Prop Help

[DOMINATOR]

I am running a 1993 Alumacraft Dominator with a 1993 55HP EVINRUDE(tiller).Motor is mounted with CMC power tilt bracket.Cavitation plate is roughly 1 inch above transom bottom.Prop is Michigan stainless measuring 13 3/4 by 15.(standard).Fully gased and loaded,including Merc9.9 kicker my GPS speed is a solid 30mph,with tach reading of 5200 rpm.Hole shot is not real solid,,,some slippage is happening.I have drilled holes behind the prop blades to help improve this but went to big on the size,,plumber puttied them back up.I would like recommendations on how I can improve top end and hole shot.I think I can get more RPM out of her,but am not sure how to proceed.Also because the engine is mounted on the CMC bracket,can I raise her up a bit more.

 

[walleyehed]

Re: Prop Help

If we know the tach is accurate, you're about 500RPM low of the Target RPM for that engine.
Which SS MWC prop do you have?

 

[DOMINATOR]

Re: Prop Help

The tach is accurate.The prop is the standard stainless replacement prop that Michigan offerd for that motor in that 13.75x15 pitch.Am I maxed out with this prop?

 

[walleyehed]

Re: Prop Help

If the tach is correct, you may need to go down to a 13P and raise the engine a hole on the lift...this should put you in the 5600-5700 range with the same load which would work much better.

 

[DOMINATOR]

Re: Prop Help

Thankyou for replying.What would you recommend for a prop,and what would be a maximum height for cavitation plate to be set at above transom bottom?

 

[rndn]

Re: Prop Help

You'll get lots of prop opinions, but to a point you will get what you pay for. Nothing against Michigan wheel, but there are better props out there although you will pay more.

 

[walleyehed]

Re: Prop Help

Prop choice would be based on whether it's a Michigan Match SS or a Ballistic SS, or even an Apollo SS....alll michigan wheel props with differing blade designs.
Do you have the MWC P/N? I can go from that.

 

[DOMINATOR]

Re: Prop Help

I will get that part #,,see what you can tell from that.This weekend I took that Michigan prop off and put back on the original (black) stainless prop back on to compare.Mind you,this stock prop has about 1/4" vent holes drilled into it.It does better on the whole shot,and really catches up fast as rpm's go up.The wot rpm's with this prop are 5400,,compared to 5200 with the Michigan.gps speed turns out to be about the same.I had drilled the same size holes on the Michigan,,expecting the same "improved" results,,but for reasons I don't know the hole shot was terrible.Which makes me wonder why this would be,,,differnt style(shape) exhaust ports on the blade.Any way...I'm thinking of staying with these props and raising my motor up about 1 inch,,I hopwe to improve my hole shot and top end some.Appreciate all comments,,,,,,Mike

 

[DOMINATOR]

Re: Prop Help

PART # on Michigan stainless is 013028.

 

[DOMINATOR]

Re: Prop Help

why does oem prop give me 5400 wot,and the Michigan Match give me 5200 wot?.Both are same pitch

 

[Esox]

Re: Prop Help

why does oem prop give me 5400 wot,and the Michigan Match give me 5200 wot?.Both are same pitch

Maybe the Michigan Match has more cupping/slightly different blade design.