Anonymous
01-22-2003, 10:15 PM
mytime
normal member in standard member. 1. ENGINE HEAT
CAN ANY ONE HELP WITH THIS ONE? I HAVE A 1987 302. BEFORE AND AFTER CHANGING MANIFOLDS AND RISERS STARPORT MANIFOLDS AND RISERS GET HOTTER THAN THE OTHER. THE TEMP GAUGE STAYS AT 150 DEGREES WHEN RUNNING ON A HOSE. I HAVE NOT TRIED IT IN THE WATER YET.
Date: 08:51 a.m. on 04-01-2001
Leprechaun
premium member in standard member. 2. Re:ENGINE HEAT
It has to do with how the water feeds the two manifolds. You must have more restriction to one side than the other. Take a look at the routing. I had the same problem with my FWC PCM. Had to do some fancy re-routing to solve the issue. Really though, its not much of an issue unless one side is so hot that you can't kep your hand comfortably on the hotter riser. Do you have RWC or FWC? Rgds, Leprechaun
Date: 11:23 p.m. on 04-01-2001
mytime
normal member in standard member. 3. Re:Re:ENGINE HEAT
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Leprechaun (04-01-2001 11:23 p.m.):
It has to do with how the water feeds the two manifolds. You must have more restriction to one side than the other. Take a look at the routing. I had the same problem with my FWC PCM. Had to do some fancy re-routing to solve the issue. Really though, its not much of an issue unless one side is so hot that you can't kep your hand comfortably on the hotter riser. Do you have RWC or FWC? Rgds, Leprechaun
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Lep, i have a rwc 302 the hose coming off the therm housing is 4 inches longer than the other this side, this is the side that gets hotter and sees less water, about half the water. The riser i can touch, its the new exhoust pipe that gets really hot. Any more info on a rerout. thanks.
Date: 06:50 p.m. on 04-02-2001
Leprechaun
premium member in standard member. 4. Re:ENGINE HEAT
I really don't know the answer to this one. My experience is with FWC systems. It might well be that running the engine "On the Hose" is not supplying enough water to completely fill both potr and starboard sides of the system. I would try her in the water before jumping to any radical fixes. If the boat is truely running at 150-deg and you can keepnyour hand on the hotter riser, I think you should be fine. BTW - when did you last change the RW pump impellor? My uncle pulled his just-purchased 20-footer w/RWC up from Florida and complained that "She runs a little warm." When we pulled the little Indmar RW pump apart, the impellor had only ONE blade remaining on her!!! Can you imagine? So I would look there too. Sometimes, when a pump impellor starts shedding blades, they lodge in various locations. Is it possible that an earlier owner was less than fastidious with this maintenance item and there's a piece of impellor somewhere upstream of the starboard manifold? Just a thought. Check the entire cooling system for restriction and run the boat in the water, then come on back and post results. We can take another crack at her then.
Maybe someone has another idea for "mytime?"
Leprechaun
Date: 09:04 p.m. on 04-02-2001
Engineman
normal member in standard member. 5. Re:ENGINE HEAT
mytime,
to determine wether the hose length is the issue just slowly pinch down on the shorter hose to see if it makes any difference. My guess is that the riser gasket was plugged by the sealer you used. The sealer should have been like Permatex #2 and NOT silicone.
Silicone will plug up water passages all by itself.
If none of these solve the problem then check the depth of the water fitting in the end of the manifold. We have had the threads cut too deep and the fitting will bottom out and cut way down on the water flow.
If none of these work you may have gotten a bad part.
Good luck on the fix and let us know the final outcome.
Keep COOL.
Tim
Date: 10:01 a.m. on 04-03-2001
Larry
normal member in standard member. 6. Re:ENGINE HEAT
Well, I've been wondering if I should ask this question for quite a while, and sure enough someone has the same problem. I also have a RWC 302 (pleasurecraft config) and guess what? My starboard mani is noticably hotter than the port. Engine temp is fine (runs a bit hotter on a hose than it does in the water) but I always wondered if I had made some mistake somewhere when I installed a rebuilt long block last summer. Hmmmm.
Larry
Date: 02:14 p.m. on 04-03-2001
chuckash
normal member in standard member. 7. Re:ENGINE HEAT
This seems like the perfect time to ask my question. I have the PCM exhaust manifolds, and whenever I had to take the elbows and maifolds apart, there are more water passages in the cast iron parts than PCM puts into their gaskets. Seems as though there are 6 passages (one fore, one aft, two port and two starboard) in the manifolds/risers, but only five on the gasket. Does the orientation of the "blank" have any impact on the cooling of the manifolds? Anybody else notice this when they buy PCM gaskets??
