Dirthead

Barronbob,

What you are saying makes since. I am not really sure why my rossover has an outlet to feed into the thermostat housing... unless it is to insur that the headers are always reciving a constant supply of water. In any case this may be the problem. Let me ask you this. If I remove the crossover hose to the thermostat housing (by plugging both ports) and force all of the water through the engine and out the thermostat, will having (3) 1/4 inch holes in the thermostat be enough water to cool my headers?

Currently the water flows into my headers this way... From the thermostat housing into the header, out of the header into a T that has a valve on it to dump excess water out of the boat ( these valves are 7/8 ths compleatly open, essencially dumping most of the water out of the boat and allowing only about 1/8 th of the water back into the exaust to cool the rubber couplers. It is set up this way to keep excess water in the exaust and to prevent reversion).

My question or concern is this. When the thermostat is open, I should be getting plenty of water out of the T's and an adquate amount into the couplers. However, when the thermostat is closed and I only have the water coming out of the (3) 1/4" holes, will there be enough to adquatly cool the couplers with the valves onthe T's dumping most of the water out the bypass? I mean I risk the issue of reversion on on hand, and burning up the rubber couplers on the other.

Thanks for the help!

baronbob

I can't answer your question as I am not familiar with the set up you describe. But I can tell you this. My rubber couplers have done fine however they do see all of the (3) 1/4" holes have to offer. What I can suggest is that you temporarily remove the thermostat, plug all hoses between the block and the crossover, have the only cold water inlet through the crossover, run the boat to see if your over-heating problem has gone away. Then address the cold thermostat flow to your headers with respect to your reversion potential. I am not sure of your exact configuration but if you have a direct connecting hose from the crossover to the top of the thermostat, it may be flowing too much. Place a valve in this hose, run the boat and begin to curtail the flow until the block begins to cool. If you see cooling beginning to take place because you are pinching off this return path and this might prove my theory. You also would not have to drill holes as this hose/valve combo will act as a variable by-pass allowing you to adjust flow pressure during hard runs and provide by-pass during cold start. I hope this is not getting too complicated.

Dirthead

Thanks for the help!

I will try this this weekend. One thing I have never understood is the need for a thermost in a boat at all. I have always been told that an engine needs some heat to run at opptimal temperature however have never been given a reasonable explination at to why. I am not arguing the fact that some temp is benifitual tot he engine to reach peek erformance. HOWEVER, how much is one reallly sacraficing on a 475- 500 HP engine by removing the thermostat cmpleatly and keeping the engine very cool? Is the sacrafice of a cool or even cold engine simply a small performance drop or is it a BIG drop..... or is the negative of running no thermostat simply more than a loss of performance (engine failure of some sort)?

I am just tired and quite simply worn out of 3 years of never ending fustrations with this boat. If I loose some performance but have the piece of mind that I am not going to cook the engine, so be it. I just want to go to the lake, have fun, and not worry. After I cooked the engine the first time, I rebuilt it with reliabilitly #1 and added performance a distant 2nd.

baronbob

I understand the frustration. You don't want to hear what supercharging has done to frustrate my happy boating life. Here is why you do need a thermostat. Your engine fit tolerances are centered on an operating temperature, piston fit, ring fit etc. If you run cooler than spec parts will either be too tight or too loose causing wear. Please do not loose confidence as I do believe we are on to something here GOOD LUCK and keep the faith. If you need a boost or just want to have a conversation about what you are about to do please call. By the way I am not in the marine business. I am an engineer who deals with heat every day. Good Luck and Happy Father's Day if you are one.

Dirthead

Thanks alot. That means a bunch. I am a proud pa pa of a 5 and 2 year old, Hopefully Sunday will be an enjoyable Fathers Day at the lake for mom, dad, and the kids! Happy Fathers day to you also.

hoozeyurdaddy

dirthead and baronbob
as of right now, my thermo housing has 3 ports, 2-3/4" outlets for exaust water and 1 #8 fitting in the top, at this point i'm not sure what the fitting in the top is for, the housing didn't come with a diagram,If I cap off the #8 fitting and run a non drilled thermo it destroys my water press gauge (40+psi) but when the thermo opens all is good until it closes again. If I drill 2 1/4" holes in the thermo, press is still a little high but workable, but the engine will not come to temp.
Now if I hook up what I think is a water supply for the exaust,
the #8 fitting on top of the housing, with a 1/2" hose from the waterpump crossover, water pressure becomes normal 15-20psi, the thermo will not open and the engine will overheat, with or without a drilled thermo, I'm not sure if it's because it equals the press. in the block or if the cold water is closing the thermo, I would think if it was equalizing press. I would see it on the gauge.
I am wide open to suggestions on this issue. I think baronbob may be onto something by restrcting the flow to thermo housing. merc offers a press. releif valve I'm going to look into.
you also need engine temp to evaporate condensation that an interal combustion engine creates.
Its been great chatting with you 2, hope you both a great fathers day.

