Model Boat Mayhem

The Shipyard ( Dry Dock ): Builds & Questions => Pleasure boats, Sports, Race, Power and Leisure Boats: => Topic started by: snoopy on December 06, 2007, 06:22:24 pm

Title: Water Inlet
Post by: snoopy on December 06, 2007, 06:22:24 pm
Hi Guys

I am new to this boating lark and know absolutely nothing about setup of the boat or water intake.  I would like to ask, please please, for help or pictures or posts.

I am running a Zenoah260pum engine with a water cooled exhaust pipe, a water pump and clutch.

the questions I am asking are:

a) Where does the water pipe go from the rudder into the boat
b) Where does it fit onto the exhaust pipe
c) What side does it go onto the engine
d) Where does it go onto the water pump
e) At what point does it leave the boat
f) How do I set the fuel up, is it an IV bag or a fuel tank and how does it go i.e inlet and outlet
g) and any other thing I havent mentioned as I am a total beginner.  Any help very much appreciated.
Title: Re: Water Inlet
Post by: bigtee on December 06, 2007, 07:13:15 pm
the inlet from the rudder pick up goes to the ( righthand ) lower inlet on the black cooling head then out of the upper one into the exhaust pipe , either one , then out of the exhaust then out of the hull where you can see it
as for the water pump this will go inline between the rudder and the lower inlet on the black cooling head , i do not run a water pump myself but ones i have seen have flow direction arrow on them

hope this helps  , here to help tony  O0
Title: Re: Water Inlet
Post by: snoopy on December 06, 2007, 07:36:53 pm
Hi tony

thanks for your time and effort.  I will have a look at what you suggested.

Here is a pic if its any help

Title: Re: Water Inlet
Post by: martno1fan on December 06, 2007, 07:45:27 pm
Hi mate as said in above post sounds about right ,i run two picckups on mine one seperate for the motor then another one for the header and pipe.this way im getting cool water to both equally,id suggest another piccup for your header and pipe,you can buy them that just hang off the transom.
Title: Re: Water Inlet
Post by: bigtee on December 06, 2007, 07:51:36 pm
snoopy

does your exhaust have water nipples  on it ? not the cooling flange the tuned pipe if so you need to come out of the black cooling head into the lower nipple on the exhaust header out of the opersite one up into the top nipple out of the opersite one , back on yourself then into the pipe ( if it has cooling ) then out of the hull  O0
Title: Re: Water Inlet
Post by: martno1fan on December 06, 2007, 09:19:32 pm
heres how mine runs,i have a piccup from the rudder it runs directly to the bottom nipple on the water jacket on the motor then it runs out of the top one and straight out of the boat via a water outlet .the second piccup runs to the header flange then out the other side and into the pipe then out of the pipe and then out of the boat via a water outlet nipple.your pipe will have two o rings so when it slides onto the header pipe it seals and water runs between these two rings to cool the pipe.you can run one piccup as suggested but i prefer two as im not confident one is enough for a zenoah as they run high revs and high temperatures.I dont know of anyone who just runs one piccup to be honest as most ive seen or people ive talked to run two.
Title: Re: Water Inlet
Post by: snoopy on December 06, 2007, 09:35:02 pm
Hi Guys

Thanks for the information guys.  It has helped a lot. The exhaust pipe has a hole either side, is this where I put the nipples in ? it has screw threads in the holes. Or is his just for fixing the u bend onto the pipe?

many thanks again
Title: Re: Water Inlet
Post by: martno1fan on December 06, 2007, 09:44:35 pm
do you have a close up pic of it ?,sounds like it needs nipples is it like mine? heres a pic.does it have two o rings inside the end part ?.
Title: Re: Water Inlet
Post by: glennb2006 on December 07, 2007, 03:41:48 am
Hi Guys

Thanks for the information guys.  It has helped a lot. The exhaust pipe has a hole either side, is this where I put the nipples in ? it has screw threads in the holes. Or is his just for fixing the u bend onto the pipe?

many thanks again

From looking at your photo,the tapped holes you refer to are cooling water in / out points.

What I do on my boat:

Rudder: pick up to motor lower point, then over the side.

Hull pick up: to the tuned pipe cooling jacket, then to the exhaust manifold, then over the side.

Glenn
Title: Re: Water Inlet
Post by: martno1fan on December 07, 2007, 12:55:37 pm
Hi Guys

Thanks for the information guys.  It has helped a lot. The exhaust pipe has a hole either side, is this where I put the nipples in ? it has screw threads in the holes. Or is his just for fixing the u bend onto the pipe?

many thanks again

From looking at your photo,the tapped holes you refer to are cooling water in / out points.

