shawn

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

Active Mike

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.

US1 Fountain

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.

shawn

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

US1 Fountain

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.

Mudball

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

Mudball

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

JaayTeee

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.

Scott

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

Mudball

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...