Plumbing

[Jetaholic]

Well guys it looks as if my boat may be ready the beginning of next month for rigging. Was coming up with a way to plumb the motor and think I've got it right. Figured I'd post here and let you experienced guys see it and let me know if it needs any changes and what not.
http://www.***boat.com/forums/attachment.php?attachmentid=21578&stc=1&d=1168303037

[jbone]

Is there a reason why the sand strainer would not go first, directly from the pump supply?
I say that because those valves have a way of getting filled with sand and clogging.
J

[Jetaholic]

Is there a reason why the sand strainer would not go first, directly from the pump supply?
I say that because those valves have a way of getting filled with sand and clogging.
J
No...just where I thought to put it. This is why I posted this here...thanks for that tip.
I guess my way of thinking was that it would strain out stuff from the garden hose supply as well when I'm runnin' dry on the trailer. But it can be moved.

[Fire Water]

I didn't see any plumbing for an oil cooler. If you plan on making any long runs I would strongly suggest putting in an oil cooler. Jets are noted for having low water temp and high oil temp. My cooling water for the engine passes thru the oil cooler first. This way the incoming water is preheated so I can avoid thermal shock when running in cold water. I also use an Earl's sandwich style oil thermostat to keep the oil temp consistant. From the oil cooler water outlet my water goes to the engine and I use a bypass thermostat. Make sure you have both a water temp gage and an oil temp gage. Just my .02.
Almost forgot. Are you going to use a pressure regulator? High block pressures can cause major problems. I regulate my system to 16 psi.

[Heatseeker]

You might consider using only one overboard from the engine. The reason I say this is that it will keep the water in the engine a little longer(allowing a little heat build up) and provide a little pressure in the block to help purge the air pockets. If the outlets allow more volume to flow than the inlet does, you may not build any kind of block pressure and you may experience "hot spots" in the engine. Just my theory...
Also, I've found that the exhaust metering valve wasn't needed. The Bander-valve has some very small passages restricting the flow already. I like alot of water to help keep the chrome on my pipes from getting discolored. Most guys still run the valve, but I left mine out without any problems.
Otherwise, you got about the same thing as I do going on.

[Jetaholic]

I didn't see any plumbing for an oil cooler. If you plan on making any long runs I would strongly suggest putting in an oil cooler. Jets are noted for having low water temp and high oil temp.
I hadn't planned on putting an oil cooler in, but I have been known to want to do some long runs so I might actually consider doing that.
Almost forgot. Are you going to use a pressure regulator? High block pressures can cause major problems. I regulate my system to 16 psi.
That's what the water bypass valve is in the schematic.
You might consider using only one overboard from the engine. The reason I say this is that it will keep the water in the engine a little longer(allowing a little heat build up) and provide a little pressure in the block to help purge the air pockets. If the outlets allow more volume to flow than the inlet does, you may not build any kind of block pressure and you may experience "hot spots" in the engine. Just my theory...
Hadn't thought of this...good advice.
Also, I've found that the exhaust metering valve wasn't needed. The Bander-valve has some very small passages restricting the flow already. I like alot of water to help keep the chrome on my pipes from getting discolored. Most guys still run the valve, but I left mine out without any problems
This is also very good to know. Thanks.
Keep the cool tips comin' guys!

[squirt]

I run the metering valve, I don't like alot of water out the pipes tho. I'd plumb it in and run it the way you choose, wide open or pinched down. Yep sand will stick the valve.........and fill an engine block too! If ya ever have a problem with a stuck valve just get ahold of me and we'll get it fixed.
Don

[sanger rat]

Supply water to the banderlog valve before the bypass.

[Jetaholic]

Supply water to the banderlog valve before the bypass.
Yep...that's how it is in the diagram. Figured that so that you get full pressure and can turn the pressure down if need be.

[squirt]

Supply water to the banderlog valve before the bypass.
Doh:redface: :redface: :redface: missed that

[sanger rat]

Yep...that's how it is in the diagram. Figured that so that you get full pressure and can turn the pressure down if need be.
In your picture you have it after the bypass. Yes, you want full pressure.

