Thermostat or no thermostat

['78 gt boat]

I have gotten a few different opinions. So I say to the group......... Thermostat or no thermostat. It's for my BBC. I found out that the plumbing is not right. This has been I hope the answer to the problem of water in the oil. Bought a new Bassett T and am getting ready to put it back together. Take the thermo housing off to check it out and it's gutted. It's a 4 port thermostat. Should I put a thermo or not. Should I just try it and then see what happens? HELP!! :mad: :mad: :mad:

[NELSON#109]

Some people dont like them, but i ran one on my bbc and loved it. the thing worked perfect. water temp was always between 160 & 170 if i remember right. i had a temp sender on the oil pan to, and it was always perfect too. i ran it in all sorts of lake temps & it always worked perfect. i would use one again if i had a lake boat. NELSON#109

[SmokinLowriderSS]

I'm not running one and regulate my engine temp to between 140 (WFO and 170 (idle) by restricting my water inlet with a gate valve. The valve would be needed anyhow with a thermo. I'm not so sure I'd want one as I've seen so many posts here of bypass springs jamming and other troubles leading to milkshakes of 1 kind or another (another reason I'll be running jacketed headers next year and not injected ones).
There's my side. :idea:

[Rexone]

I've seen so many posts here of bypass springs jamming and other troubles leading to milkshakes of 1 kind or another
Please elaborate as I've never had a thermostat bypass spring jam that I recall of out of several thousand in service over about 15 years. In fact inside the thermo housing there isn't anything for the bypass spring to jam against. It simply supports a valve against a tapered seat.
Bassett Tee Valves on the other hand will cause milkshakes when the spring fails but this has nothing to do with a thermostat vs. not a thermostat.
Also restricting water with a gate valve will many times result in overheating at idle to achieve 160-180º running temp. Not an ideal method of getting motor temp up IMO. This method is quite sensitive to lake temp as well.

[HammerDown]

8 years w/ the Rex Thermostat system...never any issues.

[Aluminum Squirt]

Run the thermostat and put on a pressure regulator or relief valve near the pump and before everything else, presto, no more milk shake and perfect temps. I run all kinds of sand through my system and no problems so far-Aluminum Squirt

[BobS]

Just got back from a week at the lake. I'm plumbed with a Rex thermostat kit, a bypass valve like you can get from Duane at Hi Tech and a Banderlog water valve. Ran dead nuts 180 degrees, idle, WOT, you name it, no milk shake and the best thing, I was able to keep my headers cool enough to keep from branding myself. Your mileage may vary.

[jtmarten]

I installed a Rex thermostat last year. Sits right at 165-or-so idling or WOT.

[76elimspecial]

I have gotten a few different opinions. So I say to the group......... Thermostat or no thermostat. It's for my BBC. I found out that the plumbing is not right. This has been I hope the answer to the problem of water in the oil. Bought a new Bassett T and am getting ready to put it back together. Take the thermo housing off to check it out and it's gutted. It's a 4 port thermostat. Should I put a thermo or not. Should I just try it and then see what happens? HELP!! :mad: :mad: :mad:
IM NOT AS KNOWLEDGABLE AS ALOT OF PEOPLE POSTING, BUT I DO KNOW I HAVE NEVER RAN ONE ON ANY OF MY 3 MOTORS AND NEVER HAD A PROBLEM. SET THE INLET ONE TIME AND HAS ALWAYS RAN 160 IDLE AND ABOUT 140 ON THE THROTTLE. EVEN UP AT WILLOW WHERE THE WATER IS REALLY COLD YEAR ROUND.

