Yes haha

So how do you burn off moisture..Water boils @ 212 F. seems way too cool for me. So if your running 170 ish and 190 ish you must have some white sludge somewhere maybe under the valve covers. An engine trying to generate heat with no oil or water thermostats will condensate.

You're correct in your thinking. Counter-current flow is the best scenario for maximum heat exchange, there is no arguing that. On the other hand as you mentioned, you're passing a LOT of cool water through that exchanger and if sufficiently sized the efficiency loss to co-current flow will probably go unnoticed.

The stock oil cooler (HX) is a shell and tube setup, oil on the shell side and water in the tubes. As the HX gets older there can be mineral deposits from raw water on the tube's ID or varnishing from oil on the tube's OD, probably a little of both. This is known as tube fouling and will reduce the tube's ability to transfer heat. (On big HX's this decreased capacity is accounted for in the initial design stage.) So as one approaches the effective limit of the HX these small differences may begin to amount to something more significant.

Funny things happen when you ask something to operate continuously at 100% capacity. I think that's what OP is seeing here, and he probably needs a bigger cooler. Plus they look better on the bellhousing anyway. :)

/nerdiness

Only in spring I get it till about beginning in June if I don't run it hard, but I also run my boat much harder then most people do... I have zero condensation issues from June-nov.

So if my cooler is not big enough, then why when I install my water dumps (which i am going to do this week) my water pressure and my oil temperature drop. I believe the issue here is the Eddie Marine Risers are holding back too much water, creating pressure and not letting the water flow faster thru the cooler

You've changed it's operating conditions and now it's performing acceptably. Pressure is resistance to flow here so you're indirectly seeing an increase in water flow and thus an increase in heat transfer. This is especially true because the impeller isn't a positive displacement pump, it's flow rate is directly, though not linearly, correlated to discharge pressure.

You opened up the flow path, efficiency increased, temps came down. :)

My sensor is in the oil filter which is before the cooler

Thank Cole2534 This is what i have been trying to explain here ....I only said this 10 times....With the water dumps the water flows thru the cooler at a faster rate lowering the oil temps..NO BIGGER COOLER NEEDED..The faster the water flows thru the cooler the more heat gets extracted. .But this makes my Stainless riser run a bit warmer at idle with idle water pressure.. At this point i say let the ss riser run warmer...its not going to melt..:cool-smiley-027:

Eddie, If you increase the water flow thru the cooler it will extract more heat from the oil. I did this by dumping some water between the exhaust manifolds and the risers. Temps will drop.

So in my case i have high water pressure, high oil temperature, all because my water flow thru the cooler,engine,exhaust, can't exit fast enough and is being held back by the 3 small holes at the end of my exhaust risers. How much water pressure is needed to cool..I'm sure you don't need 16lbs @ 3200 rpms and over 20-25 or more @ wot. So the Merc pump is pumping more water than the engines, hose size, fitting size water outlet sizes and in turn is slowing down the flow increasing pressure increasing oil temperature because the water outlets are too small and can't get out fast enough

Why do I say your cooler is too small? Well, for starters, some of us prefer to have an oil system that cruises with oil temps in the 190-200 range, and maybe get to 210-220 when holding it at 6000RPM for several minutes at a time. With no oil thermstat, and cruise oil temps of 220-240 degrees, your clearly taxing your oil cooler. Hold it WOT for a couple minutes, and you'll probably start cooking the bearings out of it. But hey, if you are into cruising along at 3500 rpm , and can care less about wot oil temps on hard runs, by all means, its your boat.

What Eddie Marine said about keeping pressure up in the exhaust, is a valid statement. This ensures that the risers/tails are FULL of water, even at idle. We get that reducing flow, made your oil temp hotter. I agree that increasing flow, will remove more heat. What would solve both your issues, would be a larger cooler. This way your tails would stay cool at idle, and your oil/heat exchanger, would remove more heat per gallon of water flow.

