Honda-SOHC

SOHC.co.uk Forums => CB750 => Topic started by: AshimotoK0 on August 05, 2014, 01:07:21 PM

Title: CB750 bearing shells
Post by: AshimotoK0 on August 05, 2014, 01:07:21 PM
Anyone know the going rate for NOS in bag Genuine Honda crankshaft bearing shells ( mains and big end)? I am pretty sure also that CBX1000 parts are the same. Can anyone confirm this and reasonable price to pay because I have been offered some for my 750 (not..eBay thank God)

Cheers ... AshD
Title: Re: CB750 bearing shells
Post by: Trigger on August 05, 2014, 06:58:53 PM
Ash , a tenner a shell.
Title: Re: CB750 bearing shells
Post by: Bitsa (Ralph Wright - RIP) on August 05, 2014, 08:33:01 PM
Shit a big ouch now.Glad I kept my old ones only changed em because it was apart
Cheers
Bitsa
Title: Re: CB750 bearing shells
Post by: AshimotoK0 on August 06, 2014, 06:57:58 AM
Ash , a tenner a shell.

I mean't what do I offer for NOS not new, the guy has 36 but a small amount  are not in the bags so only any good really for 'blueprinting'

To be honest I am going to Plastigage the big ends of the crank Bryan kindly sold me yonks ago and if the shells  look nice,  they are going back in.  The shells for sale do include a set of mains, which would be OK for my crank and crankcase letter combination but obviously after I mic the crank that may not be the case. I am going to mic the spare crank I have too, that way when I sell it on,  the buyer will know what they are  in for. Why can't more people on eBay do that too? In all my years of eBay trading I have never seen it done.

What do I offer each for the NOS shells, I don't want to lose out on them?

Cheers ... AshD
Title: Re: CB750 bearing shells
Post by: Trigger on August 06, 2014, 07:45:37 AM
Ash, you are confusing me on what you think NOS means. NOS, stands for New Old Stock. So, Nos is new or are you on about secondhand shells? Secondhand sells are worth nothing or whatever someone is willing to pay.
Title: Re: CB750 bearing shells
Post by: AshimotoK0 on August 06, 2014, 07:57:38 AM
Ash, you are confusing me on what you think NOS means. NOS, stands for New Old Stock. So, Nos is new or are you on about secondhand shells? Secondhand sells are worth nothing or whatever someone is willing to pay.

NOS to me is New Old Stock  as opposed to new bought from Honda for resale. i.e my 750K0 exhaust was new because DSS bought it from Honda and then shortly afterwards sold it to me. The gear lever they sold me was 'NOS' because it came from an ex-dealers inventory of stock bought in the 80's.

The shells I am looking at are not used they are NOS mostly in the Honda bags, I wouldn't dream of using secondhand shells (other than the unworn ones fitted to the original crank). There are a couple not in the bags but I have seen them and they look new.

Cheers ...AshD
Title: Re: CB750 bearing shells
Post by: Trigger on August 06, 2014, 08:38:00 AM
OK Ash, we are a little clearer now. I would offer 3 to 5 each but, it is down to what he is willing to sell them for.
Where did you find those small screws and nuts? They fitted a treat to the button on the switch gear. Cheers for those Ash.

Title: Re: CB750 bearing shells
Post by: AshimotoK0 on August 06, 2014, 08:51:24 AM
Quote from: trigger6969 on Today at 08:36:30 am

OK Ash, we are a little clearer now. I would offer 3 to 5 each but, it is down to what he is willing to sell them for.
Where did you find those small screws and nuts? They fitted a treat to the button on the switch gear. Cheers for those Ash.

I think he is looking at 5.50 GBP  each  for the bagged ones and 3 GBP for the non bagged ones but I need to be quick as someone else is sniffing round them.

Screws ... I make a focusing mechanism for an add on to a scanning electron microscope for a company near Cambridge. It has M1.4, M1.6 and M2 screw on it. If you need any more M2 screws / nuts  just shout  you can have them for free!!

If you want to buy a large quantity here is the RS Components P/N 528-693 (screws)  248-4551 Full Nuts  they are both A2 grade SS The nuts fit the 400/4 and others switch push button . The screws the same but also fit the 250/400/4 trip meter knob (not the 250K0 though 'cos it doesn't have a trip meter!)

The smaller than M2 screws we get from these people
http://www.microfastenings.com/Home.aspx


Cheers ...Ash
Title: Re: CB750 bearing shells
Post by: Trigger on August 06, 2014, 08:56:35 AM
Ash, grab them before someone else does.
Title: Re: CB750 bearing shells
Post by: AshimotoK0 on August 06, 2014, 09:54:44 AM
Ash, grab them before someone else does.

I will do and after I have measured my crank/looked at my big ends  ::) I will offer any spares I have on here for what I pay for them plus post. This will be my one and only 750 restoration so I won't need any spares.

Cheers ... Ash
Title: Re: CB750 bearing shells
Post by: UK Pete on August 06, 2014, 10:38:01 AM
Ash I an af :-[ter the tiny screw and nut which hold my f2 horn button on they are the smallest I have ever seen ,do you thiink what you have will do the job
Pete
Title: Re: CB750 bearing shells
Post by: AshimotoK0 on August 06, 2014, 10:50:48 AM
Same one I think Pete I will post you a couple.

Posted !!!!!!!!!!!

