Author Topic: Case re-assembly questions and advice  (Read 5195 times)

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Offline cakey

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Case re-assembly questions and advice
« on: October 25, 2013, 06:45:12 PM »
Just about o button the two cases back together and wanted to double check a couple of things and ask some advice.

1. In between the two case halves there is just the one smaller dowel each side of the case and one larger dowel in the middle at the front with a o ring around it.

2. I am still waiting for the piston clips but have all the new bearings so is it ok to just put the rods on and put piston on after putting cases back together.

3.in the Honda manual it says to put the arrows on the pistons facing towards the front exhaust but on page 36 Fig. 3-35 it shows the arrows pointing towards the rear. Just wanting to confirm.

4. Does it matter which direction the rod caps go on the crank but as long as the etchings on the caps match. I cannot remember which way they came off the crank?

My plan is to install new mains and rod bearings and plastiguage. Then use the three bond sealer between the case halves and lower tiger and torque down and finish putting the two halves together by joining with the lay shaft bearing.

Any advice on these questions appreciated.

1971 CB750 K1 (restored)
1975 GL1000 Goldwing (restored)

Offline cakey

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Re: Case re-assembly questions and advice
« Reply #1 on: October 25, 2013, 06:50:29 PM »
5. It also says in the manual to torque 8mm hex blots to 16.6-18.1 ft-lbs any then says to tighten 6mm hex bolts but does not indicate a torque value. What would be recommended in this case?
1971 CB750 K1 (restored)
1975 GL1000 Goldwing (restored)

Offline cakey

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Re: Case re-assembly questions and advice
« Reply #2 on: October 26, 2013, 01:05:41 AM »
I don't know if I am over thinking it but I have run into a couple of concerns.

1. Either side of the crank journal on number 3 rod there seems to be some discolouration which might be wear marks. I am not sure wether to keep proceeding or research into getting the crank ground or polished?

2. One of the head bolts was pretty mangled and I can remember it giving me grief when I was taking it out at the time but did not know it was a head bolt. I have ground the head back to 11mm but wandering if I should just bite the bullet and look into buying another.

3. I have found that each end cap has a K and a 58 stamped on either side. Wondering which one should face towards the front or exhaust?
1971 CB750 K1 (restored)
1975 GL1000 Goldwing (restored)

Offline cakey

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Re: Case re-assembly questions and advice
« Reply #3 on: October 26, 2013, 04:01:43 AM »
And it's just going downhill. Put the new bearings on the rods and there is a big gap between the bearing and the cap in no4. The gap was there with the old bearing and it's even worse now.

It's from the same cylinder that was seized.
1971 CB750 K1 (restored)
1975 GL1000 Goldwing (restored)

Offline martin99

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Re: Case re-assembly questions and advice
« Reply #4 on: October 26, 2013, 07:36:23 AM »
Cakey, unless your description of events so far is accidentally ambiguous, I think you need to take a step back here.

If I'm teaching you to suck eggs, I apologise, but I wonder if you know how to use plastigage? It's purpose is to indicate the amount of wear (in this case between rod bearing and crank journal) that currently exists, and that figure when arrived at determines whether it is in acceptable tolerances to fit standard size bearings or oversize ones, the latter requiring a crank regrind. If you have just blindly ordered new bearings without checking this first, then I would suggest you do it now before you end up with a set of new bearings that are non-returnable. You could well be ok, but better to check now than find out later.

That rod cap in my opinion is distorted. The gap will be more evident with the new bearing because the old one will have taken on the shape of the cap to some degree. Caps are usually matched to their rods, so I suggest you find a good rod/cap to replace what you have. If the previous measurement of bearing to crank was favourable ie no regrind needed you should be able to use a new rod (are they available?) but if you opt for a used rod check measurement again to ensure it is compatible.

You can fit the pistons after the cases are back together - indeed this is preferable to prevent damaging your pistons. But don't worry about this yet, you are getting ahead of yourself.

Build threads:
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Offline Bankerdanny

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Re: Case re-assembly questions and advice
« Reply #5 on: October 26, 2013, 10:18:04 AM »
discolorization is generally a sign of excessive heat.

