PAUL - Yes, I know ALL about the two different bore sizes but didn't add that fact into my post because it would have made a too long post even longer. When you figure out the specific engine output per CID, the .7133 CID increase of the 2-15/16" bore over the 2-7/8" bore in displacement equals about 3/10ths of a horse power. I'm not sure but doubt you'd be able to notice that small 4% increase in HP. To me, the real advantage is the fact that once the early small bore K161's were bored to .030" O/S you could bore them to 2-15/16" and start over again with the +.010", .020", .030" O/S pistons and double the life of the block.
You look at the HP & torque charts and the 1/4" longer stroke in the K181 makes much more difference while adding 1.694 CID compared to the larger bore K161. When we installed the K181 in the 70 we noticed a distinct improvement in performance when mowing.
I agree that the 7 & 8 Hp tractors perform WAY better than they have any right to seeing that even push mowers have 5-6 HP motors on them now days. I used my 70 off and on all summer to pull my big tandem axle dump cart, which weighs about 600# empty to haul mulch, tree trimmings, etc. Only down side to the 70 is it doesn't have hyd remotes like the 982 so I couldn't dump it. I also run my 12V 15 gal sprayer with the 70, pulling the small cart with the sprayer & hose in the cart. 2-3 yrs ago when I used my 50 gallon sprayer to spray the yard a couple times I used the 70 to pull/run it. Main reason is because it'll run at idle all day on a quart or two of gas.
My 70 was bought new in May, 1965 after the cogged timing belt on the timed 38" deck on the '63 original broke for the second time. That belt was $22 back then. Not really that much more expensive now. The 70 was mowing two large farm yards around an acre each in size, and both had some hills or banks to climb, and depending on how much road bank we mowed could be up to 1-1/2 acres each. The K161 was rebuilt in 1968, and again in 1971, then replaced with a K181 in 1974. I don't know if it was a good thing or not, but the K161 would pull the 38" deck most places in the slow 16T 2nd gear, but it was a load for it when the grass was four inches or more tall.
With my #72 when I got it, w/K181 & 38" deck, I could run a few places in the 72's fast 19T 2nd, but not until I put the K241 in it could it really handle it. I had a small yard and did most of my mowing in 1st gear.
I do remember over-hearing a manufacturing engineer at FARMALL saying the 7 & 8 HP CC's didn't have the drive shaft roll pin problems the 10 HP & larger GD tractors did. The back roll pin hole on the drive shaft where the coupler connects to the input pinion shaft would elongate, then hammer away at the roll pin and eventually break it. That back hole is the only place one 1/4" dia roll pin drives the whole tractor, the hardened pinion shaft won't wear, and all the other roll pins around the clutch only handle half the load. My 72 did that about five years after I installed the K241 in it, then sheared that pin again after 14 more years. The 1965 model 70 I have that Dad bought new probably still has the factory drive shaft & roll pin in it after 47 yrs.
I agree, as a die hard gear drive guy, I like running the old 70 with the K161 or 181 in it, not sure what engine is actually even in it anymore, but I think it's a 181. It saves wear & tear on the larger CC's for the small jobs and saves a little gas in the process.
You look at the HP & torque charts and the 1/4" longer stroke in the K181 makes much more difference while adding 1.694 CID compared to the larger bore K161. When we installed the K181 in the 70 we noticed a distinct improvement in performance when mowing.
I agree that the 7 & 8 Hp tractors perform WAY better than they have any right to seeing that even push mowers have 5-6 HP motors on them now days. I used my 70 off and on all summer to pull my big tandem axle dump cart, which weighs about 600# empty to haul mulch, tree trimmings, etc. Only down side to the 70 is it doesn't have hyd remotes like the 982 so I couldn't dump it. I also run my 12V 15 gal sprayer with the 70, pulling the small cart with the sprayer & hose in the cart. 2-3 yrs ago when I used my 50 gallon sprayer to spray the yard a couple times I used the 70 to pull/run it. Main reason is because it'll run at idle all day on a quart or two of gas.
My 70 was bought new in May, 1965 after the cogged timing belt on the timed 38" deck on the '63 original broke for the second time. That belt was $22 back then. Not really that much more expensive now. The 70 was mowing two large farm yards around an acre each in size, and both had some hills or banks to climb, and depending on how much road bank we mowed could be up to 1-1/2 acres each. The K161 was rebuilt in 1968, and again in 1971, then replaced with a K181 in 1974. I don't know if it was a good thing or not, but the K161 would pull the 38" deck most places in the slow 16T 2nd gear, but it was a load for it when the grass was four inches or more tall.
With my #72 when I got it, w/K181 & 38" deck, I could run a few places in the 72's fast 19T 2nd, but not until I put the K241 in it could it really handle it. I had a small yard and did most of my mowing in 1st gear.
I do remember over-hearing a manufacturing engineer at FARMALL saying the 7 & 8 HP CC's didn't have the drive shaft roll pin problems the 10 HP & larger GD tractors did. The back roll pin hole on the drive shaft where the coupler connects to the input pinion shaft would elongate, then hammer away at the roll pin and eventually break it. That back hole is the only place one 1/4" dia roll pin drives the whole tractor, the hardened pinion shaft won't wear, and all the other roll pins around the clutch only handle half the load. My 72 did that about five years after I installed the K241 in it, then sheared that pin again after 14 more years. The 1965 model 70 I have that Dad bought new probably still has the factory drive shaft & roll pin in it after 47 yrs.
I agree, as a die hard gear drive guy, I like running the old 70 with the K161 or 181 in it, not sure what engine is actually even in it anymore, but I think it's a 181. It saves wear & tear on the larger CC's for the small jobs and saves a little gas in the process.
