Chevrolet CMP Engine variants

[Phil Waterman]

Hi Rod

First my understanding is that the 2 port version of the 216 engine is actually post war. But as the engines are otherwise identical you will find them as replacement engines in CMPs.

My solution to the throttle link is simple it that I fabricated a new cross shaft bracket that moves the shaft forward about 1 1/2".

This picture is of the stock bracket
W 41 Pat 12 Throttle Linkage modified 017.jpg
W 41 Pat 12 Throttle Linkage modified 018.jpg

This is of the fabricated bracket

W 41 Pat 12 Throttle Linkage modified 007.jpg
W 41 Pat 12 Throttle Linkage modified 008.jpg

You also make new lever arms but it is all done from simple materials. You also have to check the arm angle on the shaft to be sure to get full throttle swing. Also check your side engine bell crank that connects the link age up to the carb. Be sure that it is free and allows the peddle linkage to over swing with out trying to push the carb past full throttle. (Carb will break if this happens.)

Little difficult to post all the measurements on MLU if it would help I can post all the photos on my web site I took 40 some photos of the two throttle linkages.

There is also a slightly different approach if you are installing a 261 or 235 because the thermostat housing is different shaped and I'll post pictures of that version as well.

Now to the coincidences of you asking this question while happen to have the bracket out of the truck. I'm in the process of swapping out bent cab frame on my Pattern 12 for a straight one (thanks to Santa Bob for the straight cab frame) also trying to solve an engine over heating problem so the whole nose is off the truck. Also plan to swap out the 216 for a freshly rebuild 235.

But the coincidence is even bigger because earlier this week when I start the project I came in from the shop to find a private message from Alex van de Wetering asking a question about how to tell the difference from Pat 11 and Pat 12 Cab Frame.

The wonderful world of CMPs and MLU

Hope the information helps.

Cheers