Hello wizards, I have been watching too much TV,getting fat etc. Haven't been in the garage getting shit done except for today. I dug the 270 gmc from unde the bench and fired it up. No radiator, and fuel directly to the carb. It was sold to me as a running engine. It fired right up but after a few seconds,I saw smoke coming out of the water pump inlet... Bad head gasket? I'll be doing a compression test tomorrow... #6 has 40# so far,,I didn't test the rest,got excited and fired it up... pretty happy that it fired and it ran for 10 seconds. .would love to hear your ideas.. I do have a new head gasket somewhere. I'm planning to put a 400th behind it for the homemade COE. TIA.
Never fire up an engine without coolant. Messed up water pump seal, cracks valve seats, and the list goes on.
He doesn’t behave a water pump on the engine. Smoke is coming out the water pump hole at the front of the block. Possible head gasket, crack in a cylinder wall, or possibly a crack in a combustion chamber but that probably would smoke out of the head water outlet. GMC’s are easily sleeved.
Any time I have fired up an engine without coolant and no hoses on it, it would smoke out of the cooling system. I think it's just residual chemicals burning off.
I wonder what it smelled like? Moisture inside the engines' cooling passages, from sitting, is going to steam up probably? I wouldn't over think this or worry. The inline GM engines are almost indestructible. You have the truck engine. I'm sure it can take a little heat for a few seconds without melting to the floor. Cue the Wicked Witch...
the damn thing is probably junk. Send it to me and Ill take it off your hands Ill be doing you a favor, trust me
My local junk yard years ago would prove what a good used motor he had for you by starting it up sitting in a tire on the ground. Smoke out of the hoses cut off with a hack saw was actually moisture cooking out of the cast iron I always thought. He did not run them very long, but it never caused a problem that I am aware of
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