Newbie question about the cranckshaft bearings
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Newbie question about the cranckshaft bearings
Hi,
Please dont beat me hard but i have this novice question. What size bearings do i need? I got an engine for free (GL1100 1980) and i am thinking about rebuilding it- well not actually me but ill take it to mechanics- IF i can find all the parts needed. I have been told that most of them are hard to find.
Due to my langue skills i am having a hard time understanding the procedure how to determine the correct bearing sizes. I made a sketch (with my left hand being drunk and hanging upside down ) where you can see all the marks i found. So can you help me ?
Please dont beat me hard but i have this novice question. What size bearings do i need? I got an engine for free (GL1100 1980) and i am thinking about rebuilding it- well not actually me but ill take it to mechanics- IF i can find all the parts needed. I have been told that most of them are hard to find.
Due to my langue skills i am having a hard time understanding the procedure how to determine the correct bearing sizes. I made a sketch (with my left hand being drunk and hanging upside down ) where you can see all the marks i found. So can you help me ?
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Re: Newbie question about the cranckshaft bearings
Not a dumb question at all, but too hard for me.
I know the bearings are hard to find, Old Fogey on this site sometimes has brown ones.
Soon someone smarter will answer.
Gord
I know the bearings are hard to find, Old Fogey on this site sometimes has brown ones.
Soon someone smarter will answer.
Gord
"I'd rather Ride than Shine"
‘14 KLR650 ... not a rat ... yet
‘84 GL1200i ‘R2B6' (Rat to Be 6, the last, adopted by twowings)
My Original 'RAT' was a hybrid '82 CB900/1100F
‘14 KLR650 ... not a rat ... yet
‘84 GL1200i ‘R2B6' (Rat to Be 6, the last, adopted by twowings)
My Original 'RAT' was a hybrid '82 CB900/1100F
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Re: Newbie question about the cranckshaft bearings
There will be two sizes for the main bearings and the big end bearings , so it needs to be measured with a micrometer, the manual should have the tolerance , the first undersize is .25mm , take it to a machine shop if you want to know what clearance you've got with the old bearings , clean it all up and install the shells and torque to spec , a machinist will use a dial bore gauge and can directly measure the main clearance and the 4 conrods , he'll need the crank as well .
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Re: Newbie question about the cranckshaft bearings
Most of us find a free engine as a "parts engine" and not suitable for rebuild. Getting a good once running GL1000, 1100 or 1200 engine is available for $200 and that is way less than a full rebuild. It will most likely need new belts and the carborators rebuilt. But certainly more cost effective than a full ground up rebuild.
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You should remember that it's peace of mind you're after and not just fixing the machine. R.Pirsig
1977 GL1000 BADDOG (April 2012 BOTM)
1976 LTD - '993 LTD...and so it begins'
You should remember that it's peace of mind you're after and not just fixing the machine. R.Pirsig
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Re: Newbie question about the cranckshaft bearings
The OP is in Estonia … might be tougher there …
Gord
Gord
"I'd rather Ride than Shine"
‘14 KLR650 ... not a rat ... yet
‘84 GL1200i ‘R2B6' (Rat to Be 6, the last, adopted by twowings)
My Original 'RAT' was a hybrid '82 CB900/1100F
‘14 KLR650 ... not a rat ... yet
‘84 GL1200i ‘R2B6' (Rat to Be 6, the last, adopted by twowings)
My Original 'RAT' was a hybrid '82 CB900/1100F
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Re: Newbie question about the cranckshaft bearings
Good point. Yes, likely no inexpensive engines in Estonia.
Proud member of the NGW Cartel (Rochester MI)
1977 GL1000 BADDOG (April 2012 BOTM)
1976 LTD - '993 LTD...and so it begins'
You should remember that it's peace of mind you're after and not just fixing the machine. R.Pirsig
1977 GL1000 BADDOG (April 2012 BOTM)
1976 LTD - '993 LTD...and so it begins'
You should remember that it's peace of mind you're after and not just fixing the machine. R.Pirsig
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Re: Newbie question about the cranckshaft bearings
Yes sir, there is basically zero available here... or i havent found them. And i like the idea of a " brand new engine" and i want to educate myself a little. The mechanic im working with is very talented (race bikes) and skilled so i know if i can source the parts the work will be done on high level.
The engine i got was already disassembeld.... i can do ebay but it is a gamble and minimum 500eur shipped for en engine i cant even be sure it turns over.
And this is just an idea... if its not realistc on paper i will not do it.
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Re: Newbie question about the cranckshaft bearings
If everything is still there, have your mechanic measure it all to see if any new parts are required. If the engine has been maintained at all, there will be no need for new parts on the crankshaft or main bearings. The rings will probably be fine, also. The heads may need the seats lightly faced and new valves are available as well as valve stem seals. New head gaskets applied to straight head and block surfaces, properly torqued, a new water pump, and you should be good for a long time.
