Author Topic: Anyone tried the $120 CB550 big bore kit yet?  (Read 42905 times)

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Offline dave500

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Re: Anyone tried the $120 CB550 big bore kit yet?
« Reply #50 on: November 10, 2012, 11:14:42 PM »
the plain ring is the top one.

Offline ben.cb500

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Re: Anyone tried the $120 CB550 big bore kit yet?
« Reply #51 on: November 11, 2012, 02:18:29 PM »


I am rebuilding a 550 motor. I'm considering the $120 kit, but if I did head work (hemi bowling as described elsewhere) and the 650 cam, would it be comparable?

Thing is I would like to use the 500 tach (my bikes a 71, engine build is for kicks). Are there other cam alternatives? Maybe a regrind?

Keen to hear about seat of the pants impressions on this kit.


Offline FastCB550

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Re: Anyone tried the $120 CB550 big bore kit yet?
« Reply #53 on: November 15, 2012, 09:15:05 PM »
I found a good local shop to do my boring and they are going to slip fit the pistons to the cylinders. My question for those who have already done this is what kind of piston to cylinder clearance should I be shooting for?
1978 - CB550
600cc Overbore, Velocity Stacks, 4 into 1 Carpy Exhaust, Seat & Electronics by Kott Motorcycles, PD46C Carbs with 42 idle jets and 115 mains.
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Offline dave500

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Re: Anyone tried the $120 CB550 big bore kit yet?
« Reply #54 on: November 16, 2012, 12:53:03 AM »
your good local shop will know what to do,,if they asked you what it should be take it somewhere else!!!!!

Offline FastCB550

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Re: Anyone tried the $120 CB550 big bore kit yet?
« Reply #55 on: November 16, 2012, 01:14:14 AM »
your good local shop will know what to do,,if they asked you what it should be take it somewhere else!!!!!

Yeah Im sure they know but I want to hear what the opinions of the collective here thought since they probably have more experience specifically with SOHC4 bikes.
1978 - CB550
600cc Overbore, Velocity Stacks, 4 into 1 Carpy Exhaust, Seat & Electronics by Kott Motorcycles, PD46C Carbs with 42 idle jets and 115 mains.
www.HondaBB.com

Offline Hasenkopf

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Re: Anyone tried the $120 CB550 big bore kit yet?
« Reply #56 on: November 20, 2012, 08:50:53 PM »
still waiting........tumbleweeds.....it snowed the other day anyway!
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Offline FunJimmy

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Re: Anyone tried the $120 CB550 big bore kit yet?
« Reply #57 on: November 20, 2012, 09:28:36 PM »
your good local shop will know what to do,,if they asked you what it should be take it somewhere else!!!!!

Yeah Im sure they know but I want to hear what the opinions of the collective here thought since they probably have more experience specifically with SOHC4 bikes.

I had my 555 yoshimura pistons fit with 1.2 thou clearance.
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Offline FastCB550

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Re: Anyone tried the $120 CB550 big bore kit yet?
« Reply #58 on: November 20, 2012, 09:41:00 PM »
Quote
I had my 555 yoshimura pistons fit with 1.2 thou clearance.

Thanks Jimmy! I was thinking right around .0012-.0015" but would love to hear more feedback.
1978 - CB550
600cc Overbore, Velocity Stacks, 4 into 1 Carpy Exhaust, Seat & Electronics by Kott Motorcycles, PD46C Carbs with 42 idle jets and 115 mains.
www.HondaBB.com

Offline Flying J

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Re: Anyone tried the $120 CB550 big bore kit yet?
« Reply #59 on: November 20, 2012, 10:32:12 PM »
Are they forged? dynomans pistons call for .0028
http://www.dynoman.net/engine/pistons/piston-install/61mm.pdf

Offline FastCB550

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Re: Anyone tried the $120 CB550 big bore kit yet?
« Reply #60 on: November 20, 2012, 10:53:20 PM »
Are they forged? dynomans pistons call for .0028
http://www.dynoman.net/engine/pistons/piston-install/61mm.pdf

Not sure if they are forged or not. How can I tell? These were from the seller on eBay selling these 600cc overbore sets. Other then the diameter they look very identical to the stock pistons. You can see the photos of them further back in this thread.

