Greetings from across the pond.\
********* last caution.....when fitting the adapters into the head of your 261////DO NOT overtighten the adapter....used liquid sealant of white teflon tape,,,,, you can actually crack the block you can never
a tell how much rust has weakened the inside of the water jacket you are screwing into.
Very nice cab 13. Your new registration to Stovebolt was brought to my attention.
You are very lucky to have the 261....which gives you about a 50% increase in horsepower and it is a direct bolt in...... exception being the water pump which needs to be a 216 water pump to save space.
Some general suggestion....... the ENGINE section is very good for motor related issues........ I am currently in the Drivertrain section trying against all odds to find a source for the tie rod ends....
Over the years I have learned a lot from Stovebolt members and still learning....... amazing how the web has shrunk the world.....
First of all I am a die hard CMP nut with a totally rebuilt cab 11, 1940 Chev.....purrs like a kitten...... You are very fortunate to be in Holland as you have the largest part dealer Stefan at LWD CMP Parts.
There are a lot of other CMPs in Europe and you have the best and largest flea market, gatherings that exist....... and do not forget your friends in Australia who were supplied by Candaina made trucks and USA vehicles.
Do a search for Maple leaf up and you will find the MLU Forum......... lots to read and lots to ask questions from.
First if you do not have one already get yourself a GM shop manual and eventually a parts manual MB-C2
Now on MLU you will find me under restoration.....The Hammond Barn....... and for ease of exchanging photos I will eventually give youo my personal email address....... I have thousands of pictures on the "Puter.........
This is not an attempt to short circuit the Stovebolt forum....... I tend to use both.... the more is posted on either Forums the more people will benefit from the now rare to find information.....
Lets tackle your first question of the oil gauge sender......... the problem started when the engine was switched...... the location of the oil sender/bulbis correct fromt he last photo you sent...howeever the odd thread size of the original 4 sided nut that hold the bulb in the head will not fit the 261 head and you need a brass adapter...... and it is not metric..... I will need to measure up what Ihave on my truck.
Another consideration is that the original army 216 had a special fitting in that location and itis referrd to as a steam line that connects to the filler neck or tank of your radiator. In very rough cross country driving up steephills and down steep slopes the head would sometimes develop steam pocket in the head at the rear section....... having that steam line allowed the steam to purge itself. Now yoour 261 has had some engineering improvements by GM as the drilled 2 steam holes between cyl. 2 and 3 and between 5 and 6 which was done for a similar purpose. On my 261 I did instal as steam line with t fittings etc. and added a quarter turn brass valve...... as a test.....drive around for a while with the steam valve closed...... then open the valve and watch the bubbles run to the radiator tank. I had installed a clear vinyl line for the test. Repeated the process and has the same results...so I concluded I was better to have one and installed a permanent steel line ( brake line tubing) to the radiator. I run a 160 thermostats and the engine Summer and Winter and never gets up above 165 F.
You may have some difficulties finding the proper British Imperial size brass fittings but I am sure that some of your fellow Dutch have already resolved that issue....... if not we can certainly send you some by mail. I can count on my fingers they items that are exclusive to CMPs ....such as the tie rod ends..... Master brake cylinders...... but in most situation we....the CMP nuts ... have found practical solutions.
Remember that the design was British....so overbuilt, super heavy and awkward to work on...... the production was a collaboration between GM and Ford........ so some of your brake parts are Ford... except for the engines which were unique to each almost everything else can be interchanged...
I will find pictures of how I connected my steam line...... and refresh my memory (failing) on how to post pictures. On the same picture you will see, no doubt, a very different carburator I am using a recommended YF Carter thanks to CarbKing...... and I have a rebuilt spare Zenith from a 270 GMC.
Hang in there..... from Canada
Bob C.
Last edited by RAC1812; 01/19/2023 4:06 AM.
