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318 steam form exhaust

6

69_nautaline

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"I just bought a 1969 nautalin

"I just bought a 1969 nautaline super cheap. 318 engine, raw water cooled, dana stern drive. I get quite a lot of steam out of the exhaust and the temp gauge bounces around alot. I have the winter here in Wisconsin to work on it. Water Pump new, thermostat seams to be working.

What is the source of the Steam and how do I fix it?"
 
"Often indicative of a blown h

"Often indicative of a blown head gasket or cracked head. Start with a compression test of all cylinders. If the numbers from that are OK then I'd take a hard look at the manifolds and elbows.

Make sure that the temp gauge fluctuations are an electrical problem. "Bounces around a lot"
More info... i.e., It changes xx degrees in yy mins zz times an hour when I am running the engine at.....?"
 
"You most likely have bad mani

"You most likely have bad manifold and or risers. The cooling water can't circulate through them fast enough to avoid getting to the boiling point, thus steam. I would definitely check water flow from the pump, first disconnect hoses and see if water is flowing to trans cooler, then out of it, and into manifolds. I'll bet those manifolds haven't been changed for a long time. They only last for about 4-5 yrs, and if they rot out, they will leak water into the cylinders causing hydro lock and a whole lotta problems"
 
"I think I may have a similar

"I think I may have a similar problem as I noticed some white smoke from the exhausts while running. Not a lot, but enough. If the manifolds need changed, where is a good place to get new ones ? Thanks for the advice !"
 
"Steven and Gregg:

First of

"Steven and Gregg:

First of all, buy an infrared temp gun and findout IF you have a problem. Shoot the motor and the entire exhaust system. Temps should be consistent, side to side, and not over 150 'F for a raw water cooled motor. If they are--especially on one side--you have a blockage on that side.

Some steaming is normal, especially after a long, hard run. That mass of metal isn't about to cool down instantly, especially with the reduced coolant flow at idle.

Jeff"
 
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