78 Spitfire project

[400brian]

With the new bearing on, I am just waiting on the O-ring that goes on the bearing, and I will be ready to reassemble the case.

[400brian]

Getting ready to reassemble the Kohler. I cleaned up the studs and installed them into the new jugs. Yes, those are NOS jugs. I was able to find a pair, the price was a bit more than having the originals re-plated, but it was the fastest way to have serviceable jugs at my door. They are not perfect, you can see in the photo that the top fin is bent on one, but I guess I can live with that.

The intake manifold is cleaned up, that needs to be installed to align the jugs before you tighten them down.

The last thing I did was check the ring end gap. I need .010 to .015" gap, and I do not have it. So it appears I will have to file the rings.

The O-rings have arrived, and I am satisfied with them, so once the rings are good, assembly can begin.

[400brian]

The crank, jugs, and pistons are all mated with the case.

The Kohler has to be assembled to this point all at the same time. Unlike a Kioritz engine that you can assemble the crank into, then come back later to assemble the pistons and jugs.

Much fussier that the Kioritz. You install the crank, then the bearing shims and C-clips. When all that is fought into place, then you can apply sealer to each case half and assemble them together. Now you can install two 1/4 inch bolts to each side of the case to keep things together. At this point you now have to install the pistons, so you can install the jugs, so you can tighten the eight main fasteners that clamp everything together. A mix of studs and long bolts that come up through the bottom of the case.

I don't know about all of you, but I find installing pistons on the rods and messing with the circlips to be a fussy time consuming job. Plenty that can go wrong here. Then sliding the jugs on is perhaps the highest pucker factor of all! And here you have the added pressure of wanting to get this done before the Yamabond has set up.

I had checked the ring gaps the night prior to case assembly. I had never filed rings in my life. Note I said "had". The book calls out a ring gap of .010 - .015, I had no gap at all. I clamped a 6" file in the vise horizontally, and carefully did what the book said, file each side of the ring equally, and tried to keep everything straight. I shot for the middle, opening them up to .013", then installed the rings on the pistons, and marked each piston to stay with the jug I had filed the rings to.

You have to slide the jug down over the piston, while compressing the top ring with your fingers while keeping the ring indexed with the pin in the ring groove. Then once the delicate top "L" ring is started in the jug, you then repeat the process with the second ring. You can rock the jug gently, but you cannot twist it, you will break a ring, been there done that in the past. The second jug was the hardest as access was more limited by the installed first jug, but I got everything squeezed in, and ready to install the final bolts.

You install the fasteners loosely, as you now have to install the intake manifold to the jugs to line everything up, just as with the Kioritz engines. Quite a bit of time has elapsed at this point as you are trying to get the washers and nuts on the bolts and studs, but I finally got everything on and tightened up. Now of course you take the intake manifold back off so you can tighten the bolts behind it.

[AirborneX4Special]

[400brian]

So before I install the heads I want to soda blast them. I don't know if it will make much of a difference, but they do stick out through the hood in plain sight, so it would be nice if they at least were clean. So I haven't gotten around to that job yet, so I installed the ignition system. I had marked it so I could replace it in it's original position. With that done, I moved on to the bell housing. I de-greased it and scrubbed the oxidation off with a wire brush, and it cleaned up half way decent.

[400brian]

I keep the service manual open as I work on this thing, as this is the first Kohler I have worked on, and I don't want to assume too much. One of the things mentioned in the book at this point, is timing the ignition system. You can time it with a timing light hooked to a 12v battery, shooting through the hole in the bell housing, and looking for a mark on the flywheel. However, the engine is to be running at 6000 RPM to do this, so that is pretty much out. AND, if it isn't spot on, you have to tear everything apart to move the ignition plate, and guess how much to move it.

But, there is an easier way! JD made a tool that slides on the end of the crank shaft, indexes on the key, and has a pointer that shows you where you are at. You use a dial indicator to find TDC on number one piston, then rotate back .085". The pointer should be aiming right at the center mark of 3.

I was surprised to find out my brother had this tool, but he dropped it off, and I put it to work.

