Wanted: 261 Chevrolet engine

[chris vickery]

I am looking for a good 261cid Chevrolet truck engine. These were also known as the Jobmaster.
These were commonly used in the 2 to 5 ton civilian trucks of the 1950's.
The truck engine has mechanical lifters, a more robust cam and torque than the similar Pontiac car motor of the era.
Prefer a runner, take out.
Have $, have other stuff to trade.
PMs please

[Bob Carriere]

You are looking for a 1955-1961 Chevrolet 261 larger truck engine.

GMC would have been 248 , 270 etc....

Cruise Kijiji or even local rural discount journals they do come up but very rarely as a runner.

Cheers

[chris vickery]

Bob, thanks for th clarification. Not being a GM guy per se, they are all the same, GM, GMC, Chevrolet etc.
I am sure the bowtie guys will give me a learnin'.
Always have my eyes open in the rag mags, Kijiji etc.
What I need is a WW2 235 but I want the extra HP and torque etc.
If I have to rebuild my 235 I might as well get a 261...
Now, for my next question; how does a 261 mount compared to a stock 235???

[Phil Waterman]

Hi Chris

I assume you have been researching these engines but just in case you missed this information source you'll I think find it interesting. http://www.stovebolt.com/techtips/en...tification.htm

Once you find one you will be please with the performance. If you are including US versions the last year of manufacture is either 61 or 62. But you really have to look closely to figure out what is in any Chevy in the 1950 to 1962 as engine swapping is very common. I have a 235 and a 261 that both came from junkers both took full rebuilds but note that neither engine started life in the trucks I got them from.

True 261s of the later construction are easy to spot they have huge oil lines coming out of the block. Bye the way you can not run a 261 of the later style with the oil lines blocked off they are a full flow system, so no oil line they die. With the large oil line they also empty all oil out of the engine in a blink of the eye if a oil line or filter fails.

I've posted the entire engine section of the overhaul manual for the later 235-261 on on my web site http://canadianmilitarypattern.com/1...e%20Manual.htm

The index for my web site needs to be updated as it is not showing some pages concerning the 235-261. Use the search feature at the top of the page just put in 235 or 261. One page in particular http://www.canadianmilitarypattern.c...ifications.htm you may find interesting.

If you find a actual late model 235 truck version you might want to consider it or if the price is right grab it. They are a sweet running engine as well. My 235 which is in my 1941 C60L is a nice running truck and happens to have hydraulic lifters it is quieter than any 216 or 261 with solid lifters.


Keep us posted on your search.

Cheers Phil

PS Chris's question

"What I need is a WW2 235 but I want the extra HP and torque etc.
If I have to rebuild my 235 I might as well get a 261...
Now, for my next question; how does a 261 mount compared to a stock 235??? "

There are two different 235 engines one the WWII late 40's and early 50's version, which really are just up sized 216s. Then there is late 50's early 60's which are quite different, water pump location oil system etc.

Both the later 235 and 261 are capable of being bolt in replacements for a 216. They both require the water pump adapter to lower the water pump see http://www.canadianmilitarypattern.c...ifications.htm. Once through that which is not too difficult you can put the bell housing and flywheel from a 216 CMP on them. I went this route with both 41 C60L and 42 C60S.

[motto]

Thanks Phil, the information you've provided has relevance to me also.
Last year I purchased a 1945 G506 Chevrolet 1-1/2 ton 4x4 from a fellow in New Mexico. When I drove it home from the import agent's premises I was very impressed with the performance and on further enquiry was informed that the engine in the truck was in fact a 261. It seemed even more peppy than I would expect from a 270 which I am very familiar with.
The unfortunate part is the engine rattles badly on start up until it gets oil pressure and it leaks oil like the Exxon Valdez so I think it best if I give it an overhaul.
These engines are a rarity in Australia so nobody knows much about them. This one has an oil filter attached to the manifold and we were wondering if it was full flow with its large diameter hoses. That question has been answered.
I feel a little more confident now knowing that information is readily available (and I assume parts also) so thanks again.

David

[Bob Carriere]

Rest assured Chris the 261 will fit... bolts right in with no modificaton to the CMP BUT as Phil pointed out the water pump from a 216 with a suitabe adapter plate is mandatory.... and easily found on EBay.

