Vintage-izing 2-Strokes

twowheeledfox

twowheeledfox

New Member
I would like to make my 2-smoker HT look like an antique/1910s or 20s motorcycle motor, in several different ways... this is likely a popular topic with antique bike lovers and Board trackers on the boards so it shouldn't be too difficult.

Here's what I was thinking:

Round cylinder head (would it impair cooling? How to file/buy/make it?)

Belt drive (biggest mod there is, probably not too much info on it but hypothetically possible right?)
How to age/paint motor and other parts.

How to make it sound older. I love the sound of old engines, and if anyone has made one of these HTs sound older it would be great to see how.

General tips on vintage-ness.
 
I contoured my head and jug on a belt sander freehand. I tried to keep material removal to a minimum and was able to get rid of the modern angular style. I'm not sure how much the heat exchange would drop if you went to a completely round shape so I compromised.
 

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Maybe some details? Like brass tubing for a fuel line and one of those vintage looking fuel filters.. (thats what i´m gonna do :-)
 
If you have a drill press you can do what I did and machine turn the side covers. Just use a 3/4" or a 1" fine wire brush bit and overlap each turning by a little less then half of the diameter of the brush. another tip is to wrap the brush in electrical tape to keep it from flaring out.

Practice on some scrap sheet or flat bar.
 
Actually KIP I have been thinking about the same thing one day as I am into the puch heads myself and instead of rounding it out totally I am thinking of setting up on the rotary table and putting a set of large radiuses so as not to reduce the cooling area.
 
There was a style of dirt bike head in the late 70's and early 80's on called the Porcupine Head that had notches in the fins. This later metamorphosed into the Radial Head before Honda developed the water cooled technology that everyone uses now.
 
My engine was made with round cooling fins, and when compared with a square one it looks like I have a little less cooling area. Heat has never been a problem form me, so I would say that it would be alright to sand them down to a round shape. Still, I would try to leave as much metal there as possible.
 
I'm diggin' this topic & I hope to get some ideas offn you guys, while building my Rollfast I wanted to do my best to make the HT look as old school as possible... but I eventually decided to let the engine itself age naturally while distracting the eye with brass and copper doodads wherever possible. Leather too - but I've not gotten to that yet lol

There was some cool suggestions made, like gun-bluing treatment for the aluminum case & what you guys are chatting about - reshaping the cylinder & head for a more rounded look, I even thought about Rock Solid's round billet head... but I got a lil worried about a few things as I went along. Don't get me wrong - I'm not sayin' it's impossible or even a bad idea, I just had some concerns is all lol

The gun bluing treatment would be easy and inexpensive & because it's just a liquid dye there's some different color options - I really don't think there'd be an easier, faster way to add a vintage appearing patina/old iron look (it's not actually blue BTW), but I had the thought that I ride the heck outa my builds and I wondered how the treatment would withstand the abuse as I use my ride as a commuter. While it might age in well and look even better/older - it might just as easily just get scratched and silly looking. As I was "experimenting" with too many other things at the time I dropped this good idea (I think it was Tom/2door's) & let the engine age naturally - but ya might wanna look into it, it's only like $20 for a quality cold-bluing treatment kit: Blue Wonder Gun Bluing Kit : Cabela's and here's some examples of how it looks: http://pic20.picturetrail.com/VOL12/1104763/22762860/378856564.jpg

As for reshaping the cylinder - once I actually got into it I realized that as the castings for the fins was so bad that by the time I dressed just the deformities out I had already lost about 1/8-1/4" off the outer radius, I decided I was pushing my luck as it was and dropped the idea of a round cylinder also - going for just a tidy look instead... challenge enough with the casting the way it was lol here's some before & after pics;

(click to view)


So I rolled with just accessorizing instead heh, using an older style fuel bowl/filter/petcock (NAPA part# 7-02350) and copper fuel line - the right side of the engine & CNS is less noticed (I hope anyway), the left side was a lil harder to distract from as there's not much to put there - but I added the fuel sight gauge on the left with that thought in mind & the fact the right side was getting "cluttered" anyway - adding in copper straps instead of conduit clamps to hold the tank in place and a lil brass thingie to hide the 1/2 round hole left from the forward motor mount;



These are build pics ofc, I've been riding the heck outa the bike and the copper, brass, even the engine itself is tarnishing & wearing nicely. The bike isn't done (they never are right?), this is all a "preliminary" set up - I'll be tearing it back down and repainting it "final" this winter, I may even try the gun bluing trick & I'll be definitely be keepin' an eye out for any tips/ideas you guys have - I've about run out lol

Here's some more up to date shots... though I've finished the rear fender (no more gap) & some other stuff since then, the chain oil stains & other filth is coming along nicely heh;
 

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All that sparkles is not gold. I'm in the let it age camp myself. Here is my CDI treatment based on a fellow members post. Regrettably I don't know who it was please chime in as I don't want the credit. I used some simple materials rather than leather to tone down the plastic. This is masking tape, string, wood stain, and clear coat. I free handed some printed reference numbers in an attempt to replicate a stamped code. It looks OK when seen on the bike as a whole.
 

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No doubt! Additionally it turns out to be an awesome filter, catching all kindsa junk left over from building the tank & the water that sneaks in there - the quality built in petcock alone I'd have happily spent the $10 er so that the whole thing cost.

It's a shame it's so large and "odd" looking else I'd get another for my mountain bike build... but that'd be kinda weird :p
 
Thanks for posting the link to mekano's work. That indeed was the thread that inspired my interpretation. Credit goes where it is due.

I will add another thought here, be mindful of the fastening hardware selected for the motor. Cap screws and phillips head screws are not period correct and look like a sore thumb to anybody with historic knowledge. Stick with hex heads and slotted screws. I actually kept my original fasteners intact. I think there are only four allen head cap-screws and button heads on my whole build and there not easily spotted. It might seem trivial but details add up.

Barely, I also give a thumbs up on that bowl and copper line, that looks nice.
 
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Thanks for the awesome replies guys .thumbs up.

My motor looked somewhat period-correct as it came with slotted screws and I used allen bolts to mount it in place of the threaded studs. I guess the cylinder will stay square for practicality, though i might try aging it a bit. Come to think of it, 2 strokers in those days were generally square cylinder setups as even at low speed they run hotter than four-strokes and the limited fins on most early round cylinders were not enough to cool it properly.

What would be great for us vintage lovers is a pushrod or flathead 4-stroker with a round cylinder, exterior valve springs, etc. Maybe 80 or 100 true ccs and 3 1/2 to 4 HP? After all it's not like the Chinese companies we order from are using "high-tech" manufacturing laff

How about some tips on making the other parts look vintage, or parts such as handlebars that look like old motorbike parts? I have found some old-style longhorn and throwback bars, even with the old-fashioned crossbar on them, but they seem damned expensive. Any cheap sources of those types of parts? Replicas are fine too.
 
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