Cmp c15a gs

[Bob Carriere]

This is the plumber's nightmare I adapted on my 261 to allow the use of a modern Princess auto temp guage to the 261 block.

Since that picture was taken the 1/4 turn valve has been removed and a proper 3/8 copper tube with heat shield has been added...... the valve was just an experiment to see what would happen if the engine was run and the valve closed...... interesting to see all the air/bubbles froth that came out towards the radiator when the engine had been running for a few minutes..... a lot of air seems to build up inside the head..... which convinced me that the tube should be open and allowed to flow all the time to prevent air pockets.

I will have pictures of the infamous large original steel fitting that was installed on 216 CMP engines tomorrow......

Keep warm..... 'tis colder than a mother-in-law's heart tonight.

Bob

[r.morrison]

Thanks 2 Bobs for your insight. I may have to add this item to Joel's wish list. But I'll double check with the 2 Bobs first. Mr "not so mechanically inclined"......... Robert (Bob)

[Phil Waterman]

There seems to be a huge variability in the size and location of the temperature sender on the Chevy inline 6. The original 216 engines from all three of my CMPs had the large tapped location rear of the block for the steam relief tube and temperature sender. The recent 1941 replacement NOS head I got for my HUP has only the smaller tapped location about 6" further forward, between cylinders 5&6. My 235 engine has the same small tapped location but it also has a cast boss for the other tapping directly over the #6 exhaust port. While the 261 has the large hole tapped at the forward position between 5&6.

Picture below shows the 235 head before cleaning, and yes this cleanup and is on the 235 engine now.

I have found inexpensive replacement gauges which had a full set of adapter busing to use with the different size tappings.

The steam relief tube is not needed in most conditions except for real steep up and down hill off roading. When the rear of the block may get to hot to quickly and form a steam bubble before the heat causes the thermostat to open fully.

So to some questions: How many people actually ever open the valve?
Lacking the large tapped hole for the steam tube and temperature sensor has any body used heater tube tap on the thermostat housing at the front of the engine?


What ever happened with the problem of the truck stalling when the clutch was pushed in? Has the problem been solved?

Cheers Phil

[Joel Culliford]

They believe it was a leak in the gas line, though they haven't tested it yet. One of the students is using the CMP as his final exam and decided that wiring it up would be what he would do. This means that there will be new students at the beginning of February working on it. I will try to get a complete update on everything that is going on with it. The problem is the students sometimes start a job but move on to something else that catches there eye...I don't mind but it can make for a long to do list, but I understand.

Joel

[Bob Carriere]

here is a pic of the bulb on an original 216 CMP temp gauge..... that screwy square nut will not fit on most modern brass fittings and when it does it does not allow the funny odd tapper on the bulb to fit modern brass fittings..... so it leaks..... the Barn as no solution yet to that dilemna...... maybe a hand made lead washer....???? comments

Bob

[Phil Waterman]

Hi Bob

I have seen the adapters for this on line within the last month. I'll try and find them again they came with a generic replacement gauge unit.

I book marked the site but my browser favorites list got misplaced in a recent computer rebuild, but I'm pretty sure it is on my backup drive.

Was looking for the fittings because I wanted to install multiple thermometers on the HUPs rebuilt engine while I'm running it in on the test stand. Wanted the normal rear of the head, just under the thermostat using the heater tap, and the radiator return temp at the water pump using the other heater tap.

Cheers Phil

[Phil Waterman]

Hi

This is the type of kit I was talking about, this one is on NAPA http://napaprolink.com/detail.aspx?R...975_0330718988 it cost about $72.00 not the cheap version I as mentioning though which I think was more like $20 bucks

The three bushings included lets you use the normal sender unit in a variety of applications and yes the bushings with the gauge I have fit the standard CMP Chevy gauge sender. See the photo below with old CMP sender bulb installed in thermostat housing tap.

I'll keep looking for another source.

Cheers Phil