Topic: '72 CB 750 - "Kinetic Aline"

[sangyo soichiro]

I got a few more things done this weekend.

I started with de-flashing the head and jugs.  When the castings are cast in a mold, there is a parting line where the mold separates.  This parting line wears (and maybe wasn't that close to begin with - depending on the skill of the mold maker), and you get excess metal in this area called flash.  Not only is de-flashing a little detail that makes for a nice touch (in case someone really gets close in to inspect your engine), but also lets air flow through just a little bit more (which may be important for these air-cooled engines...  In the photo, you can see one area that I started to de-flash.  The holes to the left still have the flash, and the far left is pretty bad.


After de-flashing and a good cleaning, paint it black.  I used Duplicolor high-temp engine enamel.


I cleaned up the rear sprocket (man was it dirty...), and took a pencil grinder to break all the sharp edges (a pet-peave of mine from my tool and die days).  I also added the 3/8" holes toward the outside and between the large holes.  I know it's minor, but any time you can reduce the mass of rotating parts, you not only reduce the overall mass, but also the moment of inertia.  And since the moment of inertia goes like the radius squared, it's more effective if you take away the mass further away from the axis of rotation.  


Then it was on to the Hondaman mods that Doctor_D brought to my attention.  I used the poor man's drill press (a hand drill) and a countersink center drill.  The idea was to leave a "funnel" that oil could pool in.  I did this to the four inside spots where the core pin from the molding process left its mark.



And finally I started the process of swapping the rims.  I have Sun brand rims.  The difference in weight from the new and old rims are 1.83 lb on the front, and 2.02 lb on the rear.  I'm basically at the point where the hubs are cleaned and ready for the rims.  

[heyjones]

I'm looking to do these same steps today! On the Duplicolor, did you use the Gloss Black (DE1613), Low Gloss Black (DE1634) or Ford Semi-Gloss Black (DE1635)?

[sangyo soichiro]

I'm looking to do these same steps today! On the Duplicolor, did you use the Gloss Black (DE1613), Low Gloss Black (DE1634) or Ford Semi-Gloss Black (DE1635)?

Hey heyjones,
I believe it was gloss black.  Here's the story behind the color...
I could have sworn that I had some high-temp black at my house that we used on one of my girlfriend's engines.  But when I looked for it, I couldn't find it (as usual).  I don't know what color it was, but whatever it was, that was going to be what I was going to use.  Anyway, I couldn't find it, so my girlfriend offered to pick some up on her way to my place.  I asked her to get high gloss, but I didn't check, and it didn't really matter to me, as long as it was black.  I wasn't going to be picky.  But I think it was high gloss, and that's what I asked her to get.  

Sorry I'm not at home to check.    

[heyjones]

No problem, I'm just on the fence about going gloss or matte... I get the feeling the difference between them isn't that noticeable.

[sangyo soichiro]

I wanted gloss because the rest of my bike is gloss.  If that helps you decide....

[heyjones]

Yeah, I got my frame powder coated gloss black, so I'll probably go for the gloss to match. Just looked at some of the earlier posts in this thread... where'd you get the wrap for your exhaust?

[sangyo soichiro]

I got the wrap at one of the local auto stores.  I can't remember if it was Advanced Auto, or AutoZone, but it was some place like that.  It took one roll of the 2" thick (by 50' I think) at a cost of around $45 if I remember correctly.

[wannabridin]

just make sure on your wrap that you soak it in a jug of water first!  makes it a LOT easier to work with!  also helps keep down the fiberglass itches too!  and don't pressure wash black wrap, the black will wash away and you'll be left with quite the ugly wrap job.  ask me how i know!   

looking good soichiro!!!

[sangyo soichiro]

just make sure on your wrap that you soak it in a jug of water first!  makes it a LOT easier to work with!  also helps keep down the fiberglass itches too!  and don't pressure wash black wrap, the black will wash away and you'll be left with quite the ugly wrap job.  ask me how i know!   

looking good soichiro!!!

