to try.
I was planning to have a local shop put .004 of piston clearance in the jugs, and take .020 off the top of the jugs. I was then going to run a .020 copper gasket to get my quench down to .040. As it stands it is at .080.
My question is, does this sound like too much? From what I know proper quench actually reduces the chance of predetonation by sending vapours towards the plug, resulting in complete compression. I haven't heard much about people taking anything off of the cylinders when I was reading about these motors, just skimming the heads. I know these are older but this engine is 90% of the way there so I might as well try it out.
Thanks all
