Author Topic: 400 four main bearings - will need replacement STD bearings.  (Read 2865 times)

Offline Bryanj

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Re: 400 four main bearings - will need replacement STD bearings.
« Reply #15 on: March 21, 2021, 04:34:35 PM »
They NEVER mix colours on one pin but different colours on different pins is common.
Non of the numbers on the shells mean anything apart from production code, last thing done in production is measure thickness to 0.001mm and colour code them

Offline McCabe-Thiele (Ted)

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Re: 400 four main bearings - will need replacement STD bearings.
« Reply #16 on: March 21, 2021, 04:47:50 PM »
They NEVER mix colours on one pin but different colours on different pins is common.
Non of the numbers on the shells mean anything apart from production code, last thing done in production is measure thickness to 0.001mm and colour code them

I'm learning here I have never encountered a car with such complications as different coded journals on the same crank - wonder why STD didn't mean just that with oversize being +0.1 or whatever.
Honda CB500 K1 (new pit dug out ready)
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Link to my full restoration http://www.sohc.co.uk/index.php/topic,23291.0.html

Online K2-K6

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Re: 400 four main bearings - will need replacement STD bearings.
« Reply #17 on: March 21, 2021, 06:03:30 PM »
"I'm learning here I have never encountered a car with such complications as different coded journals on the same crank - wonder why STD didn't mean just that with oversize being +0.1 or whatever."

It is, in essence, a view of the lengths they went to in production tolerancing. Ordinarily in most process as it advances the tolerances are accumilative (unless by happy accident one error cancels another) with the accepted machine accuracy and repeatability available producing the components being recognized, the range of 5 different shell dimensions is planned to compensate for that process capability. It effectively pulls all of that production line tolerance back to as close to zero that they could get it.

In terms of "old money" a BMC A series built with en40b crank fully balanced, ground, nitrided, micro polished to perfection,  with rods balanced end to end and rod to rod, etc etc, effectively the best hand finished blue printing only gets close to what these engines came off the production line as absolute standard.  With near 100bhp/litre and usually ten thousand rpm ceiling to go with it, that really shows just how good this design and production was, that's in mid to late sixties and early seventies, there's nothing that came close to them.

Offline Bryanj

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Re: 400 four main bearings - will need replacement STD bearings.
« Reply #18 on: March 21, 2021, 06:20:59 PM »
In production Honda used air gauges to measure pins and housing which were accurate to parts of 0.001mm and as such could selectively fit parts to get the EXACT design clearance.
When did you ever hear of an "old" car doing 120 000 miles and on stripdown find everything in tolerance and yes i have seen that, chains were shot but all the rest was good enough to refit

Offline McCabe-Thiele (Ted)

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Re: 400 four main bearings - will need replacement STD bearings.
« Reply #19 on: March 21, 2021, 08:20:08 PM »
What journal was the green shell on Ted?

Must be either 2 or 4.

You are right Oddjob the Green Shell was on number 2!

As D6I-A was the bearings on 2 & 4 I guess they are both the same.

I have just removed the Conrods a C is marked  on the front edge two of them have number 2 & 3 on the other side but they were not in the respective cylinder bore so I am thinking this number in black print is meaningless. They were all fitted the same way round as regards the side casing number on the side  "S59" on all four.

Tommorow I will lift out the crank & check for markings on the shells being carefull they do not lift out with the crank. I will then check each bearing for any colour markings and double check the shell codes.
« Last Edit: March 21, 2021, 08:45:25 PM by Macabethiele (Ted) »
Honda CB500 K1 (new pit dug out ready)
Honda CB400 four super sport (first money pit)
Link to my full restoration http://www.sohc.co.uk/index.php/topic,23291.0.html

Offline McCabe-Thiele (Ted)

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Re: 400 four main bearings - will need replacement STD bearings.
« Reply #20 on: March 21, 2021, 08:33:52 PM »
"I'm learning here I have never encountered a car with such complications as different coded journals on the same crank - wonder why STD didn't mean just that with oversize being +0.1 or whatever."

It is, in essence, a view of the lengths they went to in production tolerancing. Ordinarily in most process as it advances the tolerances are accumilative (unless by happy accident one error cancels another) with the accepted machine accuracy and repeatability available producing the components being recognized, the range of 5 different shell dimensions is planned to compensate for that process capability. It effectively pulls all of that production line tolerance back to as close to zero that they could get it.

