Reply With QuoteDr. Eagle:
Having sold my Eliminator offshore boat with the twin big blocks this summer, I decided I was going to downshift back to that 21' openbow daycruiser like I had before buying the Eliminator.
So I bought an Ultra 21 footer yesterday and it has the same engine/drive you have been discussing here. I am not going to get crazy with the boat in modifying it, my take is to get a good prop, do the exhaust if you want to pump up the holeshot and midrange, perhaps have the heads worked over, you may be able to get a cam and install it too, but I would not build more than 300 HP if you want reliability. Giving the rule of thumb I have heard many places, that would give you between 3 and 4 mph.
As far as the high five prop is concerned, my understanding is that it is really a low end prop for holeshot. If you want top end a three or four blade stainless prop may actually be a better choice.
You might want to contact a reputable shop, like Teague Custom Marine or someone that deals with these boat/drive/prop combinations. I have grown wary of the local boat dealer. You may want to look at the advertisers in Hot Boat and contact one of them for recommendations. I recommended the high 5 since I had the same hull as his for 11 years.I tried many different Laser,Mirage and other props on that boat.The 5 blade lost nothing on top end,was much faster getting there and smoother as well.I know they are designed as a ski prop but ON THIS HULL they worked the best.I finally wound up with a 25p 5 blade with the blower setup.Might have been due to having a smaller diameter than the Laser II which allowed more trim.I have been to the Reinell factory,And they also build Blue Water on the same assembly line.On my friends 2050 Bayliner the high 5 sucked. Point is,what works on one hull may not on another.
