Cooling system flow?

[sinkn-feeln]

I have downloaded a couple of diagrams for a cooling system with a raw water pump and engine water pump. One shows the flow through the exhaust manifolds first, the other shows through the block first. Is one way better than the other?<br />I will be on fresh water lakes in Texas, if that makes a difference. I also assume that I need to put a recirculation loop or blow off on the raw water pump, Positive discharge pump.<br /><br />Another thought, What if I split stream from the raw water pump and feed both block and exhaust. The exhaust would exit through the tips, and I could provide another transom exit from the block. <br /><br />Thanks<br />Todd

 

[McKenzie]

Re: Cooling system flow?

Could you post the pics you are talking about? Is one pic with the thermostat closed and the other with it open?

 

[sinkn-feeln]

Re: Cooling system flow?

Here are the two links.<br /><br /> http://www.marinemechanic.com/new-folder2/v8_cool_flow.gif <br /><br /> http://www.glen-l.com/inboard/cooling-plate41.jpg

 

[Bondo]

Re: Cooling system flow?

The marinemechanic is a pretty common system.... you Don't need overboard dumps, just pump it out the exhaust....

 

[sinkn-feeln]

Re: Cooling system flow?

If I go with the marinemechanic diagram, what is the best way to keep the raw water pump from over-pressurizing?

 

[akriverrat]

Re: Cooling system flow?

usually a bypass in tstat housing routes water to exhaust manifolds whenever engine is running. otherwise the exhaust hose burns up befor tstat opens. some use spring loaded check valves others just a passageway.

 

[sinkn-feeln]

Re: Cooling system flow?

Akriverrat,<br />If I understand you correctly, my thermostat housing doesn't have a bypass. If you look at the diagram here , http://www.marinemechanic.com/new-folder2/v8_cool_flow.gif . If I add a tee on the outlet of the raw water pump to tie into the exhaust feeds, this would keep the manifolds wet at all times. But would the engine water pump have a problem pushing water out when the thermostat opens?<br /><br />Thanks<br />Todd

 

[akriverrat]

Re: Cooling system flow?

that is a very basic diagram. the bypass would be between upper and lower tstat housing and is not shown. the amount of water bypassing must be enough to cool exhaust but not so much that engine circ pump will be robbed when tstat open. the easiest thing would be to let one of the big boys do the engineering and buy the parts that perform this function from vp,omc,merc,pcm,kem,... the error part of trial and error can be quite expensive in this case. or do a search for coolcraft and get a closed system which increases life of anti-freeze cooled pieces.http://ebasicpower.american-data.ne...TGY&Store_Code=ebasicpower&Category_Code=COOL a quick search produced this

 

[sinkn-feeln]

Re: Cooling system flow?

Akriverrat,<br />Thanks for the info. I think the biggest problem I'm going to have is on the small block Ford, the thermostat housing is on the front of the intake, and there is not a lot of room between it and the recirculation pump on the block. But now that I understand more details, I'll check with some of the contact you've listed. Surely I can't be the only one working on an older small block Ford.<br /><br />Thanks again for the information.

 

[sinkn-feeln]

Re: Cooling system flow?

OK, I need to re-open this topic.<br /><br />I finally got the motor started, after re-wiring the electrical system, and I'm very confused.I am currently working on the boat in dry dock until I'm comfortable with the cooling system.<br /><br />This is a small block Ford with Edelbrock aluminum log style manifolds. I am currently feeding the block recirc pump with a garden hose, plenty of water. I have copied the old cooling system, as far as flow paths, but the motor is heading for high temps. I have pulled a water plug on the intake, near the t-stat, and attached a 1/2" hose to dump water overboard. This keeps the engine at operating temp. The edelbrock manifolds have 1/2" hose connections. I am getting cool to lukewarm water from the exhaust with motor at idle. The old system had 1" hose throughout system,<br /><br />I have a .GIF image or a .BMP image I can email someone to look at.<br /><br />Can use all the brainpower available, I'm running out of summertime with the hunting seasons approaching.<br /><br />Thanks