In terms of "old money" a BMC A series built with en40b crank fully balanced, ground, nitrided, micro polished to perfection,  with rods balanced end to end and rod to rod, etc etc, effectively the best hand finished blue printing only gets close to what these engines came off the production line as absolute standard.  With near 100bhp/litre and usually ten thousand rpm ceiling to go with it, that really shows just how good this design and production was, that's in mid to late sixties and early seventies, there's nothing that came close to them.

Ah the good old EN40B nitride crank standard in all the S variants 970S, 1071S & 1275S that all takes me back to my teenage days K2-K6 !!
« Last Edit: March 21, 2021, 11:49:50 PM by Macabethiele (Ted) »
Honda CB500 K1 (new pit dug out ready)
Honda CB400 four super sport (first money pit)
Link to my full restoration http://www.sohc.co.uk/index.php/topic,23291.0.html

Offline McCabe-Thiele (Ted)

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Re: 400 four main bearings - will need replacement STD bearings.
« Reply #21 on: March 21, 2021, 10:55:49 PM »
Lol, Ted the numbers on the rods don’t refer to the cylinders they are fitted to, it’s how Honda identified the journal size so further down the production line whoever was assembling the engine just needed to check those markings and the letters on the crankshaft to know what colour to fit.

It sounds complicated but once you get your head around it it’s really very easy and logical

At the moment my head is awash with contradiction including the fact that when I split the crankcase it was almost perfect - no bits flying out everything stayed in the top half that was face down except the main bearing to number 5 journal that stuck to the crankshaft - the other 4 stayed in the casing.

Now here is an observation having just had a double Glayva to heplp me sleep tonight - the four main bearings that remained in the lower half of the crank case as I lifted it off all stayed in place. The one bearing that was stuck to the crankshaft does not sit as it should in the casing when I pressed it back in it seems looseish as it does not click into place like the other four. This bearing is the one that appears to be the worst for wear is there a reason for this is it connected to the proximity or not of the oil feeds?

I feel pretty confident that the casing has not been split before based on the 6 bolts being so tight, the white residue of what I assume is Hondabond & the brown staining of the engine casing. The drive chain is clearly worn consistent with being original plus the two guides appear to be made of solid black steeel like substance - it looks 42 years old.
Honda CB500 K1 (new pit dug out ready)
Honda CB400 four super sport (first money pit)
Link to my full restoration http://www.sohc.co.uk/index.php/topic,23291.0.html

Offline taysidedragon

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Re: 400 four main bearings - will need replacement STD bearings.
« Reply #22 on: March 21, 2021, 11:25:20 PM »
Ted, I strongly suggest that you buy a Clymer or Haynes manual for your bike and read the section on measuring and selection of bearing shells.
It will save you having to ask so many questions on here. These engines and tolerances are nothing like old car engines.
The colour codes are selected for a brand new engine assembly with no wear on the journals.
If there is any wear on the journals now then the codes probably don't apply any more. The journals need to be measured very accurately,  as has already been mentioned.
Gareth

1977 CB400F
1965 T100SS

Offline McCabe-Thiele (Ted)

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Re: 400 four main bearings - will need replacement STD bearings.
« Reply #23 on: March 21, 2021, 11:43:32 PM »
Ted, I strongly suggest that you buy a Clymer or Haynes manual for your bike and read the section on measuring and selection of bearing shells.
It will save you having to ask so many questions on here. These engines and tolerances are nothing like old car engines.
The colour codes are selected for a brand new engine assembly with no wear on the journals.
If there is any wear on the journals now then the codes probably don't apply any more. The journals need to be measured very accurately,  as has already been mentioned.

I have a Haynes Manual & a Cycleserve Servicing manual that came with the bike. I've found the Haynes one to be less than ideal as it covers the CB400 & CB 550 Uk & US versions & many of the sections seem unlike my bike. I will take a look at the section on journals as you suggest it might clarify what looks to me like a very over complicated situation. 

