Hello, I'm in the process of getting the 511 in the bobcat to replace the 411 in the bobcat 721. The engine is out, and all is going well except the flywheel. I've attached the 411 flywheel to the 511 engine, it bolted up fine, but there are some issues. The starter does quite line up, the new engine/old flywheel. I think I can change the gear, or maybe put the old starter on the new engine. My main concern is weight, the 511 flywheel/damper is heavier by maybe 10lbs, that's just a guess. I think this will impact the crankshaft, and tear up the engine. The reason I did not use the 511 flywheel is because of the plate I need to connect the yoke. Does anyone have any suggestions?
Help Support SkidSteer Forum:
I uploaded photos to the ' bobcat 721 repower ' folder under the photos tab. I don't want to come off the wrong way, why is it so complicated to post pictures with your posts? I followed the directions under html editor, checked the box and it does not allow me to input or paste anything.
SkidRoe
Well-known member
- Joined
- Dec 10, 2009
- Messages
- 1,885
What web browser are you using? Unfortunately, the Forum software only really works with Internet Explorer. I have had some luck using Google Chrome with an IE add-in, but it becomes clunky very quickly.
Back to your flywheel dilemma. I looked at your pictures. Is there any way that you could get the 511 flywheel machined to match the coupler mounting on the 411 one? It should be a simple job for someone with a mill and a rotary table.
In a pinch, I have even created paper templates in CAD with cross hairs on all of the holes, printed it out 1:1, taped it on, center punched the hole centers, and drilled them on a drill press. Not entirely recommended, but in a pinch....
Cheers - SR
It's fine, I'm using Chrome. I took the flywheels up to a place here in Columbus, Ohio called Fowler Engines. They are doing just what you said. He is going to turn down the 511 flywheel about 3/4 of inch and then cut place for the adapter plate, he said taking off the additional weight will not be an issue. I should get it back next week and proceed on with the install.
SkidRoe
Well-known member
- Joined
- Dec 10, 2009
- Messages
- 1,885
That's good news! Look forward to hearing how the transplant goes.
Cheers - SR
Hello, good news, the transplant is complete (minus the air filter hook up and the up piping for the exhaust). I added some photos under bobcat 721 repower, including the flywheel being machined. If anyone wants to do this job, it's not bad. The motor dimensions are nearly identical. The bolt holes for the motor mounts, the height of the pump shaft to the yoke of engine and the depth of the engine are the same. Here are a few issues I ran into. The intake and exhaust are plumbed different from the 411 to 511. I cut the exhaust outlet off, plugged it, cut a hole on the opposite end and welded on an outlet. The intake still needs some thought. Also, the exhaust hit the side wall and a piece about 2" by 18" was cut out, this is the only body modification I did. I could have did some cutting and welding with muffler itself, but decided not to mess with it. The 511 flywheel is 1/4" bigger than the 411 so about 3/16" had to be shaved off the top of the rear motor mount. Other things, the oil drain plug is in a different place (The 411 is in the middle/bottom of the engine, the 511 is near the flywheel, back right as you are facing it) I'm buying a barbed fitting and connecting that to a hose with a cap to make oil changes easier. It has more power and turns smoother than before, runs good, I'm happy with it. Here are few of the costs, the 511 cost $2250 and the machine work cost $387. The prices range a lot, I have seen them for $1500 and there is one on ebay for $6000. As far as the 411 rebuild would have looked like, I found pistons and rings for about 900 euros from an ebay seller in German. The cylinder jugs are around $1000 for both. So, the cost was about the same. I'll play with the 411 and see if I can get it running a little better this winter. The nice thing is that rebuild kits for the 511 are available and at a reasonable price. Thanks for your support.
