Water Cooling - 1963 Chris Craft

[richandkaren]

Several years ago, I purchased a 1963 Holiday 20' with 283 engine #831909. I have loved owning and operating it, but from day one there have been water leaks around the engine (not to mention hull leaks). The outsides of the cooling manifolds appear to have been patched with some kind of different (hard) material along one edge of the long rectangular sections, and when the engine is operating, you can see water seeping along the borders of these repairs. Question one is, are there more professional ways to repair a leaking cooling manifold, or do I need to be thinking of replacements? There is also a significant drip from the engine-driven cooling-water pump (Sherwood #L9980). I dis-assembled this and found a 0.031 inch thick gasket in fairly bad shape. Blog posts seem to indicate that these water pumps are finicky, so I am concerned about the advice I received, which was to just make a replacement and go with it. So the second question is, are these water pumps actually fairly robust and I should continue my own crude efforts, or is it time to turn the pump over to some kind of expert for a proper rebuild? Any and all advice would be appreciated - if it matters, I am actually preparing the boat for sale, as I think I have reached the end of my capacity to keep it up.

[dag55]

You should absolutely get new manifolds. Are they leaking on the outside, then they are completely rotten on the inside. Manifolds rust from inside out. It's great risk of getting water in the motor.

[richandkaren]

Thanks for the guidance! For the record, I also had a very helpful phone conversation with Bud Brackett from Marine Classics in Maine (207-247-6862). I will update this string when I get the results of his investigations.

[Greg Wallace]

Manifolds may indeed be "rotten" but may have been cracked from freezing if a northern boat. Common fix back in the day was "marine tex" and was often very effective in lieu of a replacement manifold. If the jacket is only compromised externally then a redo of similar material may fix your leak. Make sure is not cracked internally. It will need to come off to check.

[dag55]

Leaking manifolds are the shortest way to serious motor problems, like bent connecting rods etc... I would never try to repair a cracked manifold with whatever compound. Maybe welding if possible.

[mbigpops]

You can have them pressure tested and if they fail you can take them to someone who does "stitch welding" if you can find someone who still does it. Even then if they stitch weld all the external cracks it could fail pressure test and have internal cracks which is "game over" for the manifold.

Exactly the scenario that I went through before buying a new one.

Mark

[Greg Wallace]

If cost and availability are of no concern then by all means replace. If the boat has a salt water history I would likely plan for replacement. HOWEVER, IF cost or availability are a factor AND you can determine that the crack was a freeze related fracture AND there is no internal leakage and/or excessive corrosion THEN welding or chemical repair may be a viable solution.

We always recommended replacement to our customers who suffered freeze damage. Many did not want to pay the replacement penalty and instead decided to do the Marine Tex (epoxy) fix themselves. Despite our misgivings at the time we were amazed at how many of these repairs held up, some outlasted the motors. If welding or epoxy is chosen then both repairs should be monitored for leakage.

An internal leak can indeed cause major engine damage through oil contamination or hydraulic locking. An external leak will not.

[dag55]

The problem with freeze cracks, is that if a manifold is damaged, you will almost for shure have a crack in the motor block...

[Greg Wallace]

That would be true if the hard freeze event occurred prior to winterize where the entire engine was vulnerable. If the manifold in question was inadvertently neglected or did not drain properly then that individual component could have been isolated. I've seen this more times than I can count. The most common cause is failure to clear drain passage (hole) of silt, sand, crust etc allowing for complete drainage. I would still check out the rest of the drive train for signs of previous damage.

[richandkaren]

Thanks to all of the experienced folks who provided counsel! I am not strong on engine repair, but I have now secured (and will soon install) replacement manifolds which are used, but supposed to be tested and in good condition. The real discovery will be when I remove the old manifolds and see what they look like inside. Yes, I suspect that the old patches were epoxy of some sort, and the potential pitfalls made me think that further attempts at repair would be a bad course. The advice I received on the water pump was twofold - that the gears were probably worn out if I could see significant backlash in them (I could), and that upon dis-assembly by a knowledgeable person, it appeared that a less knowledgeable person (not me) had already done some damage by not lining things up properly during a previous assembly and dis-assembly. Plus the gasket and spacing dimensions are apparently very sensitive, so I was glad that the rebuilding was being done by a professional instead of me. So this was not the minimum-expense route, but I am hopeful that replaced manifolds and a rebuilt water pump will resolve the leakage problems, and may address a couple other concerns in the process - I had noticed some high water temperatures and questionable water circulation, which may have been caused by pumping inadequacies and trouble priming upon startup. This latter problem can apparently be addressed by adding a little heavy grease into the gear mesh before starting - and a fitting for this purpose had been added to my pump, but I was not aware of this patch-fix, and had not been turning the cap to inject a little more grease at every start-up. So much to know, so little time to learn it all!

[jim g]

Make sure your replacements are original Chris Craft manifolds or Osco manifolds. If they are Barr manifolds the engine will over heat due to Barr leaving out a divider in the water jacket of the manifold.