Imco Shorty Not Picking Up Enough Water @ High Tri

[Carl C]

I need to run more trim to float the bow but when I do the water inlet is almost parallel to the water and water pressure drops. Here are some pics to show what I mean. There is water running out of the drive that makes the pics look funny. Can the inlet be reshaped to help? Do I need to fill the inlet and go with a stern mounted water pick-up?:confused::confused:

[gcarter]

A transom pickup will work 100 % of the time! :yes:

[Carl C]

A transom pickup will work 100 % of the time! :yes:

How much speed will it scrub? Will filling the existing pick-up off-set the drag?

[MOP]

Ditto! Plus fill it and fair it in it will be more hydrodynamic, might add a tiny bit of speed!

[Sweet Cheekz]

Or keep it and plum a hose and fitting and send it back out the transom onto your drive for a cheap drive shower.
Parnell

[mrfixxall]

Call imco! i think you can open the hole up towards the skeg a bit,this will give you a better attack angle..

[Carl C]

Or keep it and plum a hose and fitting and send it back out the transom onto your drive for a cheap drive shower.
Parnell

Too much drag, I'd be dumping tons of water on the drive most of the time and almost none when it needs it the most.


Call imco! i think you can open the hole up towards the skeg a bit,this will give you a better attack angle..

I will do that.

Need more feedback on the transom mount pick-up and filling the lower. I don't want to lose speed.

Thanks.

[Sweet Cheekz]

Too much drag, I'd be dumping tons of water on the drive most of the time and almost none when it needs it the most.

.

Carl
The drive needs water the most at the highest rpm's which coresponds with the most water being dumped on it FYI LOts of people do that and it works good It is a bit of monkeyshine to get it hooked up right but it would add a little drag
Parnell

[gcarter]

Carl, the hull bottom at the transom can be scalloped slightly so that the pickup doesn't protrude below the bottom but a small fraction of an inch. You'll never see it.

I didn't scallop mine because I don't have a desire to cruise at 80.:yes:

[Cuda]

My Formula had dual transom pickups. They were barely below the hull. I can't see a transom pick up scrubbing much speed. If it does, it's certainly better than burning up the drive, or overheating the engine.

[gcarter]

Mine sticks below about 3/8" at the trailing edge, it can be less.

http://www.donzi.net/forums/attachment.php?attachmentid=53757&stc=1&d=1266101607

[Carl C]

I'll call Imco and look into a transom pick-up and make a decision.

[BlownCrewCab]

Do you have a water pressure gauge? whats the difference in pressure when your wfo trimmed up and when your cruising going 60ish? if you can keep 7-10 psi minimum you won't overheat. if your bumping real low pressures like 5 psi or less then you need to do something.

[MOP]

[quote=Carl C;Need more feedback on the transom mount pick-up and filling the lower. I don't want to lose speed.

I would worry less about drag and more about added water pressure, Griz needs to jump in on this he has some numbers.

[The Hedgehog]

Carl
The drive needs water the most at the highest rpm's which coresponds with the most water being dumped on it FYI LOts of people do that and it works good It is a bit of monkeyshine to get it hooked up right but it would add a little drag
Parnell

Yep. This guy named Phil does that on all of the Cigs he customizes. Eddie Young does it too. Not exactly amateurs there.

I have both a transom like GCarter's and the IMCO lower pickup. I don't seem to be scrubbing much speed but then I am too scared to hold the throttle open long enough to know:nilly:!

[Carl C]

Do you have a water pressure gauge? whats the difference in pressure when your wfo trimmed up and when your cruising going 60ish? if you can keep 7-10 psi minimum you won't overheat. if your bumping real low pressures like 5 psi or less then you need to do something.

The 525 needs 30-50 psi. If I let it drop under about 20 psi the horn sounds.

[gcarter]

Carl, I really reccomend the Stainless Marine 1" pickup.
It allows you to use screws to attach the pickup.
Some have studs, and it's almost impossible to drill six perfectly parallel holes through the thick part of the transom.
Some are adjustable which may or may not be an advantage.
Don't use one w/a screen, that's why you will have a strainer.
Good luck.

[BlownCrewCab]

The 525 needs 30-50 psi. If I let it drop under about 20 psi the horn sounds.


Wow, thats allot, looks like you need the transom pickup (and some 5200)

[MOP]

Seems strange that the pressure wanted by Merc is so high, up on Boat Freaks there are guys with a lot more HP restricting pressure to 15-20 psi. At those pressures you will surely end up with weeping head gaskets, 30psi should be an absolute maximum. You must be turning over 5200 and running under 23 lbs tripping the computer.

http://forums.boatfreaks.org/showthread.php?t=15347&highlight=pressure+relief
http://forums.boatfreaks.org/showthread.php?t=9196&highlight=pressure+relief
http://www.offshoreonly.com/forums/general-q/220781-water-pressure.html
This link related to closed cooled engines where you need more flow/pressure: http://www.offshoreonly.com/forums/general-q/212314-merc-600sci-water-pressure-drops-high-rpm-2.html
Teague relief valves for offshore race boats are set much lower
http://teaguecustommarine.com//store/index.php?main_page=advanced_search_result&search_in_description=1&keyword=pressure+relief+valve

[VetteLT193]

Seems strange that the pressure wanted by Merc is so high, up on Boat Freaks there are guys with a lot more HP restricting pressure to 15-20 psi. At those pressures you will surely end up with weeping head gaskets, 30psi should be an absolute maximum. You must be turning over 5200 and running under 23 lbs tripping the computer.

http://forums.boatfreaks.org/showthread.php?t=15347&highlight=pressure+relief
http://forums.boatfreaks.org/showthread.php?t=9196&highlight=pressure+relief
http://www.offshoreonly.com/forums/general-q/220781-water-pressure.html
This link related to closed cooled engines where you need more flow/pressure: http://www.offshoreonly.com/forums/general-q/212314-merc-600sci-water-pressure-drops-high-rpm-2.html
Teague relief valves for offshore race boats are set much lower
http://teaguecustommarine.com//store/index.php?main_page=advanced_search_result&search_in_description=1&keyword=pressure+relief+valve

don't forget the 525 is closed cooling so the pressure would only affect the heat exchanger and the header tails.

