Lurker's V-twin build

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Lurker

Lurker

New Member
Jan 29, 2010
403
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Pittsburgh
It's finally here. All 23 glorious hp of it. I got the engine last night and immediately began stripping the garbage off it and did a test fit. The bad news is that it doesn't fit. The oil filter is in the way of the counter shaft. So I am going to have to modify the down tube and push the engine further forward which I don't mind. The more weight I can get closer to the front the better. I am afraid this thing will be a wheelie machine so the extra weight closer to the front is welcome. I also got my rear wheel built which you will notice in the photos. Its a Worksman rim with a 95mm Sach moped rear hub and 38t sprocket and 11g spokes. This wheel must weigh close to 10lbs super heavy duty.

After I ordered the engine I came to the realization that 23hp is way too much for your standard 40/41 chain that most people use on their bikes. So I did some research and found out that a 420 motorcycle chain will fit on 41 sprockets. The chain has the capability to handle 30hp with a tensile strength of 5,200lbs which is almost 3x that of the normal 40 chain.

Another helpful hint to those using Simplex tires. When you are putting them on the rim if you start from the opposite side as the valve stem and work towards it the tire goes on pretty smoothly.
 

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cobrafreak

New Member
Feb 16, 2011
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sacramento ca
First off, congratulations on getting the Vanguard. That is going to be a rewarding engine. Where did you purchase it? Are you going to use the motor as is or are you going to do any mods to it? The 420 chain sounds interesting just for the fact that I can get it in 0-ring chain. I cant for the life of me find o-ring chain in #41. You know we can't call your bike a motorbike anymore. It's officially a motorcycle now :) Nice rear hub. I want to call attention to the rear bearings of your hub. My rear moped hubs bearings failed and I ended up modifying the unit to take 5 bearings vs the stock 2 for more durability which I feel is a worthwhile fix. For your power output I think it would be a good idea to consider this option. Sachs never envisioned 23 hp being put into this part.
 
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Lurker

Lurker

New Member
Jan 29, 2010
403
133
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Pittsburgh
I totally forgot to thank ccc for that link. I got a few ideas from that, so thanks.

I plan to keep it stock for now but once I get it running and get a feel for it I will upgrade the valve train and get some nice connecting rods and what. To be honest with you guys I think 23hp maybe a bit too much thats some thing like 630cc. Which is defiantly motorcycle territory. I really don't want to do any thing that will give it more power.

Also thanks for the fyi about the bearings. I got the hub used and did a complete overhaul on it. So it should be good just to test the waters but upgrading is a good Idea. I will have to go back to your thread and see how you did it. However I don't have a lathe nor the skill needed to do such a task.
 
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baslok

New Member
May 25, 2011
19
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germany
ich tritt dir in den arsch!

nice build so far! very interesting engine, i think i have to look out for that beast in europe!
 
Lurker

Lurker

New Member
Jan 29, 2010
403
133
0
Pittsburgh
So I got the 420 chain in the mail last night and it is huge. I tested it on a 41 sprocket, a 40/41 drum clutch, 41 Sach moped hub, and a spare sprocket that was marked 40 and it fit all of them perfectly. I want to test the 40 sprocket again because according to the measurements I found it shouldn't fit. If any of you are planning this upgrade, keep in mind not all 420 chains have a tensile strength of 5,200lbs. EK brand was the strongest I found. In the photo below you can see the 420 chain on the left and a normal 40 chain on the right.
 

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5-7HEAVEN

Well-Known Member
Aug 2, 2008
2,661
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Lurker said:
So I got the 420 chain in the mail last night and it is huge. I tested it on a 41 sprocket, a 40/41 drum clutch, 41 Sach moped hub, and a spare sprocket that was marked 40 and it fit all of them perfectly. I want to test the 40 sprocket again because according to the measurements I found it shouldn't fit. If any of you are planning this upgrade, keep in mind not all 420 chains have a tensile strength of 5,200lbs. EK brand was the strongest I found. In the photo below you can see the 420 chain on the left and a normal 40 chain on the right.
Click to expand...
How much was the chain?
 
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cobrafreak

New Member
Feb 16, 2011
1,049
9
0
sacramento ca
420 is common motorcycle chain and you can get it at any motorcycle shop. O-ring chain is cool because it keeps the lubrication inside the chain and keeps the dirt out. Lasts a lot longer than non O-ring chain.
 
Lurker

Lurker

New Member
Jan 29, 2010
403
133
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Pittsburgh
The chain was fairly inexpensive for how strong it is. I only payed $30 for 120 links. I got 2 of them because of the setup I will be using. If you are running a cvt you should be fine with 120-130 links. If any of you are thinking about using this chain with a standard bike engine kit I don't think it will work as it is much wider than a standard 40/41 chain.
 
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5-7HEAVEN

Well-Known Member
Aug 2, 2008
2,661
240
63
One of my projects is twin CY460 4.5hp engines on Staton chain drive and NuVinci hub. If it fits my sprockets, it'd be the perfect chain.
 
Lurker

Lurker

New Member
Jan 29, 2010
403
133
0
Pittsburgh
Modified the down tubed this weekend and tacked in the cross bar. I also got all of the pieces cut for the engine mount that I will tack together tonight. I only have a crappy Harbor Freight welder that isn't powerful enough to do the thick tubing I'm using. I will go to my buddy's shop this weekend and get it all welded up. I also got my seat in the mail last week. I was going to get one of pats seats but because of the unusual frame construction I need a seat with a high back. Its not exactly what I wanted but I found a old H-D with a similar seat shape. But I'm ok with that because in this latest photo you can really see the H-D influence starting to peek through. It wont be too much longer until she can move under her own power. I'm really dreading the tank construction. But I know I am making it out to be a lot worse than it really is. I think the last tank I made only took me a weekend to do. Sorry for all the boring side shot photos but its all I got to work with at the moment.
 

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