[NELSON#109]

like some others have said, you should also run a regulator at the inlet. also, regulating engine temp with a gate valve is the absolute wrong thing to do. thats like using duct tape in place of hose clamps. it has been done that way in the past, but you will not find any boat builders or good boat shops doing it, and they dont for a reason. get the thermostat kit, you wont be disapointed. i dont run one on my boat, but thats because it only runs long enough to get it down the 1/4 mile. i do however use a preasure regulator at the inlet. Nelson#109

[ANY&ALL]

Dude just call the # told you before ask away. I'll save around 10,000 dollars worth of motor work, kicking and screaming and bleeding on your self. We have the same boatand the same motor Call 209 267 5885 chad

[FHI-prez]

I've never run a T-stat in a raw water cooled motor. Nor would I. I wouldn't mind if Rexone set me straight here, but I think restricting the water flow at the end of the cycle through the motor seems less than desireable to me. If you get junk from the lake into your system (weeds, sand etc.) I wouldn't want to put a restriction there.
Besides, I see it over and over again. The temp is not accurate in a open system. If you want to compare to a closed system, your oil temp is a much better guage. If your temp guage is showing 140 deg, it's not the same as a closed system. All that means is that the water heated up from lake temp (around 80 deg lets say) to 140 deg. In a closed system the water is not 80 deg entering in the motor. Probably more like 120-130 depending. Your water temp guage in a raw water system should serve nothing more than a comparison to what it usually runs. The actual number doesn't mean crap. There is no comparison to a car water temp. :argue: Setting a Jetboat to run 180 water temp will probably lead to unnecessary flash boiling in the heads around the combustion chamber. I see no point.
If you think your motor is running too cool, adjust by the oil temp, not the water temp.
,
I suppose that if you run a strainer, bypass valve, and T-stat, it could work, but there is no antifreeze/boil to help protect from flash boiling. Keeping the water in the motor long enough to heat it up to 180 º (thus restricting flow) I'd think would only lead to more likelyhood of flash steaming in the heads. That T-stat will never open up as far as it would in a closed system because it has to keep the water in the motor much longer. It has to heat up the water 100º or more instead of 20-30º like it does in a car or in a closed marine set up. That means the water sits around the combustion chamber longer, with less flow to move the steam pockets.
I'd be willing to bet that if you get your lake water temp up to 180º showing on your temp guage, you are dangerously close to pre-detonation. Keep an eye for little black spots on your spark plug insulators, and good luck.
Just my .02
Nick
BTW, you guys that are running a raw water system and get water temp readings of 180º, what's your oil temp running? Just curious. Would like to know if I'm way off base here.

[SmokinLowriderSS]

My apologies Rex. Yes, the spring problems I have seen posted a lot have been Banderlog valves and Basset T's. I have a bad tendancy to overgeneralize at times, I need to work on that. Thx for the call on it.
I only intended to say in my post that I have a very simple system that fits, works well, has never overheated me (unless closed to far), has never in 27 years caused a milkshake or any other problem, and that I do not wish to make it more complicated (or troublesome).
A non-thermostated cooling system works great for me in Ks, Ok, Tx, etc all summer in lake temps from 60 to 90 From about May to October. I have only ever been out on colder water this spring (March/April breaking in my rebuilt 454) and, as expected, I did have to close it down just a bit to get above 110 running on plane. Had to open just a bit once May arrived as she wanted to get hotter than I keep her. I don't let her idle above 170, the powered temp drops to about 140. I doubt I have any hot-spot troubles. I also do not believe I am "damaging" my engine running her at these temps. The only reason my 454 needed the rebuild it got was that I replaced the rod bolts in the power upgrade so the rods/pistons had to exit the cylinders. I had no Cyl wear. I am not even .10 over after over 300 hard wrapping hours AND the cylinder hone. I do think running one arround 100 degrees (as I have seen posted) is not good on them either.
Running my Performer RPM manifold, I did elect to use the additional water lines (external) from the back of the heads to the outlet crossover (supposedly to assist head cooling according to Edelbrock).

[BigBlockBaja]

Im running a Kit similar to the Rex kit. I got mine from CP. But I love mine. Temps goes right to 180 or so all day. Im just wondering if the spring in there kinda acts like a pressure relief. Cuase im not running a regulator.

['78 gt boat]

Well........ bad news. I was going to order the Rex thermo housing and all of the XRP hoses and fittings until I brought the boat to Glen at PBS. He said the boat is veryy pretty but....... Since Olympic boat centers has sat on this problem for three weeks now and never changed the oil or did anything the cam is rusted, lifters are rusted, rods have rust on them and rust on one of the cylinders that we can see without taking the entire motor apart. Only the tunnel ram is off at this point. Now I'm looking at approx. $2500.00 for R&R of the motor and Olympic is not sure if they want to spend the money to fix it. They want to possibly just give back my $3600.00. :220v: :220v: :220v: :mad: :mad: I don't want my f____ng money back I want to "Float out with my boat out!!"

