What size oil cooler do I need ?
 

489 cubic inches, 500+ hp. Still running stock Merc oil cooler. Oil temp sender in bottom of pan. Seeing 260 degrees at WOT. 230* at cruise rpm.
What size oil cooler would you recommend? Where is best place to buy from? What kind of money should I expect to spend?

Re: What size oil cooler do I need ?
 

I am having the same problem. I built a 496 and have also surpassed the cooling ability of my stock 454 mag oil cooler. I thought it might be an issue with the added HP but I just hoped for the best. Not sure of my temps but my oil pressure stays at 60psi as long as I keep the rpm below 4000. A 5500rpm run will cause the pressure to drop to 40psi and will go right to 60psi after a short low rpm cool down. Will be looking forward to readers input.

Re: What size oil cooler do I need ?
 

The information I received from my earlier post is that your oil temp is fine. Don't fix what ain't broke.

Re: What size oil cooler do I need ?
 

Higher Power,
Your temps seem fine. 260* Pan at WOT
But, is temp sender matched to gauge?

TC,
Need to know your temps before you can make an educated assessment of your needs.
A 5500rpm run will cause the pressure to drop to 40psi and will go right to 60psi after a short low rpm cool down.
Is that 40lbs. at idle or 5500 RPM?
If those are idle pressures, they look good to me.
General Rule of Thumb is 10 lbs oil pressure for every 1000 RPM.

Put an oil temp gauge in that boat. Make sure sender is matched to the gauge.

Re: What size oil cooler do I need ?
 

My gauges are Gaffrig, the sender was purchased at same time as gauge, from same source. The sender came in a Gaffrig box, so I`m assuming they are a match.
My concern is once temp hits 260 at WOT, it stays there for a while, even after backing off throttle.
I would just prefer the oil temp to be a tad lower.
I`ve heard "acceptable" oil temps all over the scale, from 230-280 and even 300 if not there long.

Can somebody please elaborate more on the subject of oil temps ???

Re: What size oil cooler do I need ?
 

you should be reading your oil temp after the cooler.
we like to put the sender in the oil filter assy before it
goes back into the motor.
what cooler are you running? mercury make a
few different sizes and the HP500 is using the 3"dia
cooler, you should at least be running that but i
would try relocating your sender first before spending
the money on another cooler that you may not need

Re: What size oil cooler do I need ?
 

Teague,
Your post indicates that you are filtering oil after the oil cooler.
Am I reading that correctly?
Filtering after the cooler is new to me.

The HP500/502 Carb oil cooler is 2" x 17". Not to say they didn't change along the way. The HP500/540 Bulldog used a 2" x 21".
Maybe the HP500EFI uses the 3" oil cooler.

Re: What size oil cooler do I need ?
 

the cooler from the HP500 would be a part # 849952T01
and we do filter the oil after the cooler or better yet
we filter all the oil before it goes back into the engine

Re: What size oil cooler do I need ?
 

I've never seen a Merc 3 inch cooler I use only 3 inch coolers in my marine packages CP and TCM offer them the way I run then is after the filter and I also install the sending unit on the filter adapter but I want to know the temp of the oil as it comes out of the engine not after the cooler I feel thats more important to me . I've had this same problem with other engines and a simple fix has been changing to synthetic has brought the temp down as much as 30-40 degrees you dont want to make the oil any cooler then 220 wide open thats optimum operating temp for any oil . Good Luck Laz Mesa www.mesabalancing.com

Re: What size oil cooler do I need ?
 

Teague,
Thanks for the information and oil schematic.
Eickert also filters after the cooler. That's two identical responses from the pros worth implementing.

Just for clarification.
Part # 849952T01 is for HP500EFI

1994-95 HP500
816074T 17.50"
848192T 21.75"

1996-98 HP500
848192T

Do you guys run any thermostatic controlling devices in your oil systems?
Thanks again!

Re: What size oil cooler do I need ?
 

