really cool.



UD

Shakedown run at the local lake...
http://www.youtube.com/watch?v=2aMJrMypZoo

I came up with another prop to test, courtesy of Bobby Moore. It's a 15.5 x 31 five-blade versus the 16.5 x 29 four-blade I've been running. It should have 3 degrees more rake as well. I hate to change more than one thing at a time when testing (in this case, it's four things...), but this is all that's available right now. I'm going to try it with the 1" spacer, since it's still installed, then try it a zero propshaft height. It may or may not be better, but it's bound to be different!

Some new videos

That prop wasn't the correct one, unfortunately...

Since all the props that I have found to test were 14 degree rake, I've ordered a 16.5 x 29 x 18 degree five-blade from Hering. They're willing to re-work it until it's right, and will hopefully deliver it in a couple of weeks. Stay tuned.

We ran the new Hering at last weekend's Northern Chesapeake Poker Run, and it seems to be better, but the water was so much rougher than the local lake, it's hard to tell. We're going out on Blue Marsh Lake tonight and do a back-to-back test the Hering versus the original 4-blade.

After two Poker runs, I've had ZERO problems or issues with the engine and drivetrain. I'm as impressed as ever with Ilmor's work. I even put their new logo on the boat...

I can certainly say you weren't babying it either. Very impressive all the way around!

BT

We tested a 15" x 27" x 16 degree prop last week, courtesy of Hering, and discovered that the top speed issue was not a result of spacers, but simply a matter of having over-propped the boat and keeping the engine from getting to the meaty part of the power band. The speed was back immediately on the first run: 95 mph @ 5700 when I lifted. The porpoising is still there, so the next step is to try the 2" spacer again to get the bullet down into the water to eliminate the "ski" effect and allow some positive trim. Looks like I'll wind up somewhere near a 15.75" or 15.5" x 28 specification. These surfacing drives are tricky beasts on single-engine boats....

Urgh, the part I'm so not looking forward to. So many factors & combinations, not to mention the expense of props & labor necessary to add & remove spacers etc. Hoping Skaters experience & access to props & spacers will help.

You're in w-a-y better shape that I am in terms of examples and experience. Skater (and others) have built a lot of cats in that size range with #6's and similar power. There are far more props available in the size range that you'll need for testing than there are for my application.

Mine is a unique one-off, and likely to remain that way...