[steelcomp]

I know this can be controversial, but think about filing the block from the two drain holes in the bottom/ sides. Drill and tap to 3/8 pipe, and use a #8 fitting. I've done this for years, and never had a problem. More even heat distribution through the block, and it keeps what crap might be in there, in suspension. I've never had a block fill with sand.
Also, you really don't need a bypass valve, just run a regular 1/2" NPT water pressure regulator, and save some plumbing.
Just a thought.
Sanger Rat...I like your signature. :D

[squirt]

I know this can be controversial, but think about filing the block from the two drain holes in the bottom/ sides. Drill and tap to 3/8 pipe, and use a #8 fitting. I've done this for years, and never had a problem. More even heat distribution through the block, and it keeps what crap might be in there, in suspension. I've never had a block fill with sand.
Also, you really don't need a bypass valve, just run a regular 1/2" NPT water pressure regulator, and save some plumbing.
Just a thought.
Sanger Rat...I like your signature. :D
Dang steel never even occured to me to plumb incomming water there....kinda like that idea;) And yep like that JBG line too just next time watch out for those quick right hand turns:eek:
Don

[sanger rat]

Thank Steel.;) Just wish I could have been there to see it.:D

[steelcomp]

Thank Steel.;) Just wish I could have been there to see it.:D
Every dog has his day. :D

[steelcomp]

Dang steel never even occured to me to plumb incomming water there....kinda like that idea;) And yep like that JBG line too just next time watch out for those quick right hand turns:eek:
Don
Don, I'm going to pre-empt the typical arguement here...usually someone will say that engineers designed the engine to be fed from the front, and that's true...for an enclosed circulation system where the water and engine reach a common operating temp, but that's not the case, here.
Yeah, those quick shutdowns in rough water can be a biOch! I thought I was going swimming. :jawdrop: :D

[Jetaholic]

In your picture you have it after the bypass. Yes, you want full pressure.
You know what? You're right! Gotta change that. :D

[Wicked Performance Boats]

Steelcomp, If you feed the block with water on the side of a bbc, what makes the water go around the front 2 cylinders on each side? there is no hole in the front of the head gasket to circulate whats there up into the head. How does it keep all the cylinders even temp? standard bbc head gaskets are meant to have the water flow in the front down in between the cylinders, up to the head and foward and out at thermostat housing. Do you punch holes in the head gasket at the front? Pat

[drysumpjet]

[QUOTE=steelcomp;2330081]I know this can be controversial, but think about filing the block from the two drain holes in the bottom/ sides. Drill and tap to 3/8 pipe, and use a #8 fitting. I've done this for years, and never had a problem. More even heat distribution through the block, and it keeps what crap might be in there, in suspension. I've never had a block fill with sand.
I like adding water down there too but I do it a little differently. In addition to the water piped to the front, I add water to the back too by silversoldering brass bungs on the rear freezeplugs, (between cylinders 5&7 on the left and 6&8 on the right)
My water exits in multiple places too. It exits in the typical thermostat location and also at the the rear of each cylinder head...at the water block offs on the intake manifold. (I drilled and tapped the rear intake manifold blockoffs)
Totally agree on the importance of more heat distribution, at least for me, as these modifications have resulted in more consistant spark plug readings.
I also noticed that while cruising, I can feel (by hand) a more even temperature around the block. Too hairy to do while at speed!--watch out for those belts!

[Wicked Performance Boats]

Drysumpjet, Is this application you have a race deal or an everyday river cruiser? I've always tried to run a constant temp in the block so it will promote better ring seal. Isn't what your doing kinda like removing the thermostat in a car? If the water flows too fast and dumps half before it makes it half the way through the system, How does that promote good ring seal? Do you build tighter piston to wall clearance? Do you suffer from blow by and have to have a breather catch system? I always thought that with a constant cold water source like a boat has, that we should have head gaskets that are solid[no flow between block and head] and we make the block water regulated to promote good constant water temp for ring seal, and straight cold water to and from the heads to keep detonation to a minimum. BL:idea:

[drysumpjet]

