Category: Projects

As promised, here’s a short video of the 1949 Chris Craft K Engine, rebuilt and running.  Sounds great, doesn’t it?

Back in 1949, Chris Craft did not include an oil filter on their engines.  My research revealed that an internal Chris Craft memo said they expected the engine to outlast the hull, so they decided an oil filter was unnecessary.  This might strike you as odd especially since the engine shares its oil with the transmission.  I certainly found the engine to be very gunky when I took it apart.  I used up ALOT of de-greaser cleaning the inside of this engine!  There were more deposits than I’ve seen before.

Now the old advice not to use high-detergent oil in an old engine makes sense.  I could just see that detergent knocking a blob of gunk loose that would clog a small oil passage somewhere.  Better by far to, as the Beatles say, just “let it be” and hope that gunk stays put.

But since I had it apart and was able to clean it, I decided that I could not in good conscience put this engine back in without an oil filter.  That required fabricating a mounting bracket and finding a place to stick it, and adding plumbing lines to get it into the flow.  I plumbed it so that the oil passes first through the filter, then the oil cooler, then back into the engine.  As you can see from the photo, I mounted it at the rear of the engine, next to the oil cooler.  It will be easy to service here.

We still won’t be using high detergent oil though.  That would interfere with the operation of the reverse gear, which as I said, gets its lubrication from the engine oil.  We’ll use straight weight SAE 30, or SAE 40 depending on where the boat ends up.

I had originally intended to have someone else rebuild the engine.  I was going to open it up to make an assessment of how much of a rebuild was needed, and once I got it apart, I found that it was in pretty good shape.  Re-boring would not be necessary,  and valve clearances appeared to be good–no major wear on the lobes of the camshaft. The crankshaft was in good shape and did not need machining.  So I decided to handle it myself.  I don’t have the machinery to do serious machining, but I can handle a moderate rebuild.

The engine for the boat is the original Chris Craft K engine.  It bears the number shown on the hull card for the boat that I got from the Maritime Museum (see previous post).   The engine block– a flat-head 6 cylinder, was built by the Hercules Truck Company, and Chris Craft marinized it by adding their own manifold, and some other pieces.  It is a 95 hp hunk of cast iron that weighs in at 660 lbs.  In 1949, they weren’t doing a lot of pressed steel, so even the oil pan on this engine is cast iron.  It has a single barrel up-draft carburetor, naturally aspirated.

The rebuild involved tearing it down to see what kind of shape the bearings, crank, pistons and cylinders were in.  The word I got from the previous owner was that he had fired his mechanic in the middle of rebuilding the engine and some one else had put it back together.  This is never good news.  I wanted to make sure there were no critical missing parts (like bearings!) and see just what needed to be done to get this baby running again.

First things first–I ran a compression test on the engine before opening it up.  It had oil in it, and it was dirty, so it had be run.  But I wasn’t going to risk running it without seeing the inside first.  The compression test results were good–all cylinders within 12 psi of each other and around 125-135 psi with no significant leakdown.  The bearings and tolerances were in reasonably good shape, but were replaced since I had torn the engine down to that level anyway.  Many of the ancillary pieces such as the  ignition coil, and distributor had to be replaced.  There was no one to rebuild the existing water pump (a brass gear pump), and an impeller pump was a better alternative for a raw water pump anyway.  Both the generator (not alternator) and the starter motor were shipped out to be rebuilt and converted from 6 volt to 12 volt systems.  Also, I rebuilt the original updraft carburetor.

Stay tuned for a short video of the first running of the engine.

95 Hp “K” engine

One of the first major things to come out of the boat was the engine.  It’s a 95 horsepower Chris Craft “K” engine, weighing in at 660 lbs.  The block is a flat head six cylinder style engine built by the Hercules Truck Company.  Chris Craft marinized it by adding their own intake/exhaust manifold, adding a raw water pump, and turning it around 180 degrees, so the “front” of the engine faces aft.  This last was done to get a”right hand” rotation of the prop (make the propeller rotate in a clockwise direction if you’re looking at it from the rear facing forward).  So now the flywheel, which in a truck would be at the rear of the engine, connected to the pressure plate of the clutch, is on the front of the engine.  A special casting was made to accommodate the generator and the starter motor at the front of the engine.  Also, Chris Craft added an oil pan with a slanted bottom to allow for the correct mounting angle of the engine in the boat.  The oil pan is cast iron, not pressed steel like on a modern engine.

Next step is to continue stripping the boat of as much as possible to get it ready to flip over, and to rebuild the engine.  Onward!

Soon it was time to begin dis-assembly.  Much of this was accomplished with the boat still on the trailer.  This can be a slow process because you need to document every little step. Of course having a phone with a camera greatly helps–less time drawing diagrams.  But I need a lot of notes and pictures to help me remember how this thing came apart if I hope to get it back together.

Stripping out all of the parts helps identify which parts need more work (in the case of a 60 year old boat, almost everything) and reduces the weight that will have to be born by the hull in the flipping over process.  We’ll have to flip the boat to get the bottom off and rebuild it.  Well, I suppose it’s not absolutely necessary to flip the boat, but I can’t imagine not doing it!

One of the first things I did when starting this project was research it.  I found to my surprise that plans are available for many old Chris Craft boats.  As a matter of fact, Chris Craft donated their archives to the National Mariners’ Museum in Newport News, VA.  The have a great website here:  https://www.marinersmuseum.org/

So I ordered what they had, which was pretty extensive, from line drawings and plans to owner’s manuals, to marketing material.  They even had a copy of the “hull card” which is the factory data sheet that tells you what options my boat originally came with.  Pretty cool stuff.  It was fun reading through the engine manual.  I enjoyed their emphasis on using “oil of good character and quality”.  That’s something that can’t be overstated, but is pretty much taken for granted today–apparently no so much in 1949 when this boat was born.

I”ve uploaded a picture of the Lines Drawing of this boat, with some of my measurement scribblings.  The boat had retained much of its original shape with only a little hogging (sagging at the front and/or back end).

The current project for Ashley River Boatworks is a 1949 Chris Craft 17 ft. Deluxe Runabout. This boat will receive a new bottom, upholstery, cockpit ceiling, and engine rebuild, and be completely refinished. It’s a long road, starting with a lot of research and investigation into how it was done originally at the factory. A good resource for this is the national Mariners Museum in Newport News, VA. They have an extensive archive of Chris Craft drawings, literature and marketing material. The original lines drawings were available for this project from the museum. I’ve actually been working on this boat for some time, and will be trying to catch up with posts on progress that has been made. By the way, did you notice anything funny about that bow light?