motors higher=boat slower

[markt111]

not the typical set up here but would love some input

30' Scarab, twin V8s, been playing with engine height when I have time, had the boat out to clean a couple weeks ago and raised another inch, running about the same rpm but about 3MPH slower!!!

maybe the props I'm running are not good at high engine height (still 4-5 below the hull thou) running Mirage plus stock props, feels like I'm running very wet, not getting much bow lift

is this typical??

[terry taylor]

HI. Yes it can and might happen especialy with a bigger heavier boat .Props.lose some bite and throw water back,many boats have a sweet spot. You may have reached yours and surpassed it a little. thanks.

[markt111]

thanks for the reply, forgot to mention it gets out if the hole pretty good still, can give it 3/4 throttle getting out with out blowout,

starboard motor only slightly cavitates on occasion cruising

[150aintenuff]

to give ya a good answer you need to give a bit more info on setup... but mirage props are designed to be submerged so you are definatly to hight for the props, try a different set and see if you pick up and then gain some...

[markt111]

heres a running shot at almost 60mph in pretty flat seas

boat is fairly heavy and equipped

def need to try some Rev 4s if I can find a set to try!! not easy to find, time to play with setup is limited also

[Wizard]

Slip when up a soon as the props lost bite. The Mirage is at it's limit. Switch to Bravo's with the same pitch. You'll be good for at least another 3/4" height more likely an inch.

[Pro300x24LD]

PM STV Keith or kimswang ? I think they both are running V8's on similar boat.

[kimswang]

Hi Mark,

Looks to me as you have too much boat in the water. If you are sure you trimmed it right and the tabs where up, well maybe try some other props. here is a picture of how mine is running. Keep in mind that I am running over 3 feet of setback with my bracket and I am running Rakers...

[STV_Keith]

Yep, you need those Bravo's I kept telling you about. ;) With their larger 15.25" diameter, you'll have a faster cruise speed and probably more on top...plus they will come out of the hole at least as good as what you have now.

Some setback would help too...

[kimswang]

Keep in mind that the OMC lower units is famous for braking while surfacing, so maybe try to gain speed with other mods?? Plenty to do with those monsters.... Boat looks awesome though, love that color combo..

[gotboostedvr6]

kim do you have any pics of the Scarab 34 SS with Triple OMC 4.0 V8's?

[markt111]

was thinking a smaller diameter 4 blade like a Rev 4 would be better for the lower unit!! and told they had more bow lift then a Bravo

either way I need to try them all I guess

[STV_Keith]

Bravo is more of a stern lifter. You want it to help get the weight out of the water. Submerged running is easier on the gearcase...and SLOWER. Pick your poison. :)

[kimswang]

kim do you have any pics of the Scarab 34 SS with Triple OMC 4.0 V8's?

Send me your email and I'll send you some....

[markt111]

breaking lowers is another reason I was thinking Rev 4s instead of Bravos, less diameter=less strain on lower, also more of a bow lifter which I know I need with limited setback

[markt111]

I will try either if I can get my hands on them thou

[STV_Keith]

Did you ever do anything here Mark?