[BlownCrewCab]

don't forget the 525 is closed cooling so the pressure would only affect the heat exchanger and the header tails.


That makes allot more sense then.

[gcarter]

don't forget the 525 is closed cooling so the pressure would only affect the heat exchanger and the header tails.

A certain minimum pressure will guarantee a certain minimum flow in GPM.
That velocity through the heat exchanger is what gives a certain heat transfer rate.
But too much pressure will start blowing hoses. That's a problem I had w/the Minx was leaking hoses while running. The TR will have an adjustable relief valve.

[Carl C]

Would this one be a good choice? The 1 1/4 inch tube will be compatible with my existing system and I am confident doing business with Teague. It looks like it screws on.

http://teaguecustommarine.com//store/index.php?main_page=product_info&cPath=0&products_id=465

Edit: I just talked with a technician at Imco and he said to open up the inlet toward the front and that I won't add significant drag at cruising speed. That would sure be an easier fix if it works.....

[mrfixxall]

Would this one be a good choice? The 1 1/4 inch tube will be compatible with my existing system and I am confident doing business with Teague. It looks like it screws on.

http://teaguecustommarine.com//store/index.php?main_page=product_info&cPath=0&products_id=465

Edit: I just talked with a technician at Imco and he said to open up the inlet toward the front and that I won't add significant drag at cruising speed. That would sure be an easier fix if it works.....


i dont like teagues,that style puts to much stress on the 3 screws holding it in place...George hit it spot on with the stainless marines..their stronger and have more mounting points:)
http://www.stainlessmarine.com/waterpick.htm

[mattyboy]

i dont like teagues,that style puts to much stress on the 3 screws holding it in place...George hit it spot on with the stainless marines..their stronger and have more mounting points:)
http://www.stainlessmarine.com/waterpick.htm


funny I thought the same thing looks like a speedo pickup and looks like if it did catch something would bend up or break off. the stainless looks like it will stay in place and will just plug.

[Cuda]

Would this one be a good choice? The 1 1/4 inch tube will be compatible with my existing system and I am confident doing business with Teague. It looks like it screws on.

http://teaguecustommarine.com//store/index.php?main_page=product_info&cPath=0&products_id=465

Edit: I just talked with a technician at Imco and he said to open up the inlet toward the front and that I won't add significant drag at cruising speed. That would sure be an easier fix if it works.....
Nothing's going to add drag at cruising speed. I thought you wanted to travel at the speed of sound with your hair on fire.

[handfulz28]

Rogue thought....how about talking to "your prop guy" :D and see if there's room to massage it for more bow lift?

[Cuda]

don't forget the 525 is closed cooling so the pressure would only affect the heat exchanger and the header tails.
Doesn't the water flow through the block and heads too? I don't understand how it could cool an engine otherwise. I had CC on my Minx. 50 pounds of water pressure should blow the head gasket I would think.

[BUIZILLA]

Doesn't the water flow through the block and heads too? I don't understand how it could cool an engine otherwise. I had CC on my Minx. 50 pounds of water pressure should blow the head gasket I would think. it'll push the intake gaskets out first...

[mrfixxall]

Carl, have you considered a 1/2 drive spacer?

[VetteLT193]

Doesn't the water flow through the block and heads too? I don't understand how it could cool an engine otherwise. I had CC on my Minx. 50 pounds of water pressure should blow the head gasket I would think.

With CC if you have 0 psi of raw water pressure you still have coolant flowing through the block. same goes if you have 20, 30, or 100 psi. the closed side is not related to the raw side other than the heat exchanger. the water pump on the engine circulates the coolant and the raw water pump in the drive or engine mounted pump.

think of it like a radiator in a car. if there is no air flow over the radiator it mimics 0 psi. if there is 100 MPH of air flow it mimics a high PSI of water. the coolant through the block is only affected because of temp or lack thereof.

[gcarter]

Ya gotta go w/something w/some beef and SM is the only way to go.
Also I don't like anything w/a hose barb on it.
A threaded end will allow you to have a shut off valve on hard piping so that if there's a major failure, you can shut off all the water coming in.
I always disliked the way Merc and Volvo drives did that. Ask Jim collins about losing the incoming hose behind the engine and being in calf deep water..............

[Cuda]

With CC if you have 0 psi of raw water pressure you still have coolant flowing through the block. same goes if you have 20, 30, or 100 psi. the closed side is not related to the raw side other than the heat exchanger. the water pump on the engine circulates the coolant and the raw water pump in the drive or engine mounted pump.
think of it like a radiator in a car. if there is no air flow over the radiator it mimics 0 psi. if there is 100 MPH of air flow it mimics a high PSI of water. the coolant through the block is only affected because of temp or lack thereof.
I realized that after I had posted. It's been a while. :(

[Cuda]

With CC if you have 0 psi of raw water pressure you still have coolant flowing through the block. same goes if you have 20, 30, or 100 psi. the closed side is not related to the raw side other than the heat exchanger. the water pump on the engine circulates the coolant and the raw water pump in the drive or engine mounted pump.
think of it like a radiator in a car. if there is no air flow over the radiator it mimics 0 psi. if there is 100 MPH of air flow it mimics a high PSI of water. the coolant through the block is only affected because of temp or lack thereof.
I don't agree with your analogy of a car radiator. They normaly have 14.2 lbs of pressure no matter what speed they are moving.

[Carl C]

OK, after looking at it more I agree that the Teague pick-up is no good and I will go with one like George posted if I go that route. I might try opening up the water intake a little first though.

No spacer! Everything else is working too well right now.

Not sure why the 525 needs so much raw water pressure but it has been discussed to death on some other forums. One post:
http://www.offshoreonly.com/forums/2629265-post5.html

[MOP]

Carl take the time to read the links I provided, you are raw cooled and I believe flirting with doing a set of head gaskets. Only one link refers to closed cooling all the rest are raw with a ton of horse power.

[DonziJon]

it'll push the intake gaskets out first...

Closed Cooling means there are two seperate circulating systems..NO..? High pressure in one dosn't mean high pressure in the other. Maybe I'm screwed up. I just don't think this is all that complicated.
:wink:

OK: SO: Is Carl raw water cooled or NOT...??

