oil temp too hot any suggestions?
 

I have a new bbc, dart block etc. the motor has about 4 hours on it and I cant control the oil temp. the temp will get up to 140 while idling for a little while and thats fine but as soon as I run the motor at any rpms it will heat the oil up to 260 to 300 degrees. the wierd thing is that the oil doesnt cool down when you slow down you actually have to let the boat idle for a while to cool down the oil. the engine temp never gets over 150 degrees. I have a remote filter and I am using the mercury racing filter. the lines are plumbed properly, I have a 3x18" cooler. the cooler is the first thing fed from the pump, the oil runs opposite from the water direction. the oil lines are routed from the block adapter to the remote filter from the remote filter to the cooler from the cooler back to the block adapter. I can take the drain out of the oil cooler and with the boat running the water is hot so I assuming that the cooler is dissapating heat? the sender is in the pan and I have changed the sender already but I am not eliminating a bad sender(wishfull thinking). I am open to suggestions. could the cooler not be any good? the dart block doesnt use the 11 or 30# bypass to my knowledge.

good oil pressure? Are you SURE everything is plumbed correctly? Doesnt sound to me like oil is flowing through the cooler for some reason. The way it sounds, the oil is relying solely on the water flowing through the block to cool it down, which will not happen with any rpms.

Are you sure that your water pump is pushing water? do you have a water psi gauge?

Do you have an oil thermostat installed? could be sticking shut.

I do not have an oil thermostat, the pump is pushing water at least it is out the exhaust, I ran the motor with the drain on the cooler open and it was pumping water through the cooler but the water was hot, I do have a water psi gauge and it has water psi. I have plenty of oil psi about 70 psi cold and 45-50 hot at idle. I am thinking that the cooler may be partially clogged on the oil side or????? I guess I will replace the cooler next. both lines running to and from the cooler are hot to the touch after running it. as far as the plumbing it runs from the pad adapter to the filter inlet from the filter outlet to the cooler from the cooler to the inlet on the pad adapter. I believe that this is correct?

how do you have the water lines ran.

the water comes into the pump and out of the pump to the cooler, out of the cooler to the power steering cooler, out of the ps cooler to a crossover on the front of the block, through the motor and out the exhaust. I do not have a circulating pump on the motor. this setup worked fine on my other motor?

Not much to an oil cooler. I suggest you have it checked out a local radiator shop before you buy new.

What kind of oil pan and how much oil in the engine.

I have a dooley pan its a 10 quart pan and thats what I run in the engine.

U need a bigger oil cooler thats all. or it maybe klooged somewhat/where.

I am going to order one today, anyone have any reccomendations?

I wonder if your cooler is partially plugged causing the bypass in the filter to bypass most of the oil past the cooler?

3 X 18 oil cooler should be good for a min of 750 HP @ 6000+ RPM. If your cooler is good, you haven't likely found your problem.

Do a search on here for oil pressure by pass valves. It's located in the oil filter pad on the block.

If it's the stock valve, the oil will take the path of least resistance and by pass the filter and cooler.

its a dart block. I dont believe it has the bypass valve.

What is the jetting in the carbs and what carbs? Lean will cause this problem.

Do you run flat tappet lifters and is so what is the seat pressure?

But in all likelyhood the engine clearances were set up too tight. Do you know the rod and main clearance? What weight oil are you running?

the cam is a hydraulic roller, the carb is a pro systems dominator I will have to look at the jets again. the plugs are nice and brown. I ran the boat shut it off and checked them. I dont have the rod and main clearances but I will find out what they are. I am running valvoline vr1 race oil 20w50.

Make sure your raw water pump is good. I recently had higher than normal oil temps with normal coolant temps and what appeared to be plenty/normal amount of water out the back. Changed the raw water pump and all is well.

its new but I will pull it off and check it anyway.

I had the same issue last week and also had a loose belt so at idle all and low speed cruise all was fine but above 3500 rpms oil temp would start to creep past 220 deg. After cruising @ 3800 for about 45 minutes it slowly made it up to 260-270 deg before I decided to back down to 3400 and let it cool. I was nervous it was blow-by or a bearing going away so first I decided to replace the raw water pump, back-flush the cooler and tighened the belt and all is good for me.

