Rage

Well then I need to look further in that direction.

Mr. Cool

This is a good thought above, but I'd like to suggest a twist to it. If you completely block off the bypass instead of opening it up, you could evaluate whether the cooler will handle the heat rejection from the engine. If it continues to climb and you have no blockages in the cooler, it suggests the cooler you have is not capable.

I realize it's your engine, but this is becoming personal.

A note: Sometimes aluminum components (e.g. blocks) are used and if so, they can leave an aluminum oxide (as I remember) that attaches to the copper forming an insulating barrier on the tubes you can't see that substantially reduces the cooling capability of the cooler. If it is a used cooler, that may have happened before you ever got it. The easiest way to remove it is phosphoric acid. It doesn't happen often, but it does happen.

I don't think the counterflow is going to get you where you need to be my friend. Please post results of the test. I'm very interested.

realistic possible causes (not intended to be a complete list): oil volume, water volume, aluminum oxide, internal blockages, air in either of the lines, overall oil volume too low, . I'd start a list and start crossing them off as you test for them.

It is not: Cooler size, construction, thermostat blockage, etc.

I use an IS/IS NOT matrix to track the resolution of issues like this. I'll email one to you later today.

Rage

Mr. Cool,

Thanks for your considerable input. Plenty to keep me busy for a while. I will post updates when anything significant is learned. I think I mentioned before but the unit was new when installed about two years ago.

Any suggestion on how best to "block" the thermostaic oil bypass on the Hardin design oil cooler?

Rage

Hardin Marine advised the the 620-700 oil cooler is rated for 700 hp when the cooling water temperature is 70F flowing at 14 gal/min at 15 psi (open cooling) and the 'cooled' oil temperature should be 190F (same as the thermosate setting). Some more parameters to check.

Mr. Cool

Any suggestion on how best to "block" the oil bypass on the thermostatically controlled oil cooler?[/QUOTE]

OPtion 1: If you use a 170F Tstat which will actuate very early in the temp cycle. The one in the picture is a 170F.

Option2: Quite risky. Take the set pin out of the end of this one and unscrew it a bit. Remember this is not a long term solution. I have to say that this is an "at your own risk" trial. You have to make sure you have the cross pin gets put back in place or it could go back through your oil system and into the engine. Be very very careful. But this will force the oil through the cooler.

I've had better ideas in my life, but this is a possibility. I'd almost solder or braze or ~something~ that end in place.

I'd try option 1 first. I'm checking the config of the T stat shown to make sure it's going to seat. So I'll be back to you on that.

I have them here. $30. Boss says I'm to sell product, not give it away.

Sorry. :-|

Rage

OPtion 1: If you use a 170F Tstat which will actuate very early in the temp cycle. The one in the picture is a 170F.

Option2: Quite risky. Take the set pin out of the end of this one and unscrew it a bit. Remember this is not a long term solution. I have to say that this is an "at your own risk" trial. You have to make sure you have the cross pin gets put back in place or it could go back through your oil system and into the engine. Be very very careful. But this will force the oil through the cooler.

I've had better ideas in my life, but this is a possibility. I'd almost solder or braze or ~something~ that end in place.

I'd try option 1 first. I'm checking the config of the T stat shown to make sure it's going to seat. So I'll be back to you on that.

I have them here. $30. Boss says I'm to sell product, not give it away.

Sorry. :-|[/QUOTE]

Thanks Mr Cool. I'll think about that.

Rage

Mr Cool,

Attached are some oil temperatures recorded going into versus coming out of the Hardin Marine 620-700 thermostatically (190F) controlled oil cooler per my installation. Do these numbers seem to indicate that this oil cooler is functioning properly?

smiklos@sunprint

iTrader: (1)

While I have had many hi output 496's> I have never had one apart is it possible that you are bypassing some oil and it is not going through the cooler? I would ask Ray or Dave at Innovation.
Steve

Rage

A not so quick synopsis. I'm trying to keep my motor's crankcase oil temperature below 250F during long WOT runs.

The 3X18 oil cooler seems to be working within its capability though maybe just not big enough. I am getting plenty of sea water pressure at WOT from my low water pickup Bravo drive in excess of 43.6 psi at the pump output (which is full scale for the PCM555 ECU readout) and still 38 psi at WOT when I add an additional 5/8"ID sea water dump (similar to Whippled 496 intercooler) just down stream of the oil cooler to increase the oil cooler water flow/cooling. If my Bravo was side water pickup only I would need an external water pickup. I do not think ext P/U would improve my cooling. I also have plugged the Bravo drive's side sea water inlets above the waterline when trimmed out to prevent water pressure loss or areation. I am planing to try closing them off completely to see what happens.

The stock 496HO coolant thermostat is 160F. I am running the 120F coolant thermostat which keeps coolant at ~130F normal operation and 150F max for long WOT runs so still better than stock.

In a nut shell I think everything seems to be working well i.e. no malfunctions but it is just not enough. One thing that caught my attention was a comment that the 3X18 oil cooler is good for ~50F oil temperature drop which seems to be confirmed in general by my oil IN versus oil OUT temp measurements (the oil IN temp was from a temp sensor in the oil flow but the oil OUT temperature was from a thermocouple attached to the aluminum -AN cooler output fitting so OUT readings will be lower than the actual oil OUT temp). The thermostat is set at 190F-215F per Hardin Marine. Using that number the oil cooler thermostat will work to maintain (190F-215F) + 50F in the crankcase = (240F- 265F). 'Mr Cool' has a 170F thermostat that will work in the Hardin oil cooler which I am considering. I am concerned that completely blocking off the oil thermostat bypass would result in the oil never warming up enough to burn off condensation during normal low HP cruising/wake boarding/tubing/etc at 2500 - 3000 rpm that makes up about 95% of this motor's operation. See attached Merc Tech Bulletin on the subject though that may be related to blower motor fuel contaminating the oil rather than condensation.

Whipple says that for the 'Porker Run Types' he recommends the 1200hp Teague Extreme oil cooler or similar and the Sen-Dure 1" bigger diameter heat exchanger than stock for the Whippled 496HO at ~650hp or ~50 hp more than mine.

Guidance is welcome.

Rage

Hey Steve,

Thanks for the input.

I have had those conversations. The answer is yes via either of the the bypass valves in the engine block's oil filter boss that has an oil filter adapter mounted there for the Merc marine engines that routes the oil from the engine to the remote oil filter. With the Merc 496 setup the one bypass valve is blocked off completely by the oil filter adapter but the valve is still present from the GM base truck engine that Merc purchases from GM. The other bypass valve is still functional in the Merc engine. The stock bypass valves open at ~11 psi of back pressure from the oil filter or plumbing blockage which allows oil to then bypass the oil filter which also alows the oil to bypass the oil cooler. Ray gave me 30 psi bypass valves which I installed. So under normal oil filter/cooler plumbing operation no oil should be bypassing the oil cooler.