[gcarter]

Carl take the time to read the links I provided, you are raw cooled and I believe flirting with doing a set of head gaskets. Only one link refers to closed cooling all the rest are raw with a ton of horse power.

Phil, apparently a 500 is raw water cooled, but a 525 is fresh water cooled.
Maybe Carl will post a picture of the HE on the engine.

[gcarter]

I don't agree with your analogy of a car radiator. They normaly have 14.2 lbs of pressure no matter what speed they are moving.
Joe, closed cooling has a pressure cap too.

[Carl C]

It's closed cooling. The pressure is measured on the raw water side. The water flows through the heat exchanger, fuel cooler, p/s fluid cooler, oil cooler and out the exhaust. I think I'll modify the water inlet first and of course I need to get the rest of the gauges working.

I just went out and verified that I am measuring raw water pressure. The mechanical gauge connects to the oil cooler. This has nothing to do with the pressure in the engine. My 35 psi gauge is often pegged but I have verified that this is normal with the 525. I don't know what engine temp is but the horn seems to sound as soon as the pressure drops below 15-20. I think it is the pressure drop setting it off and not engine temp because engine temp wouldn't rise instantly like that. There is an electric sensor mounted with the mechanical sender. I need to get my gauges working though. Regardless, I need to keep raw water pressure over 25 psi.

[Cuda]

Joe, closed cooling has a pressure cap too.
Yes, because when it warms up, that coolant is under pressure also.

[Pismo]

Horsepower equals heat..

[Cuda]

Horsepower equals heat..
But corrolary is, the less heat you make, the more horsepower you can make.

[gcarter]

But corrolary is, the less heat you make, the more horsepower you can make.


??????????????????????????????????????????????

[mrfixxall]

But corrolary is, the less heat you make, the more horsepower you can make.


big blocks make more power when they heat up :)

[thehow33]

But corrolary is, the less heat you make, the more horsepower you can make.

Are you thinking of the air going into the motor? Because the rings and the pistons need the motor to warm up to a certain range for them to operate efficiently, not to mention the oil system needs to warm up too. However, if the air going into the motor and the intake itself are cool than that will help make more horsepower. Problem is its hard to keep the intake cool because of heat transfer from the motor. Hence, the constant battle a turbo has to struggle with. Compressing cool air is much more efficient than compressing hot air. I know there are more reasons than what I mentioned. If I'm wrong let me know? Thanks

[MOP]

You are 100% right on both counts, not only will a proper temperature develop more power but will out live a raw cooled one! Look at the discussion on the Merc 1300, with no other changes except piping cool air to in it jumps to 1350. No way would I run raw!

[yeller]

Ok, seeing as Carls thread is now completely off track...I'll throw in my 2 uneducated cents. I believe a cool engine will make more HP because the pistons/rings expand less and cause less friction.

Case in point: when I had my 16C (350sbc/berkeley) I ran the motor for years without a thermostat. Being in Canada, I boat in cool waters and the temp gauge never moved off the coldest point. Then one day I put in the thermostat and temp gauge rose to 150 and I lost some rpm and 3~4mph. Pulled out the t-stat and rpm/speed picked up. ....and I never saw any engine damage because of it. Believe me when I say I ran that engine HARD and maxed out OFTEN.

Colder air will make more HP. A hotter engine will make less HP

[gcarter]

That may be in some cases w/carbed engines. However, for high tech engines w/sophisticated engine mangement systems, pretty close control of temperature is mandatory. Every segment operates w/in pretty close tolerances.
In the case of your SBC, w/proper tuning, you may have seen even more power w/higher temps. SBC's are noted for responding well to a little more heat.

[Pismo]

I think he ment a more efficient engine would make less heat and more HP. 85-90% of the gas energy is lost as heat now, get that to 50% and you would have huge HP on the same fuel usage.

[VetteLT193]

That may be in some cases w/carbed engines. However, for high tech engines w/sophisticated engine mangement systems, pretty close control of temperature is mandatory. Every segment operates w/in pretty close tolerances.
In the case of your SBC, w/proper tuning, you may have seen even more power w/higher temps. SBC's are noted for responding well to a little more heat.

In my experience less heat is better for most cases. Spark scatter increases with temperature. The 'fix' for scatter is retard. If you aren't running as advanced as you can be for any given moment you won't be making the most power.

Also... the intake is part of the cooling system and air has to flow through there. Hotter air == less dense.

I understand the theory of heat == more power quite well but the outside factors tend to net this a wash at best. Even in more sophisticated systems that are designed to help things like spark scatter cooler tends to work better in actual practice. From what I have seen most manufacturers are increasing temperature not for performance reasons but for emissions. In the auto world a hotter cat is more effective.

now... with all that said there is a point things are too low.

[Cuda]

Are you thinking of the air going into the motor? Because the rings and the pistons need the motor to warm up to a certain range for them to operate efficiently, not to mention the oil system needs to warm up too. However, if the air going into the motor and the intake itself are cool than that will help make more horsepower. Problem is its hard to keep the intake cool because of heat transfer from the motor. Hence, the constant battle a turbo has to struggle with. Compressing cool air is much more efficient than compressing hot air. I know there are more reasons than what I mentioned. If I'm wrong let me know? Thanks
I meant you have X amount of gas, with the X amount, you can make power, or make heat.

[Pismo]

I meant you have X amount of gas, with the X amount, you can make power, or make heat.

Exactly....

[CHACHI]

Smokey Yunick thought motor heat should be retained.

I would consider him a pretty savy and clever guy.

Ken

[Cuda]

Smokey Yunick thought motor heat should be retained.

I would consider him a pretty savy and clever guy.

Ken
If you asked him if he'd rather make heat or power, I'm betting on power.

[thehow33]

I meant you have X amount of gas, with the X amount, you can make power, or make heat.

got ya...I wasn't sure what you were trying to say earlier.

[The Hedgehog]

The heat thing depends on how your engine is toleranced. Eddie likes to run them cool and tunes that that way. He also runs a good bit of compression. Grizz sets his up to run at a constant temp. So does merc for that matter.

[gcarter]

If you asked him if he'd rather make heat or power, I'm betting on power.

