Engine ideas

[2manyrocks]

Pictures????????

 

[Oneaxepony]

Although my project is a long way from being done, here are a few pictures to give everyone an idea of what I am up to. The first is of the 1/2" aluminum plate after I cut it with a circular saw (it needed a little clean-up with a jig saw). The second is with the adapter unit bolted to the engine. The third is a side view showing two small rectangular plates serving as spacers behind the large 1/2" plate. I needed a 1 1/4" spacer behind the large plate but didn't have one so I used a 1/2" plate along with a 3/4" plate. The last photo is the engine bolted loosely to the tractor. Notice the small aluminum plate covering the crankcase (studs are poking thru). I deliberately made the 1/2" plate bolted to the crankcase tall until I figure out how to attach the handlebars. It will eventually get cut down to the needed height. By the way, the total width of the plates and crankcase is 4". This will leave about 1 1/2" of the gear shaft available to be covered by the the keyed sleeve. Hope this helps describe what I'm doing.

 

[gravelymay]

Although my project is a long way from being done, here are a few pictures to give everyone an idea of what I am up to. The first is of the 1/2" aluminum plate after I cut it with a circular saw (it needed a little clean-up with a jig saw). The second is with the adapter unit bolted to the engine. The third is a side view showing two small rectangular plates serving as spacers behind the large 1/2" plate. I needed a 1 1/4" spacer behind the large plate but didn't have one so I used a 1/2" plate along with a 3/4" plate. The last photo is the engine bolted loosely to the tractor. Notice the small aluminum plate covering the crankcase (studs are poking thru). I deliberately made the 1/2" plate bolted to the crankcase tall until I figure out how to attach the handlebars. It will eventually get cut down to the needed height. By the way, the total width of the plates and crankcase is 4". This will leave about 1 1/2" of the gear shaft available to be covered by the the keyed sleeve. Hope this helps describe what I'm doing.

That is the cleanest place to work I have ever saw.
Look like you can use a piece of angle to attach the handlebars.
I believe you will only need 1 inch of gear shaft.
Happy Gravelying
Thanks Bruce g

 

[Oneaxepony]

Clean workplace? Ever since I got the clone in last Feb I have kept it in my family room due to lack of space in the garage. So thats why the middle two photos look clean. The tractor photo is in the garage which, trust me, is not very clean - you just cant see the mess. I really need a garage like my Father-in-laws which is about 20' X 50'. It has wall phone and a refrigerator. A man could live in there if he had to...

 

[2manyrocks]

Thanks for those pictures. I take it that the adaptor plate is the critical part here? What does it look like by itself? I have trouble visualizing what it takes to adapt an engine to the gravely I guess because I've never taken one apart to this level or tried to adapt an engine to one.

 

[Oneaxepony]

Here is a photo of the adapter plate by itself. The large hole is for the crankshaft, of course. The four next larger holes are for attaching the plate to the universal bolt pattern on the engine. The remaining holes around the perimeter are for the attaching the gravely crankcase which then bolts up to the tranny. As I progress I'll take more photos to show how it works in more detail. As you can see some of holes I drilled were not properly located and had to be elongated for proper positioning. I have since worked out a much better way to locate the holes and I'll share that later on.

Edited to add the smaller rectangular area the top of the plate is for connecting the handle bars and is not needed to attach the engine.

 

[2manyrocks]

Thanks much. Measuring where to put the holes would be a challenge to me.

The other part I don't understand is how you make the mechanical connections from the new engine crankshaft to the Gravely parts. Any explanation and pictures of how that goes would be appreciated, too.

 

[Oneaxepony]

The whole trick to the mechanical connection is to somehow attach the drive pinion gear (see photo below) from the Gravely engine to fit on the crankshaft of the new engine. One way to do this is to take advantage of the fact that both the drive pinion gear and the new engine have 1" shafts. If ones cuts the drive pinion gear so there is 1 to 1 1/2" of shaft and then cuts a keyway in it, you could attach it to the new engine crankshaft by putting a 1" id sleeve with a keyway over both shafts. To hold the shafts together, you would bore a hole through the length of the drive pinion gear and use a long bolt into the crankshaft. This is the principle behind many of the mechanical connections described and used on this site. This is a so-called rigid connection and requires the shafts to be perfectly aligned.

This is not the only way to do it. Oldmech used a commercially available shaft connector (LC-type) which is kind of like a sandwich system. One connector piece goes on one shaft and a similar piece goes on the other shaft. Then a flexible material is placed between the two before they are connected together. This is more forgiving to alignment issues than rigid connections. Very clever approach in my opinion.

These are just a couple of ways that have been tried by people on this site and worked successfully. Hope this helps.