[Rexone]

I've never run a T-stat in a raw water cooled motor. Nor would I. I wouldn't mind if Rexone set me straight here, but I think restricting the water flow at the end of the cycle through the motor seems less than desireable to me. If you get junk from the lake into your system (weeds, sand etc.) I wouldn't want to put a restriction there.
The thermo unit really doesn't restrict anything when open. When the thermo closes the spring loaded bypass immediately opens (with very slight pressure) so water continues to flow through the exhaust unrestricted. I would be more worried about weeds getting caught in hoses or fittings than the thermostat and weeds would be a problem weather you have a themostat or not IMO.
Besides, I see it over and over again. The temp is not accurate in a open system. If you want to compare to a closed system, your oil temp is a much better guage. If your temp guage is showing 140 deg, it's not the same as a closed system. All that means is that the water heated up from lake temp (around 80 deg lets say) to 140 deg. In a closed system the water is not 80 deg entering in the motor. Probably more like 120-130 depending. Your water temp guage in a raw water system should serve nothing more than a comparison to what it usually runs. The actual number doesn't mean crap. There is no comparison to a car water temp. :argue: Setting a Jetboat to run 180 water temp will probably lead to unnecessary flash boiling in the heads around the combustion chamber. I see no point.
I disagree. The temp reading (providing the sender is in the intake or stock head location) will be the "hottest" water reading in the motor. 180º is a long way from 212º (boiling). IMO you will not see any flash boiling or steam pockets with a temp sender reading of 180º or even as high as 200º for that matter. I've run engines with thermos installed at these temps with no boiling issues of any type.
If you think your motor is running too cool, adjust by the oil temp, not the water temp.
Too cool water temp will cause too cool oil temp as well, which is a bigger problem IMO than the water temp. Raising the water up into even the 160º range in turn gets the oil up to temp so it can lubricate properly as well as burn off condensation that normally collects in the oil which is in itself very important. Oil temps consistantly under 212º are not good particularly if they're substantally under 212º. Running water temps down in the 100-120º range with an open system won't get the oil temps up unless you're full throttle alot (which most boats are not). Some motors make as much or more power running cool water temps. But how much and at what cost in terms of sacraficed oil lubrication characteristics and the inability to evaporate off condensation due to too low of oil temp over time. To me it's not worth it unless you're drag racing, which is a totally different scenario.
I suppose that if you run a strainer, bypass valve, and T-stat, it could work, but there is no antifreeze/boil to help protect from flash boiling. Keeping the water in the motor long enough to heat it up to 180 º (thus restricting flow) I'd think would only lead to more likelyhood of flash steaming in the heads. That T-stat will never open up as far as it would in a closed system because it has to keep the water in the motor much longer. It has to heat up the water 100º or more instead of 20-30º like it does in a car or in a closed marine set up. That means the water sits around the combustion chamber longer, with less flow to move the steam pockets.
When the water reaches 160º the thermo opens (no less or more than in a closed system) until the temp goes under 160º enough to close it. This is what creates the temp cycling effect we experience with the thermo system. Typically it cycles about 20º open, shut, open shut.... At no point should any water sit in the combusion chamber area long enough to get over 180-190º. When the thermo opens that water moves on and is replaced by cooler water from the block. The difference between temp around the combustion chamber and at the sender my guess is negligible and not close to enough to cause any boiling. With the block filling from the bottom as factory designed you cannot have boiling until some part of it reaches over 212º (probably slightly higher considering altitude and a little system pressure). We've never experienced any boiling or steaming problems with the use of our thermostat system running 160º stats that I've ever experienced or heard about. In the past 2 decades we've made and sold approximately 10000 of them and the company that made them prior to Rex probably sold at least that many more. They're simply not a product we've had any problem trends of any kind with.

