[stano316]

I have been running a 40" comm mowing deck on my L8 since the beginning of the cutting season, and I have been pretty pleased with it. Initially I had some issues with a gear noise that stopped when I tightened up on the mower neck to allow it to level with the ground, it was really loose. I have greased all the fittings, sharpened and balanced the blades, checked the belts and topped off the gear box with fresh gear oil, typical maintenance.

Like I said, I am pretty pleased with the cut, but how can I improve it? I only have one baffle on the left side, would it be worth it to bend up some baffles? What about blades? I have been doing some searching and can find stock replacement blades, but what about hi lift or a gator style blade.

I mow with the axle in low, and PTO in high so my ground speed is nice. Any suggestions?

 

[WH401]

For the most part, the only blades available are the factory blades. If there's a high lift available then it would have to be from another manufacturer or a custom part. Adding a proper baffle will make a small difference, but running at the highest possible engine RPM will make the most noticeable difference.

Rick


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[cmeyers77]

This is what I did to my 40" mower deck, it started life out as a Homeowners deck, I added the arms for the casters, better baffling, as well high lift blades. I got the blades from Richards lawn and garden. Keep in mind if you want good results from the four bolt 40" mowers you need to operate the L in high gear and high throttle.

Some will disagree with me saying either an L does not have sufficient power or that it's not advisable to operate an L at max throttle. Well neither is true, a properly tuned L can absolutely power a four bolt commercial mower as well handle sustained operation at high RPM's.....Oh and I feel a governor is an absolute must.

 

[stano316]

I run my L wide open, with the PTO in high, and those blades are definitely moving at a nice clip. I have cut pretty high grass (my father in laws lawn) without a problem.

I was just wondering if moving to a hi lift blade or adding baffles is a worthy return on investment. If adding baffles will only make a subtle difference, then Im not going to do it. But I do need new blades, and if the hi lift are only a small amount more than the factory then I may do it.

I was just curious what peoples thoughts were.

Thanks for the ideas

 

[stano316]

Any one ever run or possible conceive of running a cross blade set up?

 

[franklin2]

I don't think baffles work good for high grass. The grass bends over and sometimes doesn't "pop up" into the blades when it enters the baffles. I personally think high lift blades are noisy and waste power.

These mowers are old school, lower rpm with lots of grunt to cut rough terrain and tall grass. Newer mowers you get now have higher horsepower engines with higher rpm blades and high lift blades for getting a nicer cut at higher ground speeds. If you notice also newer decks are shorter. The grass clippings are shorter. The older Gravely decks are very tall, and when they cut the grass the clippings are longer. This uses less horsepower and is an advantage when cutting taller grass. But the longer clippings don't look as good when you are done.

These are just my observations and some of the differences I see.

 

[WH401]

Any one ever run or possible conceive of running a cross blade set up?

A cross blade setup might not be too hard to do, but it would take more HP from the engine on an L. I too run a 40" comm on an L8 and it has plenty of power.

Rick


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[cmeyers77]

The baffles allow for a much better cut then without, trust me I ran the mower a good bit before adding the baffles and was completely dissatisfied with the cut. That noise that you hear is a good thing, it's the sound of the blades creating lift, though using high lift blades without adding baffling is probably a waste. The baffling in combination with a high lift blade creates a bit of suction, pulling the grass up allowing for a better cut. Again WOT and high gear is what the 40" four bolt decks require to yield a good cut.

 

[stano316]

Looks like I will have another winter project...adding some baffles to the deck

 

[cmeyers77]

Looks like I will have another winter project...adding some baffles to the deck

If I hade to do it again I would have not made the baffles so tight, the grass needs a bit more space to move easily around the baffles. I do agree with the previous statement that baffles are not so good in tall grass, the way I see it is add baffles and stay on top the the yard and get a good cut or don't add baffles and live with a lower Quilty cut. I recently raised the height of the blades to about a 3,3.5" cut height, works soooooo much better than the 2" the blades were set to.

 

[TexasT]

I don't think baffles work good for high grass. The grass bends over and sometimes doesn't "pop up" into the blades when it enters the baffles. I personally think high lift blades are noisy and waste power.

Looking at his pic I don't see where the front baffle is any lower than the front of the mower but I could be wrong. If baffles didn't work why would any modern manufacturer go to the trouble and extra expense of including it in their product? The whole point of the "high lift" blade is to suck the grass blades to full extension so it can be cut off to length. I think travel speed has more to do with cut quality than baffles. The faster you are moving the more you need to "suck" the grass blades up in a short amount of time to get it cut off. Otherwise you do have your scenario where blades aren't cut off because they are leaned over.

 

[CADplans]

A cross blade setup might not be too hard to do, but it would take more HP from the engine on an L. I too run a 40" comm on an L8 and it has plenty of power.

Rick

I wish someone could come up with hard data on cross blade HP requirements,,, :dunno:

My daughter mowed her "new to her" 3 acres with the JD 650 and Woods 60" RFM

The Woods has 6 brand new blades, installed in an "X"

The PO of the home had not mowed for over a month.

I was assisting with the 24G in 2H,,,
the 650 was going faster than the 24G

Well,,, neither machine labored going through foot high grass.

That 650 only puts about 16HP to the PTO,, it had NO trouble mowing.

The 24G was about maxed out,,, I think the crossed blades reduced the HP needs.:swow:

We were BOTH tossing out a LOT of clippings,,,, :fing32:

(Note: We mowed the 3 acres in 1 hour and 15 minutes,,,
next time, I believe we will do it in under an hour,,,)

 

[cmeyers77]

I wish someone could come up with hard data on cross blade HP requirements,,, :dunno:



My daughter mowed her "new to her" 3 acres with the JD 650 and Woods 60" RFM



The Woods has 6 brand new blades, installed in an "X"



The PO of the home had not mowed for over a month.



I was assisting with the 24G in 2H,,,

the 650 was going faster than the 24G



Well,,, neither machine labored going through foot high grass.



That 650 only puts about 16HP to the PTO,, it had NO trouble mowing.



The 24G was about maxed out,,, I think the crossed blades reduced the HP needs.:swow:



We were BOTH tossing out a LOT of clippings,,,, :fing32:



(Note: We mowed the 3 acres in 1 hour and 15 minutes,,,

next time, I believe we will do it in under an hour,,,)

CAD I'm not sure HP is what you are looking for but the ability to turn the Blades to certain speed as well as the ability to keep the blades at that speed. I would image that an engineer figured out that a certain blade speed is required for maximum efficiency of a particular blade. The amount of torque that the machine creates will keep the blades spinning with little slow down. There have been plenty of engines that have HP but fall short of torque.

One of my biggest complaints of Gravely two wheelers is that the PTO is governed by the speed selector of the machine. When cutting grass you want the blades spinning at a high speed. I've always said that a gravely two wheeler, especially an L, is more suited to a job that doesn't require fast PTO speeds. I'm not saying that they can't be good mowers, there are just better machines out there for mowing.

 

[franklin2]

Be careful and don't compare a diesel's horsepower ratings with a gas. I know it should be the same, but the diesel's is usually at a lower rpm, the higher rpm gives the gas engine a false "lead" in the horsepower wars. All I know is, in high grass the diesel will have a low in grunt that the gas engine doesn't have, much like the old gravely L's have a very low horsepower rating but have a low end grunt that really gets the job done.

 

[stano316]

Much debate, It would be nice have someone in the industry who designs mowing decks put this to rest.

I did a little googling and came up with this, if you have the time to read....
Patent US7555887 - Mower deck enhancement - Google Patents

In the meantime, I will keep my blades sharp, and blade speed high.