This is getting out of hand w/o any guide lines.
I know nowhere near as much about the finer details of gas and Diesel engines as Buizilla, but I'm a good general theorist.
So lets set rules;
Scenario #1:
No thermostat, cold water, raw water cooling, it probably runs at about 120*-maybe less, oil NEVER gets over 140*-it retains water because it never gets warm enough to vaporize, fuel doesn't get hot enough to vaporize very well before it enters the cylinders.
I suspect, but don't know for sure, that this engine is giving up a lot of potential power.

Scenario #2:
Closed cooling, 160* thermostat, engine water temp. runs between 140*-180*, not sure of oil temp but normal for this setup, very good plug readings, no soot on the transom.

I don't know of any engine that runs at over 25% efficiency. And those that do, you can count on one hand probably. So the other 75+% goes out the exhaust as heat and unburned fuel, the oil cooler as heat, and the coolant (whatever it is) as heat.

So why don't we start over?

[Cuda]

This is getting out of hand w/o any guide lines.
I know nowhere near as much about the finer details of gas and Diesel engines as Buizilla, but I'm a good general theorist.
So lets set rules;
Scenario #1:
No thermostat, cold water, raw water cooling, it probably runs at about 120*-maybe less, oil NEVER gets over 140*-it retains water because it never gets warm enough to vaporize, fuel doesn't get hot enough to vaporize very well before it enters the cylinders.
I suspect, but don't know for sure, that this engine is giving up a lot of potential power.

Scenario #2:
Closed cooling, 160* thermostat, engine water temp. runs between 140*-180*, not sure of oil temp but normal for this setup, very good plug readings, no soot on the transom.

I don't know of any engine that runs at over 25% efficiency. And those that do, you can count on one hand probably. So the other 75+% goes out the exhaust as heat and unburned fuel, the oil cooler as heat, and the coolant (whatever it is) as heat.

So why don't we start over?
Senario1
Why is there water in the oil? I've never added water to the oil.
Fuel doesn't need to be hot to vaporize, fuel especially if it's carbed vaporizes very well, and the cooler the fuel, the more dense it is, therefor more power is made.
EFI engines are designed to run at specific temps. We are talking hypothetically here.

Your final paragraph makes my argument.

[gcarter]

Senario1
Why is there water in the oil? I've never added water to the oil.
Fuel doesn't need to be hot to vaporize, fuel especially if it's carbed vaporizes very well, and the cooler the fuel, the more dense it is, therefor more power is made.
EFI engines are designed to run at specific temps. We are talking hypothetically here.

Your final paragraph makes my argument.
Water condenses in the oil from the cooling process.

[thehow33]

First off water condenses in oil every time you start a motor in the cold and then run it for only a short period of time because it never runs at its optimal operating temperature (180degreeds) long enough for the condensation to burn off. This scenarios happens every winter with my truck. I went to change my oil this winter and couldn't believe how much had built up on the oil fill cap within just 2 weeks and my truck never ran for less than 30 minutes at a time for those 2 weeks.

From my understanding of motors, there are optimal operating temperatures depending on the properties of the materials that are being used in the motor. Such as oils, fuels, and metals. These 3 items which are needed to make a motor all have certain properties which have efficiencies that are all regulated by temperature. They can be combined and setup different ways to run efficiently. If only colder was better, than the I'm sure the perfect motor would have already been designed and copied by all major companies.

In theory a motor may make more HP if its cooler, but there is still is a range. This range is limited by loss of compression or engine damage. You can set up the motor with loose tolerances so that you can run it at lower operating temperatures, but you can only go so low before you lose compression. Also, the oil system can't warm up enough which doesn't allow it to lubricate the motor properly, which inevitably means engine damage due to cylinder wear and then loss of compression (HP).

What was this thread even about?

[yeller]

Carl's threads never stay on track....don't worry about it, he's use to it.:biggrin.::biggrin.:

You can't compare a motor in a boat to the one in your truck. I do agree with others that EFI and carb need different temps to run properly. I'm only talking about a carb'd motor. I never had condensation issues with my motor and I highly doubt the temp every reached 120. I'm sure it was much less, but I am very confident my oil heated up. Take the thermostat out of you truck, fire it up and run it under a heavy loat at 3500~4500rpm for 20 minutes and then check to see if your oil is hot. I ran the same SBC in my boat for 12 years with no t-stat (in Canadian water) and never saw any premature engine damage or had condensation in my oil. I then rebuilt it for slightly more power, threw a t-stat in it and saw almost no increase in speed. Ran it that way for one summer, then yanked the t-stat and instantly picked up 3~4mph. Everyone has their own opinion and I respect that....but no one will ever be able to convince me that a t-stat is needed in old-school boat motor. (The key point here being I'm talking old-school, which is what I had. No air/fuel sensors, no egt's, etc)

[thehow33]

Carl's threads never stay on track....don't worry about it, he's use to it.:biggrin.::biggrin.:

You can't compare a motor in a boat to the one in your truck. I do agree with others that EFI and carb need different temps to run properly. I'm only talking about a carb'd motor. I never had condensation issues with my motor and I highly doubt the temp every reached 120. I'm sure it was much less, but I am very confident my oil heated up. Take the thermostat out of you truck, fire it up and run it under a heavy loat at 3500~4500rpm for 20 minutes and then check to see if your oil is hot. I ran the same SBC in my boat for 12 years with no t-stat (in Canadian water) and never saw any premature engine damage or had condensation in my oil. I then rebuilt it for slightly more power, threw a t-stat in it and saw almost no increase in speed. Ran it that way for one summer, then yanked the t-stat and instantly picked up 3~4mph. Everyone has their own opinion and I respect that....but no one will ever be able to convince me that a t-stat is needed in old-school boat motor. (The key point here being I'm talking old-school, which is what I had. No air/fuel sensors, no egt's, etc)


I agree carb vs EFI need to be different. I also don't doubt that your boat ran fine the way it was set up, I was just saying that all parties on both sides of this fence are right. But there are still limits to what both parties are claiming.

