Hi there,
I have been working on a diesel swap for several months and I am very close to finishing the project. I originally planned to wait until it was done to post a build thread as I did not have time to do so while the build was in progress. I will still do this but in the meantime I am hoping that I may be able to get some help with one of my last problems which is stopping me from completing the bike 100%. I had the flywheel of my D722 machined to mate with a toothed belt style pulley (htd pulley). In doing so a portion of the three balancing holes on the backside of the flywheel were removed (please see picture). In the picture, the back side of the htd pulley is visible through the holes. I am wondering if anyone has access to a d722 flywheel which they could use to measure the depth of these 3 holes in order for me to use in order to machine my flywheel back to factory spec. The bottom of the holes are spherical so if possible I am looking for the depth to the middle of the holes where they are deepest. I have also included a picture of my bike just for the heck of it, many more to come once the bike is finished in about a weeks time.
Thanks in advance for any help which anyone is able to offer.
Welcome Garbs. Great to have another project join the board. Excellent choice in engine and donor. Would seem to be the perfect power/weight ratio. Reminds me of Heiko's CX500 with the CVT. Regarding your question as to the flywheel, whatever material removed with the lightening holes in the process of balancing is likely now offset by any imbalance in the HTD pulley (and a big pulley it is). In the ideal world you'd have the entire assembly rebalanced as a matched set. But your question is not an unreasonable solution in the absence of a rebalance. Again, we're only talking 3600 RPMs. Unless others respond sooner, I can check my engine next time I'm in at the shop and get back to you.
And now tell us more about your planned primary drive.
I fully agree that a rebalance would be the best solution and is what I originally hoped to do, however I was not sure of where to find the balance spec which kubota has set for this engine. I have searched online some without much luck. If anyone knows of how/where to find this information that would be appreciated. My dive sytem goes as follows.
1. 80 tooth htd pulley to 40 tooth htd pulley (2:1) ratio. This doubles the rpm to a more cvt friendly range while also allowing me to use a smaller cvt sytem as there is now more rpm but less torque beng transferred through it.
2. Comet 40 series cvt clone (genuine comets are very pricey)
3. 10 tooth 40 series sprocket to 16 tooth 40 series sprocket. The 16 tooth sprocket is on the shaft which drives the back wheels as the cx500 is shaft drive. These sproclets allow m to change my final drive ratio very easily if needed.
When starting the build I first located the engine as far forward as I thought reasonable and then measured how much room I had to fit my drive system in. 7 inches. Through clever design and a LOT of machining, I have fit all of the above witin 7 inches of depth. For example, the nose cone (cant find a better term) of my secondary clutch sits within my htd pulley which is "hollowed" out to allow this. Pictures of all this will be posted soon. I have had to relocate my rad but I feel it will stll get enough airflow.
garbs wrote:...1. 80 tooth htd pulley to 40 tooth htd pulley (2:1) ratio. This doubles the rpm to a more cvt friendly range while also allowing me to use a smaller cvt sytem as there is now more rpm but less torque beng transferred through it. ....
I believe this concpetually is how Polaris has done their latest Diesel quad
An idea hit me to hit up a fellow who might have a used Flywheel . If he did I asked him to read this thread and see if he could help. He does have one but felt he couldn't help cause he had no to way to measure with enough accuracy what your asking.
I'll see who else I can hit up if I can't reach Curtis soon
Thanks for the efforts coachgro. Did this person have any way of measuring the holes. I only ask because I will be at the machine shop tomorrow and if he could get a measurement within say a mm I'd use that for now until I can find the factory specs.
garbs wrote:Thanks for the efforts coachgro. Did this person have any way of measuring the holes. I only ask because I will be at the machine shop tomorrow and if he could get a measurement within say a mm I'd use that for now until I can find the factory specs.
That was his point......... he's got no way to measure.
Sorry I thought he may have been under the impression that I needed a very precise measurement and simply couldn't measure "accurately" enough as you said. My apologies.
garbs wrote:....When starting the build I first located the engine as far forward as I thought reasonable and then measured how much room I had to fit my drive system in. 7 inches. Through clever design and a LOT of machining, I have fit all of the above witin 7 inches of depth. For example, the nose cone (cant find a better term) of my secondary clutch sits within my htd pulley which is "hollowed" out to allow this. Pictures of all this will be posted soon. I have had to relocate my rad but I feel it will stll get enough airflow.
Thanks for asking coachgeo. I have been meaning to follow up with the progress of the build once I finished as I stated I would. Your inquiry has given me the incentive to do so. The bike was finished, however, not a week after my original post as I had planned, more like a month later. Due to finishing so late in the riding season, basically at then end of it, the bike was not put on the road last riding season. I guess I cant really do a proper build thread as the bike is already complete, but I will make a thread in the bike building forum to detail the build in order to provide problems/solutions, part sources and other general information to the forum members as well as answer any questions. I do have a good video of me driving the bike around on the day it was ready to move under its own power which I will upload or link to once I find the usb stick it is on. Unfortunately the video does not show the bike in completed form, nor do any of my pictures. I will make sure to get some current pics uploaded soon. The attached pictures are of the bike on the day the video was taken. As stated above it has since been completed. (all those wires have been cleaned up)
