john deere 70 horsepower

How much hp would some of yas guess a 70 gas would crank with mw high compression.125 over pistons. All fresh and in tune.

44.2 HP at the Drawbar originally..

50.4 at the PTO..

If everything else is original, don't figure on more than an additional 5 HP..
(But, find a way to carry more Gas Cans..!!).

Most 70's I have seen are real hungry for Gas..

Ron.

Highly doubt it would even be 5 hp over stock. In my experience I'd say 2 or 3, AFTER you work it hard for a few hrs @ full temp to seat the rings. Stock head, cam & valve sizes are not HP friendly.

They make 50 HP on the crankshaft/belt pulley, not on the powershaft. They are closer to 42 on the PTO.

Adding MW style pistons will not make it burn any more fuel than the factory pistons. If anything it should accomplish more work on the same amount of fuel because of the gained efficiency of the higher compression pistons. The bore and stroke remain the same which means the amount of air entering the engine remains the same as with the old pistons. Air fuel ratio remains the same as well, its just that you get more bang for your buck with the MW every time they fire due to the higher pressures when the piston reaches TDC.

My HP estimate is around 50 on the powershaft at the rated speed of 975. It will make more power than that at a higher RPM. This will only be achieved if the camshaft is up to snuff and fuel and ignition are fine tuned. You'll also likely have to clean the air cleaner screen mesh inside the oil bath air cleaner. They get gummed up over time.

Have that head worked with new valves and hardened seats. Have the block and head flattened and adjust the tappets just a couple thousandths on the tight side with new valve springs.

It'll still be thirsty but at least it will give you a few more ponies per gallon than the factory setup.

Mine is nothing fancy, just an old work tractor. I figure it burns around 4-5 gallons an hour when working (last Sat. with a 10 ft disc in chisled ground, was in about 4 inches), a bit less when baling.

When I seen the post that says John Deere 70
& Grandad I hafta reply..

When I was about 20 years old & had a friend/
neighbor who was trucker, He called me one
morning after chores, he was in Indiana & found
a John Deere 70 Gas sitting in a little
pasture beside a coop. Had 1/2 dozen turkeys
roosted on it, he could buy it for 600.00..
I said buy it, I"ll go 1/2 with ya.

He got it loaded, but said I would hafta
meet him of I 80 to haul it the rest of the
way home because he had a Wide load & wasn"t
aloud to leave I80. OK.. Met him at a place
& he wasn"t happy, got a fine for having this
tractor on his Load that wasn"t part of the
heavy haul.. When I seen the 70 wheel out as
far as they would go & I"m thinking how is
that going to haul on our 3 axle trailer that"s
2" under 8 feet wide with Low tires on the
tractor & I have 50 miles to drive at night with
a expired plates on the trailer. But we got it
loaded with 4" of tire hanging out both sides.
Then chained it down & aired the tires up
from the trucks air brakes. I made it home,
without trouble but had a couple cops look at me
kinda funny but let us go..

Well after clean"n the turkey poop off, 2 new
pistons, valve job boring the block 90
over. & repairing, rebuilding anything it
needed. Started right off like a new tractor.
Put 5 gallons of gas in it & went 3 miles up the
road to bring home a load of hay. Ran GREAT!
Got the hay off the wagon & went to park the
wagon & it quit. Looked in the gas tank & was
Dry? I thought well maybe that gas can wasn"t as
full...

I used it some, & GRANDAD thought I lost my mind
cause he thought we didn"t need a bigger tractor.
Come spring time he ( Grandad ) said I think I
might try to plow with the 70, Finally I thought
he was getting around to my thinking. Hooked the
3 bottoms on the tractor & he went to plowing.
At noon he came back & said the tractor runs
great, he always had plowed with a cyclone A
& at noon you had to be home or you"d run out
of gas. The 70 Tank was much bigger, he had it
full when he left. After lunch he filled the
tractor again with the hand pump, said he had to
rest pumping, I think I put 20 gallons in it?
After spring planting he said I had to figure
out a way to make run on water, cause he
couldn"t afford to use it everyday. I asked
what about Milk? He said If I could make run on
Milk, the Milk truck wouldn"t hafta stop anymore
& we would have a darn Dime coming in..

But it ran GREAT, Sold to guy up in New England
who wanted it for a Puller! I said man I have a
tractor for you!

Sorry Long winded..

(quoted from post at 21:33:00 04/14/14)
44.2 HP at the Drawbar originally..

50.4 at the PTO..

If everything else is original, don't figure on more than an additional 5 HP..
(But, find a way to carry more Gas Cans..!!).

Most 70's I have seen are real hungry for Gas..

Ron.

Click to expand...

Check the Nebraska tests for the 70's fuel consumption.
Seems to be a lot of mathematically challenged persons . They can notice a 70 burns 2-3 times more fuel per hour than a B. However they don't seem to understand the 70 is performing 2-3 times more work per hour.

My experience has been that my 70 is a real pig on gas, even a light load or no load it uses a lot.

You and RLA should think about this...

I suggest you tune up your tractor and measure the lbs fuel per HP per hour.
The Nebraska tests with the main jet richened up for max power.
The 70 gasser made 48.29 belt hp burning 4.5 US gph.
The 40 gasser made 24.25 pto HP burning 2.32 Us gph.
Odd how nobody calls a 40 a fuel pig even though it burns more fuel per HP per hr than the 70.

Well, Sir, I have carried gas to this particular 70 in question (pulling a 3x14" with no coverboards, jointers or moldboard extentions..

At the same time we had 2 WD-45 AC's pulling 4x14" with coverboards and moldboard extentions..

In that 1/2 mile long field, I would PASS the 70 every 2 rounds with the WD-45.
The WD-45's averaged 1 1/3 Gal per Acre plowed..
The 70 was burning over 2 Gal of gas per acre..
The 70 was fairly "Fresh", with a new valve job that Spring..
I can assure you that my 630 uses far less gas than a 70 and will do the very same job..
From my personal experience, I would not own one of those 70 Gas Hogs..

Ron.

(quoted from post at 00:09:52 04/16/14)
Well, Sir, I have carried gas to this particular 70 in question (pulling a 3x14" with no coverboards, jointers or moldboard extentions..

At the same time we had 2 WD-45 AC's pulling 4x14" with coverboards and moldboard extentions..

In that 1/2 mile long field, I would PASS the 70 every 2 rounds with the WD-45.
The WD-45's averaged 1 1/3 Gal per Acre plowed..
The 70 was burning over 2 Gal of gas per acre..
The 70 was fairly "Fresh", with a new valve job that Spring..
I can assure you that my 630 uses far less gas than a 70 and will do the very same job..
From my personal experience, I would not own one of those 70 Gas Hogs..

Ron.

Click to expand...

I would suggest that you trouble shoot and repair the 70 instead of blaming it. The Nebraska test shows the 620/630 using 4.2 US gph making 46.75HP.
I'll take accurate calibrated lab tests over what Bubba thinks what is going on.
The fuel consumption difference between a 70 and 620 is too little for Bubba to notice .

Our 70 gas has been on the haybine for 20yrs! Its ok on fuel, it is running a 9ft hayine w.o.t. fof hours at a time, we make about 7000 bales, never had to adjust the pto! We do bale with the 730 diesel though