Damn it Laz,
Now I have to ask, "Filter before the cooler or after the cooler?
Two out of three engine builders agree, filter after the cooler.
This is probably one of those proverbial "Six of one. Half a dozen of the other" situations.
:cool:

Re: What size oil cooler do I need ?
 

synthetic is great so don't get me wrong but we find
that in hyd roller motors it doesn't work (too slick)
rollers tend to slide instead of roll and after a while
starts to create flat spots and stop rolling all together.
now as far as the oil cooler being 3" now i have to go
measure one. you all got me discombobulated

Re: What size oil cooler do I need ?
 

RLW,remember this argument 6 months ago? The only way I'd consider filtering the oil AFTER the cooler would be if you were running big hp6 filters like in teagues drawing. Other wise most filters flow ratings are too close to the flow capabilitys of the filter. In a motor with bypass valves in block plugged while your first idling motor(especially with a BIG cooler) you may open bypass valve in filter. The warmer oil is the better it flows thru the filter hence less pressure drop and chanch of opening bypass valve,bursting filter or stressing pump drive shaft/distributer gear. If you were running a hp-6 with its 20 gpm rating or whatever it is you could run cold gear oil thru it if you wanted so it would be a non-issue,Smitty

If your not running hp-6 filter but have the room run the longest filter you can like I do!

Re: What size oil cooler do I need ?
 

I thought it depended on spring pressure? I'm running 190 seat/450 open w/morel lifters,would this still be a possibility,thanks,Smitty

Re: What size oil cooler do I need ?
 

RLW, My oil pressure drops to 40lbs during a hard run. I am aware of the 10lbs of pressure per 1000 rpm rule and my throttle hand is directly related also. :D Pressure starts out great and drops as the oil heats up assume. It still maintains 40lbs at idle after the hard run. After giving It a few minutes of idle time or motor around the local raft up party spot the pressure is right back to normal. I guess I am overheating the oil on the 5500rpm range and giving it time to cool back down in the lower rpm range. Seems pretty simple.....I hope! Should I ask Santa for thermostatically controlled larger oil cooler this Christmas?? FYI I am using Valvoline 40wt racing oil.

Re: What size oil cooler do I need ?
 

Thats one BIG A filter

Re: What size oil cooler do I need ?
 

Here is a pic of a stock mpi oil cooler compared to a aftermarket one,I had similar problems when I first started modifying my 502. To give you a idea how small the stock cooler fittings really are I stuck a 3/8 bolt in the hole in the 2nd pic,Smitty

Re: What size oil cooler do I need ?
 

TC,
Still need to know your temps before you can make an educated assessment of your needs.
Get an oil temp gauge for Xmas, too.

Smitty,
As always, I value your input. Basically, if provisions are made (i.e. higher flowing filter) filtering after the cooler is an accepted practice.
Check out the Wix Racing Filter info.
http://www.wixfilters.com/filterlookup/racing.asp
Russ

Re: What size oil cooler do I need ?
 

My oil cooler is even smaller than the MPI cooler in that photo !
Geez.....

I ordered a 3" X 18" cooler Tuesday. Should receive it tomorrow.

Re: What size oil cooler do I need ?
 

RLW, I forgot to mention in my last short story (post) that I have a temp gauge and will be installing before my next trip on the water.

Re: What size oil cooler do I need ?
 

1. When running a remote oil cooler and filter on a Gen VI block we recommend to remove the the bypass in the center
and leave the one in the block on the outside or plug it. Allows the oil to return to the block.

2. Syntec or not to Syntec? breaking in the piston rings take longer to seat, roller lifters slide instead of roll. Our choice is for engines up to 400hp is SAE 40WT Racing and 500hp to 1000hp is SAE 50WT Racing(We prefer Kendall GT1) Multi-weights tend to break down.
If you have to use synthetic oils in the engine try this after the first 30 hour break-in.

3.TCM recommends the oil temp sender to be installed in the remote oil filter head after the oil cooler so we can see the temp. returning to back to the engine block.(not elevated oil pan temps). See attached diagram of our oil cooling system....

Re: What size oil cooler do I need ?
 

