Re-powering a CCKW?

[timpage]

Has anyone replaced the 270 in thier CCKW's with another engine? With another Chevy Inline 6 perhaps? The CCKW I just got a hold of still has its 270, however it is going back to the guy I bought the truck from for another one of his projects... so I will be in need of a replacement. I know ideally it would be great to find another 270, BUT... it does seem much easier to find Chevy inline 6 cylinders here in my area. Hope no one thinks this is 'blasphomy' but just weighing my options without a drastic change (which is not the route I plan to go ).

[armydriver]

I would not do it myself as the 270 was used for the needed additional power and torque for the heavier CCKW to operate in a proper manner.

[snow man]

http://www.cckw.org/270_to_302.htm I'm thinking of doing a engine swap i think i have found one out of a 50's model GMC fire truck { low miles }

[John V Cliche]

Hi Tim

You can do as you wish after all it is your truck
But keep in mind that the further from original you modify your truck you are also diminishing its resale value .and the ability for it value to increase over time.
As I said only you can decide which route to take.

Hope this helps
John

[timpage]

Thanks for the input so far guysl. Im certainly not looking for a 'hot rod' or to massively diminish the value. Im in the exploritory stage right now.

thanks
Tim

[timpage]

I thought I would point out (and am not trying to stir up too much controversy, Honest ) the biggest reason I have thought of putting in a Chevrolet 6 cylinder in place of the GMC 270 (which is being kept by the owner I bought the truck from in my case) is the ease of finding such engines and still keeping a very slight degree of appearing original. Certainly not looking to gain incredible power increases (if I wanted big horsepower I would buy a sports car ), just want to be able to drive and enjoy the truck as well. GMC engines seem hard to come by in my area... though if I could come up with one with some degree of ease that would be great! I do understand the point of originality and keeping value in this piece of history however.

Thanks for letting me ramble a bit...
Tim

[John V Cliche]

Hi Tim

Dr Deuce has been repowering his trucks with the 302 inline six from the post war GMC ie M135 and M211 series.
Have you tried locating these power plants ?
There is a lot of info concerning the swap on this site.
There are lots of engine choices some will require more work than others .
I saw a post somewhere about a user installing a GMC 427 tall deck in his CCKW ( can't find it now )
A pressure oiled 235 cu in Chevy from '54 on, can be juiced up with after market parts and deliver good power. As you know the more power you want the more money you have to spend.


Hope this helps
John

[dr deuce]

I guess as the person with the most experience with the 302 and 270 update, ( I presently have 3 and in the spring will have 4) let me state a few things I have learned:

As the article in here states, the civy 302 or '50's 270 is the way to go for more power and over the road speed. The mil 302 has a different block which may or may not create problems.

Utilizing a chevy 235 or better a 261 will work. The bellhousing will bolt right up. The engine is shorter though then any 270/302 by about 1-1.5 inches. You can make a plate out of 3/8 steel with 4 holes in it to "lengthen'" the Chevy. I have tried this on my tanker when I installed a 261 temporarily before I found a modern 270 for it. Be aware, many of the 235 Chevys will not accomodate the vacume connection for the PCV valve and brake booster connection at the intake manifold.

You should be able to find a 50's 270 or 302. They are around unlike the chev 261 which I have found 4 in 36+ years of looking (I own 2 of them). Unfortunately during the 50's, GM perfected body rot, so in the snow belt of the US you will have a somewhat harder time finding them. I have found and bought 2 (soon to be 3 ) 1956 GMC 2 ton tankers that the USAF had. They were given to local fire departments. All low mileage.

The later 302's (with round intake runners) do have a flaw. All that I own or have seen have cracks or pieces missing in the heat box under the carb where the exhaust passes up under the carb for winter operation when the heat riser valve on the ex manifold is in the winter position. Regardless of what engine you have, newer, original, bigger or stock, you should always run this valve in the summer position. A good professional welder can fix this issue without difficulty

The only time you will "feel" a difference (at least with the 302) is when pulling a hill or in my case when hauling the searchlight trailer with the airborne dozer in it (+9200 lbs). I towed this combo only once with the original 270. I also haul the 57mm AT gun a lot (+2995 lbs). You can also cruise at 45 mph without being at the redline of the engine. The redline on the 302 is 54 mph I think in a CCKW. The engine sounds the same, runs the same etc so you will still have the feel of the original setup.

Read and reread the article in here I wrote before you do anything.

http://www.cckw.org/270_to_302.htm

Make sure you have all the parts you need, especially the flywheel and front foot plate (if necessary) before you begin

[timpage]

I actually put a bid on a 50's vintage GMC with a 302 on Ebay a few days ago (the GMC was within getting distance for me) but it sold for more than I could afford. That is certainly one route I would go!

Do any of the 'newer' Chevy sixes bolt up to the CCKW bellhousing? If I do go Chevy power, I would much prefer a 235 as John suggested as I know they are available fairly easy. But I also see plenty of 292's and 250's as well.

Tim

[dr deuce]

292 and 250 do NOT bolt up. You then have pedal problems

[oldreliable9_47]

Kevin Kronlund www.armycarsusa.com has a couple T/O GMC 270's ready to bolt in

[snow man]

Thanks for some more insight on this engine swap DD ,I'm going to try one when the weather permits, It will feel like my old hot rod day's in the sixties working on a 65 GTO i had . Being we are discussing this and you have done several would it be possible to get some photo's of your motor swap Dr Deuce .