To echo some of oldskool's comments, did you have the crank and other areas measured to see if they are withing spec and round? Without that it's a total crap shoot whether or not new bearings will fit properly
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Offline Jerry Rxman Griffin aka MuthaF'er

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Re: Case re-assembly questions and advice
« Reply #6 on: October 26, 2013, 12:06:28 PM »
5. It also says in the manual to torque 8mm hex blots to 16.6-18.1 ft-lbs any then says to tighten 6mm hex bolts but does not indicate a torque value. What would be recommended in this case?

Just did this. I have 4 manuals and found it - 8 ftlbs. Don't go higher like I did the first time. Those 6mm will stretch and/or break!
As of today 3/13/2012 my original owner 75 CB750F has made it through 3 wives, er EX-wives. Free at last.  ;-)

Offline Jerry Rxman Griffin aka MuthaF'er

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Re: Case re-assembly questions and advice
« Reply #7 on: October 26, 2013, 12:10:27 PM »
And it's just going downhill. Put the new bearings on the rods and there is a big gap between the bearing and the cap in no4. The gap was there with the old bearing and it's even worse now.

It's from the same cylinder that was seized.

As log as it Plastigauges out you're good. Press it in by hand and one edge should protrude ever so slightly.

Just read the other reply. Yeah could be distorted? Compare it to one of the other caps before using.
« Last Edit: October 26, 2013, 12:13:23 PM by Jerry Rxman Griffin aka MuthaF'er »
As of today 3/13/2012 my original owner 75 CB750F has made it through 3 wives, er EX-wives. Free at last.  ;-)

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Re: Case re-assembly questions and advice
« Reply #8 on: October 26, 2013, 12:22:10 PM »
#3 was discolored but #4 was siezed?

Are any of the rods discolored ie yellowish, brownish, blueish at the big end?

Cranks can be polished but you can not take much off. Each bearing set only has .008mm difference in thickness. Just had mine done. Went from green bearings, fitted brown but had to go with black and still have close to .050mm clearance. That's the best I can do.   

I don't know if I am over thinking it but I have run into a couple of concerns.

1. Either side of the crank journal on number 3 rod there seems to be some discolouration which might be wear marks. I am not sure wether to keep proceeding or research into getting the crank ground or polished?

2. One of the head bolts was pretty mangled and I can remember it giving me grief when I was taking it out at the time but did not know it was a head bolt. I have ground the head back to 11mm but wandering if I should just bite the bullet and look into buying another.

3. I have found that each end cap has a K and a 58 stamped on either side. Wondering which one should face towards the front or exhaust?
As of today 3/13/2012 my original owner 75 CB750F has made it through 3 wives, er EX-wives. Free at last.  ;-)

Offline 754

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Re: Case re-assembly questions and advice
« Reply #9 on: October 26, 2013, 01:05:25 PM »
Check another shel in case that one is distorted.
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Offline cakey

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Re: Case re-assembly questions and advice
« Reply #10 on: October 26, 2013, 02:59:40 PM »
Check another shel in case that one is distorted.
Checked the other shells and none distorted. I also put the cap and rod together and tightened the nut and the gap was still there.

#3 was discolored but #4 was siezed?

Are any of the rods discolored ie yellowish, brownish, blueish at the big end?
[/quote]

#3 bearing journal seams to have a shallow in it on either side of the journal
#4 piston was seized and has the distorted cap.

None of the rods are discoloured that I can see.


Just did this. I have 4 manuals and found it - 8 ftlbs. Don't go higher like I did the first time. Those 6mm will stretch and/or break!

Great thanks!

discolorization is generally a sign of excessive heat.

