Closed Cooling Question

[Glasply]

It seems I'm not getting enough water out of my Alpha drive impeller to cool my engine at mid-range or higher. It's a new pump/impeller kit, and was staying cool around 2700 rpms when I hit the water this spring, but now, especially as the inlet gets covered in marine growth, I'm lucky to run 2100 rpms without climbing temps beyond safe range. Manifolds especially are not getting enough cooling and are peeling paint.

So, boost pump? Anti-fouling inlet screen? Both? Neither? Does anyone have any diagrams or part numbers that'd help?

I'm running a throttle body 300hp 350 with closed cooling.

 

[achris]

Re: Closed Cooling Question

Assuming the tune on the engine is good.... Blocked elbows/manifolds... blocked thermostat, faulty thermostat, leaking water pocket cover....

 

[Don S]

Re: Closed Cooling Question

I'm running a throttle body 300hp 350 with closed cooling.

Is that an Alpha I Gen II drive along with that engine? I know Glasply (your username) didn't make any with Gen II, they didn't exist then.

 

[Glasply]

Re: Closed Cooling Question

Is that an Alpha I Gen II drive along with that engine? I know Glasply (your username) didn't make any with Gen II, they didn't exist then.

it's a gen 1 alpha, new drive in '07, on an MR transom

 

[HT32BSX115]

Re: Closed Cooling Question

It's a new pump/impeller kit

today? or back in the Spring?

was staying cool around 2700 rpms when I hit the water this spring, but now, especially as the inlet gets covered in marine growth,

I think you answered your own question. The inlet is covered with marine growth. That restricts water flow.



Clean all the growth from the inlet ports.....

 

[Glasply]

Re: Closed Cooling Question

today? or back in the Spring?



I think you answered your own question. The inlet is covered with marine growth. That restricts water flow.



Clean all the growth from the inlet ports.....

Well, I may not be the brightest light on the tree, but I've got that part figured out... See the original question. It's a water flow issue, that happens with a totally clean drive and pickup. The marine growth exacerbates the problem, which confirms what the issue is in the first place.

Where I'm really going with this thread is: How do I get more cooing water flow?

 

[Don S]

Re: Closed Cooling Question

Assuming the tune on the engine is good.... Blocked elbows/manifolds... blocked thermostat, faulty thermostat, leaking water pocket cover....

Have you checked any of the items Chris mentioned?