Fitting into a cab 11 CMP requires a bit more finess... you have to use a Cab 13 draft tube and you will need to run a small distributor from a 216 as the later 55 to 61 rubs on the engine cover.... no such issues with the cab 13.

I chose to use the original 261 flywheel with the HD 11 in. clutch plate....all rebuilt by Ottawa Brake and Clutch... of course I am running on 12 volts.

I found an after market hot rod twin oil filter mount that accepts the modern PH 8... this gives me an additional 1.6 liter of oil......oil pressure 40 pounds at idle .
Vacuum steady at 22 inches. The twin oil filters are mounted inside the frame on the pass. side and not visible. Had the original GM 1/2 in steel line refitted with modern rubber oil lines for the plumbing.

Runs very nice. Ran a Rochester B for a while and dids not like the gas leaks an switch to a YF carter manual choke.

Carbs were rebult by the Oak Brothers in Toronto they still use the old fashion flow bench to test and set up there rebuilt carbs.

Cheers

[chris vickery]

Who said anything about a CMP???

[Bob Carriere]

.... your skiddoo????

[chris vickery]

Nope... but it is a HMV

[Hanno Spoelstra]

Originally Posted by chris vickery

Nope... but it is a HMV

1943 Chevy M6 G506 ...

H.

[motto]

Maybe a little bit of inside knowledge there Hanno?

David

[Hanno Spoelstra]

Originally Posted by motto

Maybe a little bit of inside knowledge there Hanno?

Lucky guess indeed, based on the inside knowledge gleaned from Chris' signature

H.

[chris vickery]

Ahh, that was fun

[motto]

I didn't look at the list and there it is in plain sight!

David

[Phil Waterman]

Hi All

If you find a good running 235 or 261 that leaks oil at the crank seals, do not despair or assume that rebuild is only fix. I have had good luck with speedi-sleeves at both ends that and new seals will help a lot. The other thing to watch concerning the general health of these engines as to is a rebuild needed, oil pressure 20PSI at 2000RPM. Both of my 235 & 261 are running well above 35 PSI.

Keep up the search they are good engines.

Chris if it is not going in a Pat 11 or 12 it should be an easy fit. One question right or left side clutch?

Cheers Phil

[Hanno Spoelstra]

Interesting topic. With the relative abundance of GMC 270 cid engines compared to the Chevrolet 216 / 235 / 261, that is the engine of choice here for conversions. I know of one HUP and one C60S here in Holland with GMC 270 engine swaps. Another C60L I know is fitted with what could be a 235, I will check.

How does the GMC 270 compare to the Chevrolet 235 / 261, both in performance as well as modifications needed to make it fit in a CMP?

H.

[chris vickery]

Not too sure how they compare but the main difference is the block.
The 216/235/261 all share the same block, so mounting and fitting motor mounts, transmissions etc is interhangeable.
The 270 is a whole different animal.

[Bob Carriere]

...only by a few inches but significant enough to have the nose section of a C60X with the 270 sligthly modified for the extra lenght..... bell housing attachements are also different and requires two smaller brackets instead of the usual CMP one piece.

The Caldwells had a HUP with a GMC engine and the engine cover would not fit due to lenght.

Cheers

[motto]

My perception of these two engines is that the 270 is more likened to a Clydesdale with a goodly amount of grunt but no sparkle. The 261 comes out of the stall eager and impatient to get going with instant response. It brings the truck alive. (G506. Originally these trucks had a 235 splash feed) I put 9.00-20 tyres on in place of the 7.50-20s for a recent 200+mile round trip and the 261 handled them with ease. Definitely a better proposition than the 270 if you want to up engine. The block length alone makes a good argument for that.

David

[cletrac (RIP)]

If you're looking for power go with the 270s big brother 302. It was a good truck engine.
The 261 is a higher rpm engine than all the others and hence has more zip. A good 261 could handle a 283 V8 in a similar sized vehicle. I have 3 or 4 261s that need overhauling. They're a direct replacement for a 235.

