Sell Rotella T 30 weight... worst oil EVER

[pfarber]

I've read that the 270 was a kludge from a smaller motor.

HEAVY DUTY is NOT THE SIZE OF THE VEHICLE IS IS PUT IN (GEEZE).

TORQUE (the single thing that make your vehicle to forward) is the biggest factor in HD engines. Lots of torque requires lots of internal structure to handle the stresses and support systems to keep it running.

TM 9-2800 puts the GMC 270 at 109hp (no torque listed). At less than 7:1 for compression there is NOT a lot of torque at the flywheel.

The fact that the 270 WAS in an 11000 lb vehicle is the PROBLEM, not any reason to call the 270 HEAVY DUTY.

In comparison the GPW/MB made 54 HP at 106ft-lb of torque in a chassis weighing 2500 lbs.

[42cckw]

I repeat the GMC 270 was and is a heavy duty truck motor for its DAY (geeeze) we are talking 1940's technology here. Compare the GMC engine to the chevrolet engine and you will see a world of difference it was the best truck engine made. You are comparing today's technology against 1940's tech. Yes the truck weighed 11,000lbs and the 270 was the biggest and best engine they had at that time to put into the 2 1/2 ton truck, it was the HEAVY DUTY TRUCK ENGINE OF THE 1940's cckw truck

[dr deuce]

As I stated, the 270 was a revised (stroked and bored) 256 cid GMC engine. They are about the best, easiest to work on engine from the WW2 era. If youhave ever worked on a Dodge or Jeep engine.... Bolts into the water jacket? You have to be kidding!

It has low end torque due to the long stroke. Not too much hp due to the comp ratio. In the 50's, it was a HOT racing engine in some classes!

[oldreliable9_47]

The GMC 270 did does not have a lot of torque or HP and yes, compared to todays standard it is a undersized engine for the CCKW....thats why the CCKW is geared down to gain maximine pulling power from 94 horses...downside..you lose speed. This is a good combination for the army in the 40's..when do you remember the army needing speed to get anywhere..load carrying ability was priority.....all thsi equiates to a good match of 11000lbs of truck and a HEAVY DUTY GMC 270

[Degsy]

The British Army heirarchy didn't like them. They were TOO FAST.

[Chappers]

The British Army heirarchy didn't like them. They were TOO FAST.

Tyipical of the British Army...LOL The real reason was there was No TEA making facilities with the truck.
Avery interesting Topic this,So to finish it off ,What is the Best Oil to put into my GMC lump???????.

[Karoshi]

Well, I'll go with the one the manufacturer recommended.

[Degsy]

As I think you may be aware Karoshi I entirely concur.


Cheers
Degsy

[pfarber]

GEARING DOWN is not what makes an engine HEAVY DUTY.

I cannot believe that some people have NO IDEA what HEAVY DUTY MEANS.

Gear ratio? Low HP and Torque make an engine HD? COME ON!!!!!

Do you think a 270 can go all day long at wide open throttle and still work reliabily day in and day out? I don't.. I know they don't.

You fellas need to understatnd DUTY CYCLE (getting rated power from an engine over a specified time) and how the GENERIC TERM 'Heavy Duty' relates to getting 100% power 100% of the time in the engines operating conditions.

EXAMPLE: My MIG welder is rated at 10% duty cycle. THat means the welder can produce RATED amps and voltage for 10% of the duty cycle (which for my welder is 20 minutes). SO that means that I can weld for 2 minutes before I have to wait 18 minutes (for cooling off, ect).

Ask any welder and they will explain this. THats why THEY use HEAVY DUTY equipment. Thier gear will produce RATED amp and voltage 100% of the time (100%duty cycle) and they can weld CONTINIOUS for hours.

SAME THING FOR ENGINES.

It really is that simple.

[snow man]

WOW......... A triple tap

[pfarber]

This baord get very laggy/slow on my connection

[snow man]

I thought maybe you were getting upset ,any engine can be put through " H D service " but not nessicerily a H D engine try 30 wt NON detergent i believe that is what the TM recommends . If a GMC 270 is not a HD engine then nothing is. just my $.02 .

[dr deuce]

With my original WW2 270 cid engine, I would have the pedal matteted to the floor about 80% of the time to make it do what I asked of it for power, load and speed. People told me that this could not be. It was true, so by those standards, and the fact that I got about 40,000 miles on an engine that had been rebuilt sometime in the 28,000 miles before I bought it says something for the durability of that engine. It works it's heart out trying to move 10-11,000 lbs of truck. Tha manual says that the engine was to be replaced every 10,000 miles.

It may not be a Mack, IHC or Cat, but it stood up to the abuse of that day ane more!

[42cckw]

I went out into my barn tonight to have a talk with GMC jimmy, jimmy I said I have to tell you something , you don't have a heavy duty 270. I don't says jimmy no you don't , but but I have always hauled much much heavier loads than I was rated for says jimmy, I know but you only have a light duty 270, but but I ran 24 hrs a day 7 days a week very heavly loaded hauling supplies to the troops at the front I think they called it red ball I know but you only have a light duty 270. But but I worked my cargo body off fighting a heavy duty war and was one of 5 pieces of military equipment that General Eisenhower said won world war 11, I know I know but you only have a light duty 270, but but , I know I am sorry people feel that way, I think you earned it, but just look at the bright side you are retired now and I will never again ask you to do a heavy duty thing again, only light duty parades with old glory proudly flying high, and now I have to go so keep your grille up I am still proud of you And as I left jimmy and closed the barn doors I think I heard
a

JIM AND MY FAITHFULL 42CCKW

[admin]

What a great way to end this thread !....

The Admin