Alloy con rods.

[garagiste]

Searching through boxes of stuff I acquired years ago I have come across a set of four alloy con rods with p/b shell bearings, dimensionally the same as my steel OHC rods. Where/when were these used?

[Ian Grace]

Wolseley Hornets. I have a set of six myself, but have been advised not to use them because of crystallization of the alloy. Not sure if this is an old wive's tale or not. I bought them for the Mac off eBay a while back, but I'm probably not going to use them.

[Toby]

crystalization of the white metal, surely the alloy would be ok?

[Sam Christie]

I understand the fatigue life of these alloy rods is a worry. A chap with long experience in the motor trade (one time owner of 2M 371) said that his very early M-type started out with alloy rods which it was advisable to anneal from time to time.

[Ian Grace]

So annealing them is a solution to their ageing - interesting. I have a set of six with +30 pistons if anyone is in need.

[Simon]

OHV Minor engines from No U35392 to 1933 used alloy rods. Reference Remax part No MM 171/309 and Brivec part No EB 11/309 lists the bearing shells and also the longer con rob bolts. I have a set of + 40 thou shells and four substandard rods.

[Ian Grace]

Not sure that is correct - the rods were re-designed and took shells, but I believe they were steel. WR Morris wasn't a fan of any performance-enhancing mods if they compromised reliability in any way. M Types were made until 1932 and they all have steel rods as far as I am aware.

[Simon]

I am pretty sure that they are alloy as if you look at the Remax and Brivec parts list you will find that the small end clamp bolts are longer to suit the alloy rods. Also I believe that the gudgeon pins in the Hornets are a different diameter, one being imperial and the other metric. Would you please check the diameter of yours and I will check mine.

[Sam Christie]

Below,some alloy rods with what looks like white metal,if this is possible - are they white metalled steel shells?

[Simon]

Sam, They are heavy brass or bronze shells which are factory white metalled. I have a set of four new 40 thou undersize (crank pin) shells but the rods have damaged locating pins for the sheels and the caps may have been filed.