1978 - CB550
600cc Overbore, Velocity Stacks, 4 into 1 Carpy Exhaust, Seat & Electronics by Kott Motorcycles, PD46C Carbs with 42 idle jets and 115 mains.
www.HondaBB.com

Offline bwaller

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Re: Anyone tried the $120 CB550 big bore kit yet?
« Reply #61 on: November 21, 2012, 04:18:01 AM »
I imagine they're cast but contact the seller to be sure. You don't want cast clearance for a forged piston.

Offline Flying J

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Re: Anyone tried the $120 CB550 big bore kit yet?
« Reply #62 on: November 21, 2012, 12:27:25 PM »
here was thread i used for when i had my 61mm gentlemans express pistons bored.
http://forums.sohc4.net/index.php?topic=68776.msg780524#msg780524
« Last Edit: November 21, 2012, 08:42:30 PM by ffJMoore »

Offline RAFster122s

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Re: Anyone tried the $120 CB550 big bore kit yet?
« Reply #63 on: November 21, 2012, 07:12:06 PM »
ffJMoore, If you used the Dynoman pistons, I think they are forged.
I cannot imagine these pistons are forged pistons for $120. 

From wikipedia (talking about automotive pistons):
"Forged versus cast
When a piston is cast, the alloy is heated until liquid, then poured into a mold to create the basic shape. After the alloy cools and solidifies it is removed from the mould and the rough casting is machined to its final shape. For applications which require stronger pistons, a forging process is used.
In the forging process, the rough casting is placed in a die set while it is still hot and semi-solid. A hydraulic press is used to place the rough slug under tremendous pressure. This removes any possible porosity, and also pushes the alloy grains together tighter than can be achieved by simple casting alone. The end result is a much stronger material.
Hypereutectic pistons can be forged, but typically are only cast, because the extra expense of forging is not justified when cast pistons are considered strong enough for stock applications.
Aftermarket performance pistons made from the most common 4032 and 2618 alloys are typically forged."

These cheap $120 piston kits are likely to be cast & machined, not forged.  The Dynoman 61mm piston set is a forged piston set that is nicely finished with very little to no clean up needed.
HondaMan has written up some of his recommendations of the cheap overbore kits for the 750.  It is worth reading as these $120 sets are likely to need the same level of work as the 750 set.

David
David- back in the desert SW!

Offline Scott S

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Re: Anyone tried the $120 CB550 big bore kit yet?
« Reply #64 on: March 10, 2013, 06:49:53 PM »
 So....any updates?
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Offline Hasenkopf

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Re: Anyone tried the $120 CB550 big bore kit yet?
« Reply #65 on: March 26, 2013, 05:20:08 PM »
I got my cylinder back from APE.   They marked the pisons, and left them in the bore, but they are out of order......also, I now have to go and look for the rest of the parts that got lost....
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Offline Scott S

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Re: Anyone tried the $120 CB550 big bore kit yet?
« Reply #66 on: July 17, 2013, 06:35:01 PM »
 Still waiting to hear from anyone with a 550 that actually finished a build and used these kits.
'71 CB500 K0
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Offline Hasenkopf

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Re: Anyone tried the $120 CB550 big bore kit yet?
« Reply #67 on: July 17, 2013, 08:39:15 PM »
it's gonna be a while, can't find rings....
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Offline Scott S

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Re: Anyone tried the $120 CB550 big bore kit yet?
« Reply #68 on: July 18, 2013, 03:15:45 AM »
 Why do you need rings? I mean...I know what the purpose of the rings are. ;) But what's wrong with the ones you have?
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Offline alacrity

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Re: Anyone tried the $120 CB550 big bore kit yet?
« Reply #69 on: July 25, 2013, 12:43:22 PM »
On my 77cb550k project bike...
I got this 600cc kit from Japan.

I now have the machine work done: Cyl decked, sleeves bored and the pistons matched and fitted and checked for clearance by the machinist. GTG.

Am about to check ring end gaps in situ.

Will update as info becomes available.

Am also gonna run a cb650 cam.
I recently restored and sold a 77 cb750f, and am nearly finished with a (former basket case) cb750k5.  This is a place to share, learn and enjoy.  I am grateful to and for 99+% of this site's membership.

