maichor

I have searched on this, but had trouble finding anything on motors that have been sitting a while.

I have transplanted an LS1 into a 1972 Datsun 240Z. The motor has 10K miles on it but has been sitting for more than a year. I have had the motor running for some time, but the coolant is not circulating. I pulled the water pump, it appeared to be fine. Pulled the thermostat, still no go. When the motor was out of the car, I tried to blast the coolant passages with a hose and water did come out the other side. So, I replaced the pump anyway. So, now the motor is back in the car and still no go.

I have a hose circulating the feed and return for the heater. I also have and ASP underdrive pulley. I have had the motor up to 220 degrees. I dare not go any further until I figure out what is wrong.

HELP ME PLEASE! Could I have blockage? How hot is too hot (where I am risking damage to the motor). What would you do?

Mike94ZLT1

iTrader: (3)

On the passenger side above the starter there is a plug in a coolant passage. Pull the plug and see what comes out. If nothing comes out then you probably have a blockage somewhere. How much coolant/water have you got this thing to take? How do you know the coolant isnt circulating?

maichor

The first time we had two hoses in a bucket, put hand in front of the output hose and no go. The second time I filled the radiator to capacity, it took about half of that, which I can only guess is about a gallon. I have added 2 and 1/3 gallons total coolant + H20. Radiator does not get hot and cannot see things moving with lid off.

wrencher

iTrader: (2)

The thermostat to the lower hose inlet of the radiator? with the stock fan settings it will get up to 220 degrees.It is a suction regulated cooling system you prolly wont see much move until the stat is opening.

MyersRacing

I had a similar problem but what was thought to be the orange mud they install in the coolant system ended up being a t-stat. I finally ordered a stat from the local dealership and installed, and it has been fine ever since.

You can also pull the temp. sending probe from the block as well located on the drivers side toward the front of the motor in which you should be able to see since you had the engine out, the reason I pulled this was to see if maybe I had air trapped and was causing and air pocket inside the block somewhere.
I pulled the stat from the houzing and remounted it without the stat filled her up and started and the water flowed thats how I decided that it was a stat.

1971ssLS1

are you using the heater hoses for your heater? if not and you blocked them off, that might be your problem. those two fittings need to be connectd in some how, its were the water flows, but make sure its not kinked.