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Ex 2006 GL1800 - the Black Pearl SOLD! to make room for:
2021 Can-Am Spyder RT Limited Dark Chalk Metallic
1975 Red GL1000 project - ex Pistol Pete project
1972 Triumph T150V Trident rescue - finished and FOR SALE!
1976 Yamaha RD400c
1978 GL1000 with '75 engine - the Hunley
Ex 1978 GL1000
Ex 1979 GL1000
Ex '79 CB750F rat bike
Ex '86 SEi
Ex '77 GL1000
Ex '76 RD400
Ex '72 Penton 125 set up for flat track
Ex '73 RD250
Ex '68 TR6C - chopped
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Re: Newbie question about the cranckshaft bearings
Can't offer any more advice then has been already but welcome to the site. You will fit right in here.
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Re: Newbie question about the cranckshaft bearings
No plain-bearing Honda I ever saw had undersize bearing shells available--if the crank is worn, you throw it away. Unless possibly you have a very knowledgeable machinist, who could turn it and source shells from another engine of some kind. Which I don't believe is very common. I'm not certain the bearing surface is not hardened either, which would possibly be removed with turning.
Honda designed these engines so that the clearance was exceedingly precise, which is why there are several different bearing shells, all identified by color. These were select-fit for each engine, based on measurements taken at initial assembly, and they only vary by about eight 10-thousandths of an inch (two hundredths of a millimeter) across the entire five replacement shells. They thoughtfully provided a code for each measurement so the proper parts could be ascertained if it ever needed new bearings. But the replacement bearing shells for these are nearly gone, so the codes are not so helpful. And when you come right down to it, there's not a lot of difference between one size and the next.
Honda designed these engines so that the clearance was exceedingly precise, which is why there are several different bearing shells, all identified by color. These were select-fit for each engine, based on measurements taken at initial assembly, and they only vary by about eight 10-thousandths of an inch (two hundredths of a millimeter) across the entire five replacement shells. They thoughtfully provided a code for each measurement so the proper parts could be ascertained if it ever needed new bearings. But the replacement bearing shells for these are nearly gone, so the codes are not so helpful. And when you come right down to it, there's not a lot of difference between one size and the next.
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Re: Newbie question about the cranckshaft bearings
My understanding is that the cranks CAN NOT be turned. And difference between the sizes IS very small. But they are different. Honda wanted it that way ro help build a near perfect engine. I have 500 thousand plus miles on my 78, and credit the way the factory did their work for that. I would rather have a good used engine, then one re-built to a lesser standard
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1977 custom with 1200 engine
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Re: Newbie question about the cranckshaft bearings
Sorry, but most of that is incorrect. Honda used a kind of 'blueprinting' technique, with FIVE different sized colour coded shells for both crankshaft mains and conrods. Also the rods use different shells in the caps and rodsBloodhound wrote: ↑Mon Jan 16, 2023 1:56 pm There will be two sizes for the main bearings and the big end bearings , so it needs to be measured with a micrometer, the manual should have the tolerance , the first undersize is .25mm , take it to a machine shop if you want to know what clearance you've got with the old bearings , clean it all up and install the shells and torque to spec , a machinist will use a dial bore gauge and can directly measure the main clearance and the 4 conrods , he'll need the crank as well .
There are no '0.25 undersize' shells as the crankshaft is not supposed to be ground.
All the four cylinder Wings now have major problems in this respect, as the vast majority of the OEM shells are extinct.
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Re: Newbie question about the cranckshaft bearings
Has anyone ever approached a bearing company like clevite about producing them?
1982 1100 standard. (sold)
1986 Yamaha FJ1200
2000 Yamaha Roadstar
1976 GoldWing. running but not on the road
1978 Goldwing. future cafe project.
2019 Can-Am ryker (boss's new ride)
2002 Shadow American Classic(sold)
1983 Shadow 500. (sold)
1986 Yamaha FJ1200
2000 Yamaha Roadstar
1976 GoldWing. running but not on the road
1978 Goldwing. future cafe project.
2019 Can-Am ryker (boss's new ride)
2002 Shadow American Classic(sold)
1983 Shadow 500. (sold)
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Re: Newbie question about the cranckshaft bearings
Not that I am aware of. I know I have read some folks using Bearings meant for other applications.
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"The book is wrong, this whole Conclusion is Fallacious" River Tam
2008 GL1800 IIIA "TH3DOG"
1975/6/7/8/9 Arthur Fulmer Dressed Road bike
1975 Naked Noisy and Nasty in town bike
and a whole garage full of possibilities!!
Psst. oh and by the way CHANGE YOUR BELTS!!!!
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