 

[wstr75]

Here is the Lovejoy pdf for LC couplings. Side view drawings are near the bottom of the document.

http://www.lovejoy-inc.com/uploadedFiles/Technical_Resources/JawInstruction.pdf

 

[2manyrocks]

For the rigid connection to be aligned, does that mean that the real difficulty is in fabricating the engine adaptor plate to hold the engine in the right place relative to the Gravely side? Is there more to it than this?

OldMech--I always like his posts.

I appreciate the clear explanation about the details of what is really involved in adapting a new engine to the Gravely.

 

[Oneaxepony]

Getting the holes on the adapter plate properly positioned is critical in getting the alignment correct. There is something working in your favor on this. I noticed that on the Gravely engine crankcase, the bolt holes used to connect to the tranny are slightly larger than the bolts that go thru them. This gives you some play, wiggle room if you will, to get the alignment correct.

In my project, I plan to used the large brass bushing to set the position of the front crankcase half on the adapter plate. Before connecting the gear and sleeve to the crankshaft, the bushing can be inserted into the 2" hole in the crankcase. When properly aligned, it should slip on the tip of the crankshaft. Once that's done I can tighten a couple of bolts to maintain that alignment. Then I would remove the bushing and connect the gear and sleeve. This is just a plan at this point but it should work.

 

[oldmech]

Hi! Everybody! I find a pict on Belos Site. for the adaptor sleeve you need for connect crankshaft to Gravely planetary tranny. This adaptor can be machined from a steel shaft and tempered but can be very expensive as $200-300 . Here Machinist work is $60-70 hour. Good Luck Oldmech

 

[Oneaxepony]

I plan on buying a shaft coupler like the one in the link. A local machine shop said it will be much cheaper to buy a pre-made coupler than to have one made.

1" Shaft Coupler with Keyway

 

[gravelymay]

Here is some Ideas of how we can attach the 1 inch crank to a L model
Gravely transmission

 

[js5020]

Excellent Bruce,,, simple and not a bunch of spendy machine work by the looks of things. Sooooo,, have you got a running machine yet??

 

[gravelymay]

Also another way of spacing or a adapter.
Use a Kohler adapter drill out to fit the model L transmission.
Then use two aluminum plates 1.370 thick gives you 2.740. with counter bore to help line up everything.
The reason for two plates they are cheaper then trying to get one long one.
Cut the old Gravely input shaft to 1 in before the gear and drill thru and counter bore the end for 3/8 X 24 bolt.
If your engine has 7/16 X 20 we cut the end off the gear enough to clear the head.
Get a 1 in coupling and slide over both the engine and input gear.
with bolt holding all together.
I can make the two spacers and machine your input shaft for about 250.
Thanks Bruce g

 

[gravelymay]

Excellent Bruce,,, simple and not a bunch of spendy machine work by the looks of things. Sooooo,, have you got a running machine yet??

Well Finally some one wanted a shaft done so got me back into it
I am completed sold on this being the way to go.
I am in process of installing a Honda 13 Hp Manual start.
on a box of bolts called a C10A It had been apart for 10 years.
I Got it from the guy that owns it in boxes and not all the parts where there.
We have got most of the parts on order to get it back together.
The high and low slides where missing.
I happened to have a set.
I kelp working this method in my mind That we talk so much around in my mind for what about 2 years .
So we will see how it goes.
With 2 spacers and machining your gear at say about 250.
That will be cheaper then other med are
Thanks Bruce g

 

[2manyrocks]

So are you saying that you use the two piece adaptor to mount the engine to the Gravely transmission housing, and the input shaft to transfer power from the engine to the transmission? That's what is involved here in repowering a Gravely with a new engine?

What about repowering with those 11-13 HP "Chondas" from HF? The 6.5 engines made by Lifan appear to have a following on some websites, but I wondered if the 11-13 clones did as well as the 6.5 clones?

 

[js5020]

I Really need to get off my duff on this,,, the Com12 has been down since early winter with a tossed rod and that L has been in the basement for 3yrs now. Sometimes I'm just right on the stick with getting things done let me tell ya. I did do some work on the Kohler and found its not as bad as it looked, in fact I cleaned up the crank and it looks fine, I just need to measure the bore and the crank journal so I can order the right sizes and get the 12 back into operation and hopefully move on to the L.

 

[gravelymay]

So are you saying that you use the two piece adaptor to mount the engine to the Gravely transmission housing, and the input shaft to transfer power from the engine to the transmission? That's what is involved here in repowering a Gravely with a new engine?

Yes a Kohler adapter and 2 spacers


What about repowering with those 11-13 HP "Chondas" from HF? The 6.5 engines made by Lifan appear to have a following on some websites, but I wondered if the 11-13 clones did as well as the 6.5 clones?

I don't know?