Offline Powderman

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Re: Anyone tried the $120 CB550 big bore kit yet?
« Reply #70 on: July 25, 2013, 02:41:32 PM »
Yeah I didn't realize that the machine shops charge by how big you are going. I was thinking a bore job is a bore job. Guess not!

Since this set is 61.5mm and stock is 58.5mm (CB550) this is 3mm over which falls into the overbore pricing. I failed to add this to my calculations.


It's not like the boring machine takes a big hog cut and then a final cut to spec. If it's a big bore the have to make many small passes until they get there. A .010-.020 rebuild bore is going to be cheaper than a big bore boring job.. For a big bore 466 on my 400 the shop wants $50 a hole, for a standard over bore it would be $40.

Offline RAFster122s

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Re: Anyone tried the $120 CB550 big bore kit yet?
« Reply #71 on: July 25, 2013, 04:16:32 PM »
Yeah I didn't realize that the machine shops charge by how big you are going. I was thinking a bore job is a bore job. Guess not!

Since this set is 61.5mm and stock is 58.5mm (CB550) this is 3mm over which falls into the overbore pricing. I failed to add this to my calculations.


It's not like the boring machine takes a big hog cut and then a final cut to spec. If it's a big bore the have to make many small passes until they get there. A .010-.020 rebuild bore is going to be cheaper than a big bore boring job.. For a big bore 466 on my 400 the shop wants $50 a hole, for a standard over bore it would be $40.

I have heard of people paying $400 for an overbore, so relative to that, $200 for the overbore isn't bad.  The standard overbore is $40 total?  That's pretty cheap.
According to HondaMan, the metal surround the cylinders allow them to drift initially and going one size up and align boring (to ensure the center of the 4 pistons are aligned in a straight line) can restore the power lost by this drift.
It is captured in the thoughts of HondaMan thread on the FAQ I believe.

There is a fellow on ebay that advertises something like $123-125 plus shipping for an overbore of up to 4mm if I recall correctly. Owns the machine shop mills and boring machines to do the work in the garage. Apparently there are lots of home machinists around who do it as a hobby. Finding them is the trick. 
Back when I was living in Columbus Ohio I found one and had him do some hobby work for me. Building me a starter cup for a homemade electric starter for my 0.049-0.051 airplanes and to machine a venturi to fit an old O.S. .35 motor I was converting to control line from RC. I drew up an engineering drawing for the first part and just supplied the replacement venturi for the 2nd along with the motor and he resized the venturi insert to fit.  His shop was very clean with epoxy painted floor and everything was sparkling clean.

Good luck with your motor rebuild.
David- back in the desert SW!

Offline alacrity

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Re: Anyone tried the $120 CB550 big bore kit yet?
« Reply #72 on: July 25, 2013, 11:54:14 PM »
Pistons are now on the rods.

There was one ring that had too small of an end gap.

There was one small machined burr on one of the ring landings that was binding the ring. Easily filed off.

There were a few score marks and dings on the piston skirts - but these could have come from my friendly machinist who matched the pistons to the bores and set em all for proper clearance.  It's likely there was a tiny bit of scrapy-scrapy as he did this. In fact - some of the scratches look like they could have been feeler gauge edges.  But they are below the rings, are basically cosmetic and so aren't relevant.

Also above Dave500 said the "plain one goes on top." Actually it's the chromed/treated/hardened one that goes on top (closest to the crown).  The plain one is in the second (middle) notch above the oil control rings.

I recently restored and sold a 77 cb750f, and am nearly finished with a (former basket case) cb750k5.  This is a place to share, learn and enjoy.  I am grateful to and for 99+% of this site's membership.

Offline classic bike tuner

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Re: Anyone tried the $120 CB550 big bore kit yet?
« Reply #73 on: July 26, 2013, 02:39:49 AM »
piston / cilinder clearance   0,025 - 0,035 mm

the bore size of this set is +3mm for a 550  thats 61,5mm
cilinder walls wil be after boring 2mm in the cilinder the part that sticks out of the cilinder
on the bottom even thinner walls
getting the piston / pistonrings in the cilinder wil be difficult

butt its a good set of pistons

gerrit

Offline SF

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Re: Anyone tried the $120 CB550 big bore kit yet?
« Reply #74 on: July 26, 2013, 09:19:25 AM »
i am very interested in the results of dynoman's pistons in fjj bike. i have 3 550 motors that i want to build mild to wild.
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