To echo some of oldskool's comments, did you have the crank and other areas measured to see if they are withing spec and round? Without that it's a total crap shoot whether or not new bearings will fit properly

I think I have totally confused everyone by saying "discolorization" what I meant was that the metal is a different shade so it is not like shiny polished crank journal the metal is slightly duller in colour like it was never polished out of the factory. Hope I am not digging myself a bigger hole trying to describe that.
« Last Edit: October 26, 2013, 03:10:00 PM by cakey »
1971 CB750 K1 (restored)
1975 GL1000 Goldwing (restored)

Offline cakey

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Re: Case re-assembly questions and advice
« Reply #11 on: October 26, 2013, 03:08:21 PM »
Cakey, unless your description of events so far is accidentally ambiguous, I think you need to take a step back here.

If I'm teaching you to suck eggs, I apologise, but I wonder if you know how to use plastigage? It's purpose is to indicate the amount of wear (in this case between rod bearing and crank journal) that currently exists, and that figure when arrived at determines whether it is in acceptable tolerances to fit standard size bearings or oversize ones, the latter requiring a crank regrind. If you have just blindly ordered new bearings without checking this first, then I would suggest you do it now before you end up with a set of new bearings that are non-returnable. You could well be ok, but better to check now than find out later.

That rod cap in my opinion is distorted. The gap will be more evident with the new bearing because the old one will have taken on the shape of the cap to some degree. Caps are usually matched to their rods, so I suggest you find a good rod/cap to replace what you have. If the previous measurement of bearing to crank was favourable ie no regrind needed you should be able to use a new rod (are they available?) but if you opt for a used rod check measurement again to ensure it is compatible.

You can fit the pistons after the cases are back together - indeed this is preferable to prevent damaging your pistons. But don't worry about this yet, you are getting ahead of yourself.



Yeh your right Oldschoolnuts I did need to take a step back last night and I lost internet because a monsoon came through and knocked it out. No need to apologise I have only ever built up one engine on my GL1000 and I am finding this one to be a different kettle of fish all together so I am learning all the time thanks to people like yourself who kindly offer advice.

I have not had the crank checked at all. Is it something that I can do with a set of digital callipers or would it need to go to an engineers. I had my barrels and heads done at the engineers here in Darwin but I don't know if they do cranks or if there is a crank place here in Darwin but I can check.

I went through the process of cross referencing up all etchings and markings to order the new bearings and I have them already.

I think that I would need to try and track down a second hand rod to keep moving forward but I am not sure what measurements I am looking for on the crank or what measurements to give to the engineers if they checked it.

Also still needed to confirm

1. which way the rod caps face on the crank
2. which way the piston faces (triangle towards front?)
1971 CB750 K1 (restored)
1975 GL1000 Goldwing (restored)

Offline martin99

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Re: Case re-assembly questions and advice
« Reply #12 on: October 26, 2013, 03:57:04 PM »
You can use a mic on the crank to check for round, but it won't give you an accurate indication for wear between the journal and bearing surfaces. You really do need to learn how to plastigage it, I'm sure you will find plenty of tutorials if you Google it. If in doubt, your idea of taking it to be checked professionally is probably a good one.

As far as I know, the rods and caps are installed with the bearing tangs (those little pressed bits that locate them) facing front, ie toward the exhaust.

You might find this link helpful regarding your piston fit -
http://forums.sohc4.net/index.php?topic=62224.0

Build threads:
77 750F2 Refresh Project http://forums.sohc4.net/index.php?topic=144075.0
TRIBSA http://forums.sohc4.net/index.php/topic,160296.0.html

1977 CB750 F2
1958 Norton Model 99
2011 Triumph Street Triple 675

Offline cakey

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Re: Case re-assembly questions and advice
« Reply #13 on: October 26, 2013, 04:07:35 PM »
I have three sheets of plastiguage here and know how to use it ( that parts cool).

I was going to put the case halves together yesterday and plastiguage them when I found the damaged rod.

So I don't want to put words in your mouth but if what I understand you are saying is correct then I should put my new bearings in the case halves(which I have already done) and then bolt together and plastiguage. Once I find put if all those clearances are ok on the crank then I can unbolt and worry about the rods next.

