Hp500 Oil Temp
 

What should the oil temp be in the HP500? I am running a crossover and no thermostat and my oil temp usually runs around 100 - 140 and no hotter. Should I look to replace the thermostat in the filter housing? The engines are 1999 carb and I doubt the previous owner changed them. How long do they last?

thanks
Shawn

Re: Hp500 Oil Temp
 

Shawn,
First of all the oil temp is to low if you are reading the temp correctly.
You want the oil temp up to the boiling point to flash the moisture off the oil, 220, 230 mark.
There has been a lot of threads on this matter. Do a search on OSO and you should find all the answers that you are looking for.
Good luck.

Re: Hp500 Oil Temp
 

Doesn't your HP 500 have the oil t-stat unit?
Is your engine temp also low?
Like Active Mike said, A LOT of threads on this very topic.
Crossovers create low engine and oil temp if not plumed right. I would recommend against installing a t-stat in the housing unless you have a bypass hose, otherwise another set of problems can arise.

Re: Hp500 Oil Temp
 

I removed the water pumps and replaces with a crossover with a #8 bypass line which caused the engines to overhead. I eliminated the bypass and cured the oveheating, the engine temp runs about 100 - 120 at cruise.
I am wondering why the thermostat in the factory oil filter housing is not letting the oil get up to a higher temp. Do I need to replace the thermostat in the oil housing, or is it not capable of oil temps up to 212 with out the water thermostat installed? I am running carbs.

thanks

Shawn

Re: Hp500 Oil Temp
 

Welcome to the world of crossovers on otherwise stock motors. Had the HP500 oil stat unit on my last blower motor. Engine water and oil temp and water pressure can be a pain to dail in, as you are experincing. Even with my oil stat, if I had no engine temp, the oil temp would still be way under. The cold engine temp was enough to keep my oil from reaching temps. Put your pump back on, and your problems will go away. ;)

Re: Hp500 Oil Temp
 

Hi Shawn:
I have exactly the same setup. A 1999 carbed hp500 with an EMI crossover with a bypass. I installed this when the circulating pump developed a leak.

Be careful when you install a thermostat. With mine and a thermostat, the water pressure went through the roof. It pegged the 35psi gauge at 3,000 rpm's and popped off a hose at higher rpm's!! With no thermostat in there, there was no water pressure to speak of. With a Whipple washer restrictor, now the water pressure is good (~20psi at WOT), but the temps are way low. The water temp gauge never moves off the peg. What I do now is wait for the oil temp to just come off the peg at 1,200 to 1,500 rpm. Then I get on a slow plane, about 30-35. Then after about 10 miles of this, the oil temps will get up to 180. Then I romp it, if I want to. I've seen the oil temps hit 210, but when you let off, they quickly drop back to 180. That's a HUGE amount of time to have to wait for the temps to come up!! I don't like it one bit.

I'm still in the process of debugging this issue.
Here is what I'm doing very soon:
1. I am reinstalling a 140 thermostat with 3x3/16" holes drilled in it (to let the air and steam out). I hope you had at least one hole drilled in yours!
2. I'm installing a Merc Racing water pressure bypass, plumbed outside the boat. These limit the water pressure to 28psi or so. P/N 863208A3.

I'm hoping this will fix the issues...Crossovers can be a real PITA...

Best of luck.
Kent

Re: Hp500 Oil Temp
 

I forgot to mention that either without the termostat or with the Whipple washer, there is a HUGE volume of water coming out the exhaust. It looks like a jet boat.

I know this is affecting performance, as I am running restrictive Corsa mufflers. Not for long though, as I just bought some new GGB's!!!! I can't wait to try them out...
Kent

Re: Hp500 Oil Temp
 

Mine run 190* when cruising, and up to
220* at wot

Take the thermostat out of the housing,
heat up a pan of water, up to around
boiling, put the thermostat in the pan.
The rod should extend out when the temp
reaches 210*.

That will tell you if the t/stat is working properly.

Re: Hp500 Oil Temp
 

Wouldn't it be easier/safer to run with the recirculating pump? I just see all this time money and frustration spent on a couple HP you will never even notice :confused:

Re: Hp500 Oil Temp
 

You are right Scott.
When I installed the crossover, I assumed that since so many blower guys run them that I would not have much trouble.

But, they sure do look nice, and don't cost much different than a new circulating pump...

Re: Hp500 Oil Temp
 

Guys, thanks for the input, but my question involves the thermostat in the oil cooler, not the engine. What temp is it set for and do they need replacement?

thanks
Shawn

Re: Hp500 Oil Temp
 

The thermostat in the oil filter housing
should be fully open at 210*.

You can test it like I made mention of
earlier in the thread.

Re: Hp500 Oil Temp
 

Now Who Has An Oil Thermostat At A Reasonable Price.