Thanks WBR. 

Yeah, it's pretty much impossible to wrap the exhaust if you don't soak the wrap.





I just contacted Dynoman today and ordered my crankshaft bearings, along with the six rubber nickels, oh... and a couple of these:



I can't give Dynoman (Buzz and Debbie and all the rest there) enough credit.  They are really a great crew to work with.  They've been my main supplier of things SOHC4.

[wannabridin]

you'll have to post us on how those shocks handle!  they seem to be one of the best bangs for your buck for a suspension upgrade!

[heyjones]

Not to mention they look pretty bad ass.

[tweakin]

just make sure on your wrap that you soak it in a jug of water first!  makes it a LOT easier to work with!  also helps keep down the fiberglass itches too!  and don't pressure wash black wrap, the black will wash away and you'll be left with quite the ugly wrap job.  ask me how i know!   

looking good soichiro!!!

Thanks WBR. 

Yeah, it's pretty much impossible to wrap the exhaust if you don't soak the wrap.





I just contacted Dynoman today and ordered my crankshaft bearings, along with the six rubber nickels, oh... and a couple of these:



I can't give Dynoman (Buzz and Debbie and all the rest there) enough credit.  They are really a great crew to work with.  They've been my main supplier of things SOHC4.

Nice choice on the shocks, thats what I am trying on my 750 build.  Good price and should perform well.  What are you doing in the front?  I put the progressive springs in my forks and am looking forward to trying them out.

+1 on Buzz and Debbie at Dynoman.  I have been dealing with them on my build and Buzz is a great tech help and the customer service is great.  I have some CR's in the mail and a F2 836 kit on order.

Looking good.

[sangyo soichiro]

Thanks tweakin.

I'm not entirely sure what to do with the front yet.  As far as the suspension, I'm leaving it alone for now.  As far as the rest of the front, I have some nice Magura clip-ons coming in the mail from fastbroshi (thanks again!), and those fork ears I pictured above.  I will likely order the tapered steering bearings (probably tomorrow), and I need either the dust caps, or the tight-fitting gaiters.  My forks are rusty, so that poses a problem.  Also, I would like an aluminum lower triple tree.  I'm toying with the idea of a front dual disc brake - that was the main purpose of the parts bike I found and posted earlier in this thread, but I found out that brake wouldn't work for me.  Now I may just stick with a single front brake.

So that's the front end plans in a nutshell.  If I keep this front end in the long run, I'll look into replacing the springs like you did. 

[Zaipai]

Who is Dynoman? What is the website? With endorsements like that I have to check them out on my next order..

Great work so far.. Looking forward to the final product! And doesn't painting the motor negate any gains from removing the flash? Being a novice at this stuff I have conflicting idea's on it.

.: Scott :.

[tweakin]

Who is Dynoman? What is the website? With endorsements like that I have to check them out on my next order..

Great work so far.. Looking forward to the final product! And doesn't painting the motor negate any gains from removing the flash? Being a novice at this stuff I have conflicting idea's on it.

.: Scott :.

http://www.dynoman.net/

[jaguar]

ive used them before and they are great
sometimes they have great deals on dyna set ups.
i got my dyna 2000 for a great price

[sangyo soichiro]

Who is Dynoman? What is the website? With endorsements like that I have to check them out on my next order..

Great work so far.. Looking forward to the final product! And doesn't painting the motor negate any gains from removing the flash? Being a novice at this stuff I have conflicting idea's on it.

.: Scott :.

Thanks Scott.

Dynoman Performance is worth checking out.  Follow the link tweakin gave.  Good stuff.


About the de-flashing/painting…
Like a good politician, I'm going to answer the question I wish you'd asked... 
Is painting the engine a good thing?
Or... what I think you were really getting at - does painting affect how the engine cools?

I want to give this more thought. 



In the meantime, more updates!
I ordered the tires.  Avon AM26 Roadriders.