This about right?
1971 CB750 K1 (restored)
1975 GL1000 Goldwing (restored)

Offline martin99

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Re: Case re-assembly questions and advice
« Reply #14 on: October 26, 2013, 04:33:00 PM »
I was specifically talking about the rod to crank fit (big ends) but yes, the mains will need checking too.
Build threads:
77 750F2 Refresh Project http://forums.sohc4.net/index.php?topic=144075.0
TRIBSA http://forums.sohc4.net/index.php/topic,160296.0.html

1977 CB750 F2
1958 Norton Model 99
2011 Triumph Street Triple 675

Offline cakey

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Re: Case re-assembly questions and advice
« Reply #15 on: October 26, 2013, 04:38:41 PM »
Just checking mains now :)
1971 CB750 K1 (restored)
1975 GL1000 Goldwing (restored)

Offline cakey

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Re: Case re-assembly questions and advice
« Reply #16 on: October 26, 2013, 04:50:24 PM »
All mains fell between .025 and .040 on the clearance
1971 CB750 K1 (restored)
1975 GL1000 Goldwing (restored)

Offline cakey

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Re: Case re-assembly questions and advice
« Reply #17 on: October 26, 2013, 05:24:46 PM »
All mains fell between .025 and .040 on the clearance

Sorry not everyone. I double checked myself

Rods

1.  .025
2.  .035
3.  .035
4.  Did not want to check because of warped cap

Mains

1.  .025
2.  .035
3.  .038
4.  .038
5.  .050
« Last Edit: October 26, 2013, 05:41:21 PM by cakey »
1971 CB750 K1 (restored)
1975 GL1000 Goldwing (restored)

Offline cakey

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Re: Case re-assembly questions and advice
« Reply #18 on: October 26, 2013, 06:20:23 PM »
I put the case halves back together with oiled bearings. Turned really easy. I torqued it to 215 inch-lbs and rotated it with the rotor bolt. Didn't catch anywhere and was real smooth.

My problem is every time I look at something another problem presents itself. I noticed this pitted mark on number 4 mains. There was no obvious scoring on the bearing that I can remember though, maybe because it's in the middle groove. I will go back and check the old bearings.

So what I got at the moment is.
1. A warped cap on number 4 rod and a stripped thread on one of the cap bolts
2. Pitting on the middle of number 4 mains journal
3. A stuff 140mm 8mm hex bolt from the mains. I had to grind it down to a number 11 socket.
1971 CB750 K1 (restored)
1975 GL1000 Goldwing (restored)

Offline Jerry Rxman Griffin aka MuthaF'er

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Re: Case re-assembly questions and advice
« Reply #19 on: October 26, 2013, 11:52:24 PM »
That cap does looked #$%*ed! At this stage you may be better off sourcing another crank with 4 attached rods. Plenty of them available. This way you should get matching parts with matching weights. You'll need to determine the bearing specs on the replacement from the crank markings and re-chart with your case letters.

Your differences in clearances, while they should be fine according to Honda specs, can be made more similar if you really wanted to. If I was ordering bearings I'd probably go 1 size smaller on #1 main and 1 size larger on #5. Then Plastigauge again. But we're not all anal or have to be as precise as possible  ;) If you replace the crank you'll need to re-match the bearings first anyway.

Patience! Above all else and ask many questions. Do not get in a hurry. You seem to have a decent handle on the necessities. 
As of today 3/13/2012 my original owner 75 CB750F has made it through 3 wives, er EX-wives. Free at last.  ;-)

Offline cakey

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Re: Case re-assembly questions and advice
« Reply #20 on: October 27, 2013, 02:14:04 AM »
Fair call Jerry
That cap does looked #$%*ed! At this stage you may be better off sourcing another crank with 4 attached rods. Plenty of them available. This way you should get matching parts with matching weights. You'll need to determine the bearing specs on the replacement from the crank markings and re-chart with your case letters.

Your differences in clearances, while they should be fine according to Honda specs, can be made more similar if you really wanted to. If I was ordering bearings I'd probably go 1 size smaller on #1 main and 1 size larger on #5. Then Plastigauge again. But we're not all anal or have to be as precise as possible  ;) If you replace the crank you'll need to re-match the bearings first anyway.

Patience! Above all else and ask many questions. Do not get in a hurry. You seem to have a decent handle on the necessities. 