I ask questions as I am looking for the correct answers I do not understand so much about these engines. I appoligise if you find my thirst for knowledge in some way too basic, tiresome  or too numerate. I have a sound long standing knowledge of car engines spanning decades - I find a bearing shell marked as STD to  then be colour coded to more exactness an alien concept.
Honda CB500 K1 (new pit dug out ready)
Honda CB400 four super sport (first money pit)
Link to my full restoration http://www.sohc.co.uk/index.php/topic,23291.0.html

Offline taysidedragon

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Re: 400 four main bearings - will need replacement STD bearings.
« Reply #24 on: March 22, 2021, 12:34:55 AM »
Ted, I  didn't mean to criticise you, just pointing you in the direction of the knowledge that is necessary to get these engines right.
The manual section on bearing codes clearly explains the colours/sizes available. It helps me to have prior knowledge on things like that before I get into the guts of the motor.
Gareth

1977 CB400F
1965 T100SS

Offline McCabe-Thiele (Ted)

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Re: 400 four main bearings - will need replacement STD bearings.
« Reply #25 on: March 22, 2021, 03:37:49 AM »
Ted, I  didn't mean to criticise you, just pointing you in the direction of the knowledge that is necessary to get these engines right.
The manual section on bearing codes clearly explains the colours/sizes available. It helps me to have prior knowledge on things like that before I get into the guts of the motor.

Hi Gareth, No offence taken I'm just being a bit contextually oversensative making me defensive.  I blame lock down making me a bit stir crazy, putting up barriers in my mind to the point where I wish I had never split the dam crankcase. I've felt completely out of my comfort zone for the last couple of days - that's not the normal me. I've read the section in the Haynes Manual as you suggested tbh it makes sense so I have a plan.  I'm going to measure up the main journals at 90 deg intervals and record the findings on a Excel chart. I have a couple of friends who are skilled in micrometer work that can help me out. That will enable me to make the right choice of main bearing replacements I need. The big end shells are all good thank goodness.
Cheers Ted
Honda CB500 K1 (new pit dug out ready)
Honda CB400 four super sport (first money pit)
Link to my full restoration http://www.sohc.co.uk/index.php/topic,23291.0.html

Offline Trigger

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Re: 400 four main bearings - will need replacement STD bearings.
« Reply #26 on: March 22, 2021, 07:07:34 AM »
As we used to say in the trade Ted, "you old boys worry too much ".
You just have to get your head around it. Forget everything you know from the past on English cars and bikes. It confuses my head the other way round as, i learnt Japanese engineering first so, when i look at a english built engine i wonder how the hell it ever worked  :o  The Honda engine relies on high oil pressure to float the crank and cam on a very thin film of oil.
   
Japanese engineering was a cut above the rest when they started all those years ago. It is a bit like racing engineering with the clearances and balance of the engine to enable a high revving engine. Down load a Honda Manuel and as you have the basic's so, it should come clear.   

Online AshimotoK0

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Re: 400 four main bearings - will need replacement STD bearings.
« Reply #27 on: March 22, 2021, 09:23:49 AM »
Eees a seemple  says Manuel  ;D ;D

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A old guy I know owned a Vincent Comet and Moggy 1000 Traveller from new in the mid 50's. He changed the oil in both machines religiously, probably sooner than required and he used both  as his regular transport until 2010. The Mog had done 300k and never had the engine rebuilt so he stripped it and took the crank to  Alex Carrs in Hull (Orcadian will know them  :) ) and they told him that the crank was still in tolerance.

I think it's all about oil changes and probably the luck of the draw with many old Brit engines.

Trigs right, download the manual from the Dropbox links and read several times and it all makes sense in the end. Getting Black & Blue  mains shells for the 400 is another matter as they are rocking horse poo.   
“Alright friends, you have seen the heavy groups, now you will see morning maniac music. Believe me, yeah. It’s a new dawn.” Grace Slick, Woodstock '69 .. In the year of the Sandcast.

Offline McCabe-Thiele (Ted)

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Re: 400 four main bearings - will need replacement STD bearings.
« Reply #28 on: March 22, 2021, 12:22:56 PM »
I agree about oil & filter changes I had a Manta GT/E that eventually started to get a timing chain rattle at 120,000 miles due to tensioner travel  issues. I had to take the cylinder head off to remove the front timing cover - almost everything I checked on the head, the bores etc was within manufacturers tollerances - I had owned it for most of it's life being a stickler for oil changes every 5k miles or 12 months. Never used cheap oil unless it was fully synthetic. Likewise I sold my Mk2 Carlton 2.0CDi at 190k miles - it never had a camshaft or chain replaced - my brother had it off me befor parting with it at a tad over 250k miles. Body work eventually rotted out.
Honda CB500 K1 (new pit dug out ready)
Honda CB400 four super sport (first money pit)
Link to my full restoration http://www.sohc.co.uk/index.php/topic,23291.0.html

 

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