Turned out the timing was close. The pointer was dead on the retarded of the 3 marks. So I loosened the 2 screws holding the plate, turned it to align the pointer to the center mark, tightened the screws back up, and I was done.

I also took a look at the recoil starter. It had come disassembled and laying in the bottom of the pan. I compared it to the diagram in the manual, and found I was only missing a washer. However, things are a bit beat up, and the threads in the aluminum cover look as though the bolt has ran loose. The plastic pulley the rope winds around is fairly loose on the shaft as well. Always more to do!

[400brian]

Another JD tool in action. JDM-104 has been sitting on my bench for years, and I really didn't know what it was for until I saw it in use in the Service Manual. The Kohler flywheel has no ring gear on it, so there isn't a lot of options for holding it while tightening the nut. Kohler calls out a tightening spec of 85 - 90 ft/lbs on the nut, so it really helps to have something to hold the flywheel.

[AirborneX4Special]

Always good to have the correct tools.....

[400brian]

The engine is now pretty much complete. I still need an O-ring for the intake manifold halves to complete that, and the exhaust manifold needs clean-up and paint. The recoil is working, but it is a little sketchier than I like. The post inside the recoil housing has half the threads stripped out of it, and the bolt that goes in it is a bit dinged as well. One of the dogs is being retained by a under size C-clip, I found the damaged original E-clip stuck on a magnet inside the flywheel. The plastic pulley the rope winds on has probably seen better days as well, so I would like to re-visit the recoil, but it is working at the moment.

The heads have been soda blasted and installed. The ignition system is installed as well, however it is not functioning up to spec. If you shut the shop lights off, I can see weak spark on both sides, obviously not good enough. CDI is not my strong suit, but a deep dive is going to have to be made into that.

At some point we are going to have to bring the sled in, clean it up, and get started on the drivetrain.

[400brian]

I hate messing with electrical stuff. My experience is that after you spend a bunch of time diagnosing with a meter or by any other method, you wind up being a parts changer anyway.

The Spitfire Service Manual shows two methods of trouble shooting the Kohler ignition system. One with the JD test instrument, the other with a simple ohm meter.

My ohm meter is old, and it was very low buck to begin with, I don't put a lot of stock in anything it indicates. But I decided to see what I could learn.

The ignition generating coils under the flywheel are supposed to show 160-200 ohms. My meter shows 100+ ohms, and both coils show exactly the same. I'm thinking they are OK until proven otherwise.

The ignition coil is just tested to see if it is grounded out anywhere, and it is not, so it seems OK until proven otherwise.

The CDI box test is a bit more complicated. You check between various wires with the polarity of the ohm meter a certain way, and all you are checking for is continuity or lack of it. There are 8 tests.

The first 2 tests were supposed to be open, and they were. The next 6 tests all indicated opposite of what I wanted to see. I am not sure I have ever used my ohm meter in this way before. I made sure the battery was installed correctly, and the leads are stuck in the instrument correctly. I would need a diode to test the meter to make sure it is wired correctly.

So what did I learn? My first instinct going into this was that the CDI box was most likely the issue, and I am sticking to that til proven otherwise.
So, like I said at the beginning here, I'm going to wind up being a parts changer.

I have a new CDI box on order. We shall see where this leads.

[AirborneX4Special]

I bet faulty CDI

[400brian]

I thought CDIs for the Kohler were available, Matt showed them at his New Breed store. However, when I ordered one he told me that he couldn't get any. I finally found a new Kimpex on Amazon, and it arrived recently, $90 shipped. I installed it last night, and I now have spark that is visible with the shop lights on, looks like it should run. Installed a new set of NGK plug boots as well, as the originals were looking very weathered.

[400brian]

So just to keep things moving forward, I cleaned, painted, and installed the exhaust manifold. Next I installed a new O-ring in the intake manifold, and installed that on the engine. with that done , the only thing left was the clutch. I had a new fixed half for the Duster, I cleaned up everything else, and installed the clutch on the engine as well. This thing is ready to go back in the sled!

[SS440-80]

Nice job

[Hemi guy]

I'm curious how this is coming along. I have a Spit that could use this treatment if those pistons work....