For the folks w/ the C H I mods

I assume youre talking a p-head/RPM/Cam Research upgrade. That might put you in the 325hp range. Most people are coming from the base (240hp) engine, not the ProBoss, so the difference is more dramatic. 2-3mph up top is very solid.

Regarding the carb, Ive never been entirely happy with my Holleys on my 351w. New and used both are rich at idle and leave a mess on the transom. For optimal all around performance, consider converting to a rear metering block so you can tune the jets both front and rear. I believe Alan found the stock jetting to be pretty fat, even for a much hotter motor.

I'll probably have to give a mph back when I put the back seat and the sunpad on, but I did have 200lbs of lead in the bow which kills most of the bow rise. The glassy water wasn't helping me out either. Prop is a 328, kind of stuck there until Simone with a short driveshaft finds something better.   I guess there always the 409 or a BB.

Zach, remember that Mark has a big block, so prop selection is going to be a little different from a small block- even if hp level is comparable. Big cubes = big prop. I still think the 644 is a bit too small for optimal performance on a big block, but might be a touch too large for a small block.

Im pretty sure that we confirmed the 328 is a pancake, right? That'll push the nose down. Same goes for the lead in the bow, obviously. Anything you can do to get the nose up at speed will improve your top end. We'd need to know accurate RPM and speed numbers to really weigh in on a better recommendation.

When I got the boat and added the 328 the best it did was 49.6 @ 5200 in some pretty nasty water. Right now with lead ballast, at least 200lbs of stereo gear and 500 more hrs on the motor it running 45 @ 4600. It's still creeping up, but I notice ya bit of a pop 2 times after about 30sec @ WOT so I got out of it. Same setup was 42, maybe 43 with the right wind before. I'm sure I could get some mph if take out some of extra weight like it was originally, but that's a PITA and we don't need it to go past 30 for anything we do.

The mid range is great, from watching the PP set at 24 hard 180 turns would slow it down about 1 mph less and it would recover to +26 before it could catch itself. Before it would rarely get past 25. That mid range is really what I was looking for because we do use that for the ski show at the Drag Boat race. If anything I was hoping it would feel more like the BBC in the Epic we used this year, it doesn't, but I won't have to help it out near as much with the throttle as I did in the past. It's hard on the riders and me to keep a consistent speed with a hard turn every 200 yards. The BBC does it almost effortlessly and I'd like the Excel to do more like that.

I'm going to try and run most of a tank of fuel trough it this weekend and see if the richness is maybe just a little funk in the carb from sitting for so long. It was definitely running better when I got back to the trailer than it was when I left so maybe the improvement will continue with a little more time.   

Mark is thinking pretty hard about a 409.

Oh, and I have found that a small block Ford, modified to the hp level youre talking, to be a much more responsive engine than a stock big block. Holeshot and speed holding should be superior on the small block, and they should run similar up top. Thats another clue that something isnt quite right.

50mph @ 5200rpm and 45mph @ 4600 RPM are consistent numbers- so the prop doesnt appear to have been messed with based on that. You just dont have the same hp to pull it. A change in 600rpm is huge- thats about 80hp.

400 lbs spaced evenly around the boat is nothing. Thats 2 guys my size sitting up front... no big deal. I have found the bimini to have no noticeable effect at normal speeds, and I know Joe has found the tower and speakers to have no effect in terms of air resistance even when approaching 60mph.

I think you have other engine issues.

Thought about a blower, no intakes for a whipple so I never got to figuring out the reverse rotation issue.

Put 3 or 4 hrs on it, no skiing because we were blown out yesterday and no driver today. Quick run down the lake tonight, 4 miles cuising about 35 (gotta love that v-hull), last 1/2 mile I opened it up and about 20 secs in it pops. I got out of it and tripped it back to about 35 again. At that point I have to make a fairly hard 180 at a bridge, as I'm working it through the turn (it wants to cavitate the prop) I'm working the throttle just for fun and it backfires and dies. One pop, not loud but louder than the others. I turn the key of and back on only thing that looks bad is temp at 180, fire it up first try and everything reads normal so I run home. 35 all the way, no issues even made 20 or so turns at that speed, but left the throttle alone in the turns then put the hammer down going to the other side of the river.

Any ideas? I'm going to check the timing tommorow the heads were milled for 10:1 with flat top pistons in a mustang, I may have a little more CR, but it's full of 93 octane.