[Rexone]

Well........ bad news. I was going to order the Rex thermo housing and all of the XRP hoses and fittings until I brought the boat to Glen at PBS. He said the boat is veryy pretty but....... Since Olympic boat centers has sat on this problem for three weeks now and never changed the oil or did anything the cam is rusted, lifters are rusted, rods have rust on them and rust on one of the cylinders that we can see without taking the entire motor apart. Only the tunnel ram is off at this point. Now I'm looking at approx. $2500.00 for R&R of the motor and Olympic is not sure if they want to spend the money to fix it. They want to possibly just give back my $3600.00. :220v: :220v: :220v: :mad: :mad: I don't want my f____ng money back I want to "Float out with my boat out!!"
Well now that Sucks.
Just a thought if they're willing to give you your money back they're probably going to liquidate the boat real cheap so they don't have to deal with it. Perhaps you can just negotiate a partial refund and keep the boat. :idea:

['78 gt boat]

that's what Glen was saying. He says they will probably scrap the hull and sell the parts from the motor and that would suck ass. I will negotiate as much as possible being that is what I do for a living (negotiate). Maybe I can get them to pay the majority of it and keep the life of this pretty boat going. I would hate to see something so nice go down in a ball of flames. Maybe I can work with Glen to help out and learn a lot for a slight price drop. Who knows..... This is the luck I have been given my entire life so far why change it now. I hate the saying," If it looks too good to be true, it probably is!" :mad: :cry:

[ANY&ALL]

save the hull I'll buy it. WAIT let them scrap it then mine will go up in value one less GT. Just kidden

['78 gt boat]

:yuk: :yuk: :yuk: :yuk: :yuk: :yuk: Very funny. I'm gonna get it fixed one way or another. If I have to take the bastards to court to grt my money back I will. It's going in the shop by the end of the week to get it fixed.

[FHI-prez]

Well Rexone I think we are going to have to agree to disagree on this one. I do appreciate your lengthy reply, and I'm sure you have not had issues with your T-stat units. I wasn't implying that you would sell a bad part, I was merely saying I don't think it is a desireable application on a raw water cooled motor. The ONLY way to get water to get hotter when your are starting with the same 80º water from the lake, is to keep it in the motor longer. That means lower gph flow rate. There is no way around that. You have the same motor operating at the same workload, pulling in the same water from the lake your gph flow has to be lower to get a hotter water temp.
My temp sensor reads 145º cruising. My oil temp hangs around 235º-240º. Under stress or harsh conditions it will see 250º+ oil temp. I ran a closed system in the same boat, same motor, identical oil temps, water temp was reading around 200º with and Evans coolant system.
I've done a fair amount of research on flash boiling around the combustion chamber. I'm not saying that you will have boiling problems with a t-stat regulated system. What I am saying is that the water jacket around the combustion chamber gets much hotter than 212º F. This causes tiny steam pockets to form in these "hot spots". These steam pockets tend to insulate these areas and retard the heat exchange process. I'm not saying that your water will boil out of your motor.
There is NO correlation between a closed system car engine that won't get over 140º at cruising speeds and a raw water boat system with the same temp reading.
True, water will not boil at 180º. BUT it does mean that since your gph flow rate is down in a t-stat regulated raw water cooled marine engine that is higher water temp combined with a lower flow rate, lends itself to more flash steaming around the hottest part of the heads, the combustion chamber. I've worked on motors that were detonating (some badly, some mildly) and were only showing water temps in the 190º range. Combustion chamber temperatures have very little to do with water temperature. Since we can't run an anti-boil coolant in raw water systems, the best defense is pressure and flow rate to limit the tiny steam pockets.
The testing with the Evans coolant showed that they could run coolant temps of 220º+ with no detonation. Since the Evans coolant was so resistant to boiling, it was able to pull more heat away from the combustion chamber. Now Evans is a real pain in the ass, because it's expensive as hell and you can't add any water to the system, but they do show that water temp does not necessarially correlate with detonation.
It all goes back to the fact that you can't heat water up over 100º from ambient without reducing it's flow (restriction).
Getting weeks or debris in the inlet hose is much less likely because if something lodges in there (prior to a bypass valve) the pressure would skyrocket and hopefully blow out the restriction. If you get a weeded or dorked up T-stat, the bypass valve would limit the pressure to 15 psi or so, which could drop the water flow to the motor to nill.
Nick