[Bob Carriere]

We took advantage of the nice weather on Saturday and worked on fine tuning the C15a.

My first endeavour was to eliminate the original 1959 vacuum connection sticking out like a sore thumb for the left side of the intake manifold. The overall clearance between the intake manifold and the engine cover sheet metal is approx. 3/4 inch on my cab 11. The huge fitting currently on the 1959 manifold is sticking out almost 2 inches.

One option was to drill a hole at 90 degree to the current hole and pipe something from that location. Cloder examination of spare intake manifold showed that only the outside face of the intake manifold is full solid cast iron. All ohter 3 sides seem to have a void between the air passages inside and the outside surface. Remember that this part of the intake manifold serves as a chamber that allows exhaust gases to flow around the iar passages and heat up/vaposize the fuel mix. The only other option was to drill one or both sides of the rounded section somewhere between the 2nd / 3rd or 4th / 5th cylinders and tap for a brass fitting. I was afraid of unbalancing the fuel mix....... or even worst of introducing metal shavings into the manifold..... ( I was determined NOT to remove the good sealing manifolds).

So I copied what was originally done when they installed power brake boosters on early CMPs. I had a local machine shop make me a 3/4 inch steel spacer shaped like the profile of a carburetor gasket..... alsmot the same as the current black bakelite insulator exept a littel thicker. The 3/4 inch thickness allowed for drilling and tapping two 1/4 ID holes opposite each other for fitting brass fitting.... one forward for the PVC pipe one at the rear for the vacuum gauge and later the windshield wipers.

In the process if fitting the steel spacer I took advantage of swapping the rebuilt Rochester B carb for a newly rebuilt Carter YF suited to the 261. This one is not supposed to leak raw gasoline when I negotiate very step hills.... that has yet to be tested.

Not to waste the nice weather we also removed the valve cover and re adjusted the valves.... that eliminated the small ticking of one valve and stopped the puffing sound that was heard in the exhaust outlet...

Now idles nicely at 475 / 500 rpm...... never gets any hotter than 160 F.... and a very steady 22 inches of vacuum and 35 psi on the oil gauge.

Ran the engine with no valve cover.... found it utterly facinating to see the oil flowing from the rockers and the almost musical rythmic oscilation of these little rockers.......

So here are some pictures of the before and after. Don't be discouraged with all the rubber and vinyl hoses.... they will be replaced with proper metal tubing and /or rubber hoses as appropriate once we have worked out all the bugs.