Roger Zimmermann

I suppose you are sad on one side and happy on the other side...

Interesting reading, but does not belong exactly here...

Thanks Randy! Indeed, there are more tiny details I could add, but sometimes enough is enough! For the moment, there is no progress, I'm not at home...

Even if the intake manifold is simpler than the exhaust one, it took some time to complete the RH side. Now, I just have to do the other side!

Thanks John, but you'll have to wait a bit more!

With the exhaust manifolds done, I had two possible paths to continue: the carbs or the intake manifolds. I choose the later possibility. The intake parts should be less complex to do; I will see...For the moment, I did the distribution boxes which are sitting on top of the center exhaust manifolds. I did a small error when I did the holes for the attaching screws: they are a tad too much towards the exterior. Because of that, I could not do the countersunk holes large enough to allow the regular brass bolts I have, their heads are rather large. The stainless bolts have the ideal heads, but are way too short. Therefore, I silver soldered a threaded shaft (cut from screws) to the stainless steel bolts. Another alternative: mill the brass heads at the same dimensions than the stainless steel ones. Making the bolts longer was quicker done, this is why I choose this solution.

During the recent tests, did you use so much fuel as when you began starting the engine?

The color you choose is not my favorite, but well suited for the period!

By bending a bit the elbow at the last exhaust outlet, I could get the needed clearance. This will also help for the exhaust routing near the gear box. There is also not much space between the rear manifold and the water pump; according to the various pictures, the distance is really short. With that issue solved, I could solder the remaining outlet tubes on the manifold. The LH rear manifold will be (I hope) easier to do!

You could not paint panel after panel if the paint was metallic!

Thanks Paulie! As the flange from the water pump tube is not thick, I can only remove 0.1mm (0.004"). I already removed some material at the vertical outlet; I will have to bent is a bit. the other side is less critical: there is also a water tube, but it's nearer from the block.

I expected difficulties with that rear manifold and I got them! When the lower tube was done, I did the tube for the last cylinder, going down towards what was already done. However, the diameter from both parts is not the same. I did a tail at the upper tube and adjusted it at the lower one. When I was satisfied, I could silver solder both elements. Then, I silver soldered the flange at the cylinder head to the upper tube. This operation was delicate: if the assembly is crooked, the tube will be pointed in the wrong direction. By chance, that soldering went well, even if I had to "massage" a bit the tubing assembly. Then the more delicate job: merge the horizontal tube with the vertical one. I did not remove too much metal at once, looking if the job was right. After a while, I came to the conclusion that the horizontal tube was too short. Not wanting to do another one, I cut it and put a spacer about 2.5 mm wide (.1"). When it was done, I had a better vision how both elements could merge, removing metal here and there until I was satisfied. The next question was: how to assemble both? with silver soldering or soft soldering? To silver solder it, I should create a jig; I could however soft solder both elements when they were assembled on the engine. I now have to shape and solder the two last tubes for that RH manifold. I noticed that there is an interference between the tube coming from the water pump and the exhaust manifold ( the second picture is showing it well). I will have to solve this issue before I can go to the other side which should take less time to build

Thanks Randy! The rear manifold is not an easy one: there are indeed 3 parts merging in one place. I began the tube connected to the center manifold and realized that I cannot go further. Then, I did the tube going down and the flange where the exhaust tube will be attached. Then the idea: with that flange, I can attach the tube to a fixture screwed to the engine. From there, I will be able to continue with the smaller tube coming for the head and finally adapt the horizontal tube. All three elements have a different diameter, you can see on one picture from the repro manifolds that the tube going down is more or less flat to conform with the other parts.

The logical continuation was with the front manifold. The center one is a nice guide for the right position of the main tube. Both rear outlets near the center manifold were soft soldered on the main tube when it was assembled to the engine. Now, I will do the LH front manifold.

Those tiny "tubes" (I made them from a solid bar) were rather labor intensive because they had to be adjusted with precision. To complicate the task, they are not perpendicular to the heads, they are slightly directed towards the rear. Anyway, both sides are now ready at more or less the right position. Now, it's the time to make the front manifolds.

Indeed, I'm not much further with the manifolds. I added a flange for the carburetor to both central parts and did some holes. As I did forget the formula to make parts by looking at the pictures, I had to do something concrete: attach the central manifold on a temporarily basis to go further. This is what I did the last few days; the central RH manifold is not attached to the engine using the holes attaching the block to the crankcase. I also installed a flange to the head. I "just" have to make two tubes joining the flange and the manifold...

Bad luck with that shop...

After I did tiny parts with the fuel bowl, it was time to go to large parts: the intake and exhaust manifolds. I choose to begin with the exhaust parts; indeed, the intake manifold would be easier to do and would help to locate the exhaust with more precision. I began the job by drilling the threaded holes to attach the manifolds to the heads. Then, as I did not know how to proceed, I did the flanges for the exhaust tubes at the head. With that, I'm not very far...I wanted to begin the front tubes; did something just to realize that I'm going nowhere with that. Therefore, I decided to do the middle part (the picture from a real pair of manifolds will give the needed explanation). As my pictures were not good enough, I searched for exhaust manifolds with Google. I found very nice pictures from a company who is recasting those manifolds! Sure, they cost almost the price of a cheap new car, but they are there! The pictures I found will help a bit, but even if I'm looking at them the whole day, the brass will not be magically shaped...Anyway, here is what I have up to now...

You wrote somewhere that for the 2 and half minutes running time, you used about a gallon of gas (or half). Terry Harper wrote a list of reason why an engine can overheat, among them the two above. That huge quantity of used gasoline is making a lot of heat. Could that be our problem?

Matt, I feel your pain. That story right now is not funny. You are writing that you have difficulties to understand that in such short time the water is getting so hot, me too. I'm wondering if the whole quantity of 7.5 gallons (more than 25 liters!) is getting hot or just what is around the engine blocks? Did you measure the temperature at various spots with an infrared thermometer? I'm wondering if the water pump is really doing his job. A defective thermostat may do the same by not letting the water circulate.

Super! Not yet 100%, but it runs without alarming noises!

Yep, good eyes are needed!

The fuel bowl and its retaining hardware are ready. Man, that is small! Fortunately, the fuel bowl will be protected by the frame, so no fat finger will fiddle with it when the engine is installed.

Thanks Eric! as I used temporarily two screws during the time the glue got cured, this will be a very thin diaphragm!

The provisions for the fuel bowl were added (tiny cylinders soft soldered) and both halves were glued together. Glued? Why? Just because I did an error: I intended at first to attach both halves with .5mm bolts; when I was ready to drill the necessary holes, I switched to 0.6mm because I had tiny screws which heads are more in line with the original screws. Unfortunately, I had only 6 or 7 such screws and during all those years, I never found equivalent screws again. I decided to revert to the first decision, but now the holes are too large. To modify the lower half with silver solder would be hazardous, therefore I will put the 0.5mm bolts as intended, but glued. I attached the pump at its location, well hidden behind the front engine support. The upper part is turned at about 45°, otherwise, the fuel bowl would interfere seriously with the frame. I will do now the fuel bowl in plexiglass. I could machine that part in brass and paint it, but I have a remaining bit of plexiglass I can use for that.