[Carl C]

Carl's threads never stay on track....don't worry about it, he's use to it.:biggrin.::biggrin.:


It's cool. I've been following the discussion. My question has already been answered for now. An engine does need to operate at a certain temperature to evaporate condensation and keep oil at the proper viscosity and help with efficient fuel vaporization and combustion. Heat is an inevitable side effect of an internal combustion engine. Turbochargers help to recycle that energy, otherwise it is carried away through the cooling water and wasted. In an engine that burns fuel you cannot avoid wasting energy in the form of heat. The heat is still being produced even if you carry it away faster with increased water flow through the engine. The important thing is to keep the intake manifold and incoming air cool. The intake manifold on my 525 stays cool to the touch while running and it has a fuel cooler to help prevent vaporlock, along with the return to an old style mechanical fuel pump attached to the raw water pump and an electric fuel pump which primes the mechanical one when the key is turned on.

[Cuda]

I had eight boats at one time. The only one I ran a t stat in was the Minx, becuase I'd put closed cooling in it. None of my other boats had a t stat, and not once did I have emulsified oil from water being in it. In the Formula, the temp guage never came off the "C" mark.

[VetteLT193]

This is getting out of hand w/o any guide lines.
I know nowhere near as much about the finer details of gas and Diesel engines as Buizilla, but I'm a good general theorist.
So lets set rules;
Scenario #1:
No thermostat, cold water, raw water cooling, it probably runs at about 120*-maybe less, oil NEVER gets over 140*-it retains water because it never gets warm enough to vaporize, fuel doesn't get hot enough to vaporize very well before it enters the cylinders.
I suspect, but don't know for sure, that this engine is giving up a lot of potential power.

Scenario #2:
Closed cooling, 160* thermostat, engine water temp. runs between 140*-180*, not sure of oil temp but normal for this setup, very good plug readings, no soot on the transom.

I don't know of any engine that runs at over 25% efficiency. And those that do, you can count on one hand probably. So the other 75+% goes out the exhaust as heat and unburned fuel, the oil cooler as heat, and the coolant (whatever it is) as heat.

So why don't we start over?


Most of the guys running #1 are in warmer water and mine always ran hotter than 120 and I never had a problem with oil temperature in the Minx. I actually bought an oil cooler for it (but I never had a chance to install it). Eddies 22 has an oil cooler as well and runs this exact setup. It never sees 120 degrees except for the brief period it passes that as it warms up.

And #2 doesn't make sense to me. I have never had an engine run colder than the T-stat temp unless it was still warming up. After warm up it should be at the T stat temperature or higher. Possibly very slightly lower in perfect conditions but we're talking a couple degrees lower not 20 degrees.

[BUIZILLA]

esplain to me why every engine that comes down an assembly line is built with a thermostat..

and why?

must be a good reason, eh :popcorn:

[gcarter]

Most of the guys running #1 are in warmer water and mine always ran hotter than 120 and I never had a problem with oil temperature in the Minx. I actually bought an oil cooler for it (but I never had a chance to install it). Eddies 22 has an oil cooler as well and runs this exact setup. It never sees 120 degrees except for the brief period it passes that as it warms up.

And #2 doesn't make sense to me. I have never had an engine run colder than the T-stat temp unless it was still warming up. After warm up it should be at the T stat temperature or higher. Possibly very slightly lower in perfect conditions but we're talking a couple degrees lower not 20 degrees.
Maybe the coolant temp isn't fair as I was thinking of my Minx w/several large bypass holes in the T-stat and the electric circ pump, it really would run at 140* (Indicated) at idle and low load circumstances.

[Planetwarmer]

I don't have a T stat, and have never had a problem. I thought about putting one in (the boat came without one when I bought it), but have never really seen a need to install one. It never acts cold after it's been warmed up.

Maybe the electric choke is always on, and that's why Ive never noticed it running cold.:bonk:

[mrfixxall]

esplain to me why every engine that comes down an assembly line is built with a thermostat..

and why?

must be a good reason, eh :popcorn:

Because us northern folk need to keep our Azz's warm in the winter time,it kinda sucks scraping the windows in the winter time from the inside :)

[Carl C]

Because us northern folk need to keep our Azz's warm in the winter time,it kinda sucks scraping the windows in the winter time from the inside :)

And because modern automotive engines run much hotter than desired for emissions reasons. They need to run warm but......

[Pismo]

esplain to me why every engine that comes down an assembly line is built with a thermostat..

and why?

must be a good reason, eh :popcorn:

More complete combustion in a warmer motor.

[MOP]

All you boys that want to run cool so be it! But it is definitely not COOL, but then again these are toys some do and some don't take care of their toys!

[Cuda]

And because modern automotive engines run much hotter than desired for emissions reasons. They need to run warm but......
Are boat engines exempt from car emissions?

[Cuda]

All you boys that want to run cool so be it! But it is definitely not COOL, but then again these are toys some do and some don't take care of their toys!
I've never been towed in from running too cool.

[thehow33]

I had eight boats at one time. The only one I ran a t stat in was the Minx, becuase I'd put closed cooling in it. None of my other boats had a t stat, and not once did I have emulsified oil from water being in it. In the Formula, the temp guage never came off the "C" mark.

just because it doesn't brake or because it stays working doesn't mean its the most efficient way to run the motor

[Cuda]

just because it doesn't brake or because it stays working doesn't mean its the most efficient way to run the motor
I didn't have a set of "brakes" on any of my boats. I've been working on motors all my life, and the cooler you can run an engine the more power you can make, it's a matter of physics. Cooler air is denser than warm air. I never had one break either.

[BigGrizzly]

I just got to read this. As for heat and cold. the prime oil temperature is between 190 and 210 degrees. I have proved this and discussed it so much I am tired of it. Remember, at 140 degrees engine where is twice as much as 160. Gm has done this several times Look it up. the coldest myboats have ever run is 160 degrees. Now for the water pickup on the lower, Carl, I wish you had not done this cut out. we ran through it several times . We even cut notchesw in the hull to duct the warter to the pickup. Nothing worked untill we did the hull pick up. One reason is when you trim up with a steletto nose the water id ducted away fron the low water pickup. We had conferred with Impo and folled everything they said and ended with a hull pickup

[MOP]

Randy some glad to see you beating on the keys, that has to be a good sign.

