HP500 takes too long to heat up
#1
Registered
Thread Starter
Join Date: Jun 2005
Location: Miami,FL
Posts: 246
Likes: 0
Received 0 Likes
on
0 Posts
![Default](/forums/images/icons/icon1.gif)
I've searched all over the forum but can't figure out what I need to do. My HP500's take way too long to get up to good operating temp. The former owner removed the T-stats, and added Gil exhaust. I'm getting milkshake in my rocker panels due to the long idle out/in from Spinnaker. As you can see in the picture they're currently setup with a crossover, but I'm not sure why as it still has the stock seawater/fuel pump. Isn't somethig normally supposed to be removed there as part of the point of a having a crossover? What would be the best way to remedy this? the T-stat back in? Then do I need a 2nd hose to the exhaust to get water to it before t-stat opens? Or do I have that wrong? The former owner says HP500's don't have oil t-stats, but merc says they do in the oil filter mounting assembly, could these be bad? Should I replace the oil t-stats also? I'm confused on this one.
Last edited by miamioffshore; 04-11-2006 at 12:37 AM.
#2
~~~~
![](https://www.offshoreonly.com/forums/images/icons/charter_member_star.gif)
![Default](/forums/images/icons/icon1.gif)
Put in a 142 degree T-Stat. Make sure it has (3) 3/16" holes drilled in it.
You have to have the Raw Water pump. The recirculation pump has been removed in favor of the crossover. You will need to install the Mercury Racing Pressure Relief valve (Part # 863208A3) to overcome the water pressure increase you will be seeing/having with the crossovers.
Your crossovers have a bypass to the T-Stat housing. That is necessary in order to have water flow to the exhaust when using a T-Stat.
You have to have the Raw Water pump. The recirculation pump has been removed in favor of the crossover. You will need to install the Mercury Racing Pressure Relief valve (Part # 863208A3) to overcome the water pressure increase you will be seeing/having with the crossovers.
Your crossovers have a bypass to the T-Stat housing. That is necessary in order to have water flow to the exhaust when using a T-Stat.
#3
Registered
Thread Starter
Join Date: Jun 2005
Location: Miami,FL
Posts: 246
Likes: 0
Received 0 Likes
on
0 Posts
![Default](/forums/images/icons/icon1.gif)
Originally Posted by RLW
Put in a 142 degree T-Stat. Make sure it has (3) 3/16" holes drilled in it.
You have to have the Raw Water pump. The recirculation pump has been removed in favor of the crossover. You will need to install the Mercury Racing Pressure Relief valve (Part # 863208A3) to overcome the water pressure increase you will be seeing/having with the crossovers.
Your crossovers have a bypass to the T-Stat housing. That is necessary in order to have water flow to the exhaust when using a T-Stat.
You have to have the Raw Water pump. The recirculation pump has been removed in favor of the crossover. You will need to install the Mercury Racing Pressure Relief valve (Part # 863208A3) to overcome the water pressure increase you will be seeing/having with the crossovers.
Your crossovers have a bypass to the T-Stat housing. That is necessary in order to have water flow to the exhaust when using a T-Stat.
Thanks for your help. So the T-stat should just go right back into the t-stat housing, correct? Where does the pressure relief valve go? Where did you dump the water? Wouldn't it be alot easier to just go back to a re-circulating pump? I'm only gonna lose what about 5HP at WOT?
Last edited by miamioffshore; 04-11-2006 at 11:56 AM.
#4
~~~~
![](https://www.offshoreonly.com/forums/images/icons/charter_member_star.gif)
![Default](/forums/images/icons/icon1.gif)
Your Welcome. This is what OSO is all about.
Anyway,
T-Stat goes back in the T-Stat housing. I plumbed my relief valve after the oil cooler and before the crossover. I had to install in dump in the side of the boat. As far as going back to the re-circ pump, some guys will say yes. You are close to having a workable setup, so I would invest in the relief valves. You might have pressure problems with recirc pumps, too. Plumb in a pressure gauge so you know where you are at. That can tapped into a block drain.
Check out the thread below.
http://www.offshoreonly.com/forums/s...ad.php?t=96816
Anyway,
T-Stat goes back in the T-Stat housing. I plumbed my relief valve after the oil cooler and before the crossover. I had to install in dump in the side of the boat. As far as going back to the re-circ pump, some guys will say yes. You are close to having a workable setup, so I would invest in the relief valves. You might have pressure problems with recirc pumps, too. Plumb in a pressure gauge so you know where you are at. That can tapped into a block drain.
Check out the thread below.
http://www.offshoreonly.com/forums/s...ad.php?t=96816
Thread
Thread Starter
Forum
Replies
Last Post
Perfectmix
General Q & A
16
08-04-2005 11:24 AM
sleeker
General Q & A
12
03-08-2004 06:02 AM
Jolley
General Boating Discussion
0
05-14-2003 09:47 PM