help with boat plumbing

Hey Guys,

I have a ski boat (327 chev) i bought second hand and its about 95% complete. However i am having some problems with the plumbing of the boat and the v-drive. I have called the previous owner but he is also unsure of how it goes. Basically at the back of the motor is the pump and one side is hooked up to where you can put a garden hose to flush it, the other side has an inlet but nothing currently hooked up. I can run the engine off the garden hose and it flows through and out the outlets of the transom pipes, so that is fine. However i am not sure about the rest of the plumbing.

There is 2 pickups from the base of the boat.
I can see a couple of ways of running the plumbing.

1. run both pickups to the spare inlet on the back of the engine block and then split one side to go to the inlet of the v-drive.
or
2. run one pickup to the engine and run the other to the v-drive. However im worried the engine may overheat as one pickup may not be enough water?

Also where is the outlet of the v-drive usually plumbed back to? there is 3 bung holes at the rear of the boat and also a hole at the rear top right of the hull (above water level) that i suspect may have been used before for a bilge pump. It doesnt currently have a bilge pump but i will put one in. Can i run the outlet of the vdrive and the oulet of the bilge pump into one pipe and out the above water level hole at the back? or should i use one of the 3 bung holes?

If anyone can help out it would be much appreciated. I can try and explain better or take pics if thats easier.

 

I don't know for sure, but I suspect after cooling the V-Drive, the water should go thru the Engine for additional engine cooling.
If water is not moving thru the V-Drive it will not cool it.

 

thanks mate... do you think that the water from the return of the vdrive would be too dirty to plump back into the motor?

 

Discharge water should be relatively clean. What is the make and model of the V Drive ?

 

Pics would be good. I'm confused.

 

thanks guys, ill take some pics today and post them up

 

ok took some pics...

There is 2 pickups at the bottom of the hull:



That turn into 2 fittings inside the hull:



This is the pump on the back of the block. It has one inlet free (has an end cap on it in the pic. and the other side is hooked up to a tap fitting so it can be flushed.


It then runs up the block and out the heads:

From the heads it hooks up to the over transom exhausts and dumps

The vdrive also needs to be cooled and has an inlet on each side:



There is a hole in the right hand side near the rear that i assume was used for a bilge pump:


The engine is a 327 chev and im not sure on the vdrive.

My question is how to run the pumbing.

I.E Do i run both the pickups to one side of the pump (the blocked off side) and tap into one pickup for the water of the vdrive.... or do I run one to the motor and the other to the vdrive or would that starve the engine of water? Do i run the vdrive waste back into the motor or should i run it out with the bilge water.... Should i remove the tap fitting and run into both sides If so how do i flush it?

etc etc... so many combinations but i was hoping a few people might be able to give me ideas as to how there's is setup.

Thanks in advance.

 

Well the pics answer one question I had, how you had two inlets to your pump. The pump only has one inlet.

Don't know much about speed boats even not a lot about different types of boats just the couple I have owned.

But, I know quite a bit about pumps and since you don't seem to be getting any help from anywhere else may I put in a few bobs worth.

I have only one inlet at the bottom of my boat but my boat is often overtaken by boys on boogie boards. The only reason I can see for having two is to prevent drag on one side of the boat especially as it is a speed boat.

I would put seacocks on the inlets, I have a plastic ball valve on mine. If you burst a hose it won't flood your boat if you can turn them off easily. Also you have a flush inlet attached to your pump. If you don't have seacocks the water could go straight through the tee and out the inlets and not go through your engine. At least with the seacocks closed during flushing you know you are getting 100% of the flushing water through your engine. Don't forget to turn your flushing valve off and your seacocks back on before using your boat.

From the seacocks the hoses would join together and go into the pump inlet. From the pump outlet I would go into the engine via a hose that is Tee'd off to the drive.

If you are worried about starving the engine of cooling water, put a valve between the pump outlet and the drive. Keep an eye on your engine temperature gauge, and if it does climb, I doubt it, start closing the valve to the drive to channel more water into the engine.

The water from your drive exit through the exhaust if you had a fitting for it but you said there was another water outlet, probably where the drive water goes.

You mentioned something about a bilge pump, not sure what you mean but I don't think that the bilge water from the bilge pump would be incorporated with the engine cooling water due the problem of pumping dirty water back into the engine when the engine is not running. I would keep them separate.

Hope it helps.

 

thanks mate much appreciated. the valve on the drive sounds like a good idea and so do the seacocks.

Do you think i could filter the water from the drive outlet back into the motor? or would it be too dirty? im just trying to get the drive and motor to expell both out the same place.

If anyone else has any input it would be much appreciated.

 

I might need a bit of explanation here.

By drive we are refering to the transmission on the end of the engine that drives the prop shaft. If so why would it be dirty.

It should be cooling pipes running through the oil or in my boat it is an external heat exchanger. If the water is coming out of the transmission dirty it might be contaminated with the oil ie. you have a ruptured cooling pipe in the transmission. You will be pumping water into the oil which is mixing and being forced back into the cooling water outlet.

May I suggest taking it to a boat mechanic and having it checked out.

 

V Drives sometimes have water lines connected to pass water THRU them for cooling. Engine transmissions DO NOT pass water thru them, but instead cool the oil by circulating trans oil out of the trans to a cooler and back to the trans. The trans cooler is normally connected in the Engine cooling inlet water line.

If your V Drive is intended for water cooling, the discharge water will be as clean as was when it entered. If is Not, you have a problem. Cooling water is NOT supposed to co-mingel with lube oil.

 

Just realized your pump has TWO inlets. Sorry I didn't pick this up earlier. Apparently they are needed or they wouldn't be there. I would Plumb EACH pick -up to the pump exactly the same. . If your Transmission needs a cooler (most do) put a Trans oil cooler in either of the INLET lines and plumb oil lines.

Check with someone familar w. V Drives for plumbing. Lines appear to be TOO SMALL for water lines - may be oil lines for remote cooling like most Transmissions.