Crank not rotating

[Oddjob]

Looks like Brown, Brown, Brown, Green to me. You can still see the colour on the side of the shell. Looking at them I suspect something wrong with the oil, loads of really small score marks like the oil had little bits in suspension. Probably not changed for ages.

Still useable though.

[K2-K6]

Looks like Brown, Brown, Brown, Green to me. You can still see the colour on the side of the shell. Looking at them I suspect something wrong with the oil, loads of really small score marks like the oil had little bits in suspension. Probably not changed for ages.

Still useable though.

Yes Ken, I'd agree with your oil observations and Bryan also pointed out earlier in thread. To split it down further though, it looks like oil film breaking down and causing small parts of the shell material to stick to the crankshaft, suppose you could call that "micro seizure" with the waste going round to give score lines.
Stray particle from elsewhere in the engine or more abrasive in nature usually would get stuck in the soft shell material and cause the crankshaft itself to be scored.
So, oil film (shearing quality/consistency) below a level that can support competent bearing spacing to crankshaft.  Doesn't look too drastic as you note, but a good warning to ensure oil condition/quality is high enough not to let further deterioration happen.

[alexdecker]

Hey all

Alright, I have plastigauged both the crank journals and the connecting rod journals. My mind is getting slightly confused with all the numbers in relation to used bearings shells, and I was hoping to get your guidance as to how to proceed from here.

All measurements are in inches. For the crank journals, I got this (color of the existing bearing + plastigauge measurement):

1 (brown): .0019
2 (green): .0019
3 (grown): .0017
4 (green): .0019
5 (black): .0017

For the connecting rods, I got this:

1 (brown): .001
2 (brown): .0013
3: (brown): .0015
4: (green): .0013

As you can see, some of them fell in between sizes on the included measuring tape of the plastigauge, but I did my best to estimate where in between it fell.

Can anyone make sense of this math?

[Seabeowner]

According to the manual, fine, but I expect someone will be along later to say they are not keen on the Honda specs.

Crank and big ends:       New 0.00079 - 0.00181     Service limits 0.0031  (in inches)

[Bryanj]

Sizes are just about within spec but markings on shells wory me.
I suspect fitting new of same colour would give tighter tolerance

[alexdecker]

Sizes are just about within spec but markings on shells wory me.
I suspect fitting new of same colour would give tighter tolerance

Yes, definitely. I was hoping they would be within spec, because then I could replace them with new ones of same color (if I can get them), and all should be well. But is that the best course of action? Does some of them need to be replaced with tighter tolerances?

[murdock]

alex , what you need is a plastigauge test to see if they are all within tolerance.

[Oddjob]

Those are done using plastigauge Murdock.

I'm not a fan of plastigauging old shells, sure you get an indication of the clearance but it doesn't tell you what's worn, just that something is. However if you fit a new set of shells and the plastigauge them, the results will show you just how worn the crank is, if it is at all. So for instance, you fit new shells and the clearance is still over spec, you then know that fitting the next size shell up is the potential answer. One good reason for keeping a new set of yellow shells around, you fit them, get the clearance they give and then calculate the colour required to get the clearance back into spec.

[alexdecker]

Those are done using plastigauge Murdock.

I'm not a fan of plastigauging old shells, sure you get an indication of the clearance but it doesn't tell you what's worn, just that something is. However if you fit a new set of shells and the plastigauge them, the results will show you just how worn the crank is, if it is at all. So for instance, you fit new shells and the clearance is still over spec, you then know that fitting the next size shell up is the potential answer. One good reason for keeping a new set of yellow shells around, you fit them, get the clearance they give and then calculate the colour required to get the clearance back into spec.

I totally see the reason in that. But getting an entire set of yellow new shells for that purpose and then an entire set of something else possibly sounds very expensive and not that feasible. I could understand from earlier answers, that measuring the crank is not an accurate enough option. So if measuring the crank is not an option, and going by plastigauging old shells is also not recommended, what can I do then?

[alexdecker]

alex , what you need is a plastigauge test to see if they are all within tolerance.

Those posted numbers were the plastigauge measurements

[Oddjob]

You only need 1 set Alex, you just do 1 at a time.

[alexdecker]

You only need 1 set Alex, you just do 1 at a time.

Of course. Sometimes the most simple answers are the hardest to see. I can try and source a pair of yellow shells. Can't seem to find them anywhere, neither CMS or David Silver. Any other good resources for that kind of stuff in Europe?

Can I maybe use a green pair for the same usage?

[McCabe-Thiele (Ted)]

My starting point was to buy one pair of shells for the most common colour - in your case it looks like brown for the con rods - try them for the brown fitting places using Plastigauge for each one in turn starting with the largest clearance position first. Tricky for your mains as there are no more than two the same.

I understand some folk fit the next thickest shell or even all black shells then take longer to run them in but that sounds wrong to me. I suspect that is why black shells can sometimes be hard to source.

There is a range of acceptable clearances in the tables so I would not stress myself over small differences as long as they are within acceptable range.

[Oddjob]

Yellow are hard to find. Green would be ok to use, especially as you'd need a set of green shells anyway if you were fitting new ones. So check them all with the new greens then see what clearances that gives you for each one and work out the correct shell colour for each one.

Using blacks is ok Ted BUT I'd normally only recommend it when all the crank markings are not visible and you can't work out the correct shell.  Last time I counted them I had 58 or 59 black main shells and 30 or so conrod ones. Plus a load of yellows and some greens and some browns.

[alexdecker]

Yellow are hard to find. Green would be ok to use, especially as you'd need a set of green shells anyway if you were fitting new ones. So check them all with the new greens then see what clearances that gives you for each one and work out the correct shell colour for each one.

Using blacks is ok Ted BUT I'd normally only recommend it when all the crank markings are not visible and you can't work out the correct shell.  Last time I counted them I had 58 or 59 black main shells and 30 or so conrod ones. Plus a load of yellows and some greens and some browns.

So I should basically buy black shells of you and not CMS? 😉

On a serious note though, thank you for the advice. My big end shells are mostly brown, and then one pair of green. Should I buy a pair of brown shells for testing the big ends, or also a green? Do one always go for the biggest size possible for testing?