Just because water boils at 212, doesnt mean if it doesnt get to 212, you will forever have moisture in your oil. Theres a million stock black merc motors that rarely get over 170 deg oil temps, and dont have issues for thousands of hours. Get a soup pan, put a cup of water in it. Heat it to 170 degrees on the stove. You will see, that while it may not "boil", the water will still be steaming, and eventually evaporate. Condesation in oil can be an issue, especially if you run in 65 degree water, have 95 deg water temps in the block, and 180 degree oil. Its just like when you put an ice cold 35 degree beer out on a table in a 100 degree day. But, an 80 degree beer can, on 100 degree day, won't condensate.

I asked what your ignition setup is, because low timing at idle, can make the exhaust really hot at idle.

You came here with a question, pretty much told everyone they were wrong, and now are teaching Eddie Young about cooling systems. The man has probably rigged more big power offshore boats than anyone on this site.The ideal setup, is a cooling system that keeps all part temperatures in line, and an oil system that keeps oil temperatures in line. Theres a reason Mercury racing used an oil thermostat setup on the HP500, along with a larger oil cooler than the stock 502 mag oil cooler, with no oil thermostat. The oil thermostat elements begin to open at 180-190 deg, and are fully open by 210. If you have a merc Hp500, 525EFI, or pretty much any merc racing engine, and see 240 degree temps at only 3500RPM, something is WRONG. Matter of fact, the smartcraft alarm on the 525 will be buzzing in your ear.

If you have hot spots in your tailpipes at idle, which can really get things hot, and then give it throttle, throwing cold water on hot stainless, eventually it could split a weld, and send water into your engine. This was a common problem with stainless headers over the years, and a reason why many of them have ruined engines over the years.

Either way, sounds like you got it figured out. Good luck.

Ya, I was just putting some tech behind your findings.

I understand that completely. I never said anything about increasing or decreasing water flow. I was only talking about the direction of flow of oil and water and that we haven't seen a measureable difference between having the oil and water flow the same direction or opposite of each other.

By reading temps before the cooler, we are only guessing. What is the temp of the oil after the cooler.....the oil going into the engine? By reading it before the cooler, you are taking the cooler out of the equation. For example, lets say the oil before the cooler is 250*. If you have a 2 x 8 cooler, then the oil going into the engine may be 220* and if you have a 3 x 18 cooler, the oil may be 180*. That's a huge difference. One is a problem and the other is not. IIRC, you have about a 3 x 12 bundle for the oil cooler (longer overall but has P/S cooler also). That cooler should remove at least 50* (with enough water) when the oil is over 200*. If your oil before the cooler is only getting to 240-250 at WOT, then you don't have a problem. It's not uncommon for engines to see 230 going into the engine. This is for higher HP engines at or near WOT, of course. How hot will it get? That's my question.
Eddie

Thanks for the explanation. So my filter should be after the cooler as previously posted so I can read the oil temp after being cooled. Interesting, for now I am going to check the accuracy on my gauges and senders with a infrared thermometer. Cruising @ 32-3400 rpms it shows on port side 225-230 Starboard side is cooler.
215-220. I never saw my gauge go past 240-250 on a WOT run. Maybe i'll swap the senders. Oil lines are going with the flow on both engines. I don't know what the water temp is now on the river.I'm sure its a least 75-80 cooler would be better. I'm going to call Eddie Marine and ask if I can dump some water without hurting the risers.

It's not only the cooler, the stock merc lines, fittings, block/filter adapters are junk, very restrictive, upgrading all to run #10 lines is the way to go, I use a eddie marine cooler that works great and is priced well, also added a canton thermostat as well, as with my procharger crossover oil temps were always very low, there is a very in depth thread on here discussing the stock oiling system...

I asked what your ignition setup is, because low timing at idle, can make the exhaust really hot at idle. And I answered you several posts back 34deg. Locked

You came here with a question, pretty much told everyone they were wrong, and now are teaching Eddie Young about cooling systems. Sorry you feel that way BUT No i did not say everyone was wrong and I was not teaching Eddie about cooling systems. We were talking about direction of flow.

Good point Thanks

Here is my cooler http://bpi.ebasicpower.com/p/HEXMER817577T

You seem concerned about your water psi being too high at 15-16 lbs. water pressure is a good thing in my opinion. My boat has over 30lbs at wot and never had a problem with hoses or gaskets. With a oil thermostat my oil stays between 190 and 220. Stock merc setup.

