TOPIC:

Hi all, I need to locate someone who sells con rod bolts for my 79 Z1300, the ones I have from a second hand crank look ok, but I've been advised to get new ones due to failure issues when re-using the bolts, the workshop manual also backs this up. MCS in Germany have one of the bolts and the nut, but don't appear to sell the Hex head bolt for the other side of the con rod. Also I've checked the crank and con rod markings and I believe I need brown bearings for the con rod, does this mean the shell bearings etc are brown also?

I see there are a couple of listings for the bolt you need on ebay, albeit at eye-watering cost.   Partzilla supposedly have them, but I believe they take your money even if they don't physically have the parts in stock, so beware.  I wonder if it is worth contacting MCG to ask their advice about the bolts.  Or perhaps Zed Parts in England - they always try to help.  I wonder what i- if anything - is special about the bolts. Do they have any markings on them to indicate their strength / grade? 

Regarding the shell bearings, from what I understand having just looked at the service manual, there is no mention of different colour / size main bearing shells for the 1979 model. Yet in the supplement for the 1981 model, it mentions blue, black, and brown shell inserts. Do yours have any coloured markings?  Have you measured the crank, and the bearing clearance, to establish if replacement is necessary?  

I'm not the best person to advise you really, as I haven't even touched my 1300 with a wrench yet. Perhaps someone else might chime in.

I had to replace the bearings on connecting rod number 5 since it had been repaired by Mackgiver using an empty can to make what I found when disassembling the engine.

 

Last December I bought a new set at MCG PARTS, I remember they only had one color, brown I think.

 

As far as the crank bolts are concerned, I didn't change them, I don't see the need to do so.

As you can seeI think McGiver had a hand in the repair of this engine, thanks for the quick replies.I will take your advice and check the bolt for markings and contact MCG, hopefully they will have an answer. I did manage to get a second hand crank with the con rods already on, which is in very good nick, there doesn't appear to be any looseness or lateral movement on any of the rods, any suggestions on how to confirm bearings are ok? I thought I would change them as a matter of course seeing the engine cylinders have been re-bored out to 63mm. Once again guys thanks for the feedback.

Burto wrote:

 any suggestions on how to confirm bearings are ok? I thought I would change them as a matter of course seeing the engine cylinders have been re-bored out to 63mm. Once again guys thanks for the feedback.

The common practice to determine conrod / main bearing clearances is to "Plastigauge" the bearings. Most aftermarket automotive suppliers can sell you plastigauge. See Youtube video   How to Use Plastigauge

Page 187 in the Service Manual talks about clearance measuring using Plastigauge and they don't tell you minimum clearances, only maximum as being .1mm or .004".  What I'll tell you from my experience is that you want a minimum of .0015" ( 1-1/2 thousands of an inch ) to allow oil leakage between the journal and bearing to cool / flush the interface. More than .004" and the connecting rod will knock. My happy zone is .0015- .002"

biltonjim wrote:

Partzilla supposedly have them, but I believe they take your money even if they don't physically have the parts in stock, so beware.
 

I have found this to be true, however, I have also found that they provide an immediate refund (without being asked) when they discover they don't have the part and it's NLA.