Re: Hp500 Oil Temp
 

Just so we're on the same page, here's a picture:



http://www.mercruiserparts.com/Show_...ER+AND+ADAPTOR

item # 2 is the "thingamajig" we're talking about

Re: Hp500 Oil Temp
 

JT, that's the puppy I was talking/writing about. Before I put the crossovers on, the oil ran around 180/190 up to 200/210 at WOT, but since the engine thermostat has been removed, the oil temp doesn't show above 140/150, but there is no sign of moisture in the oil. I was just wondering if it should be replaced along with the spring?

Thanks
Shawn

Re: Hp500 Oil Temp
 

The water temps have a direct bearing on the oil temps.

Without a water thermostat and with little to no water temps, it takes forever for the oil temp to come up, and it won't stay up.

BTW: I believe my oil thermostat is 180 degrees. If it goes above that during a romp, it quickly drops back to 180, and then slowly drops from there if I go slow. It will drop down to 140 or lower after a while.

Kent

Re: Hp500 Oil Temp
 

Shawn,
Were you able to remedy this problem? If so how? I'm experiencing same symptoms with my hp500's

Re: Hp500 Oil Temp
 

I assume you are running crossovers, MOS.
===
Running a water thermostat and the Merc Racing pressure relief valve did the trick for me!

I have been running it for about a year now.
My setup:
1. EMI crossover WITH a bypass.
2. 140 degree water thermostat with three x 3/16 holes drilled in them just inside the lip for steam ventilation.
3. Merc Racing water pressure relief valve with a 1" dump.

The valve I have limits the pressure to 25psi. This is a MUST have item.

As I mentioned before, and as I'll bet Shawn found out, the oil temps are directly influenced by water temps.

Now, my water temps never go over 140, and get there quickly. My oil temps also warm up rather quickly, and run around 180-200 at cruise, and up to 220 at WOT. They will come back down to 180-200 fairly quickly after slowing. I have never seen above 220.

Please note that if you want to run a thermostat with a crossover, you MUST have the bypass (hose between the thermostat housing and the water intake to keep water flowing to the exhaust when the thermostat is closed.

What is interesting is that none of the crossover makers will even acknowledge a water pressure problem when running a thermostat!!!

Kent

Re: Hp500 Oil Temp
 

Mudball,

Where did you get the hose that goes from your water bypass down and under to your coolers? By the way sweet looking motor... :drink:

Re: Hp500 Oil Temp
 

Thanks, Vandeano...

I assume you mean the stainless piece going from the crossover to the P/S cooler? If so, that is from Jegs. It is a radiator hose for cars that comes with adapter rubber pieces that make it fit..
Actually, that is no longer on the motor. I wouldn't recommend it, even though it looks cool. It is actually the hose that would blow off before I installed the pressure relief valve!! So, in a sense, it is what saved the motor from sure head and/or intake gasket problems!
Kent

Re: Hp500 Oil Temp
 

Mudball,

Yes, that is the one. What are you using now? I have the same set up, but the hose Im using now kind of has a tight turn just before the power steering cooler. It also gets real close to the alternator belt also.

Re: Hp500 Oil Temp
 

I know what you mean, Vandeano.

Thar ain't much room for the hose!
===
Fortunately, I still had a 7.4mpi (my old motor) to scavenge from!
I used a hose that had some good bends to fit this, and whacked it up to fit.

I am pretty sure it was the one that goes from the seawater pump to the oil cooler in the rear of the 7.4....

Unfortunately, I can no longer attach pictures here, and I am not here enough to justify the cash...
Take care,
Kent

Re: Hp500 Oil Temp
 

Do stock 2000 HP500 carb motors have thermostats?

Re: Hp500 Oil Temp
 

Mudball,

No problem, I did the same thing you did. I just happen to have a hose with the correct bend from my box of old hoses.
But unfortunately it got tagged by the alternator belt. Thanks for the info anyway. :drink:

Re: Hp500 Oil Temp
 

When running the dump line for the high pressure relief valve, would there be a problem with dumping it into the exhaust? Could it be dumped in anywhere? My exhaust has what appears to be an un-used valve (see pic) could I hook it in there? The red plugged up thing on the front side of the exhaust, just below the rubber hose that connects one part of the exhaust to the other.

Re: Hp500 Oil Temp
 

MiamiOS, you can dump the overflow anywhere.
I would not personally dump it into the exhaust, but you could.

My dump flows quite a bit, especially before the thermostat opens.

I would, if given the option, dump it on the drive!

I don't have transom space for a drive dump...
Kent

Re: Hp500 Oil Temp
 

What is your reason for not dumping it into the exhaust? I was wondering specifically about the angle of that fitting and where the water would be going (reversion, etc.) . I was just hoping there was somewhere to tap it into externally, so I don't have to drill any new holes in my transom

Re: Hp500 Oil Temp
 

That's a tough call. If you had the stock waterpump, those 2 plugged fittings would be used for the extra hoses that have been eliminated because of your crossover setup. So in a cense you should be able to, but it wouldn't include the checkball assembly and the stock t-stat setup, so it may create a condition of just recirculating some of the water, or not exhausting the water from the motor and more so from the relief valve. You can always try it, but only if you have a temp gauge and WP guage and watch them VERY close. A possibilty is to have a tube welded to the end of your tailpipes right before the hose, and have the go in and point to the exhaust tips. Kinda like dry exhaust.