Wicked, it's a lake cruiser. My goal with all the water inlets and outlets is an attempt to get the rear cylinders cooler/front cylinders warmer by introducing and exiting a portion of the water towards the end of the block. To answer the blowby question--since my engine is drysumped, the scavenger pumps also pulls up to a 12" vacuum on the crankcase (crankcase sealed) and the engine is "vented" thru the top port of the oil tank. I monitor crankcase vacuum, noting a substaintial loss of vacuum may indicate a ring seal problem.(no loss yet!)
As far as the water flow question--excess water is diverted by a pressure relief valve to the intercooler. The inlet of this valve relieves pressure just after the the pump. This works out as this relief valve opens once it's off idle, so that the block temperature doesn't drop (as it does in most jetboats without a thermostat) and closes at idle so the intercooler warms up.
Being a lake cruiser which is subject to long hard runs, it's also got an oil cooler, and it's water side piped between the above mentioned relief valve and the block. The oil temperature is controlled by a manual 3 port ball valve which can be positioned to bypass water as needed to control the oil temperature.
Note, this boat was in the magazine in the Nov/Dec 06 issue, on pages 132-135.
Wicked, your post bring up a question that I have been wondering about for years---Many newer performance cars are employing "reverse cooling" whereas the coldest water enters the heads first and exits thru the block. This is suppose to reduce detonation. My question is has anybody done this in a jetboat? Would it be practicle to attempt this or would the air pockets in the heads be an issue?

[SB]

Dang, never thought about this. Corvette started doing this a few years ago, and they thought they could safely increase compression by 0.5.
Good question.
I run at about 130, nice and cold, so I guess it wouldn't matter much to me. Would you need a different head gasket?

[Wicked Performance Boats]

Dang, never thought about this. Corvette started doing this a few years ago, and they thought they could safely increase compression by 0.5.
Good question.
I run at about 130, nice and cold, so I guess it wouldn't matter much to me. Would you need a different head gasket?SB, You can do this without special headgaskets just by reversing the flow into the motor and out but you'd have to be careful because if the outlet was to low or too big, the motor would be empty everytime you started it up and air pockets could happen. I think, but I've never tried it, that if you had the overboard hose rise to the same level as the feed hose to the motor, you'd be ok. Once the motor filled with water ther'd be no air pocket. Budlight

[drysumpjet]

Wicked, I like your solution to prevent air pockets with reverse cooling. It probably wouldn't hurt to add an air bleed here and there, especially while this concept in a jetboat is in an experimental stage.
Thanks SB, didn't realize CR was increased with reverse cooling.
BUT
Another question with reverse cooling (other than the air pocket issue) is since the heads will be cooler, will this cause addition condensation to form underneath the valve covers?
In prop boats with closed loop cooling systems, does any of those employ reverse cooling...yet?

[widowmaker]

I've been running a thermostat kit with the bypass from rex. I love it. Seems to run 160 all day long no matter what I do. Oil temps are around 210 +/- 10 degrees.
I wonder am I getting everything to an even temperature at that point?? How many of you guys are running the thermostat/ bypass kit???
I like the idea of filling the motor from the bottom to reduce sand settling in the block.:idea:

[patrolman808]

Not to hijack the thread, but where can I get one of the sand strainer canisters?

[HBjet]

http://www.***boat.com/forums/attachment.php?attachmentid=21578&stc=1&d=1168303037
How much pressure can one of those strainers handle? 300+psi?
I would run a pressure regulator off the pump first (have a hose between the two, not mounted off the pump) and when you want to run a garden hose to it, take a old hose and cut off 3 feet from the female end. Then get yourself a push-on adapter with hose clamp that will thread on to the inlet side of the regulator. Then attach another garden hose to the one you modified. This way you won't have to install another piece of hardware for limitied usage. Unless you run the boat in the trailer all the time.
As for the strainer, I think it is useless and I run at the river where there is sand all over. So ditch that!
Then I would run to the motor, and as the water exits the motor, split it and run half to the banderlog control valve and the other as the water dump.
That is how I would do it.
HBjet