CB360's-from build to blog - 2013, MDS (Mo Dumb Shit)

crazypj

Split personality, I fake being smart
Re: CB360 Hear No Evil & Speak No Evil- New pics -sorta finished one


Guzzi brake pedal is about 20mm wide
Parts unlimited, probably, but, most shops just order the parts and give them to you, particularly when it's a pair of tyres tied together
 

Swagger

Putting boot to ass since 1967!
Re: CB360 Hear No Evil & Speak No Evil- New pics -sorta finished one

Hey nifty bits there PJ, hope the claw is coming along well.
 

crazypj

Split personality, I fake being smart
Re: CB360 Hear No Evil & Speak No Evil- New pics -sorta finished one

Hi swagger, still mostly numb but occupational therapy, ultra sound and massage are helping with scarring.
Things are loosening up a bit still really weak though :'(
Started putting the third CB378 motor together.
This one is probably going to end up more 'trackerish'
Haven't cleaned and painted head yet, going to clean up ports , valve job, and oil system mod.
Not sure if I'll make a right side high level pipe set, same/similar to 390 I have in Britain?
Here's pic of cylinder fitted and one of left piston.
Block has been skimmed, I forget how much though ::)
Will get piston to TDC tomorrow and measure where crown is then see if head needs skimming (or not ;D )
Managed to loose copper head gasket, I've put it too safe this time

Yes, that is a bit of 'dirt' at 11:00 o'clock position, picture shows stuff that's easy to miss.
I'll clean it out before head is fitted



I'm going to modify sprocket cover, same/similar to 'cafe' one
Probably going to paint outer covers and head/rockerbox metallic light blue, if I can find it in high temp paint (Pontiac colour?)
Clutch and clutch covers are going to be modified on all motors, plus gun drilled cam /external oil lines
 

KrashManhatten

New Member
Re: CB360's - Speak No Evil, See No Evil, Hear No Evil (and eventually, just EVIL)


Also i do realize that riding a small bike WOT is more fun then a big bike but man you put a lot of heart in the little bikes.


hows the external oiliers working?

crazypj said:
Ah, but they are stock bodies with some strategic holes and modified 'brass'.
Needles and slides are completely stock, I tried opening up lift holes and didn't like results, although they would probably work on a 360 motor. I'm going to drill them out further and tap for different size air plugs
Float level is 1mm higher than stock.
The real point is, you don't need to spend $300.00+ on VM 30/32 when you can make stock carbs work. I fitted a set without replaceable air jets, now I know it works, I'll modify anyone's CB360 stock carbs, even those with pressed in jets (for a fee ;) )



I do have to agree with the BS call with ROCAN--



There is some serious work done to the whole machine.

how is the VIB on that thing?
 

crazypj

Split personality, I fake being smart
Re: CB360's - Speak No Evil, See No Evil, Hear No Evil (and eventually, just EVIL)

It's only half the work of an inline 4 ;D
I've done serious modifications on GS550, around 170~175 mph top end, just costs a LOT
CB550, less mods, around 130mph (with panniers/saddlebags :eek: )
GS1000 easy to take them out to 1100~1425cc, 180mph.
It's cheaper and more 'fun' for my to take the Honda 'bastard child' and make something of it (only worse bike in my opinion is the Honda V-4 750)
Basically I treat the CB360 same as a Triumph 500 (it's about the same size, weight, reliability, except I know how to make them more reliable 8) )
They both have a pretty short lifespan if revved too high ???
When I've finished this 'set' of 360's I'll get back to the Yamaha 650's (with various big bore kits and modifications ;) )
Forgot to answer VIB?
if you mean Vibe, it's not much different to stock, GS pistons are lighter than the Honda stock size so you can hold it at higher rpm.
 

Swagger

Putting boot to ass since 1967!
Re: CB360's - Speak No Evil, See No Evil, Hear No Evil (and eventually, just EVIL)

Hey PJ, since we're talking about pistons....
what's your though on shorter piston-skirts? In comparison to the new stuff, the older pistons are really long. The slugs I got for the car really don't have ANY skirt below the wrist-pin to speak of. Thoughts?

Good to hear there's some progress on the arm as well, man what a long road that "modification" turned into!?
 

crazypj

Split personality, I fake being smart
Re: CB360's - Speak No Evil, See No Evil, Hear No Evil (and eventually, just EVIL)

Short skirt pistons can have ring sealing problems when cold and do tend to wear out quicker as they can/do rock in the bore.
If you have forged pistons they need more clearance so have more problems when cold.
They can be a lot lighter though and will allow more rpm and usually faster pickup.
Latest MX bikes with just enough piston to hold rings have a very short design life, 30hrs or less if you use all the rpm available.
I've found new rings around 8~10,00 miles on a street motor is a good idea as long as skirts are not too short (3~4 times land width)
The long old style pistons are really stable in bore and will do very high mileage without wearing things out as long as rpm is kept reasonable (100,000mile plus on CB500,550,750 etc)
 

Swagger

Putting boot to ass since 1967!
Re: CB360's - Speak No Evil, See No Evil, Hear No Evil (and eventually, just EVIL)

It's been something I've been thinking on for a while. I do wonder about wear though, especially with more modern metallurgy. The pistons in my toy-car for instance have a very short skirt to ring-land as I remember they're almost 1-1 and they're not forged. The OE pistons they replaced were quite as short but still short and went 140k miles I think. Didn't really need replacing, I just wanted to use these slippers.
I wonder about modern manufactured pistons in old bike specs, mainly with reference to running lighter short skirt style lumps? The next set of pistons for the car have almost no skirt at all on the 'back side'...those are crazy looking!
I'm beginning to thing that the short pistons aren't really suitable to air cooled engines given the inherently higher piston to bore tolerances. Hmm...piston squirters.....
 