...the earth is round not flat..get over this flat-topping stuff..every engine in the world uses rollers and synthetic oil these days...something must be in California drinking water...

:D :D :D :D

Re: What size oil cooler do I need ?
 

Sting,

Like Teague said remove the center bypass in the pad.

Some will remove the bypass in the side of the pad also, and plug it so all oil will return to the engine. That's fine, unless your filter becomes plugged, which it probably would not. But, Murphy's law.... So, if you plug the side bypass hole it might be a good idea to go with an oil filter that has a built in bypass. Just a thought.

Synthetic vs dino oil....Like Hydrocruiser says the world is round, not flat. I understand that Merc is now pushing a synth/dino blend. They recommended Mrec brand dino only, until they slapped their label on the blended stuff. So now that they have their label on it, it's ok...right?

When my engine was new, for break in I ran about 5-6 hrs. with dino oil then drained the oil and pulled the filter. My engine guy cut the filter open to inspect for bad stuff and found none....good. Added fresh dino and filter and ran for about 12-15 hours and changed the oil and filter again, checked filter for bad stuff again, found no bad stuff....good. Did one more dino oil change after that, and then started using full synthetic and never looked back. Just completed the 3rd season with the engine (ZZ502/502...another no no according to some). Have not torn it down. No known reason to, runs the same now as it did 3 seasons ago. No change/decrease in operation, speed/performance.

I may well be wrong here, but, I believe I read an article in Power Boat mag where Bob Teague said synthetic was ok. I think the article referenced valve spring pressure as part of the topic. Sorry, the article was in the mag about a year or so ago, so I don't remember the details. Maybe teaguecustommarine can shed some light on this??

You know my wiew on where the oil temp sender should be, after the oil leaves the engine, and before it goes into the cooler. That way I can monitor oil temp at the hottest point. But as you know, there are other opinions on this from people more knowledgeable than me. I plan to pull the ZZ in the spring or next fall for a few upgrades. And I plan to add a oil temp sender to the pan. Yep....I'll have two then. Guess I like play'n it safe. Plus, the guru's are probably right.

Best of luck with the new mill. Post the news after you've had the chance to wring it out.

Bill

Re: What size oil cooler do I need ?
 

Kidnova, I also broke in my engine with dino oil. 10 hrs on 10-40, I wanted something that would flow easily in cool spring weather, then changed to 15-50 Mobil 1 before the first poker run. At the end of the season I pulled the engines to deal with some other issues but the cam and lifters looked like new. I'm a lot more worried about the needle bearings getting enough lubrication than I am about the roller flat spotting.

Stingray, that valve spring seat pressure seems a little light. Even Crane is recommending 150 now. Alot of guys I know are going with 160 -170. Valve float kills power and damages parts.

Re: What size oil cooler do I need ?
 

I agree, 130 lbs on the seat is a little on the light side from what I have learned.

Re: What size oil cooler do I need ?
 

I gotta ditto this one. I look at 10-12 roller motors a month and have never seen a flat spotted roller due to synthetic. I think this legend got started when the first SB roller motors had some issues with the lifter brackets and the lifters would cock slightly in the bore. I have seen this in a few instances on older 502 Mercs also. But it usually is only one or two lifters at most. I have never seen or heard of an engine with most or all of the lifter rollers flat spotted due to synthetic. Another issue some of the foreign makers have is adjustable followers that are not adjusted regularly. Excessive clearance does allow hammering of the roller on the lobes and results in flat spotting of the cam and or follower rollers-in fact I just looked at a Honda 1.0 Insight motor that had done exactly that-but it was not due to the 0-20w synthetic it ran :eek:

Re: What size oil cooler do I need ?
 

My engine guy told me to go 25 or 30 hrs. with straight dino of good quality, not a blend. Gives parts a chance to wear in.

Re: What size oil cooler do I need ?
 

Good ? on where to filter. Seems that thinner/warmer oil would go through a smaller micron filter.

Better than cooler thicker oil going through a larger micron filter?

The warmer oil through the finer filter is my choice. I could be wrong.....it happens frequently.

Re: What size oil cooler do I need ?
 