What I do on my boat:



Hull pick up: to the tuned pipe cooling jacket, then to the exhaust manifold, then over the side.

Glenn

Thats interesting Glenn why to the pipe first rather than to the manifold then the pipe ?.
Title: Re: Water Inlet
Post by: snoopy on December 07, 2007, 07:12:23 pm
heres the pics just like u said mart
Title: Re: Water Inlet
Post by: w3bby on December 07, 2007, 07:46:10 pm
If you can imagine it all bolted up, this is the way I would run the water.....
Title: Re: Water Inlet
Post by: glennb2006 on December 07, 2007, 08:11:12 pm
Hi Guys

Thanks for the information guys.  It has helped a lot. The exhaust pipe has a hole either side, is this where I put the nipples in ? it has screw threads in the holes. Or is his just for fixing the u bend onto the pipe?

many thanks again

From looking at your photo,the tapped holes you refer to are cooling water in / out points.

What I do on my boat:



Hull pick up: to the tuned pipe cooling jacket, then to the exhaust manifold, then over the side.

Glenn

Thats interesting Glenn why to the pipe first rather than to the manifold then the pipe ?.

So the water that gets to the manifold is preheated and therefore not too cold and going to risk overcooling the motor in the exhaust port area. Just me martin.

Glenn
Title: Re: Water Inlet
Post by: snoopy on December 08, 2007, 08:45:14 am
thanks for the drawing on the pic Ian, it is excellent. Much appreciated

Thank you for your time and effort. Gives me a better idea

once again thanks
Title: Re: Water Inlet
Post by: martno1fan on December 08, 2007, 09:58:31 am
so now your cooking with gas? all you need is two nipples hehe and some loctite  O0
Title: Re: Water Inlet
Post by: w3bby on December 08, 2007, 10:20:18 am
I have to admit that I change the way the water runs depending on the time of year. Beginning and end when the water is cold I go to the exhaust flange first and then cylinder. With 2 inlets I cool the pipe coupler by itself.
Title: Re: Water Inlet
Post by: martno1fan on December 08, 2007, 12:44:42 pm
Thats interesting never thought about that one ,is it really needed ? .
Title: Re: Water Inlet
Post by: w3bby on December 08, 2007, 03:55:26 pm
Don't know really, all part of my theory that we are overcooling our engines. I base this on the fact that the aircooled 260s, even with pipes, don't need the piston turned down to prevent seizure whilst PUMs do.
There is a "best" temperature for the cylinder and it is my belief that we are often under it. Until I have a means of measuring whilst on the water this is just theory....
Title: Re: Water Inlet
Post by: glennb2006 on December 09, 2007, 01:42:12 am
Correct. The water temperature now at the local lake is circa 8Deg. So that's why I am running a cold water set up. If it gets to 20 degress then I will change the way it runs, but not yet.

I have to run restrictors to reduce flow in the cooling lines to let the engine get warm.

Glenn
Title: Re: Water Inlet
Post by: martno1fan on December 09, 2007, 06:05:57 am
theory sounds ok but i doubt you will see much if any diff in performance but who knows how would you know?.I doubt ill bother to be honest,i can see why a racer might try these things though.
Title: Re: Water Inlet
Post by: w3bby on December 09, 2007, 11:12:40 am
Not just a performance issue, if the engine never gets up to its optimal temperature then you have accelerated wear, piston, cylinder etc.
Title: Re: Water Inlet
Post by: martno1fan on December 09, 2007, 12:42:36 pm
ok so if thats the case why doesnt everyone do it?its the first ive heard of it thats all.
Title: Re: Water Inlet
Post by: glennb2006 on December 10, 2007, 02:28:32 am
Hi Martin,

maybe some do and do not mention it!!

Best option is the one Ian adopts - when the ice forms, retire the boats for a few months!!

Ian is dead right on my logic behind the cold weather set up, and also there is some Methanol burning history and experience behind it too.

Think of it like this, if you are driving your car, and you see the engine temperature has not moved as your car has only gone half a mile or so down the road, you are hopefully not going to floor the throttle and thrash the engine, if you did do this, I imagine that you would anticipate trouble in the not too distant future.
Same with the model engines. More so on the Methanol as the nitro does not burn unless the engine is hot enough.

Comes down to mechanical sympathy.

