Knot 4 Me

No, he does not have oil temp gauges and doesn't have the dash space to add them. Most of his boating is done on a 6K acre nuclear power plant cooling lake so the water temps are in the 80's to 90's depending on the time of year. He is currently running circulating pumps with 160 degree t-stats but was mulling over going with cross-overs with 146 degree t-stats.

ICDEDPPL

iTrader: (1)

How can you not have something as essential as oil temp gauges? Boggles my mind.
Do it right or don`t bother.
I had no room on the dash but I added 4 new gauges .. theres always room somewhere.
Or just run around guessing at it all summer

Knot 4 Me

I'm thinking A-pillar pods mounted to windshield frame!

MILD THUNDER

iTrader: (3)

I have pods on top of my dash that house fuel psi and boost. There wasn't room on the main panel, but what ya gonna do. Like ICDEDPPL said, there's always room.

Budman II

iTrader: (1)

FWIW, I built a Gen VI 489 and ran the stock 330 HP combo oil / PS cooler on it. However, I did go through the extra effort of eliminating the remote oil filter mount and lines, and went with a thermostatic oil filter sandwich adapter and #10 AN lines to the cooler. This eliminates almost all of the sharp turns and restrictions that the stock lines will have. IMO this is even more important than the cooler capacity. I generally saw temps of around 185 - 190* when cruising, and it went up to around 225 - 230* if I leaned on it. I generally do not run mine WOT for more than about 5 minutes at a time, and even that is rare. Most of the time I run between 3000 - 4000 RPM. If your buddy likes to run his at WOT for extended time periods I would recommend the bigger cooler and also better lines and fittings, especially in water temps that are that warm.

As far as a gauge, could he mount something under the hatch and just check it after a hard run? That would at least let him know if he has an issue. A low cost solution would be to just aim an infrared temp gun on the oil pans after a hard run. Hell, a buddy of mine came up with an interesting low cost / low tech solution that he ran for a while - he drilled a hole in a pipe plug and epoxied a digital oven thermometer into the hole. Gave him a reading on where he was at so he knew whether he had an issue. Of course he replaced the plug after this - I would not trust JB weld in a critical application like this. Of course, the down side to not having an oil temp gauge is that you don't have a real time reading - sometimes disaster can be averted if you shut it down when you see the oil temps starting to get too high. Bearing problems and water in the oil often show up this way before making themselves apparent in other ways.

Knot 4 Me

Trust me Gentlemen, I've already been in his ear about adding oil temp gauges. Given that we don't know what his oil temps were prior, and the fact that he is going to what we estimate will be 500 HP 496's, can an educated guess be made ahead of motor installation if bigger coolers are needed? Obviously it is much easier and cheaper to change coolers now that the motors are out. Would going to cross-overs with lower temp t-stats have any significant impact on oil temps with the stock coolers?

Budman II

iTrader: (1)

Did he find the issue that caused the one engine to hydro? I would be more concerned with making sure that was corrected. I completely understand that adding gauges and bigger coolers would be difficult at best after installation in a twin engine boat. That's why it's probably best to do it now, versus find out the hard way later, especially if he likes to lean on it.

Knot 4 Me

Crappy rubber flappers in exhaust tips and came off plane way too quick and at an angle. New tips going on with stainless flappers. Ran boat for 5 seasons with the tips in question with no problems.

Keith Atlanta

Dude! Great chart!

Saved it to my "boat engine" file. Good stuff!

bobl

Definitely upagrade to larger oil coolers. Those stock 7.4 coolers will not support much over 400 HP. Even Merc used larger coolers on the 454 Mags.

Bob Lloyd
Full Throttle Marine