496 ho cooling system

[jimbo]

i need some help from some of the pros out there!!
i have noticed the last few times i have been out the port side exhaust is running hotter than the starboard side. i changed the h20 impeller, it was in bad shape, checked all the hoses and opened up the heat exchanger. it is still running warmer on the port side (i have not actaully taken it out, just hooked up the hose to it) it also appears that i am getting less water out the port exhaust, i see some steam also.. is this inherent in this motor with closed colling??
jimbo

[DMOORE]

Might just be a BBC thing. I have noticed that both my motors port exhaust run just a bit warmer than starboard.
Darrell.

[jimbo]

i figured since the h20 pump is on the starboard side, there would be more immediate demand for water on that side ans less for the port...
jimbo

[Raylar]

Jimbo:
Under each exhaust manifold is a check ball valve that sometimes have gone bad or been sticking and hence can cause one exhaust manifold to run warmer than the other side. Your 496 is also equipped with a water temperature sensor in each exhaust manifold and a scan tool can read the exact difference in temperature. Might be worth checking with a scan tool before buying parts.
Ray @ Raylar

[Beer-30]

Like Ray said, there is a temp sensor in ea manifold. The ECM will scream at you if one is out of spec. Trust me, one was unplugged on my HO and it was screaming bloody murder until I found it. Scan tool showed it right off. If ECM is not beeping at you, all is probably well.
Funny you should post this evening. I just came in from firing mine off. I am taking it to the lake tomorrow, and it had been sitting almost a month. I hooked the water to it, and for the first time, fired it from outside the boat (standing on a ladder next to the helm).
I walked back to look at the exh, since I had only turned on the water a little (too much can be bad). I noticed no water from the tips. It usually starts spitting immediately, so I ran to the spiggot and turned up the water. It started spewing from the right side first. About 10 seconds later, it started from the left.
After some temp, I set it at 1500 and walked back again. The right side definitely had more than the left, but it was not much difference. MAYBE 25%. There was obviously plenty of water, so I didn't think anything of it.
It is probably a distribution/routing snafu, and nothing to worry about.

[jimbo]

ray:
thanks for the heads up on the check valve.. i did take it apart and cleaned
every thing out thourly.. i changed out the H2O impeller and finally had it out today.. it seems like i an getting better flow and it is not running as hot,
still warmer(15-20 degs.) i called merc last week and they said that it is normal
for the port side to run slightly warmer than the starboard side due to the routing of the wate..
jimbo

[jimbo]

beer-30
i always noticed that it takes 20-30 seconds for the exhaust water to run out the port exhaust after initial start up... i took a look at the flow chart from merc. and the water needs to ravel thru more lines to get out the port side..
all is good.. had a great day on the water today..
jimbo