One other lesson I learned a few years back. One side of the exhaust stopped passing water while going through the inlet. After quite a long ride back, I replaced the riser on that side only. First time out, the law that states water follows the path of least resistance was proven, the side with the new riser was passing all the water, the side with the old riser passed almost no water. Morale of the story is to do these things in pairs!!
normal member in standard member. 1. ENGINE HEAT
CAN ANY ONE HELP WITH THIS ONE? I HAVE A 1987 302. BEFORE AND AFTER CHANGING MANIFOLDS AND RISERS STARPORT MANIFOLDS AND RISERS GET HOTTER THAN THE OTHER. THE TEMP GAUGE STAYS AT 150 DEGREES WHEN RUNNING ON A HOSE. I HAVE NOT TRIED IT IN THE WATER YET.
Date: 08:51 a.m. on 04-01-2001
Leprechaun
premium member in standard member. 2. Re:ENGINE HEAT
It has to do with how the water feeds the two manifolds. You must have more restriction to one side than the other. Take a look at the routing. I had the same problem with my FWC PCM. Had to do some fancy re-routing to solve the issue. Really though, its not much of an issue unless one side is so hot that you can't kep your hand comfortably on the hotter riser. Do you have RWC or FWC? Rgds, Leprechaun
Date: 11:23 p.m. on 04-01-2001
mytime
normal member in standard member. 3. Re:Re:ENGINE HEAT
--------------------------------------------------------------------------------
Leprechaun (04-01-2001 11:23 p.m.):
It has to do with how the water feeds the two manifolds. You must have more restriction to one side than the other. Take a look at the routing. I had the same problem with my FWC PCM. Had to do some fancy re-routing to solve the issue. Really though, its not much of an issue unless one side is so hot that you can't kep your hand comfortably on the hotter riser. Do you have RWC or FWC? Rgds, Leprechaun
--------------------------------------------------------------------------------
Lep, i have a rwc 302 the hose coming off the therm housing is 4 inches longer than the other this side, this is the side that gets hotter and sees less water, about half the water. The riser i can touch, its the new exhoust pipe that gets really hot. Any more info on a rerout. thanks.
Date: 06:50 p.m. on 04-02-2001
Leprechaun
premium member in standard member. 4. Re:ENGINE HEAT
I really don't know the answer to this one. My experience is with FWC systems. It might well be that running the engine "On the Hose" is not supplying enough water to completely fill both potr and starboard sides of the system. I would try her in the water before jumping to any radical fixes. If the boat is truely running at 150-deg and you can keepnyour hand on the hotter riser, I think you should be fine. BTW - when did you last change the RW pump impellor? My uncle pulled his just-purchased 20-footer w/RWC up from Florida and complained that "She runs a little warm." When we pulled the little Indmar RW pump apart, the impellor had only ONE blade remaining on her!!! Can you imagine? So I would look there too. Sometimes, when a pump impellor starts shedding blades, they lodge in various locations. Is it possible that an earlier owner was less than fastidious with this maintenance item and there's a piece of impellor somewhere upstream of the starboard manifold? Just a thought. Check the entire cooling system for restriction and run the boat in the water, then come on back and post results. We can take another crack at her then.
Maybe someone has another idea for "mytime?"
Leprechaun
Date: 09:04 p.m. on 04-02-2001
Engineman
normal member in standard member. 5. Re:ENGINE HEAT
mytime,
to determine wether the hose length is the issue just slowly pinch down on the shorter hose to see if it makes any difference. My guess is that the riser gasket was plugged by the sealer you used. The sealer should have been like Permatex #2 and NOT silicone.
Silicone will plug up water passages all by itself.
If none of these solve the problem then check the depth of the water fitting in the end of the manifold. We have had the threads cut too deep and the fitting will bottom out and cut way down on the water flow.
If none of these work you may have gotten a bad part.
Good luck on the fix and let us know the final outcome.
Keep COOL.
Tim
Date: 10:01 a.m. on 04-03-2001
Larry
normal member in standard member. 6. Re:ENGINE HEAT
Well, I've been wondering if I should ask this question for quite a while, and sure enough someone has the same problem. I also have a RWC 302 (pleasurecraft config) and guess what? My starboard mani is noticably hotter than the port. Engine temp is fine (runs a bit hotter on a hose than it does in the water) but I always wondered if I had made some mistake somewhere when I installed a rebuilt long block last summer. Hmmmm.
Larry
Date: 02:14 p.m. on 04-03-2001
chuckash
normal member in standard member. 7. Re:ENGINE HEAT
This seems like the perfect time to ask my question. I have the PCM exhaust manifolds, and whenever I had to take the elbows and maifolds apart, there are more water passages in the cast iron parts than PCM puts into their gaskets. Seems as though there are 6 passages (one fore, one aft, two port and two starboard) in the manifolds/risers, but only five on the gasket. Does the orientation of the "blank" have any impact on the cooling of the manifolds? Anybody else notice this when they buy PCM gaskets??
One other lesson I learned a few years back. One side of the exhaust stopped passing water while going through the inlet. After quite a long ride back, I replaced the riser on that side only. First time out, the law that states water follows the path of least resistance was proven, the side with the new riser was passing all the water, the side with the old riser passed almost no water. Morale of the story is to do these things in pairs!!