3.25 - 19 on the front,
4.00 - 18 on the rear.
These are V rated - for speeds up to 149 mph.  And the price was not bad. 
I also got IRC tubes (IRC68 (front), IRC65 (rear)), and Kenda rim strips (18/19").  Oh, and a couple tire irons.   
I ordered from this place (someone in this forum (I forget who) linked to this place - thanks, whoever you were!):
http://www.americanmototire.com/catalog/index.php

Then I ordered a new front sprocket (the standard 18T), the bronze swingarm bushings, tapered steering bearings, two front wheel bearings (6302), and two rear wheel bearings (6304), and some new grips.  I got those items from http://www.partsnmore.com/.

From the Honda manual, there seems to be a third bearing in the rear wheel, a 6305.  But Partsnmore didn't list it.  Anyone know what's up with that?

[fastbroshi]

Is painting the engine a good thing?
Or... what I think you were really getting at - does painting affect how the engine cools?

I want to give this more thought. 

Then I ordered a new front sprocket (the standard 18T), the bronze swingarm bushings, tapered steering bearings, two front wheel bearings (6302), and two rear wheel bearings (6304), and some new grips.  I got those items from http://www.partsnmore.com/.

From the Honda manual, there seems to be a third bearing in the rear wheel, a 6305.  But Partsnmore didn't list it.  Anyone know what's up with that?

I wouldn't lose any sleep over the paint on the motor bit.  The amount of heat loss with silver vs. black or other colors can't be of that much consequence.  It's a street bike after all, and your in Indiana right?  Summers don't get unbearable up there for long.  What rear wheel are you planning on using?

[sangyo soichiro]

For the rear wheel I have the stock hub laced with stainless spokes to an aluminum Sun brand rim, and the Avon AM26 Roadrider 4.00-18 tire with the IRC65 tube and Kenda rim strip.

[jaguar]

looking good.
how do you like the sun rims?
what made you go with the avons? over say the GT501s?
ill have to keep that site in mind.  seemed like good prices
ive used motorcycle superstore for tires before.

[sangyo soichiro]

Thanks Jaguar.

The Sun rims seem nice.  Although I had to de-burr some of the holes.  Overall they are nice. 

On choosing the tires... this project has gotten to the point where I just have to start making decisions and running with them.  So I didn't put a lot of thought into it.  I figure as long as I go with a reputable brand I should be okay.  I don't know the differences between all the top tires, but I assume they are probably all about the same.  One's advantages are counterbalanced by another's.  Who knows?  But the general criteria I went for was I wanted a brand name at a reasonable price, I wanted to stick with the inch size as opposed to going to metric, and I wanted a tire that was rated for high speeds (either as high as physically possible for the bike, or as high as I have the stones to take it - say at a track, for example). 

Perhaps if I had seen the GT501s first I may have got them instead. 

But a certain individual here in the forum did recommend Avons to me...  You could say that this person wrote the book on the 750.   

[Zaipai]

Yea, I don't think you can go wrong with Avons.. As for the paint.. It was actually some thing I was wondering about. I suppose that at the end of the day a layer of paint won't effect the cooling much.. Keep at it Mr Politician..

.: Scott :.

[jaguar]

i wouldnt worry that much about heat with the paint

what are you plans for an oil cooler?

[sangyo soichiro]

Yea, I don't think you can go wrong with Avons.. As for the paint.. It was actually some thing I was wondering about. I suppose that at the end of the day a layer of paint won't effect the cooling much.. Keep at it Mr Politician..

.: Scott :.

I'm thinking about all the ways heat escapes, and trying to come up with an accurate physical picture, starting at the atomic level.  But more pressing issues are taking priority - like making a checklist for reassembly of the engine.  I'm attacking that one like the astronauts trained for landing on the moon.  I want to make a detailed procedure, and then actually simulate it.  I'm a nerd.  

[sangyo soichiro]

what are you plans for an oil cooler?

Funny you should ask... I was just going to ask if anyone had suggestions for this.   

So can anyone recommend some different oil coolers and tell me where I can get one?