What concerns me is when oil looses it's cushioning/lubricity affect due to viscocity loss. This is what hurts engines. Viscosity is lost first temporarily, then permanently due to cycling up to an elevated temp, or dwell time there. Therefore to me it is most important to know what max temp the oil is seeing. We know where oil starts loosing viscocity from viscocity curves. Knowing what temp the oil in going back into the engine means little as long as you know it's max temp never exceeded the thermal breakdown temp.

Put the sender before the cooler would be my suggestion. Also I don't know why you would want the filter after the cooler? Seems the cooler would just get contaminated for no reason.

BT :cool:

Re: What size oil cooler do I need ?
 

I have my oil pressure sensor in the front of the block. It measures after the fiter, cooler, thermostat and about 10 feet of hose. On cold startup it reads almost 100 lbs at 1000 rpm. I would guess that the cold oil is going through the filter just fine. I use a standard size Delco filter.

Re: What size oil cooler do I need ?
 

Blue Thunder explained my thoughts on oil temp sender location better than I did.

I believe the center valve is needed only when an automotive type cooler is plumbed in to the block, in the two threaded holes which are located just in front of the filter pad on the block. In a marine application when a remote oil pad and oil cooler are used, the center valve creates a restriction. cfm has posted a quote from GM on the subject. Check with him and see if he will post it again, or try a search. The GM quote gives a pretty good explanation.

Re: What size oil cooler do I need ?
 

The bypass is actually a pressure differential valve. The poppet of the valve has pressure on both sides of it. One side is pressure from the oil pump, the other is pressure coming back after the oil went through the cooler and filter. If the pressure returning from the filter and coolers drops due to blockage, the pressure on the underside of the poppet drops and the poppet opens. This allows flow past the cooler and filter but back into the normal lub circuit towards the mains.

That is if we are talking about the same bypass valve...

BT :cool:

Re: What size oil cooler do I need ?
 

Im glad Ive got mark 4's. Reading that gave me a headache.

Re: What size oil cooler do I need ?
 

I gotta believe that in Teagueland the sun rises in the West. Where I live, (and until someone can give me a GOOD reason why I should not) I will be cooling my oil AFTER I filter it and measuring the temp. at the filter pad where it comes from the pan, compressed, and is probably at max temps. (other than directly at the load surfaces). --- Jer

Re: What size oil cooler do I need ?
 

Ditto,

now, is 260 before the cooler at wot acceptable or not.

Re: What size oil cooler do I need ?
 

Now you are asking a real non-expert. I'll start by saying that I would listen to whatever cstraub says. Then I would say that I guess I wouldn't worry if I occasionally peaked at as much as 270* right out of the pan as long as that is the "occasional peak" and not the normal run temp., and I was running a good full synthetic oil. See, I avoided giving you a direct answer just like everybody else here. --- Jer

Re: What size oil cooler do I need ?
 

I may not have seen a roller lifter develop a flat spot but I did see a roller rocker develop this with the use of 15w-50 MobilOne.
It came out of a HP525SC.
My engine builder also races in some Cat class...he uses a straight weight Kendal GT1 also....but recomends 20w-50 for pleasure use.

Applications
GT-1™ High Performance Motor Oil is recommended for use in
passenger cars, vans, light trucks and sports utility vehicles
under all driving conditions, as well as in competition engines
and high-performance street engines. The SAE 20W-50 and 50
viscosity grades are fortified to provide extra wear protection
and foam resistance for use in racing applications. The SAE 70
viscosity grade is specially formulated for use in nitromethanefueled
drag racing vehicles. The SAE 30 and 40 viscosity
grades are suitable for use in older vehicles where use of a single
grade motor oil is recommended.

Re: What size oil cooler do I need ?
 

Well, as funky as it sounds, im gonna add my old 7.4 coolers to the vertical water hose coming up the front of the block, theres room and it doesnt create other mounting issues like a bigger cooler will. Then toss the aluminum pans and go back to the 8 quart sheet metal ones. Least amount of hit money wise and should give me the 20 degrees I need.