Rebuilding a 96 5.7 and would like to add closed loop cooling. Engine has new heads and intake and the block has been cleaned very well so rust shouldn't be a issue. What is a good quality brand, with avalible replacement parts?
I'll throw in my vote for San Juan Engineering as well. Great company in Bellingham, WA. Great product but as I'm sure you already know, closed cooling is not cheap!
Okay,
I am considering the Suan Juan mc-314 full kit. This will be on a 1996 5.7LX engine with the Alpha 1 outdrive. I noticed that on several websites that sell this unit it has a note that mentions a seperate seawater pump maybe required.
Any ideas on which situations this may be refering to?
If you install a full cooling system (manifolds included and are running an Alpha outdrive, it is recommended to use the belt driven pump instead of the pump in the outdrive. The belt driven pump has a higher volume output capacity.
So how is this pump plumbed in as I an not familiar with the set up? I assume the discharge hose from the pump is connected to the steering cooling. What about the intake hose, is this ran to the transom shield connected to the discharge from the out drive pump, and remove the original outdrive impellar? or does a seperate pickup have to be installed?
I just want to make sure I fully understand what I am getting into.
Ayuh,... Usually there's a thru-hull seacock installed...
The raw water would come in through it, to a strainer, through the P/S cooler, to the pump, to the exchanger, then out through the risers...
Where are you located? Whether or not you need a seperate raw water pump depends on the temp of the water you run in. Up here it is cold enough year around (exept in some small lakes) that the pump in the leg will cool a full system with no problem, I run a full system on a slightly pepped up Merc 350 and it runs at 180 under load with just the stock pump in the Alpha 1 Gen II leg
Talk to San Juan theyll know. For me(B.C.water) they said my gen 2 pump just fine for 5.0 and they were dead right. Theyll know about warmer temps,might be an issue I dont know.
The gen 2 pump works great with my motor. I think the gen 1 pump would not be sufficent. I have a full kit and love it. The manifolds run at operating temp and the risers are the same temps (never were the same on the raw system). I ran it for one full season now and the only problem I had was the Block off gaskets I got with the kit did not have metal in them so after a few hours of running my coolant escaped and mixed with salt water. I flushed the engine and manifolds real good and installed Mercruiser blockoff gaskets. These have a stainless plate in them. I have not had a problem in the 250 hours I put on the motor since. Oh and winterizing is so easy. They say you can drain the exchanger and it will be good but I drained it then ran the motor while fogging with rv antifreeze to make sure any water left in the exchanger would not freeze and break one of the tubes.
My engine gets to operating temp and stays there no matter what the load. About 175 on my gauge and the same all around the block and manifolds with an infrared thermometer.
Well not for sure what I want to do then. I do have the gen II drive and it will be getting a new outdrive pump amongst many other new goodies(complete transom service) Plan on ordering the kit in the next week or two as I would like to fire the rebuilt motor by the end of February.
I too have installed a full closed cooling San Juan kit and use a Gen II pump for the raw water side. In the dead heat of summer, with water temps around here in the 90's, my engine runs the same temp 165-170 fully loaded. Even ran that temp in the 38 degree water I was striper fishing in last month.
IMO, you'll be fine as long as you keep the raw water side healthy.
If you are interested in another source (for a comparison) check out Sen-Dure. They have been in the business of fresh water cooling systems for many decades.