Phil

[Carl C]

I just got to read this. As for heat and cold. the prime oil temperature is between 190 and 210 degrees. I have proved this and discussed it so much I am tired of it. Remember, at 140 degrees engine where is twice as much as 160. Gm has done this several times Look it up. the coldest myboats have ever run is 160 degrees. Now for the water pickup on the lower, Carl, I wish you had not done this cut out. we ran through it several times . We even cut notchesw in the hull to duct the warter to the pickup. Nothing worked untill we did the hull pick up. One reason is when you trim up with a steletto nose the water id ducted away fron the low water pickup. We had conferred with Impo and folled everything they said and ended with a hull pickup

I haven't done the mod yet. How can I plug the existing inlet that will hold up other than welding? I don't want to use it for a shower. I want to make it hydrodynamic to off-set the added drag of the new water pick-up.

[gcarter]

I haven't done the mod yet. How can I plug the existing inlet that will hold up other than welding? I don't want to use it for a shower. I want to make it hydrodynamic to off-set the added drag of the new water pick-up.

Carl, leave the opening alone!
As long as water is flowing through it, it isn't a problem.
Just let it flow through the drive. The drive needs the cooling.
If you were to block that opening AND not run a shower, you'd cook your drive in very short order.

Once again, the opening isn't a problem. If anything, the opening,w/water flowing through it, would lower pressure on the nose of the drive.

[Carl C]

Carl, leave the opening alone!
As long as water is flowing through it, it isn't a problem.
Just let it flow through the drive. The drive needs the cooling.
If you were to block that opening AND not run a shower, you'd cook your drive in very short order.

Once again, the opening isn't a problem. If anything, the opening,w/water flowing through it, would lower pressure on the nose of the drive.

Thanks George. I got your other post about the block off plate too. I will look into doing this. I found a source for the type of pick-up you posted too.

[gcarter]

Randy, the low number I used above was brobably closer to 150*, rather than 140*, but it would drop below the T-stat rated temp under no load conditions due to the electric circ pump and bypass holes. Probably most here haven't had the experience of the electric pump running at 55 GPM under all conditions. It's a different experience.
I already have another one ready for the TR.

PS: Randy, I'm glad you're posting!
I sent you a PM. I hope you get around to answering it soon.

[BUIZILLA]

I didn't have a set of "brakes" on any of my boats. I've been working on motors all my life, and the cooler you can run an engine the more power you can make, it's a matter of physics. Cooler air is denser than warm air. I never had one break either. that's actually not true at all Joe... air temp, yes.... water and oil temp? absofrickinglutely not...

[Carl C]

Some new PWCs have brakes.......

[yeller]

Carl, I was positive you had bought a transom pickup a year or so ago. I distinctly remember the thread...but I guess it was someone else.

[Carl C]

Carl, I was positive you had bought a transom pickup a year or so ago. I distinctly remember the thread...but I guess it was someone else.

That was a speedo pitot.

[thehow33]

I didn't have a set of "brakes" on any of my boats. I've been working on motors all my life, and the cooler you can run an engine the more power you can make, it's a matter of physics. Cooler air is denser than warm air. I never had one break either.

I believe that you've never had one "break"haha, but I'd bet that your motors have lost more compression over time than someone who uses a T-stat. How much oil slips past your rings and burns after a few years of running without a T-stat? Engineers didn't make T-stats for the fun of it. They have reasons for using T-stats, like altering the properties of oil and metal to run a motor efficiently and reduce engine wear.

[Cuda]

that's actually not true at all Joe... air temp, yes.... water and oil temp? absofrickinglutely not...
I specified air temp.

[BUIZILLA]

the cooler you can run an engine the more power you can make, it's a matter of physics. . I aSSumed you meant water?

[Cuda]

I believe that you've never had one "break"haha, but I'd bet that your motors have lost more compression over time than someone who uses a T-stat. How much oil slips past your rings and burns after a few years of running without a T-stat? Engineers didn't make T-stats for the fun of it. They have reasons for using T-stats, like altering the properties of oil and metal to run a motor efficiently and reduce engine wear.
I don't think so Tex, the first car I bought burned at much oil as gas, but it had good compression. Oil rings have virtually nothing to do with compression, if you have compression problems, you can almost bet the house it's either burned valves, or a cracked piston. I never had an engine in a car or boat wear out prematurely because I didn't have a t stat in it. As a matter of fact, when I have overheating problems in my car, I'd take the t stat out and throw it in the ditch across the street.

Engineers design t stats because that's what they do. They postulate some crap, and everybody swallows it because they think the engineer must be smart. You ever talk to an engineer? Two of my cousins are engineers, and I was asking one how he solved problems. He told me he'd ask another engineer that had been there longer. Some proof eh?

[Cuda]

like altering the properties of oil and metal to run a motor efficiently and reduce engine wear.
That's why they invented Mobil One about 25 years ago. Now I do believe in better oil,because I've tested it myself, not just some anecdotal testing.

[Pismo]

I didn't have a set of "brakes" on any of my boats. I've been working on motors all my life, and the cooler you can run an engine the more power you can make, it's a matter of physics. Cooler air is denser than warm air. I never had one break either.

That is a colder induction air yielding more power due to increased density. That has nothing to do with engine operating temp.

[The Hedgehog]

You guys kill me. I don't run a t stat and have posted up a bunch of pics about when you do it wrong.

I can dig some up pics if you like. It makes a nasty yellow cake on the inside of your lifter valley.

I run an EFI with no t-stat. It is programmed to run that way. I can tell you how to combat the oil condensation problem. It is called thermostatically controlled oil cooler. I go off of oil temps and do NOT run into boost until my oil temps reach 160 and climbing.

I really don't know why this is such a discussion. Stick on one of those pickups that Cgarter showed, plumb the engine through the transom pickup and cool the drive with the drive pickup.

BTW, the way I run my transom pickup it pulls maybe 15-20 psi at 90 mph. I could run it lower and more would not be a problem. Keep in mind that mine is a step hull so that takes some away.

[Cuda]

That is a colder induction air yielding more power due to increased density. That has nothing to do with engine operating temp.
That's what I was saying: Colder air will produce more power.
You open a can of worms when you start talking about engine operating temps.
Sometimes when you open a can of worms,the only way to get the worms back in is to use a bigger can?

[thehow33]

That's what I was saying: Colder air will produce more power.
You open a can of worms when you start talking about engine operating temps.
Sometimes when you open a can of worms,the only way to get the worms back in is to use a bigger can?

