Marine thermostats

[snake321]

good thing you mentioned the sand. I think that the gate valve temp. regulating system doesn't let the full water pressure through to clean the system of sand. I just pulled my 454 apart and there was almost 3 full large metel dustpans of sand in my motor. That's not counting what came out when I ran the hose through it 2 times.

[Jetaholic]

good thing you mentioned the sand. I think that the gate valve temp. regulating system doesn't let the full water pressure through to clean the system of sand. I just pulled my 454 apart and there was almost 3 full large metel dustpans of sand in my motor. That's not counting what came out when I ran the hose through it 2 times.
Exactly. It cuts back the actual amount of water flowing through the block, which can hinder being able to push all the sand out. I'll be running a water bypass valve to drop the incoming pressure to keep from overpressurizing the block, but I will have the same amount of water flowing through the block as you would with no gate valve...just not under so much pressure.

[Oldsquirt]

Exactly. It cuts back the actual amount of water flowing through the block, which can hinder being able to push all the sand out. I'll be running a water bypass valve to drop the incoming pressure to keep from overpressurizing the block, but I will have the same amount of water flowing through the block as you would with no gate valve...just not under so much pressure.
Pretty sure you will also see a drop in flow through the block, after all that is how the pressure drop is accomplished, bypassing some of the volume from the pump out your bypass line.
Best solution for you guys running in sandy, silty water is to occasionally flush the block. Just pull the block drains and run water through the engine from a garden hose.

[OverKill]

Pretty sure you will also see a drop in flow through the block, after all that is how the pressure drop is accomplished, bypassing some of the volume from the pump out your bypass line.
Best solution for you guys running in sandy, silty water is to occasionally flush the block. Just pull the block drains and run water through from a garden hose.
where are the (block drains) on a 454 Chevy???

[Oldsquirt]

Just above the pan rail, between the middle two cylinders.

[TAPPED OUT]

Okay I am going to forget the thermostat, and just build my motor clearances and tolerances for cold water conditions the way a jet boat motor should be built for and run that over pressure bypass. Remember if the motor is built right, the cooler the motor the more power you will recieve, also the gas will burn since you can advance the timming allot more without detonation. Thanks for the input.

[Aluminum Squirt]

I run a thermostat and I run in a little sand. Okay, I run my boat into sand bars occasionally to the point where I have to get out and kick it back in the main channel to get going again. Never had a problem with my thermostat. I run a pressure by-pass->through an oil cooler->into the block->through a Rex thermostat/bypass->dumped out the side. Dry headers. No doubt there is sand in my black but I have never had a problem with temp/flow, holds 180 for about 20-30 minutes of WOT, seems to work pretty good. The Kiwi's run a sand trap if you are really worried about it. I would take a serious look at running your motor at 160-180 with as few fluctuations as possible. These are automotive motors and they are designed to run at 180. I'm sure a little machining of your clearances will help but the factories put a lot of reasearch into making these motors run at 180, I think running them there makes more sense. There are a lot of things going on here besides your main clearances; there's metal expanding/contracting, fuel atomization issues, etc etc. I'll probably get flamed for this but I'd bet most of the 45-65 MPH recreational boats are running whatever system works, that's fine, its low stress. I'd bet he higher speed/HP/performance boats are running a little bit finer tuned system and are keeping their temps in the 180 range. There's a reason for this. But that's just my $.02-Aluminum Squirt

[squirt'nmyload]

First of all, if you are worried about gas mileage, you shouldn't have a jet boat.
.
LMAO

[pw_Tony]

So I need to barge in. I have a 460 with a Berk on it and I've changed my headgaskets twice already. The gaskets didn't even appear to be blown though? I was talking with another experienced jet boater that had the same set up and he told me that the berk pushes 90psi into the motor, which a BBF can't handle. He told me to regulate the water for engine temp and so water doesn't get into the motors.
You guys ever heard of BBF's holding the pressure from the pump? Thanx

[OverKill]

So I need to barge in. I have a 460 with a Berk on it and I've changed my headgaskets twice already. The gaskets didn't even appear to be blown though? I was talking with another experienced jet boater that had the same set up and he told me that the berk pushes 90psi into the motor, which a BBF can't handle. He told me to regulate the water for engine temp and so water doesn't get into the motors.
You guys ever heard of BBF's holding the pressure from the pump? Thanx
Ya know I believe this is a question for Squirtcha? He has a BBF with a Berk setup. I believe he has some photos of his plumbing setup also. You might want to PM him and ask what his numbers are. JMO:idea: