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View Full Version : BBC Cooling system questions...concerns



Big Block
02-11-2007, 01:06 PM
Sorry for the newbie question, but I don't know too much about marine engine applications yet. Bought a 21' Eliminator (454 w/Bravo 1) and ran it all last summer with no cooling issues at all. Operating temp is 150 degrees and does not flux much at all. My question is that I just found out that my hoses coming off of the thermo housing are reversed. According to my Clymer service manual the cold water circ. should be routed to the exhaust elbows, and the hot water exiting the housing should go to the actual lower manifold. Is this a common mistake with no need to worry, or should they be reversed immed.? I have run the engine in the driveway on the hose with no issues besides some steam. Just want to make sure I am not hurting anything. Oil appears to be good, no water contamination.
Thanks, Greg:confused:

jbone
02-11-2007, 02:28 PM
When I ran the stock exhaust on my jet, the intake water went through the manifolds to preheat the water, then into the water pump inlets. After circulating through the engine, the water exited through the theromstat housing and into the risers to flow out with the exhaust.
I hope this helps,
J

bigblockbill
02-12-2007, 01:39 PM
I agree with Jbone's discription on a jet for sure as I have done many of them. I now have an I/O eliminator and can not remember exactly how it is plumbed... but I still think you need to come from the top of the motor (t-stat housing) to the exhaust dumps which are usually at or behind the risers and in the exhaust stream. By reading your description of the Clymer book it sounds like it is what is backwards.