Fitting low water pick up to outboard engine

[chris3298]

Good drawing Jeff I thought how could I do this but I have a hard enough time just posting a picture.

[Glenno]

Hi all,

Sory I didnt catch this thread earlier, I love talking nose cones!

Phill, I really think you would be fine just to make a two part filler nose cone. I race the 25hp and 550cc super sport outboard here in Australia and have run a full two part filler nose cone for five years now (raced it hard with no probs). The reason for low pick ups is if you wanted to get the torpedo level with water surface or above (like my 550cc- runing 1/2 inch above water) when at full go.

I have gone to the trouble of adding low pick ups to motors before and found it to be a bit of a waist of time as a filler nose cone seems to to the job of pulling the water up to the factory pick ups just fine.
All the guys here that race run a tube from the factory tell tale up to where they can see it (beside them) to make sure the motor has water.

http://www.youtube.com/watch?v=7YX_8...yer_detailpage

I hope thats some footage of my nose cone when we where testing, it runs hiegher now ans still feeds water with factory pick ups, see how the cone pulls water up the gear case.

[phillnjack]

Good video and very good picture.
I can see what everyone is saying about the engine running in water that is comming up from the transom.
But everyone also seems to be running with atleast 6 inches of setback !!!!
with a setback yes the water level will be higher due to the water returning back to its original level.

Also in the pick above the nosecone is pointing down, its definitely not running parallel to the drive shaft,is this
for a reason ?

can you tell me what benefits you have found by using a nosecone , ive never used one but realy like the look.
do they realy give a noticable performance gain ???


phill

[Fastjeff57]

Gotta admit, they look cool! As I understand it, below 60 mph or so they don't do much. Furthermore, the Yamatos never used a 'bullet' and are certainly competitive.

Jeff

[Glenno]

Hi Jeoff,

Yeah I noticed a massive diference in a number of ways.

1) without the nose cone I would never be able to run the motor as high as i do and still pick up water (our rules dont allow us to change the factory pick ups) , thats part of the reason the my cone drops lower than centre of prop shaft by 1/2inch to pull more water up, you do need to be carfull doing that though as one of my mates went to far and caused his boat to poupus, he re-shaped and works sweet.

2) I did take the boat out once without the nose cone and experienced bad blow out (if thats where you cant steer and feel where the motor is tracking), I found that the nose cone extends the torpedo of the gear case and helps it to track better, also a little kick on the right trailing edge of the skeg for right turn prop motors helps overcome tourque steer. I will attach a pick, look at the back edge of the skeg-not the best pick.

3) One test day I raised the motor just a 1/4 of an inch and gained 3.75mph.

I here what Geff is saying about under 60mph they dont do much and do agree with him for some boats but with all respect to him I have to disagree as it really depends on the boat, total weight of the rig, how high you want to run your motor and what you are trying to achieve - I am even chasing 1/4mph as that can win a race. I have to agree with Geff again, They do look cool! and I cant resist adding a nose cone to most outboards i have owned - even fishing motors.
Some picks of other cones I have made- The second pick is the one to look at for the kick on the skeg.

[Glenno]

Hi again,

I forgot to say in regard to set back- a lot of the guys running in the mono hulls at our club have no set back at all and are running the centre of the prop shaft in line with the bottom of the hull (running plank), But like i said earlier we all run our water tell tales up to where we can see to make sure the motor has water.

Looking at your water pick ups I would start with your motor 2 inch below bottom of hull to the centre of prop shaft if you had a nose cone and work up from there and make sure all the time you have water, water, water all the time. You would definately want a different prop, the props with the converging ring at the trailing edge of the hub are like a brake, I attached a pick of a prop I rewoked and put a bell on trailing edge instead of converging ring, and a few more picks I found of nose cones I have done.

Hope this helps
Glenno

[tsrt]

Attachment 51967 easiest way

[Jfarrelly]

Where did you get or how'd you make your nosecones/low water pickup

[Krazy Karl]

Gotta admit, they look cool! As I understand it, below 60 mph or so they don't do much. Furthermore, the Yamatos never used a 'bullet' and are certainly competitive.

Jeff

Most of the guys do shape the Yamato gear cases but we aren't allowed to add a bullet in stock, however in Mod we can. This is what is usually done. I found it makes for quicker turn in on the corners.


kk

[Glenno]

Hi all,

I definately dont run extra pick ups, I would be disqualified, the scruteneers would see it strait away.

yes the cone is to pick water up but the speed is gained by reducing the amount of gear case that runs through the water (dont think of it digging down) and also getting the prop to surface pierce. If you can get the prop to run 1/2 out of the water you can run a much heigher pitch wich usualy = more speed.

Glenno