I will check with bearing supplier for some 4x10 roller pins. The journals on all three look good, and measured same. If my rollers measure .00045" smaller than metric nominal, then new nominal ones should reduce my running clearance to approx. .0009", rather than .0018".
How available do you think Suz 750 rods are? What about thickness?
As for the Dream engine just acquired, it has a S/N of 10098xx - haven't opened yet to see rods. If earlier ones were thicker on small end, what disadvantage - balancing? Advantage may be to allow for a thicker-walled bushing. Speaking of bushings, what kind of clearance did you end up with? If I do bush, I want to finish the final size by honing. On my Chevy engine, the mfr recommended .00015 - .00025" clearance - I'll look in the Honda manual to see what they show.
Two of my three cranks have slotted small ends, and one of those had the 75mm ball bearing.
BTW, when you pressed the outer crank onto the rod pins, what is used to gage or stop the crank from pressing dead against the rods? Are the rod pins shouldered?
left hand crankshaft bearing
Dick
Lots of questions which I don't have time to answer just now...:-) As for pressing the webs back on the big-end you actually press on to achieve a rod clearance (it's in the book). Some people leave this clearance large to increase the oil flow but that misses two issues. 1. the oil flow is limited by the ports in the main bearings that feed oil to the crank. 2 the bigger you make the rod side clearance the more oil is robbed from those small end feeding slots. Th heavier the press you use the easier it is to control that final pushes the stiffer press absorbs less elastic energy in bending. Unlike dismantling which can be quite explosive, you are pushing against an ever-increasing friction force so it is quire easy to nudge those last few thousandths. You can make your own choices.... My small end clearance was similar to a NOS pin and rod that I had to hand. Cannot remember the actual numbers. G
'60 C77 '60 C72 '62 C72 Dream '63 CL72
'61 CB72 '64 CB77 '65 CB160 '66 Matchless 350 '67 CL77 '67 S90 '77 CB400F
Thanks, Graham.
Sometimes work really gets in the way of important stuff, like motorcycle riding, repair, restoration - the three R's! I like your idea of taking a cut across the crank OD - I will do that on all cranks before disassembly - I've always scribed a line on these just for a basic reference. One of my cranks had a damaged center [30 degree], probably from a bearing puller in the past - I like to keep these intact/undamaged, in case I ever need to put them between centers; I just recut this one - I can then use my live center in the end to cut the OD's.
Here's a tool I designed/built for static balancing wheels, checking straightness of forks/axles, and for checking run out of cranks, etc. I made it adjustable for a variety of projects - may see the little 305 crank on it:
Thanks - I guess we can be called 'toolmakers' - sure helps with the right tools. I got the 20T press, now need to pick up some steel to properly support the crank, and make an alignment fixture. Graham, have you ever checked your cam timing, relative to the crank sprocket? Just curious as to how your 11.25 degree fixture tool worked for cam sprocket location. Pulled the crank pin plugs - the crud totally filled the flutes of my 8mm drill - this was the bike with 19K on it. The photo depicts only one side.
Dick
Not actually done a precision check on the timing but the aim is to keep the tooth on the crank sprocket at 12 o'clock. It can only be 1/2 tooth out if you did it by eye but I am a lot closer than that. I mark that 'top' tooth with a centre punch as you will notice that the 'splines' on the center shaft count around 74 rather than 72 which would make it easy to re-align at any interval. Yes - the crud in the big end oilways is always a bit of a surprise. The feed holes in the pin are cleverly placed so that you can collect a lot of muck before it gets out into the big end but imagine if you have a crank where that stuff has been drying out for years and then you shoot hot fresh oil in there..... The 'slingers' on the inner crank web which feed oil from the main bearings to th ebig end will be equally caked up. That stuff is so hard that it looks like there is nothing in there until you poke a sharp tool at it. Again if the crank has been on a shelf for years it could be flaking off... Make sure that you clean the jets in the center main bearing outers also. Many people think these bearings are splash fed but they oil pumped into the mains which then feeds the big ends and the small ends via the slots in the con-rods.  It's a clever design first used by Bugatti in the 1920s...... G
'60 C77 '60 C72 '62 C72 Dream '63 CL72
'61 CB72 '64 CB77 '65 CB160 '66 Matchless 350 '67 CL77 '67 S90 '77 CB400F
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