Re: Hp500 Oil Temp
 

By dumping the excess water from the relief valve into the exhaust, you are defeating the purpose of the relief valve.
Wet exhaust is the exit point for the cooling water that is introduced to the motor, via the sea water pump. It is the end point before returning to the lake, river, ocean, whatever.
By dumping the excess water into the exhaust, you are just bypassing the motor, and reintroducing the water back into the cooling system.
Dump it overboard.

did you ever solve the high oil temp issue in your hp500?

Ok,
Here is my Oil temp problem... I run water temps of 140-160, have a stock water cooling system, EXCEPT I have a water pressure relief valve set at 25 PSI. My engine runs cool, so cool after a 55-60mph cruise down the river, I can put my hand on the port CMI header, and it's barely warm, SB is a little warmer... Now the oil filter is HOT, but the oil cooler is warm, but not as hot as the filter. I get NO oil temp at all, verifed that the Livorsi 140-340 oil temp gauge is working, but it never comes off 140 even after WOT. My 572 uses a HP500 Oil therostat housing with the oil temp sender, just like this diagram.I don't have condensation in valve covers, or the oil fill caps, and I think it might be a problem related to where my oil temp sender is mounted, it is on the oil thremostat housing.

Thurl]http://www.mercruiserparts.com/Show_Pictures3.asp?dnbr=853984R%201&ivar=images/CRUISER/853984.R1/24.png&inbr=2450&bnbr=24&bdesc=OIL+COOLER%2C+OIL+F ILTER+AND+ADAPTOR[/url]

The engine dumps a good amount of water out the exhaust, and the DART Hi-rise intake manifold is cool and sweats after a 55-60 mph cruise...

I've verified that the Oil temp gauge is functioning properly, and the harness is good to the gauge, pulled the oil temp. sender and boiled in water and got the ohms per Livorsi tech data, so I'm still at the assumption that the engine is running really cool.... I will get a picture of where the oil temp. sender is mounted today and post it.

Ok,
Finally got a few pics of the Oil temp sender location on my oil therostat on the 572, here they are. The Q is where it is presently mounted, is it after the oil comes back from the oil cooler? I also bought a IR temp gun and if the weather is good this weekend I'll take her out for a run and gather temp data on all the oil components location and report back.
Thanks,
Dean

Ok need some advice
 

Ok,
Went out yesterday and got the following results:
1. Still no oil temp on gauge, gauge works, I ground the lead, and the neddle goes full over, Gauge is a 140-340 temp Livorsi
2. Oil Pressure at start up is 70-80psi, after running at 3000-3500 rpms, it drops to 60 psi, ( not sure if this really a problem).
3. After 3500 rpm , come back to idle, I get 40psi of oil pressure at idle 900 rpms.
4. Water temp is a constant 140 deg.
5. Bought an IR temp sensor/gun ,and shot the following readings after the 3500 rpm cruise with the engine off
a. oil filter:180 Deg.
b. oil thremostat housing: 185 deg.
c. Oil cooler: 85 DEG!
d. engine block: 120-145 DEG,
e. CMI headers: 85-90 degs
f. oil pan: 185 deg.
Engine dumps ALOT of water out the exhaust, and I have a water pressure dump valve set at 25 PSI.

NOW what really has me concerned. After watching the airshow, (Thunder birds were great). I headed back to the house, and ran 3000-3500, for a most of the way, (oil pressure sitting at 60-65PSI) I opened it up to WOT, hit 97 MPH for about 30 seconds, BUT the oil pressure starting DROPPING, down to 55PSI, so I backed down to 3000 RPMS, (55 mph), for the rest of the way home. After 5 minutes of this cruise speed, oil pressure came back up to 60PSI. This is the first time the oil pressure drop has happened while I have been trying to solve my no oil temp issue. Kinda scared me. At idle back at the dock, I get 40PSI of oil pressure, and oil pressure goes up as I throttle up...
I think that my Oil thremostat is not opening, how do I test it, besides removing it and boiling it in a pan? or is there something else going on?
Looking for some ideas, advice..
Thanks,
Dean

Just posting this for reference maybe can help someone out here. Mercruiser OEM oil filter adapter housing with the oil thermostat also has an oil bypass valve if the oil filter becomes plugged and or restricted for whatever reason. The oil thermostat side of it controls oil temperature in which improves lubrication and reduces moisture in the engine internally.

When the oil T-stat is closed the motor oil flows directly to the oil filter and then back to the engine. When the oil t-stat is fully opened the motor oil is directed first to the oil cooler then back through the filter and returned to the engine. Merc specs on the oil t-stat is - starts to open at 194 degrees and is fully opened at 284 degrees.

BUP,
Thanks for the info, I'm pretty sure it's the T-stat, justed order 1.
Dean

Dean,

What happened after you replace the t stat?