Bobs nose cone and low water pickup

[HankFrazier]

I've never put one on that when i was finished it ran slower than when it had no nose cone even on small motors running in the 40's.

[R Pierson]

Hank,

While what you say is totally true. It doesn't help the guy who doesn't know how to shape the cone. But I'm curious, why would you put a cone on a boat running in the 40's....although some of the gearcases out there are pretty blunt. Take the 3 cylinder/ 4 cylinder loop charged merc's. Those were rather bad. So I rescind the statement as to why would you...

Carry on....

[ima75man]

i build my nose cone out of bondo and then seal it with good primer

[HankFrazier]

Hank,

While what you say is totally true. It doesn't help the guy who doesn't know how to shape the cone. But I'm curious, why would you put a cone on a boat running in the 40's....although some of the gearcases out there are pretty blunt. Take the 3 cylinder/ 4 cylinder loop charged merc's. Those were rather bad. So I rescind the statement as to why would you...

Carry on....

Back in the day we had a 60 mile long river race the boats were 10 ft aluminum with eather 20 hp mercury's or 25hp omc's you couldn't run any set back because of too much transom weight the prop shafts were even with the bottom of boat it was hard to pick up water with out low water pickup although there were some guy's that cut groves on the sides of there gear cases to channel the water to the water intakes the fastest boats ran in the upper 50's the slower boats ran in the mid to upper 40's the prizes were money and boats and motors. this was 35 years ago on the sabine river

[MWhite]

Back in the day we had a 60 mile long river race the boats were 10 ft aluminum with eather 20 hp mercury's or 25hp omc's you couldn't run any set back because of too much transom weight the prop shafts were even with the bottom of boat it was hard to pick up water with out low water pickup although there were some guy's that cut groves on the sides of there gear cases to channel the water to the water intakes the fastest boats ran in the upper 50's the slower boats ran in the mid to upper 40's the prizes were money and boats and motors. this was 35 years ago on the sabine river

yep hank,, back in thoses days we would cut channels in the side of the gear case to channel the water and would sharpen the gearcase as well to cut through the water better,,mine would run around 54 with me a rider and gas. we didn't have nose cones for them little motors like we got now on the 40s. them were some fun days running them river races back then, wish they still had them

[pdt]

The reason I ask is because this.
My boat is /was a pig for speed.
The Boat is Orkney dory 13ft 3 in, very similar to boston whaler classic 13 but built slightly heavier with more of a v in the centre.
Engine is a 3 cylinder 56cu in evinrude 1995.
with a 13x19 my top speed was 38.1 at 5700 rpm, that was with cav plate just 1.5 inches above bottom of boat.
also tried a 13 3/4 x 23 at same height and got 39.8 mph, I know this prop is meant to run pretty high so I have now made a jack plate to
raise it up 7 inches so the propshaft is around 1/2 to 1 inch below bottom of the transom now with a 5 inch setback built into the jackplate.

ive not yet run it like this due to being too busy with other stuff etc, but now im also thinking about water pressure so maybe I might need a low water pick up. ??????

Now putting on a cone with a low water pick up might be the answer as long as I don't slow me down at all, I am not expecting 50 plus mph out of this pig, but want it
as fast as possible with what I have got.
I am hoping that by jacking it up and back the plate will let the prop spin faster dueto half of it being out the water and running high like its meant to.
Hopefully I get 6000 rpm or more like this.
I don't want to cook the motor obviously, but realy cannot afford for anything to rob me of speed, that's why I asked if the cones slow you down in the 40 plus mph bracket.
like said above I would be better off with 70hp carbs, but these are like rocking horse s..t over here, you just cant find them. so for now im stuck with 60hp.

I will probably have to make a cone myself and not sure yet if I am going to use fibreglass or melt down some alloy ( we don't get cones over here, and postage is just too much).
I don't even know yet if by using a set back if it will be too heavy on the transom with the extra leverage, the boat was originaly designed for 50hp and 200 pound motors.
I have taken the boat apart completely and made it a lot heavier on the transom by making it much stronger, and even put down a lot more glass on the hull bottom.

the boat weighs around 250 kilo (500 pound)without engine battery and fuel, so its no lightweight racing boat. so I need all the help I can get with the cone or without it.


ima75man
you say you build the whole cone from car filler ? and it stays on ok yeah ? is that also with low water pick built in or just the cone ?

as anyone built a cone from fibreglass ? and was it any good ?

.

[pdt]

Mike
do you have any pics of the channels you put on the gearcase etc ? and did they realy work ok ? sound like another idea if a cone is not going to suit my rig.
.

[MWhite]

Mike
do you have any pics of the channels you put on the gearcase etc ? and did they realy work ok ? sound like another idea if a cone is not going to suit my rig.
.

yes but I will have to dig around and find them old pictures of the boat and motor I had back then, yes it worked.

[HankFrazier]

Mike
do you have any pics of the channels you put on the gearcase etc ? and did they realy work ok ? sound like another idea if a cone is not going to suit my rig.
.

I have built and ran several all fiberglass nose cones on 3cyl Yamaha and tohatsu motors they work pretty well.you will have to touch them up every now and then but you have to do the same thing with the bob's to if you run them a lot.