Someone has suggested to me that withe the two dodgy journals on the crank that there is a possibility that maybe the crankshaft was metal sprayed.

It would be great if there were plenty of parts available but unfortunately that's not the case were I live mate but the search begins. It would more than likely be easier and less hassle getting another crank and then starting again.

I have already put 3K into the engine so at this point it might slow down a bit depending on the price of another crank and rods.

I'm a bit frustrated but might as well get it done right instead of splitting it down later :)

If any of my fellow countryman know where there are any K1 engine bits are can they send me a PM

Thanks
1971 CB750 K1 (restored)
1975 GL1000 Goldwing (restored)

Offline martin99

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Re: Case re-assembly questions and advice
« Reply #21 on: October 27, 2013, 05:35:19 AM »
Don't be too disheartened Cakey, you're learning all sorts of good stuff here just as we all do every day.

A new project is like a marriage - you start off all optimistic, everything going well then slowly but surely she lets you down and it all falls to #$%*. You have to make a choice - stick at it and make it work, which takes time and more tribulation, or divorce and replace with a better model.

Seeing as we're talking motorcycles here I think it's worth the effort to persevere with what you have!
Build threads:
77 750F2 Refresh Project http://forums.sohc4.net/index.php?topic=144075.0
TRIBSA http://forums.sohc4.net/index.php/topic,160296.0.html

1977 CB750 F2
1958 Norton Model 99
2011 Triumph Street Triple 675

Offline cakey

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Re: Case re-assembly questions and advice
« Reply #22 on: October 27, 2013, 02:14:59 PM »
I'm sticking the journey, if I had turned a blind eye to it then that's all I would have thought about. So I'll get it done right.
1971 CB750 K1 (restored)
1975 GL1000 Goldwing (restored)

Offline Jerry Rxman Griffin aka MuthaF'er

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Re: Case re-assembly questions and advice
« Reply #23 on: October 27, 2013, 06:38:05 PM »
PM Terry. He ALWAYS has his hand and head in some #$%*  :) At least that's because he's our most outspoken OZ member.

Saw a complete set of rods on EBay this AM. Starting bid $10 US. As I was searching for a potential replacement crank I saw more listed as complete units with rods and one even had a cut down alternator rotor. I'm saying < $100 for all but shipping is a #$%*. Around $40 minimum and that's from here to here. Didn't pay any attention to your location at first.  :-Xi

If shipping turns nasty you can always US bid and have it shipped to one of us then we can forward.

If you only knew what I've been through/going through with my 900 high tech engine! One day I'll do a tell all. Hell, it's just time, patience and money  ;) You can juggle those around into any order and it'll still apply.
As of today 3/13/2012 my original owner 75 CB750F has made it through 3 wives, er EX-wives. Free at last.  ;-)

Offline cakey

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Re: Case re-assembly questions and advice
« Reply #24 on: October 27, 2013, 08:48:28 PM »
PM Terry. He ALWAYS has his hand and head in some #$%*  :) At least that's because he's our most outspoken OZ member.

Saw a complete set of rods on EBay this AM. Starting bid $10 US. As I was searching for a potential replacement crank I saw more listed as complete units with rods and one even had a cut down alternator rotor. I'm saying < $100 for all but shipping is a #$%*. Around $40 minimum and that's from here to here. Didn't pay any attention to your location at first.  :-Xi

If shipping turns nasty you can always US bid and have it shipped to one of us then we can forward.

If you only knew what I've been through/going through with my 900 high tech engine! One day I'll do a tell all. Hell, it's just time, patience and money  ;) You can juggle those around into any order and it'll still apply.

Thanks for the words of encouragement Jerry.

I have PM'd Terry and am in the process of searching every old Honda parts dealer I can found.

I have since found out that any of the K series cranks and rods will fit, I did not realise this, so this will open up my search a bit. If I cannot find anything in OZ I will have a serious look at eBay. Thanks for having a look for me.

Look forward to hearing your story on the 900 project.
1971 CB750 K1 (restored)
1975 GL1000 Goldwing (restored)