blue thunder

What about the other engine Panther?

I think the belt drive is a great improvement. I've been designing them in to high speed production equipment for 20+ yrs and they are the catsass, particularly in reversing applications. If you think of the alternating forces (vibration really caused by the lifters riding the profiles of 16 lobes) on the driven gear of a valve train, you could easily see why a tensioned belt is best. It acts like a valve train damper.

Panther

The other engine was fixed and checked in 2007 when after 100 hrs the timing gear snapped in half and made my engine a pile of garbage.... Cast gears and boats don't mix, neither do ex engine builders with substance abuse problems.

Good thing JC Performance fixed all my issues at that time and installed a the billet timing set.

What are you running on your Scarab Engines? I don't recall seeing a belt drive in the pic, so just curious.

blue thunder

Cloyes hex ajust will billet gear. But if I had disposable $$ I would go belt drive. I'd like to be able to try different cam timing setting which is another benny. But really with my valvetrain having only 150# seat pressure, its not necessary.

What kind of oil pressure and seat pressures are you running panther?

Panther

75-80 lbs hot, 190 lbs on the seat, solid roller. http://www.cranecams.com/?show=brows...31&lvl=2&prt=5

when the first timing gear broke years ago on the other engine, the engines had a flat tappet cam, 130 on the seat.

I hear ya about the disposabe $$$ part...I'm back to building my own engines again and had to work on boats on the side this past fall to pay for it.