The benefit to higher water pressure is that it increases the boiling temperature of water.

http://www.cappusa.com/info/wp-conte...07/steam_1.jpg

My 95 502 efi has separate coolers for oil/ps, the oil cooler is 3x18, I believe its the stock system that came with it. Your engine is making a 100 more horsepower than mine, ie more heat. I agree you need to move more water, and pressure regulated dumps is an easy fix there, but you're still asking the oil cooler to more than it was designed to do.
Kinda like asking 10000btu wall air conditioner to cool the whole house.

I'm just trying to make my system a little more efficient instead of spending thousands on coolers hoses etc. We are only talking about 15-20 degrees here. When i had the silent choice my pressures and temps were lower. Now since i removed the silent choice and added longer pipes oil temp and water pressure went up

I just called Eddie marine and they said a lot of guys dump some water before the risers. They have no problem with that.

here's the one from eddie marine that I run, works great..700hp
http://eddiemarine.com/engine-parts/...-1-1-4-slip-on

I have combos so if i switched to those I would also have to get power steering coolers also. The water lines on my coolers are on top and bottom not on the sides, I would have to re-do my 1 1/4 hose setup re-routing it out of the oil cooler down the back side of the engine then into the smaller PS cooler then another hose up to the t'stat housing and i would probably have to add a different type of oil filter housing with an oil thermostat like the HP500 engines.. I think i will just bleed some water out. Its starting to add up x 2

I have same ones from Mr. Cool...

If I wanted to spend as little as possible I'd:
-Thoroughly clean the existing coolers. Bore brush the tubes, solvent through the shell.

-Open up the water dumps on your tails and any other flow restrictions. Some time with a dremel should do this.

-Check the transom piece for corrosion.

-Inspect the suction hose. It's already off, give it a squeeze and make sure it doesn't collapse.

You might want to check the jetting on your carbs . after the riser change , u might have been running lean causing ur elevated oil temps.

Good point..............My end caps come off my coolers, maybe its time for a cleaning thanks

Update
 

I just wanted to say thanks to all for the help on my oil temp issue. After Running last weekend i decided to remove the end caps on my coolers. I was shocked at my findings. I can't believe the oil wasn't showing hotter and the engine water temp was at normal 152. SAND<PEBBLES>SEAWEED CLOGGED IN BOTH COOLERS.
Curious about the oil temps after cleaning

[ATTACH=CONFIG]544596[/ATTACH][ATTACH=CONFIG]544597[/ATTACH][ATTACH=CONFIG]544598[/ATTACH]

Yea.... There might be your problem. Good find

Well done!

Glad to see it looks like you found your problem !

You don't have to boil water (ie: to turn it it turn to steam) to remove itself from oil, or other things for that matter.

Evaporation can happen at much lower temps. However, yeh, the hotter it is, the faster it will.

No strainers??

Good call!
wonder how many have ever eyeballed the inside of a heat exchanger.

Or their intercoolers !

No. The boat never had them as long as i have it..7 years. Strainers get in the way and makes it tough to work on the motors. I can sit in the front of my engines and work with ease. Plug change 1/2 hour each engine. Seawater pump out in 10 minutes etc. I never took the end caps off in 7 years and its very easy too. Now it will be a regular routine. I'm sure the water pressure will rise and i'll know where it should be. When it drops or when the oil temps starts acting up i'll know where to go.

Gotcha, mine are low out of the way also have tons of room I didn't think a fountain had much space, I have like 3 feet in front of the engines it's nice.... [ATTACH=CONFIG]544605[/ATTACH]

35 Fountain with bravo's should have plenty of room in the bilge for strainers. Here is a picture of a 35 with Speedmaster drives, and transmissions, which move the engines forward about a foot. Still plenty of room.

I hate that halon on the bulkhead wall. I either rip my shorts or cut myself on it!!

hahaha,,,,and I thought I was the only one who had that problem.not to mention how many times I have gouged my back on it.