Scarab 29 engine raise help

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12-31-2017 | 11:10 AM

#11

Scarab29Aj

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Quote:

Originally Posted by SB

Thanks for answering my second question. Could you answer the 1st ?

Sorry about that. Originally they were 350 engines.

12-31-2017 | 11:17 AM

#12

Scarab29Aj

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Originally Posted by Griff

How much are you estimating the hp gain per engine???? A 5mph gain is probably about a 75hp gain per side.

If you have 1.50 ratio drives, your prop slip is very low at only 5% which is pretty unlikely for any straight V bottom boat.
I'd try some 23 Mirage Plus props spinning out and see what happens.

i did figure about a 75 hp increase a side. Just thought my new numbers vs old numbers would be further apart with the drive height change.

With the prop slip numbers i was surprised also. GPS speed was taken off the speedometer as well as phone. And tachometer readings matched laptop data?

12-31-2017 | 11:23 AM

#13

Scarab29Aj

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Originally Posted by class6

That's why I said try the rev4. A 23p is more prop than 24 bravo but goes through the water much better and the boat will probably have a better attitude. I'd try spinning in and out back to back and see where it gets you.

i will definitely try a pitch down. I had mirage +23 originally on it and first water tests would instantly blow the props out. Should have tried spinning them out right then.