[John V Cliche]

Hi Tim
In a earlier post I mentioned a guy swapping a 427 talldeck engine

Well I found the post
He is on the G503 2 1/2 ton forum and his user name is SHONKIE you might try sending him a PM for more details.
It may be another power option for you.
Hope this helps
John

[42cckw]

Hi John
How is everything down there in northern Mass Just a point or opinion about up gun engine changes, I think you already know and agree, But with the quest for more power and speed which A larger engine will achieve, we are dealing with late 1930's technology here and trying to go 55 and heaven forbid 60 mph your transmision and drive train will not take this for long. With increased road speeds comes increased heat ,they won't take it for ever. These trucks were designed for 45 mph Max Me I just accept my truck with all its limits and Most people on there way by me just give me a wave or a thumbs up and that just makes me Because I'm driving and experiencing my truck just the way it was designed 65 years ago

[oldreliable9_47]

as much as I hate to say I dont think this site is educating to me anymore. I thought the drive to restore these vintage trucks is to preserve a piece of history. True the truck is the onwers to do with as they choose. I say if you want to butcher it up by putting anything other than OEM then buy a 70 camaro and hotrod that.

I come to this site to learn and ask questions about 1940-1945 CCKWS and get tired of reading everything about how to "modify" them....

Perhaps I need some time away..

WHY NOT MAKE A FOLDER AND USE IT TO POST NON TRADITIONAL MODIFICATONS.

[dr deuce]

A couple of times I have seen new CCKW owners take their new pride on an adventure only to have it fail on them for one reason or another. Both times, the owners have lost confidence in taking their joy on anything but a very short trip. Reliability is very important on these trucks, A failure even 20 miles from home will probably cost big bucks to get it back home. Such a failure will make you gun-shy...

Oh and there are those who say maintenance, maintenance, maintenance. Yes that is very important, but it WILL NOT prevent every thing that can happen:

I lost the diaphram in the fuel pump on my GPW a few years ago. I almost lost the engine! I have lost 2 "GMC" clutches, one to the manuals being wrong (while in a city - it wouldn't disengage) and one to me saying I could wait one more week before readjusting.

My point is that depending upon how you drive, where you drive and how far you go per year may affect your decision to make various modifications. Personally, I drive my cargo CCKW usually between 2,000 and 3,000 miles a year. That is how I have driven it over 50,000 miles in the past 26 years. I would take it anywhere on 30 minutes notice (check the fluids) and I know it would take me where I want to go and back, no matter how far; 10 miles, a 100 miles or a 1,000 miles.

What do I loose with my easily reversible modifications? I loose the possibility that a fuel pump diaphram could take out my engine and cost me ~$1,000 to $2,000. I loose the knowledge/fear that my truck might not start when hot or cold someplace far from home and alone without a 6v battery to jump me or big vehicle to tow me. I loose the knowledge/fear that my voltage regulator points are going on and off almost as fast as the ignition points and you don't replace them until they fail. I loose the ability to safely tow other HMVs in my possession: 57mm AT gun waterbuffalo, searchlight trailer and dozer or carry the GPW in the back. I loose the knowledge/fear that going 45 mph for a couple hours is running that engine at its published redline all that time.

What do I gain: peace of mind and the sheer enjoyment of driving this find truck. Does it sound different? no. Does it handle different? no. Does it have more noticeable power? maybe a little empty. Does it require less maintenance? Absolutely. Does it go faster? no. Any CCKW can go 50-55 for a while.... Do I drive 55? no.

So basically as previously stated, your CCKW is like your children: to raise-use as you see fit. Each owner has to weigh the benefits on any modifications they make.

Own a CCKW because you love it! Love to drive it! Not to use as part of your retirement portfolio....

This "modification" note is just one not among 100's

[John V Cliche]

Hi Jim

Have you been talking to Joe Hall ( he gets confused as to which state I live in also )

All kidding aside you and I are lucky that we live in a part of the country where we can drive our trucks at 35 mph anywhere we want to go,and not be a road hazard .

Although I am a purist and do not want to modify MY vehicles beyond OEM.
I do find it interesting reading about the adventures if those who do.
And the various problems and solutions encountered along the way.
I am a "gear head " at heart and a former hot rodder I look forward to adding " my 5 cents worth " to help answer some of these " misguided individuals " questions

John

[timpage]

as much as I hate to say I dont think this site is educating to me anymore. I thought the drive to restore these vintage trucks is to preserve a piece of history. True the truck is the onwers to do with as they choose. I say if you want to butcher it up by putting anything other than OEM then buy a 70 camaro and hotrod that.

I come to this site to learn and ask questions about 1940-1945 CCKWS and get tired of reading everything about how to "modify" them....

Perhaps I need some time away..

WHY NOT MAKE A FOLDER AND USE IT TO POST NON TRADITIONAL MODIFICATONS.

Im sorry you feel this way by me trying to rescue this truck, and simply trying to find the what options I have available. Maybe in your area there are 270's overflowing everywhere. But here, this 270 is the only one Ive found in the area (which Im unable to keep), and dont have the funds to have one shipped in from any great distance. Unless you want to buy me one and have it shipped to Central Oregon? LOL

Tim

[John V Cliche]

Don't take any of this personal Tim,

We don't always agree on HOW to keep them rolling.

But we ALL agree TO keep them rolling

This as you know is a diverse hobby

Enjoy
John

[timpage]

I try not to take it personal (though it is hard sometimes )...