Hello, just new to the forum and looking for some information. Restoring my third boat which is a Glastron CVX20.  I purchased in pieces, including the engine. I am curious to how the cooling system works. Looks like there is no circulating pump used on the engine and the Hardin cover that is there is badly corroded. Since the engine is in pieces and on it's way to getting rebuilt, I am looking for some insight to how the cooling system works and any pictures that someone may have to illustrate hose routing.
Thank You. ( waiting for water to turn liquid here in Minnesota) Ha!

I'm assuming logs and snails.
From the pump, to the lowest side of the logs, from the higher side of the logs to the water pump block off plate, out the thermostat housing to the snails and overboard thru the exhaust.

I prefer a gate valve on the pump to slow down the water on the way in, and to regulate engine temperature.
Mine runs at 140°f at cruise, 155°-ish in the no wake zone.

Plumbing with headers is different.

You do have a water pump.
Is says Berkeley on it.

Dan'l

Thats how mine is, but does its make a difference by downsizing the hoses diameter as it goes from pump, 3/4 to the tee then 5/8 off tee to logs as well as to water pump housing,then 1/2 inch from tstat housing to snails? I was worried the 1/2 inch was too small so i changed them to 5/8 as well, now im wondering about the 3/4 being to big

Yeah, center risers are a bit different, but the same idea. There is usually a low point port, and a high point port, plus a port for the elbow on top. Always fill from the bottom up. Some mercruiser styles only fill from the bottom and out thru the elbows.

The hose diameter isn't usually a problem, plenty of lake water to cool the engine, and the pump provides plenty of water, usually too much. My big block only has 1 dump line, ½ inch, and has plenty of flow.

Post up pics of your center risers to see how they should be plumbed.

Dan'l