Cuda I'm not trying to say this with sarcasm or anything like that. I'm just pointing out that you did talk about the air temp. And I would not have posted anything if that was your only statement because myself and everyone else who commented completely agree that colder air makes more HP.
The quote below is one of your first post and I don't see how that is talking about air temp. I just wanted to point out that both you and I and a handful of others were blabbering this whole time about engine temp and I might I add that I don't think any of us changed one another's mind.haha


But corrolary is, the less heat you make, the more horsepower you can make.

[Cuda]

Cuda I'm not trying to say this with sarcasm or anything like that. I'm just pointing out that you did talk about the air temp. And I would not have posted anything if that was your only statement because myself and everyone else who commented completely agree that colder air makes more HP.
The quote below is one of your first post and I don't see how that is talking about air temp. I just wanted to point out that both you and I and a handful of others were blabbering this whole time about engine temp and I might I add that I don't think any of us changed one another's mind.haha
I haven't changed my position on that. Look back where I saw when you have X amount of fuel, you can make X amount of power, and the rest of the fuel is wasted making heat.

[Cuda]

I agree that arguing over the internet will never change anybody's mind. It's an exercise in futility.

Dale Carnegie said in his book "How to win friends and influence peope", that the best was to win an argument is to avoid it. The more you argue your point, the more sure the other guy is that he's right. :)

[BUIZILLA]

wrong... :)

[Pismo]

So did you make the mods? Are you getting enough water now?

[gcarter]

You guys kill me. I don't run a t stat and have posted up a bunch of pics about when you do it wrong.

I can dig some up pics if you like. It makes a nasty yellow cake on the inside of your lifter valley.

I run an EFI with no t-stat. It is programmed to run that way. I can tell you how to combat the oil condensation problem. It is called thermostatically controlled oil cooler. I go off of oil temps and do NOT run into boost until my oil temps reach 160 and climbing.

I really don't know why this is such a discussion. Stick on one of those pickups that Cgarter showed, plumb the engine through the transom pickup and cool the drive with the drive pickup.

BTW, the way I run my transom pickup it pulls maybe 15-20 psi at 90 mph. I could run it lower and more would not be a problem. Keep in mind that mine is a step hull so that takes some away.

Yep, and you're optimized for a blower, aren't you?
Whole bunch more heat generated, right?

Anyway, in your case, we're talking about a whole different scale of things, as your engine is 850ish hp. So, 2545 BTU's/HP = 2,163,250 BTU's plus the inherent ineficencies.
All I can say is WOW!
And of course if you did raise the temp, you'd be at risk of detonation! And we don't want to go there, do we?

Gotta be a ton of differences there compared to the world the rest of us live in......

[gcarter]

In fact, I think it would be interesting to see how Merc sets up their blown racing engines.
They have closed cooling, don't they?

[VetteLT193]

In fact, I think it would be interesting to see how Merc sets up their blown racing engines.
They have closed cooling, don't they?

I think it's up to 700SCI. above that is raw. not sure on the new 1300 though, might be closed, probably not though because of the efficiency loss of the heat exchanger Vs. heat generated Vs. total engine footprint. Meaning, even though it is possible it would be too big to package well.

[Carl C]

So did you make the mods? Are you getting enough water now?

I decided to try a little modification to the water inlet. I haven't had the boat out again yet but maybe later this week. I elongated the front of the opening as Imco suggested and also beveled the rear edge of the inlet inside the case to better improve flow into the gearcase.

I figured it's worth a try because if I have to drag another pick-up through the water and keep the existing one open I am sure to lose a little top end.

While working on it I noticed that the front of the drive doesn't look as hydrodynamic as it could be. What if I grind/file the leading edge to a sharp edge?

[gcarter]

Carl, if it were me, I'd not polish it but just knock down any ugly high spots. If it's too smooth, it will build a thicker boundary layer and increase resistance.

As far as the pick up goes, you won't be able to exceed 100, so don't worry about it.
Think about it, if water flows through it, it's like it's not there. It's not like it's solid.

[Cuda]

wrong... :)

Smart azz! :)

[Cuda]

wrong... :)
For every complex problem there is an answer that is clear, simple, and wrong.
H. L. Mencken

[thehow33]

For every complex problem there is an answer that is clear, simple, and wrong.
H. L. Mencken


full of good quotes, you are. Well at least the thread got back on track.

[Ed Donnelly]

Wanna bet???????????????:nilly:...Ed

[Cuda]

It's called "thread drift". :)

[Sweet Cheekz]

Drift?
Holy cow, this baby went more than a bit adrift. :nilly:
Parnell

[Carl C]

Haha, at least it didn't get ugly! I don't care if things get side tracked. We're just all here to shoot the sh!t about boating anyway. 75* Thursday, looks like a good day to terrorize Lake Oakland! :)

[Sweet Cheekz]

Wednesday is 72 so I will be trying to raise the bar and terrorize Spring Lake where some ahole called the police and I was stopped already. Even the cop thought that was a bit ridiculous. Have fun
Parnell

[Ed Donnelly]

Carl; Make sure you have a really big dump before going out.
You might pick up an 1/8 m.p.h. more :hyper: ....Ed

[Dr. David Fleming]

Marginal cooling system design is inherent in the Chevrolet engine according to engine development guru Smoky Yunick. In his book Power Secrets he explored the marginal capacity of most American V-8 engines and their inherent cooling hotspots.

"The stock cooling system is basically divided into two halves. The left cylinder bank and the right cylinder bank are completely isolated except for the inter connecting passage in the intake manifold. A stream of preasurized coolant from the right cylinder head enters one end of this interconnecting passage and a similar stream of pressurized coolant from the left cylinder head enters the other end, and the two streams collide under the thermostat housing where they are supposed to make a neat 90 degree turn and continue toward the radiator. Under actual contitions this does not happen! Because of the irregular flow patterns in the internal cavities there are different temperature and pressure conditions in each 'half' of the engine cooling system and the flow in the inter connecting passage doesn't follow the 'suggested' route where the temperature is higher on one side of the system coolant from this side enters the passage under greater pressure, and overpowers the stream trying to enter the other end of the passage. This effectively reduces flow through the 'cooler' side of the system. As a result of this restricted coolant flow, the temperature rises on this side of the system, and as a consequence, the pressure builds up until it exceeds the pressure on the opposite side. At this point, the flow in the inter connecting manifold passage reverses, and the whole cycle repeats over again.