Dirthead

hoozeyurdaddy,

The #8 fitting you are refering to in my oppinion is to have a hose from your crossover to the thermostat housing. This is with the assumption that you are using the (2) 3/4" outlets on the thermostat housing to feed your headers. IF you do not have this hose connected, Everyone I have talked to says it is a HUGE no no to ever run a thermostat even with a few small weap holes in it. The weap holes simply do not allow enough water through them to cool your exaust and/ or couplers. From what I have been told, if you are not running a hose from you crossover to your thermostat, you should remove the thermostat. This weekend I am going to try to remove the thermostat and plugth crossover to thermostat hose and see what happens. I called CP and spoke with them on this. They do not think that the crossover to thermostat housing hose allows anough water through it to cause the problems (not allowing enough water through the engine by providing an easier path of flow or by messin up the thermostat because of the cold water hitting the top of the thermostat) that we are guessing to be. Their position is that the fitting on the crossover that suppies this hose is 1) smaller in diameter, 1/2" and 2) on the top of the crossover tube thus it is not like the inlet water hose has a direct flow path into this hose. The water coming out of the supply hose comes into the crossover tube, then has to bake a tight 90 degre turn to go up the crossover to thermostat housing hose. They claim it allows enough water through it to cool the headers, but not enough to cause these issues. Having sold thousands of them, they feel if this was a problem, they would be hearing more talk about it. I understand their point, hosever I am going to try removing the stat and the hose and see what happens.

If this fixes the high temp issues, then I have though about making a set of plates with various holes in them to put where in place of the thermostat. THis would force the water through the engine, would allow constant water to pass to the headers, and may restrict the water flow a bit so that some heat is generated and kept in the engine. The size of hole in the plate would be determined by the tempeture that the engine reached and the PSI that the gage shows at WOT (keeping the PSI at 22 PSI).

What do you think?

baronbob

You guys are really thinking now. The hole in the top of my thermostat housing has a temp sender in it. I would be careful with a plate for the thermostat might present other problems related to pressure over engine speed range. When I first installed my procharger I managed to blow the stock intake manifold gaskets and got milky oil as a result. Lots of milky oil threads on this forum. If you can make the thermostat work you are better off. Here is yet another idea. I have a heat exchanger on board for my domestic hot water. I rout hot water around the thermostat by taping into block water just below the thermostat in a factory port, out to the heat exchanger and then back to the top of the thermostat housing and thus to the headers. If you have ports near the bottom of the thermostat then plumb in a by-pass hose and put a ball valve in the flow. With this design you don't see the cold water coming from the crossover, you get to keep the thermostat action, no holes in same and you can adjust the amount of by-pass. BRILLIANT (I hope).

baronbob

I can't believe I am sitting here, 5:30 AM typing this post. I awoke earlier this AM thinking about your situation and mine. My stupid heat exchanger hook-up is what has kept me from experiencing some of the problems you two are experiencing. After I blew intake gaskets in connection with my Procharger install I hooked up my heat exchanger, not knowing that it in fact would solve my temp. Control problem as well. Here is the theory. Make the only cold water inlet to your crossover with no way around it. I.e. Block the hose outlet now connecting to the top of your thermostat. This means that all cold water will have to travel through the block. Do not drill any holes in your thermostat and do have it installed. Find an outlet near the bottom of your thermostat and plumb in the same size hose fitting that you once had coming from the crossover. Once in place connect the other end to the top of your thermostat. Cool water is now forced through your block under all thermostatic conditions (open or shut). The flow that you previously had will still be there only now it will come from within the block allowing the thermostat to function properly. As the motor warms up the thermostat will open and lessen the effect of your by-pass but still be flowing into the dump scheme. I have a ball valve on my by-pass because I wanted to pinch off the effect of the bypass to keep my engine warm in start up, idle as well as under way. I suggest the inclusion of the ball valve but you may want to be convinced of proper cooling first. In summary: take the hose from the top of your thermostat and disconnect it from the crossover. Plug the crossover hole. Take this hose still connected to the thermostat and find a suitable fitting near but under the thermostat. Hook it up and enjoy a cool running boat. If the block does not come up to temperature install a ball valve in the newly created by-pass and turn it down slowly until you see the temp coming up. This system will work "I GAURENTEE IT" AS THEY SAY ON THE MEN'S WHEREHOUSE COMMERCIALS. I hope either or both of you are able to try this, AGAIN HAPPY FATHER'S DAY Bob

hoozeyurdaddy

Dear Dirthead and baronbob
Yesterday my boat burnt to the ground, yes it was an accident, My right hand could not let go of the bic lighter I was holding on the fuel line. Thankfully it was insured.
Boy wouldn't that just brake your heart, (maybe-maybe not)
I'm sure there is a way to make this system work, ( I wish 1 of you would hurry and figure it out). the ball valve idea bob has is a good one, I respect what cp says, but why dont it work, If I connect the bypass hose to the thermo housing with a standard thermostat it overheats.
now that is how they designed it, why can't they tell us why it don't work? What are others doing different than me. I'm going to call teague racing and see what paul has to say, I will let you know
larry