575SCI's, Thermostats and high temp alarm.
 

Wondering if others with modified 575SCI's have removed their thermostats to keep water temps down?

Now that we are deep into the season up here, our lake temps are in the 80's, My ECM's have been re-programmed for 120 degree T-Stats but after a long hard run, (5650, 7lbs boost) temps will climb high enough for the temp alarm to go off so I pull back until the alarm shuts off and all is well again. If I'm just cruising, no boost, temps are normal. When the lake temp is cooler, Spring/Fall, I do not have this problem.

The fact that a blower motor is fitted with a thermostat just does no sit well as you always want as much cool water to the heads as possible. I'm wondering if I can have the ECM re-programmed to not run a thermostat at all to keep temps down. Can the MEFI 3 system function properly with cold water temp? Thanks in advance. Kurt

-Also, both sea pumps are replaced. This is not a new problem, happens every season once lake temps creep up.

Mines be running about 150* too. One will run about 150* at cruise, then creep up when running hard. The other seems to stay around 130* at cruise, then creep up when running hard. 8 lbs water pressure average at cruise (which is same as with new sea pumps).

I'm going to put some new sea pumps on it this week and see what happens.

I'm working on one that is turned up a bit and can't make them run cool either. Water pressure on both motors is kinda low. What are you guys seeing for water pressure?

My water pressure is 10 lbs wot. Has always been that way

What temp is it at that your alarm is going off?

That seems awfully low Kurt. My engines, while custom, cruise at 12psi around 3000rpm, 18 psi at 4000, and 25psi at 5500+. Thats with a transom mounted water pickup, no T stats. Water temp never comes off the 100 deg mark no matter how long I hold it.

How hot does your oil get? Maybe some mods to get more water in at the pickup? You running intercoolers off the system?

I have never had my temp alarm go off with stock or 120 stats. Of course most of the time I was running an imco lower with huge pickup.

Yeah, I think water pressure should be higher but that's the way it has always been. Oil temps are normal, runs about 220 wide open. They have the factory Merc Racing thermostats. Intercoolers are plumbed with separate transom mount pick-ups. Lowers are Sportmasters, wondering if they just don't flow that well at speed.

About 175 -Gaffrig gages.

I don't have chillers, but have the AZSM kit (120* thermostat and small pulley) - minus the tune that Eddie Young did over the winter. I'm now running roller cam, as well. When I first got it back from him, water pressure was much better than it is now and temps stayed around 125* on both motors (and that was with old sea pumps). But over the course of the summer, the water pressure has regressed a little and temps have increased. Eddie also put in plugs in the top 2 holes on the DWP drive and scalloped the lower holes to grab more water, and I also have nose cones installed.

At cruise speed (3200 rpm), I'm at about 6 pounds, at 5000 rpm I think I'm around 13 pounds.

If anyone has any tips to get water pressure up, I'd love to hear it. I probably should have just put pickups in it while the motors were out.

Kurt, I can program the ecm so that you can run it ice cold without a thermostat. However, you should be able to get it under 140 deg with enough water. 175* is entirely to high on that engine, especially with 7 psi of boost. What drive and/or water pickups do you have? If it just has the side pickups, you can start plugging the top 2 holes. With a high X dim., the water will enter the lower holes and come right back out of the upper holes. You definitely need to get the water pressure up some more. That is way to low. I'm actually surprised that the oil isn't getting hotter than it is.

Terry, IIRC, we moved the location of your water pressure hoses from down in the block to up higher somewhere????Is that the case? If so, then they probably aren't getting clogged up. They still may be worth checking. If they are still down in the block, they will easily get plugged up and not read correctly. If you want, you can plug the next hole down on each side. You can also drill another hole at the bottom. You would need to make a lead-in to that hole like I did on the others. That should help a bunch. If you aren't comfortable doing it, we can certainly do it. We could schedule a day where we could make the mods, go run it, and you can just take it back the same day. For that matter, we can do it at the boat ramp. Just let me know if you need our help in any way.
Eddie

[QUOTE=Young Performance;4347340]Kurt, I can program the ecm so that you can run it ice cold without a thermostat. However, you should be able to get it under 140 deg with enough water. 175* is entirely to high on that engine, especially with 7 psi of boost. What drive and/or water pickups do you have? If it just has the side pickups, you can start plugging the top 2 holes. With a high X dim., the water will enter the lower holes and come right back out of the upper holes. You definitely need to get the water pressure up some more. That is way to low. I'm actually surprised that the oil isn't getting hotter than it is.

Thanks for replying Eddie. Drives are Sportmasters, with the pick-ups just under the bullet. I'll be sending you out the ECM's in the off season. -Have you seen this issue with high water temps on these 575's in other applications?

Not that high. It has to be due to lack of water pressure. Have you checked the water hose that runs through the gimble? That plastic cone that holds the hose in place can collapse and cause a serious reduction in water flow. Is the X dim really high?
Eddie

Have not checked the water hose but the boat was only used in salt it's first season, 2002. Bee on the lake since but I will check it for sure. X is not terribly high.

Yes, you are correct. You moved the WP pickup point to the rear intake manifold. ...and I have not cleaned that out, but will try and do that this weekend, but engine is still running a little hot - so I'm guessing that the higher temp confirms that water pressure is actually low. Nonetheless, the hose needs to be confirmed.

I tapped and installed plugs in the 3rd hole down last night. I'll confirm if that helps on Thursday.

Thanks for the advice, sir!

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Installing plugs in the 3rd hole down from top (3 holes) plugged did not help nor hurt the condition. I'm planning to install a 4th plug this week, and see if I can get in and confirm the oil cooler is clean. That oil cooler is a MF'r to get to !

This weekend, I installed a total of 4 plugs in both drives and replaced sea pumps on both engines. No change. Still have low water pressure and high water temps.

Check your balls. Are they loose and dangling. Try shimming them up. I picked up a few pounds after doing this. Begin!

Ha - you and I have had that conversation on my other thread !

http://www.offshoreonly.com/forums/d...-advice-3.html

I removed the bottom plug from the side pickups - so now have a total of 3 plugs installed. I did notice something funny at Cumberland last weekend though. When turning right, water pressure goes down (to 2-3 psi) on starboard motor - when turning left water pressure goes up (to 10-12 psi) on starboard motor.

Does that mean the water intake hose is kinking or getting soft (too pliable)??

Just wondering if anyone has experienced this situation before. Didn't get a reply last year, but it was late the in season.

Any thoughts?