Cheers ... Ash
Title: Re: CB750 bearing shells
Post by: UK Pete on August 06, 2014, 01:19:19 PM
Top man ash, thanks
Pete
Title: Re: CB750 bearing shells
Post by: Bryanj on August 06, 2014, 05:20:02 PM
Ash forget about measuring mate, sorry to say no matter how good the Mic and operater you can't get the accuracy of Honda with air gauges. best way is simply plastigauge BUT make sure you know what part number/colour the shell is if you dont use it
Title: Re: CB750 bearing shells
Post by: Trigger on August 06, 2014, 08:35:31 PM
Always and i mean always use Plastigauge. OK, confession time ;D If i can not get green shells,( no longer available) i will grind the crank to fit black. This is common practice in engine building. So never go by A2,B2 and so on
Title: Re: CB750 bearing shells
Post by: Trigger on August 06, 2014, 08:42:00 PM
Pete, the screw and nuts that Ash has will fit. Once you have put the screw in, wipe the head with a little silicone sealant. That will stop it from falling out ;) Triggers top tip for today.
Title: Re: CB750 bearing shells
Post by: Bitsa (Ralph Wright - RIP) on August 06, 2014, 08:42:22 PM
Fuc ing wow to grinding crank spoke to a honda racing mechanic quite recently and he said put the biggest you can get and run it in real smooth
He said never had a problem.You sure Trig.
Always open to ideas mate
Cheers
Bitsa
Title: Re: CB750 bearing shells
Post by: Trigger on August 06, 2014, 08:49:12 PM
Mains no problem with black as long as you use a running in compound . Con rod shells can be a little difficult.
Title: Re: CB750 bearing shells
Post by: Bitsa (Ralph Wright - RIP) on August 06, 2014, 08:53:00 PM
With you so far makes sense but I know in the old days all engineering companys shit themselves with jap stuff has it progressed that good these days?
Cheers
Bitsa
Title: Re: CB750 bearing shells
Post by: Trigger on August 06, 2014, 08:57:32 PM
English engineering was shit. That is why the Japs are on top now.
I have only ever done Jap engineering. Do not do any other, i leave the english bikes well alone.
Title: Re: CB750 bearing shells
Post by: Bitsa (Ralph Wright - RIP) on August 06, 2014, 09:00:10 PM
Fair comment always thought that even in the 70s thats why I did not like brit bikes
Cheers
Bitsa
Title: Re: CB750 bearing shells
Post by: steff750 on August 06, 2014, 11:05:00 PM
 ;) ah the dark art of replacing shells ,
yes I've done my own for years , after my local shop guru failed miserably when I slapped a crank and engine cases on his counter,i never saw a bloke back pedal so fast , that was thirty years ago and he still thinks hes mister know it all,
   on the subject of Britt engineering,
 i also own a 1960 BSA a10 650 and its like riding a chariot in comparison ,apart from tightening nuts and bolts I would not like to delve to far into any Britt bike engine , while jap bikes are assembled by workers and not by engineers
I once rebuilt a CB750 engine in front of a guy who raced rocket threes and tridents he was amazed that I just torqued everything down, he said you would never get away with that with a Brit engine you would have to mic everything :o
Title: Re: CB750 bearing shells
Post by: Bryanj on August 07, 2014, 06:26:43 AM
There is not enough difference on the sizes to make grinding work. I know that you can grind a glodwing crank and use some car shells but can't remember which
Title: Re: CB750 bearing shells
Post by: Trigger on August 07, 2014, 08:20:38 AM
Bryan, i do not mean re-grind the crank. It is more of a polish on a crank grinding machine. If the black shell is showing up a little tight with the plastigauge. There are many car shells that can be used but, never found anything for any of the SOHC cranks.
Title: Re: CB750 bearing shells
Post by: AshimotoK0 on August 07, 2014, 10:36:52 AM
We do have air gauges here somewhere but I am going to use  Plastigage.  A micrometer will show up any major defects though.
Cheers Ash
Title: Re: CB750 bearing shells
Post by: AshimotoK0 on August 07, 2014, 12:37:48 PM
We do have air gauges here somewhere but I am going to use  Plastigage anyway.  A micrometer will show up any major defects though.
Cheers Ash
Title: Re: CB750 bearing shells
Post by: UK Pete on August 07, 2014, 01:35:01 PM
I have been lucky so far , and have nut had to change any crank bearings, they have a good oil pressure and filtering system and so do not really wear if the oil is changed reguar the crank floats on a film of oil, no metal to metal
Pete
Title: Re: CB750 bearing shells
Post by: steff750 on August 07, 2014, 04:01:44 PM
Quote
I know that you can grind a glodwing crank and use some car shells but can't remember which
;) yes bryan mini shells will fit ,one of my friends rebuilt his Goldwing with them in the seventies ,and the guy who supplied the shells, gave us all the mains and big end sizes straight of the top of his head, 8)
Title: Re: CB750 bearing shells
Post by: AshimotoK0 on August 07, 2014, 06:20:07 PM
Back in 2010 there was an Australian guy DEFINITELY selling CB750 sohc 0.25mm undersize shells, also for the CBX. I know because I emailed him at the timequestioning if the crank would take a regrind because of the depth of the hardening. Luckily the same  cranks were fitted from sandcast to F2, only the auto was different,  so plenty of good used original ones still to be had, particularly from the States if you can bear the delivery costs. Mine was definitely toast but the top end was absolutely  fine, so I reckon the PO replaced the top end but left the bottom end. Needless to say replaced all of the bottom end components.
I agree with Pete, if oil is changed regularly then the crank holds up very well. My 400/4 has done 25k but the crank and cam bearings / shells  were in almost perfect condition when I stripped it, so I left well alone. I got NOS barrels cheap in the '80's so fitted those too.

Cheers ... Ash
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