Check your carb jetting. 2 jet sizes are enough for mine to run 20 degrees hotter oil.

update. the cooler is an eddies marine chrome cooler. it is a 3" cooler and it is 20" long but it has the ps cooler built in. I am not using the cooler as a ps cooler as I have a separate cooler for the steering. the coller flows both oil and water either way and pressure tests fine. could it be too small? the cooler had oil in it but not as much as I thought would be in it. the jetting appears to be fine as the plugs are nice and brown but Hell I am going to try it. whats concerning is that it should cool down after running it but I actually have to basically shut the motor off and let it sit to see any decrease in oil temp. it will go down a little at idle but not like it did before with my old motor(622).???????????????????

Are you sure you have the oil lines plumbed right? Usually if they are wrong you will see a loss in oil pressure. Go with the simple stuff 1st, thats what usually bites us in the a$$.

teagues offshore oil cooler is what I run

had to get a small PS cooler from Revolution Marine

I measure oi temps in the pan

makes that shiny pos 3x18 look sad

definitely v-twin oil also

if you are using a gen4 filter adapter, then that has a bypass that needs to be plugged.

I can run 5500 rpm for twenty minutes in 100* ambient with probably 85* sea temp and see max oil temp of 280 or so.

read this thread for more good info http://www.offshoreonly.com/forums/g...-hardware.html

I have almost too much oil psi and I just checked the lines AGAIN LOL!! I now question the adapter for the remote oil filter. I had this on my old motor which was a bowtie block I wonder if it has the bypass that needs to be plugged. I guess I will go take that off now.

I am not sure about running the v twin synthetic in my motor since it only has about 8 hours on it.

Yes, some of the older merc adapters have a bypass valve in the adapter.

are you talking about the adapter that bolts to the oil filter pad? if so I just checked that and it does not have a bypass. The only thing I can think is that the cooler is too small or the mains and rod bearing clearances are too tight. the motor was built by a reputable machine shop that build performance marine engines so?????? if the bearing clearances were too tight I would think the oil would cool down after a moderate run with decreased rpm but its not... this leads me back to the cooler being too small. any one want to agree:lolhit:

I use the EMI 3" combo cooller. Upgrade your oiling sytem also, canton racing makes a adaptor that is much better than stock. Convert all your oil lines and fittings to 12AN. Check out the thread on "stock oiling?". Also use a good synthetic oil, I use Amsoil.

I already have all braided lines and an fittings but they are -10, my adapter is the canton racing version. this is a 640ci motor I have not cut any corners on any part of the build. this oil system woked fine on my other motor so???? I am not sure about running synthetic oil in a motor that only has 8 hours on it. I am not new to performance motors as I have been drag racing all my life and I even worked on mopars pro stock team but this damn thing has me perplexed.

I would wait till about 20 hrs before swiching to synthetic. The 10 AN lines should be fine, make sure you have the correct pressure valve. Remove the one in the center. There are two different part numbers for the adaptor depending on the version of BB, make sure you have the correct one. Good luck tracking it down.

Last summer I was on the bay doing wot air/fuel ratio runs. I was going down slowly in jets sizes from 98s all around. I was attempting to go to 89s all around and my bad eyesight and no glasses caused me to load 83s in all around. I figured this out on the next run when I didn't even get to WOT and I saw the oil temp racing towards 325F :eek::eek: Normally it would run around 210f for a short wot run. Popped in the 89s and right back to 210f.

If I were you I'd go up 4 jet sizes all around to see if it has an effect.

this block does not use the pressure valve setup it is a dart block.

It sounds like you have covered all the bases on the oiling sytem. I use Fuel Injection so I am not familiar with carb jetting. These guys might be on the right track with the fuel mixture. I use wideband O2, and make adjustments on my laptop. You could install O2 bungs in your risers and see were you are at. You will need a gage or some sort of monitoring system. Then change your jets accordingly. I run mine at 13.5 at Idle through midrange then 12.5 at upper RPM.

Just curious; what should oil temp be? I have a 502 (procharger) at idle it's around 120, at 3500 will gradually work up to 240, at 4000 will get to 260ish, never over 280. Is that ok?

I dont think its lean. if anything its a little rich. The plugs are nice and brown after a hard run. I dont idle around and then check them so I am pretty sure its not lean.

220-240 MAX is ideal

Thanks, so 260-280 at higher rpms is too hot?

use the merc bulldog coolers

First, check and see if air is entering the cooling system.Use a clear plastic hose, if air is present you can not conduct the heat out of the cooler and you really won't get a high water temp indication, I had this occur on a newer top gun. If this does'nt help look on Serious Offshore on the post in tech ,38 ' top gun cooling problems, I really don't want to type that all out again.

I run the Teague coolers like Wobble. But I remember reading in the CPPerformance catalog that chrome plating your cooler dramatically affects the ability for it to dissipate heat FWIW.