Matt21
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| posted on 16/2/15 at 04:59 PM |
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CBR900 troubles - big ends
Long story short, I need a new crank, con rod and big end bearings for a CBR900 engine
now.... the engine I am running is a 1999 engine, from the engine code it appears to be a US model?! (more on that below)
I have a spare engine, a UK spec 1996 engine with a perfect crank in it.
My question is, can I use the crank and number two piston/conrod from the '96 engine and put it in the '99 engine and replace all the big
end bearings for new ones (with the appropriate colour coding matched up with the numbers etc)
Now as for the engine codes, can someone else just clarify for me...
My '96 engine code is SC33E-20029**
And the '99 engine code is SC33E-23129**
Here is the table of engine codes taken from the Haynes manual
 
CBR900 engine codes haynes
can someone clarify that my engine is a US spec?
And what difference is there to UK engines?
Thanks 
[Edited on 16/2/15 by Matt21]
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woodstock
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| posted on 16/2/15 at 05:36 PM |
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I have the same haynes manual as you. As you say it looks like you have a 96 UK spec and a 99 US.
In terms of swapping parts, I have found this site really useful: Lings
Honda
You may already know about them but effectively you can get exploded views of all the parts along with part numbers so if the same part number exists
on both engines it'll be the same part. Not being the same part number doesn't always mean that it won't fit or work but
you'll need someone far more experienced than me to help you there.
[Edited on 16/2/15 by woodstock]
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Matt21
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| posted on 16/2/15 at 06:03 PM |
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Oh thats a good site!
crankshaft part numbers are the same, though i'm kind of guessing at the chassis numbers!
pistons have the same number
con rod assembly has the same number
but the piston rings have a different number, so i guess I'm best off just swapping them over from the old piston
everything else looks good!! 
Have you even purchased stuff from there?
I need to find somewhere to buy the big end bearings from
On there is says £10.49, is that for a complete bearing do you know or for one halfshell?
Thanks for your help!
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ReMan
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| posted on 16/2/15 at 07:12 PM |
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Why don't you re-use all the bearings and the piston/rings if the replacements are good.
Or even bring all 4 rods and bearings with it
www.plusnine.co.uk
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Matt21
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| posted on 16/2/15 at 07:49 PM |
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That's not a bad idea.
I'd just swap the piston rings over just in case there is a difference with them.
I just thought while it was all in bits I'd be best off just putting new bearings in. But it would be £100 cheaper to reuse the others....
Thanks ReMan
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Nickp
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| posted on 17/2/15 at 06:41 AM |
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Is there something wrong with your spare engine, or don't you know? As you've not mentioned it.
So can't you just use that? Or at least the bottom end? Keeping good used components together is always going to be better than mixing and
matching 2 engines.
Also, I wouldn't be swapping rings between the pistons. I fail to see how rings can be physically different (apart from the material, or minor
revisions maybe to oil control rings?) if they're to fit the same pistons. I'd leave the rings on the pistons they came with if
you're not fitting new ones.
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Matt21
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| posted on 17/2/15 at 03:07 PM |
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as for the old engine, its a 1996 so i dont get the speedo hole in the casing.
theres an issue with the gears too
and it was already in bits too
I'd rather get the newer crank case built up then do the other at my leisure for a spare.
I'm just piecing it all together now and left the rings on the pistons, just had to swap a few main bearings around so that it suited the crank
and block machining
managed to bloody crack the clutch basket too so trying to source a new one. the 96 one takes 2 more plates in than the 99 so i cant even reuse that
doesnt seem to be any on ebay either
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Andy B
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| posted on 17/2/15 at 04:11 PM |
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Rings will definitely need to change as up to 1997 the motors had steel liners at 1998/1999 they went with Nikasil. Personally and this is only my
opinion the 1996/1997 were the best of the bunch and whenever we selected an engine for racing we tried to pick one of them - the good news is all
parts - clutch and gearbox wise transfer straight across so long as you transfer it all as a set. Its odd that the pistons are showing the same part
numbers now as they used to be different as well. The skirts on the pistons for the plated liners had a special teflon type coating - a lot of the
older blade stuff is now listed as obsolete and an awful lot of available parts numbers "pencilled in" to cover gaps in stock - one
noticeable example is the old oil filter is now superceded by the one used for the later 929 or 954 - whilst it fits as Honda say I have definitely
noticed higher oil temps and slightly elevated pressures when using it which I put down to the smaller oil holes in the later filter. I have since
been using an aftermarket unit
Hope that helps
Andy
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Matt21
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| posted on 17/2/15 at 05:44 PM |
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Thanks for that Andy
I'll get the pistons out and swap the rings over tomorrow then! glad you cropped up now rather than tomorrow when it was all back together!
as for the gearbox parts, I'll just be buying a new '99 clutch basket as I was having issues with the '96 gears, and i dont want to
just swap the older basket to the newer gears.
I've just ordered an oil pressure gauge too, any idea what pressure it should be running at? hopefully it will help prevent any future
problems!
I'll drop you a message now Andy as I have a couple of quick questions if you wouldnt mind answering
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