This alternating flow pattern has been going on ever since the first small block Chevy was fired up - and I believe this condition exists in nearly all modern V8 engines - however, its obviously not a problem under normal circumstances. But when the engine is producing almost two horsepower per cubic inch - for extended periods of time - I think it would be a lot better to cool both sides of the engine, instead of just one at a time."

Smokey goes on to study the stock water pump pointing out that it is not capable of supplying the quantiy of water necessary, and that aside consuming using upwards of 15 horsepower will stall the flow in the system at about 65% of the optimum engine coolant needs of 100 gal per hour. He points out that wherever the coolant temp sensor is located there are undoubted hot spots in the engine, especially near the exhaust ports with temp actually around 100 to 150 degree increase. Further that the way the coolant passage in the heads and block are designed the flow is not consistant all the way to the back of the block and heads.

"After a lot of testing with the stock Chevrolet cooling system, we discovered that the most practical approach is to increase the overall efficiency of the entire system. We tried many different modifications, and of all the things we looked at, the most practical approach seems to be to step up the total volume of coolant flow through the system and make a few important modifications to control the pattern of coolant flow through the block and heads."

Smokey ended up developing a system like that found in many truck - drawing the return water out of the heads into the radiator.

Gee, I wonder if it did go 3mph faster without the thermostat? No wonder the fuel puddled in the EFI manifold when it was over cooled! Guess we have applied technology to everything except the cooling system. God I love those dumb looks when you talk to engine builders about cooling.

[Cuda]

Marginal cooling system design is inherent in the Chevrolet engine according to engine development guru Smoky Yunick. In his book Power Secrets he explored the marginal capacity of most American V-8 engines and their inherent cooling hotspots.

"The stock cooling system is basically divided into two halves. The left cylinder bank and the right cylinder bank are completely isolated except for the inter connecting passage in the intake manifold. A stream of preasurized coolant from the right cylinder head enters one end of this interconnecting passage and a similar stream of pressurized coolant from the left cylinder head enters the other end, and the two streams collide under the thermostat housing where they are supposed to make a neat 90 degree turn and continue toward the radiator. Under actual contitions this does not happen! Because of the irregular flow patterns in the internal cavities there are different temperature and pressure conditions in each 'half' of the engine cooling system and the flow in the inter connecting passage doesn't follow the 'suggested' route where the temperature is higher on one side of the system coolant from this side enters the passage under greater pressure, and overpowers the stream trying to enter the other end of the passage. This effectively reduces flow through the 'cooler' side of the system. As a result of this restricted coolant flow, the temperature rises on this side of the system, and as a consequence, the pressure builds up until it exceeds the pressure on the opposite side. At this point, the flow in the inter connecting manifold passage reverses, and the whole cycle repeats over again.

This alternating flow pattern has been going on ever since the first small block Chevy was fired up - and I believe this condition exists in nearly all modern V8 engines - however, its obviously not a problem under normal circumstances. But when the engine is producing almost two horsepower per cubic inch - for extended periods of time - I think it would be a lot better to cool both sides of the engine, instead of just one at a time."

Smokey goes on to study the stock water pump pointing out that it is not capable of supplying the quantiy of water necessary, and that aside consuming using upwards of 15 horsepower will stall the flow in the system at about 65% of the optimum engine coolant needs of 100 gal per hour. He points out that wherever the coolant temp sensor is located there are undoubted hot spots in the engine, especially near the exhaust ports with temp actually around 100 to 150 degree increase. Further that the way the coolant passage in the heads and block are designed the flow is not consistant all the way to the back of the block and heads.

"After a lot of testing with the stock Chevrolet cooling system, we discovered that the most practical approach is to increase the overall efficiency of the entire system. We tried many different modifications, and of all the things we looked at, the most practical approach seems to be to step up the total volume of coolant flow through the system and make a few important modifications to control the pattern of coolant flow through the block and heads."

Smokey ended up developing a system like that found in many truck - drawing the return water out of the heads into the radiator.

Gee, I wonder if it did go 3mph faster without the thermostat? No wonder the fuel puddled in the EFI manifold when it was over cooled! Guess we have applied technology to everything except the cooling system. God I love those dumb looks when you talk to engine builders about cooling.
I believe the LT1's cooled backwards.
It seems Smokey wasn't the last word on cooling an engine.

[yeller]

I believe the LT1's cooled backwards.

That they did. The LT1's were able to run higher compression because they cooled the heads 1st.

[thehow33]

Wednesday is 72 so I will be trying to raise the bar and terrorize Spring Lake where some ahole called the police and I was stopped already. Even the cop thought that was a bit ridiculous. Have fun
Parnell


Do you live on spring lake....I've been there once before during the smoke on the water poker run a few years back.

[CHACHI]

Of course the Evans product can only be used on closed cooling applications.

They also "reverse cool" race engines

http://www.evanscooling.com/

Ken

[BUIZILLA]

the advent of the serpentine belt helped uncomplicate the reverse cooling process...

then again,, is it really reversed?

or was it wrong to begin with? :nilly:

[VetteLT193]

What is reverse cooled from the factory now? the LT1 had it, then the LS1 didn't. Chevy thought it didn't make enough difference. I'm curious if anything moved back to it.

BTW: LT1 has a camshaft driven waterpump so you can lose the belt and still get to your destination. Also helps with premature bearing failure on the waterpump because there isn't load on one side like traditional serpentine. Lots of cool stuff went into the LT1 but not a whole lot made it back out. :bonk:

[Sweet Cheekz]

Do you live on spring lake....I've been there once before during the smoke on the water poker run a few years back.

No, my engine builder is a mile from the ramp at Coops down at the end of the lake. Its pretty empty during the week and especially before Memorial day so its perfect for me to test without many waves or wind
Parnell

[gcarter]

the advent of the serpentine belt helped uncomplicate the reverse cooling process...

then again,, is it really reversed?

or was it wrong to begin with? :nilly:

I was thinking about this this last weekend and I saw some pictures of a flat head Ford V-8.......
And while they weren't known for running cool, they did have two water pumps, one per bank. You could do a lot of interesting things w/that idea.