BBC plumbing question

[Vintage Eliminator 21]

Trying to figure out how the cooling system is supposed to go on my BBC. Now, it goes from the pump to a t and then to the logs. From the logs it goes to the front of the motor and out the tstat to the bottom of the riser. My problem has been not enough water coming throught the exhaust.
Is this how it's to go? Does anyone have a pic to post showing how their BBC is plumbed?

[MikeF]

www.liquidaddiction.net (http://www.liquidaddiction.net)
There is a diagram there :D .
[ September 02, 2003, 07:48 PM: Message edited by: MikeF ]

[littleC]

It should go from the pump to the front of the motor. Water then should come out the intake manifold to your logs.
Chris

[malcolm]

You got it right Vintage. Are you running on a trailer or in the water? Any valves before the T that might be partway closed or plugged with sand?

[Taylor LP]

Vintage Eliminator 21
From the logs it goes to the front of the motor and out the tstat to the bottom of the riser. Are you talking about coming out of the place where a tstat would normally be or do you actually have a tstat in there? The routing you have is correct, but only if you aren't running a stat.

[Vintage Eliminator 21]

Thanks for your help! No thermostat. The housing is split on the inside with two hoses coming out. One goes to the right riser and the other the left. I switched from 5/8 hose to 3/4 inch to help put more water in the exhaust. The guy I bought it from said it originally had a 455 in it and he put the bbc in. So I wasn't sure if he had it plumbed for the olds or the chev.

[Vintage Eliminator 21]

Malcolm,
Haven't been running on the trailer. Just been on the lake with it and only 3 hrs since I bought it. It does have a gate valve coming off the pump (Bayjet). The temp is ok when running and doesn't get hot when idling. It just been melting the exhaust hose.

[Cas]

VE,
Check to see if there is something restricting the hose to the riser. I remember reading about a similar problem a couple of years ago where the person burned a hole in the rubber exhaust hose....lots of water was entering the boat through the exhaust tips. I'm thinking it was Flat Broke?

[flat broke]

I had a similar problem, but the issue was that the exhaust gas was hitting the rubber hose at close to a 60 degree angle in an area. This over time would weaken, the bubble the hose. The solution was some hard pipes fabed up out of aluminum. I would suspect that the bend from your risers to the tips might be a little extreme and the exhaust gas is hitting the rubber close to head on. The rubber will hold fine when the exhaust is moved with the contour of the ruber, but once the exhaust is pointing directly at the hose, you're going to have problems no matter how much water is present. If you can, post a pic of your exhaust setup and we'll see if we can figure it out. I would also pull the rubber hoses, hook up the water and check the flow with the engine off (make sure to plug the exhaust portion of the manifold to prevent water from running back into the head). There could be an obstruction at the joint between the manifold and the riser causing reduced flow which would also hurt the hose.
Hope that helps,
Chris

[Vintage Eliminator 21]

flat broke,
It will until next week before I can post a photo. Working alot of hours between now and Monday. When I switched to 3/4 hose, I replace the fittings on the tstat housing and the riser, or at least one riser. The one on the left was an odd brass fitting and the nut part broke while trying to take it out. So, I had it drilled out and will have to put some type of thread repair in.