crazypj

Split personality, I fake being smart
Re: CB360's - Speak No Evil, See No Evil, Hear No Evil (and eventually, just EVIL)

Hi Swagger,
I don't want to get too deep into engine design, but, if you measure rod length to stroke you'll usually find extra short pistons use a relatively long rod ratio (usually 1.7~1.9:1)
There are reasons for using different rod ratio's but for majority of people it isn't an option
 

Swagger

Putting boot to ass since 1967!
Re: CB360's - Speak No Evil, See No Evil, Hear No Evil (and eventually, just EVIL)

Well it stands to reason since as a rule short skirt pistons tend to have shorter ringland to wrist pin distance. I know that longer rods tend to yield 'lower' terminal speeds for the piston at the extremes of the stroke. Should in turn lead to a more durable and hopefully less vibratory engine. Everything I've read tends to imply that there are also power gains to be had due to slightly longer period/arc ratios (more time with the combustion pushing the piston down) as well as longer valve duration support which should allow for better evacuation.
 

crazypj

Split personality, I fake being smart
Re: CB360's - Speak No Evil, See No Evil, Hear No Evil (and eventually, just EVIL)

I made some adapters for the cheap Chinese knock off K&N filters, alloy tube epoxied into modified end cap.
Going to find some radiator hose or similar to clamp them onto carb (they are also machined to fit on as far as 'rib' on intake.
I tried making them to slip over the rib but it didn't work so I had to start over.
Going to strip paint off frame in next few days, sandblast the rust off and get it looking 'pretty'
No pics at present

Swagger, I know quite a lot about 'long rod specials' ;D
I 'invented' the XS800 based on 14mm longer rod (from Honda CR500)
There's a long posting at XS650 Garage (18 pages)
http://xs650temp.proboards.com/index.cgi?board=EngineModified&action=display&thread=78
 

crazypj

Split personality, I fake being smart
Re: CB360's - Speak No Evil, See No Evil, Hear No Evil (and eventually, just EVIL)

Started on the boring stuff ::)
Spent most of yesterday cleaning paint off swing arm and frame.
Swing arm is pretty nasty, lot of rust, not sure if it's useable (even though it has been 'quite fast' when bike was assembled ;D )

It's so hot at present paint stripper isn't working, the 'nasty stuff' evaporates before it does anything so I had to use flap wheel type thing.
It's dirty sweaty work.
Anyone fot any idea's (except paying $200.00 for sand blast/powder coat, I can't afford that at present)
 

frogman

'74 CB360, '71 CB450, '75 CB550SS
Re: CB360's - Speak No Evil, See No Evil, Hear No Evil (and eventually, just EVIL)

I used an angle grinder and a wire brush or two on mine, was rather surprised at how fast the paint came off. I think I did the whole frame in an hour and half. Then I just rustoleum rattle canned it with their rust inhibitor primer and painted it charcoal grey metallic.

My swing arm was pretty bad too, looked like it had a battery explode all over it. Was mainly just surface rust, cleaned right up.
 

IanOberholtzer

green behind the ears
Re: CB360's - Speak No Evil, See No Evil, Hear No Evil (and eventually, just EVIL)

i second the angle grinder wire brush ( brass ) technique, takes it off pretty quick.. but.. BE CAREFUL, remember i showed you the big gash on my stomach from where it grabbed on my shirt, lucky it didn't do more than scuff me up a bit.
 

frogman

'74 CB360, '71 CB450, '75 CB550SS
Re: CB360's - Speak No Evil, See No Evil, Hear No Evil (and eventually, just EVIL)

Yeah mine started throwing pieces of wire out of if it after a bit so I swapped it out. Suckers hurt like hell when they hit you.
 

hillsy

Active Member
Re: CB360's - Speak No Evil, See No Evil, Hear No Evil (and eventually, just EVIL)

Wire cup brush on the angle grinder is my preferred weapon of choice - you need to get this type:



The brass ones are too weak / soft for stripping rust and paint off frames (they wear out in no time :( )



I generally use mine for cleaning up welds when I'm using my flux core, so I pretty much always wear welding gloves and my welding helmet while I'm using the wire brush grinder - they can be pretty nasty if things go wrong :eek:
 

JustinLonghorn

No Purple Hearts, No Blue Ribbons
Re: CB360's - Speak No Evil, See No Evil, Hear No Evil (and eventually, just EVIL)

I used a 3M Blue Scrubby on my angle grinder. It looks like this.



Made stripping my chop frame real easy.

From this:



To this:

 

Big R

Heaven is so far away.
Re: CB360's - Speak No Evil, See No Evil, Hear No Evil (and eventually, just EVIL)

PJ, I use a gravity fed sand blaster called the "Speed Blaster" or something like that. It was about $40 when I got it and just hooks up to a normal air line. Matter of fact, I think T71ford and Ringo use the same thing with good results.

While I don't really like to ship tools, I would make an exception in this case.
 

Kanticoy

Mad Science!
DTT BOTM WINNER
Re: CB360's - Speak No Evil, See No Evil, Hear No Evil (and eventually, just EVIL)

I use the gravity fed blaster too. It's made by black bull and I bought it from tractor supply. Holds 25 gallons of sand. I then run the compressor through a dessicant drier since the humidity is 1000% in Alabama and likes to turn sand into patties when its wet. Works great and uses the $2 play sand from Lowes.
 

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