[chris vickery]

Now that we are straying off target here, the intention was a direct replacement for a stock 235cid. No modifications, no hotrodding etc. Respectfully, 270's, 302s etc have their place and for this discussion this is not it.
While I am a purist at heart, I am also a realist. Physically, the average Joe cannot even tell the subtle differences between a 216/235/261 block. It is the small details that make it so. Internally it is a whole different story.
Back in the day, the term "sleeper" was used to convey a vehicle that from it's outward appearance was a normal, stock built car. What was under the hood was something again. In the case of HMVs, the inferior 216 has and is often replaced with the better built 235 for the interest of reliability and durability. The engineers at Chevrolet figured out how to make a 216 better.
If a fellow can essentially put a better engine with more horsepower and torque under the hood without sacrificing originality, why not?
If you had a choice of more bang for the buck and have to rebuild your old 216 or 235 why not go for bigger and badder?
BTW, a stock 216 is approx 80hp I believe and a stock 261 is 148hp.

[Hanno Spoelstra]

Originally Posted by chris vickery

Now that we are straying off target here, the intention was a direct replacement for a stock 235cid. No modifications, no hotrodding etc. Respectfully, 270's, 302s etc have their place and for this discussion this is not it.

Chris,

Sorry for high-jacking your thread. I wholly agree on improving - while essentially keeping the original looks - over hot-rodding etc. I believe any modification should be reversible if anyone wishes to do so at a later stage (i.e. without butchering the chassis etc.).

Your wanted ad triggered a question from my side because in the HMV fraternity in The Netherlands we know hardly anything about Chevrolet engines besides the related GMC 270 because of the abundance of GMC CCKW trucks.

I am looking forward to any modification tips you can share after you find the right "Jobmaster" for the your 1.5-ton Chevrolet.

Hanno

[chris vickery]

No issues with hijacking Hanno, I just know how these threads start of one place and end up another.
I do suppose that in NL and the rest of Europe, the GMC is predominantly found.
Here in North America we have the luxury of the big 3 automakers who built before and after the war., often using what was on hand and even continuing onwards later.
The Ford flathead is another example that was used before and well after the war with modifications and improvements from the factory. Thats what engineers do.

[Bob Phillips]

Hi Chris, et al:
I have just got my rebuilt 261 back from the engine shop. It is a complete overhaul bored to .030. No problems getting parts but rear main seals leaking seem to be an issue, so some shimming and gooping required to seal this engine. With respect to engine mounting mine ( 1958) does not have the holes at the front base where a 216 bolts to the front cross frame but rather has side mounts about 3 inches back from that location on either side. There is also tapped holes on either side of the block back about 10 inched from the front where you could put proper side mounts if needs be.
In my case this is going in a 13 cab CMP and I had hoped to use the heavier (synchro) tranny that came on the engine but it is longer than the CMP tranny so I may have to go no synchro.
Frame is sandblasted and painted, springs rebuilt ready to go in, just need time!! B.P.

[chris vickery]

Well I have a couple leads but like Bob C mentioned it looks like finding one will be a challenge and at best likely a rebuild.
In the meantime, looks like I might have a line on a running 235 for now.

[Bob Carriere]

Don't be shy Bob....star a new thread and show us your cab 13...... pleeeeze!!!!

You may be able to drill your front plate in situ for mounting in the CMP typical location...... have you changed the water pump yet for the extra clearance???/

Bob C

[Phil Waterman]

Hi Bob P

Best solution I have found for excessive oil leakage for any of the Stovebolt Series engines is to speed sleeve the front and rear crank seal locations.

Cheaper and better fix than having the seal surfaces reground.

Cheers Phil

[chris vickery]

Seems like this is the archilles heel of the 216/235 series of engines, leaky front and rear mains.
Last one I worked on I had to do the same as Phil recommends along with new seals.

[Bob Carriere]

Hi Chris

I have installed speedy sleeves on the front of the crankshaft to over come wear grooves in the crankshaft where the new seall would rub BUT......tell me how did you install the speedy sleeve on the rear of the crankshaft...

I have a small leak on the rear of my rebuilt engine but so is the tranny, T case and every other joint..... I regard it as my truck marking it's territory.... never enough to affect the level of the lubricant contained.

Bob C

[chris vickery]

Sorry for the confusion Bob, new speedy on front and new seals back and front.
The trouble with trans, tcase and diffs is that guys usually never bother to sleeve them or buy NOS flanges.
My M37 was so bad, all the flanges had grooves in them and the only way to solve the leaker issues was to do this. It was actually cheaper to buy NOS components rather than sleeve old junk.
And BTW, have you ever tried to install a new rope seal on a rear main in a 216/235 while its still together?
They make a tool for this but it takes a lot or perserverance and some blue words to get it done.