Oil cooler

[mcgradypilot]

Hey guys I wanted to get some opinions on adding an oil cooler and also post on some trouble I had so it may help someone else.

I have a 1993 Four Winns Horizon 210 with a VP 5.7 GLIPLKDCE with duoprop. I have read that it is normal to have oil pressures as low as 10 psi after running hard. I am not a fan of pressures that low and oil that warm. To me it promotes oil breakdown and wear. Maybe im being a little paranoid. I am thinking of adding a remote filter/oil cooler. The whole setup would cost around 300 bucks. Currently running amsoil 10w30 synthetic marine. Any opinions?

I bought the boat this summer and knew it needed some love. New fuel pumps, injectors sent to be cleaned, new plugs, list goes on. I just got done battling a saga of the boat pinging at 3000 rpm or higher, then power loss at 3000 rpm or higher (after replacing knock sensor). After checking EVERYTHING fuel and spark related I found out I had a clogged cooling passage in my port exhaust manifold. And when I mean clogged I mean took a heavy duty drill to remove clog! Eeeeek. The boat always ran at 150 or so on the temp but would get warm (200) when I came off plane and idled around. I figured it was a my abuse of starting the boat without the muffs and beating up my new impeller. Sure enough I go to winterize the boat and find that the thermostat is missing, the block is full of crud and the risers/manifolds are as well with the port being clogged. Long story short. If you get some kind of power loss dont rule out cooling. My heads where getting so hot it was causing detonation. Its a common problem in the jet boat world (not the yamaha/seadoo but Big Blocks/Berkley) to restrict cooling water flow to increase engine temps. Running temps will increase but the heads lack the necessary volume to keep them cool causing problems. Sorry for the long post but I hope to help someone with the same problem as me. Im no expert but if anyone has a question about the VP 5.7 GLI/GI/GSI (throttle body injection) please feel free to PM me.

 

[Maclin]

Re: Oil cooler

What gauge are you reading the 10psi from? If it is just the stock electrically triggered gauge, and since you are concerned about the reading, I would plumb in a mechanical oil presure gauge and compare readings in all situations just to be sure a true low pressure situation exists.

 

[dypcdiver]

Re: Oil cooler

My 5.0 Gi has run at 10/15 psi at 600rpm tickover since new and now after 551 hours it is still the same. I run Mobil S (semi synthetic) Sae 10/40 and change it every season. Like you I was a bit concerned as I am used to working on engines that tick over at 25/30 psi, however it is a nice quiet engine still, I would not be worried.

 

[jerryjerry05]

Re: Oil cooler

It would only improve an already good system.
Not really needed.
I think yours came with a remote filter.
It wouldn't be real hard to install one.
Cobe Marine in Pasadena,Md Good Volvo parts place.

 

[Scott Danforth]

Re: Oil cooler

I suggest you check with a known valid mechanical gauge.

Anything below 30 psi is either something worn or too thin of oil.

generally low oil pressure is because GM uses cheap oil pumps that start to wear quickly.

first thing I do with every SBC or BBC that I work on and have the pan off is throw in a Melling high volume oil pump and pump shaft. Best $50 anyone could spend. That is just my choice.

Since your running Amsoil, i would switch to their 15w40, 15w 50, 20w50 or go with their straight 30 weight

 

[Walt T]

Re: Oil cooler

Nothing wrong with high volume pumps, but the stock gm oil system is very very good and works best being left alone. The oil pumps last 100K+ miles on autos, and will last on marine use. The term "generally low oil pressure is because GM uses cheap oil pumps that start to wear quickly" is not true. Its because of bearing wear and it's covered up with volume oil pumps. I've built many many a high performance marine engine and as long as they are built for no more than 5000 rpms the stock oil system is fine. Rpms above that and it's a whole different ball game.

Not flaming Mr. Danforth, I'm just giving my opinion based on my experience. Mr. Danforth has his opinion he is basing on his experience and I have to agree that throwing in a new volume oil pump will do no harm at the very least. But it is the bearing clearances in the engine that determine oil pressure. If McGradypilot does in fact have that low of oil pressure after checking with a mechanical gauge, then Mr' Danforth's advice with the heavier weight oils will definitely get it up. However if you are going to pull the engine to install a new pump you may as well replace bearings while you're at it or measure clearances at the least. I agree with everyone an oil cooler is a good idea however it is not to be used as a fix. I am positive your gauge is wrong and you're fine. You do need to solve the heat and detonation problem. It is possible the detonation has crushed rod bearings a bit and now your oil pressure is low. It sounds like you're in line for a new/rebuilt engine. I would suggest you consider a stroker motor for your boat.

 

[Scott Danforth]

Re: Oil cooler

Walt, dial indicators and platigage are staple tools in my tool chest - one for thrust clearance, one for radial clearance. checking bearing clearances any time the pan is off on anything is standard practice (SBC rod clearance spec is 0.0020 - 0.0025 and mains are 0.0020-0.0030). Anything greater than 0.007 and its mike the crank and new bearing time. Heck, I even checked the cam bearing clearances on my Audi-s and VW's when I pull the valve cover. At least on the first tower near the belt/chain pulley.

I still believe in higher volume oil pumps (strongly believe in them on Buick engines)

If the OP has true low oil pressure, then more checking needs to be done.

 

[mcgradypilot]

Re: Oil cooler

I have a mech gauge I am gonna double check the pressure if I ever get a day off. If its bearing wear thicker oil will just mask the problem. It's a solid 50 lbs at 3k rpm hot. Closer to 65 cold. I had a jet boat with a 455 oil and its 10 quart pan and straight 50w kept pressures up. I am more curious what is normal for this engine. Hot pressure wise. Mercury lists 4 psi min for their 5.7's. Is hot oil pressure normally low?