Topic: Wolfey's 1976 CB550 Street/Track Build

[Wolfey]

With the Suzuki triple tree branding, you got yourself a Honduki.

What shocks are you planning to use?

I do want to replace that badge with one of the Honda wing ones. 

I am using 340mm RFY air shocks with 485lb spring rate. Here is a pic of them mocked up.

I might be reading your post wrong, but are your shocks set up for a 485lb bike? If so, it will be over-sprung.  The stock 550 weighs 423 wet, and you've shaved some of that weight.  You may also want to check your fork springs when the build is complete, as the change in weight may warrant different springs.

Your speedo/tach instrument looks similar to a Koso, but I didn't see the model on their website.  Where did you source it?

I will have to check on the shocks. They only have one rating on the springs. I havent personally tested them. They are much stiffer but I can get give out of them. I am leaning to they might just have them overrated and be rating them as a set, not individually. I did find this review of them. http://chrislivengood.net/wp/rfy-340mm-shock-analysis/ They state 140lbs per spring which seems much more realistic. The earlier information I just grabbed from the information the seller put on them. (They were an ebay purchase  ) ( They might have been posting the max spring rate too at full compression which would make sense on these since they are a variable rate spring.)

It is a Koso gauge. RX2N GP Style http://kosonorthamerica.com/product/rx-2n/ Its the BA015B15 Model.

[Wolfey]

Started working on my head porting it. I read the FAQ from Hondaman about creating the pocket above the intake valve, but I couldn't find anything more specific. So I found a few pics of other members on here and went to work. I think it turned out pretty nice! Only 3 more intakes some exhaust work to go....


Before photo:


The pocket area.


Before:

[Blackfin5]

Wolfey...you've really have me fascinated with this project.   Are you planning to stiffen the frame at all?

[sbeckman7]

This is getting good   What exactly are you doing with those intake "pockets"?  Hard to tell from the pics.

Spence

[Trad]

Are you going to rig up any kind of flow bench after you've finished the porting? Man, you are braver that I! haha. Project is looking sweet dude.

[Wolfey]

Wolfey...you've really have me fascinated with this project.   Are you planning to stiffen the frame at all?

I did quite a bit of stiffening to the frame. I braced the frame in the triangle where most of the torsion is. Also right below the air intakes I did a cross bar there as well to limit the torsion of the frame from side to side. I did the brace for the tail light ( 1/4" plate steel) that should help with torsion too. I am also putting a brace in the back for mounting of the back of the seat. Here are some pics to show the bracing.



This one shows the brace just under the front of the seat.

This one shows the cross frame brace where the intakes would be. (Sorry I dont have a better picture right now.

[Wolfey]

This is getting good   What exactly are you doing with those intake "pockets"?  Hard to tell from the pics.

Spence

Hi Spence,

So I was reading Hondaman's FAQ and he spoke about the flow of the heads in the 550. Here is the link http://forums.sohc4.net/index.php/topic,7401.0.html. So specifically in the section he wrote:

3. In the heads: all of the inline fours except the 400-4 had breathing issues. Grinding a "pocket" above the intake valve(s) and matching the ports to the carb tubes will improve them, especially at high RPM. Polishing the intake valve(s) helps, too. Don't back-cut the intake valves or you'll pop off a valve head - an expensive day, at best. (Backcutting exhaust valves will make them burn, and quickly - the CB650 malady). Trim (narrow) the intake valve guide bosses for a smaller profile, and polish it. Smooth, but don't polish, the intake tract. If you're good at heliarcing, raise a bead about .100" high along the bottom of the intake ports (CB750 only) in a half-moon shape, then smooth it off along the sides so it "restricts" (apparently) the bottom passageway about 1/3 of the way around. The floor of the port should ramp up to it, then be fairly abrupt in fall-off on the valve side. Do this at the point where the intake track bends down toward the valve (no, it's not easy). Although not obvious, this mod creates some "free turbocharging" at RPM above 6000, all the way to 16000 (lots of work), which deals more with fluid dynamics than I will put into this post.

So initially I am just doing a big bore on the engine. I will probably put it all together and just run it this summer as is. Then this next winter I am going to build the top end out quite a bit more with cam, valves, rockers, springs, etc. But to build up to all this I am trying to get the porting on the head done now to help with the response because I would like to track the bike this summer some. I am going to try and get dynos done at each stage too since I dont see many actual numbers and have the opportunity to do it.

Ernie

[Wolfey]

Are you going to rig up any kind of flow bench after you've finished the porting? Man, you are braver that I! haha. Project is looking sweet dude.

I hadn't planned on it. Maybe next winter when I build the motor out more.

Haha its only a head right? 

[sbeckman7]

Very cool (and interesting), thanks for sharing

[mrfish2]

I'm subscribing to this, interested to see how everything works out for you.

[FunJimmy]

My instrument guage I am using.

Interesting project. I really like the instrument cluster and welded cases.
One more than the other though.