Glenn


Title: Re: Water Inlet
Post by: martno1fan on December 10, 2007, 12:12:59 pm
i can see where your coming from guys ive not run my boat for a few weeks so cant say if the cold has affected it yet though.Might get her out in the new year once ive moved the motor forward and removed the weight from up front.if its cold ill maybe change things a bit,would you suggest smaller tubing for the motor maybe to restrict some water flow?.the pipe is easy to change over its not like i dont have enough bloody tubing  {-).
Title: Re: Water Inlet
Post by: glennb2006 on December 10, 2007, 04:59:18 pm
If you want to try it there are a couple of options.

1. Insert a small dia section of brass tube into the cooling line to restrict flow.
2. As you suggested, use smaller diameter cooling line.
3. Pinch the tube with a tie wrap or similar.
4. You could go to one pick up, run through the pipe, to the header then round the motor, just for the cold weather. Lots of choice, and this last one still might needd restriction to work well.

Why not try to remove the weight from the hull first, then move the engine forward if it is required? Removing the weight will most likely free up the boat a lot and gain you considerable speed. Free performance!!

Getting closer to my magic 60 figure on the Panther now by the way!!

Glenn

Title: Re: Water Inlet
Post by: martno1fan on December 10, 2007, 06:30:12 pm
Yea i did think of trying the boat as is but she is a bit heavy at the back so im a little scared to be honest,im sure the speed will be a lot better but i think she will be to flighty.Wont get her out befor exmas so i thought why not just move it now ready for the new year.I might hold off doing it just yet and see if i get a chance to run it and see what happens .Glad to hear your Panther is close to your magic number thats good ,look forward to the video mate.A local fella just contacted me hes bought Daves mercury cat with a zen 7 that thing should motor so were gonna hook up sometime.This is his first boat ,hopefully it wont scare him too much lol  :o.
Title: Re: Water Inlet
Post by: glennb2006 on December 10, 2007, 08:30:21 pm
Go for it, the throttle goes both ways, you can always back it off if it gets out of shape too much....


(Advice I should try to take on board sometimes...)

Glenn.
Title: Re: Water Inlet
Post by: martno1fan on December 11, 2007, 12:13:00 pm
Go for it, the throttle goes both ways, you can always back it off if it gets out of shape too much....


(Advice I should try to take on board sometimes...)

Glenn.
yea i think ill test her out as she is first and see,maybe a little negative on the stut will help a bit.time for a bit of testing i think  ;).
Title: Re: Water Inlet
Post by: Stavros on December 11, 2007, 09:43:39 pm
Hi Guys,

We've had notification of some unsafe / untested advice on this and other OMRA replated topics.

Please may we remind ALL Mayhemers that they must make it clear that any modifications or suggested changes offered are personal recommendations and not hard and fast fixes... unless of they have been tried and tested by yourself.

Along with with, if offering suggestions that may be difficult to "undo", please state clearly any possible consequences of recommend action.

Stavros - Topic Moderator.
Title: Re: Water Inlet
Post by: catengineman on December 11, 2007, 11:06:57 pm
Hi guys,

I have not got any of the farst craft you chaps run but I have been reading this thread with interest. restricting the water flow on your engines is a very easy and adjustible item.  pop down to your local aquatic supply shop and get some air pump valves. these are adjusted by screwing down or up a tapered threaded valve. I think it would give you the adjustment you are after depending on weather conditions.

Now to throw some ideas to increase power which I dont know if it would work on model size engines but yes you need the cyl temp to be hot enough but then colder intake air gives out better performance (intercoolers)
could you have the first influx of your cooling water run around your intake filter then to the exhaust then to the jacket then out or am I getting this ALL wrong.
Forgive me for my ignorance of your type of craft I'll keep quiet if you think I should :-\

R,
Title: Re: Water Inlet
Post by: glennb2006 on December 11, 2007, 11:32:54 pm
Not at all Catengineman. You are correct in your statement, when the air is cold and damp is when the best power is made, most of the motors we use are unfiltered on the air inlet, the carb is open into the hull.

Not sure charge cooling would be beneficial, unless, of course, forced induction were being used.

Speaking for myself, all ideas are welcomed.

Glenn
Title: Re: Water Inlet
Post by: w3bby on December 12, 2007, 12:08:18 am
Hi Guys,
We've had notification of some unsafe / untested advice on this and other OMRA replated topics.
Thanks for that however this is a discussion forum, if someone believes a certain piece of information is unsafe then they should post in the thread, that way it reaches all that read the thread. Generalisations such as this do not promote discussion and do not highlight the allegedly suspect/unsafe items.

Other than that, good reminder however I believe that the gist of what you are saying is understood by forum members the world over.
Title: Re: Water Inlet
Post by: martno1fan on December 12, 2007, 12:43:20 am


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