Classic cars forum & vehicle restoration.

[mid]

I'm looking to replace the core plugs on the morris as most are leaking slightly, I've measured them as best i can in situ with some digital calipers and the ones in the head are coming out at 35.5mm / 1.39" and the ones in the block are 39.25mm / 1.55"

I'm just looking for some conformation that this sounds about right and what sizes are available?

[Jim.Walker]

Why measure the core plug holes in Millimetres? The car is a British car and they would most certainly have been machined in Imperial sizes (inches). And also in proper fractions of an inch rather than decimals.

A tip:- Years ago when the norm. was to drain cooling systems in winter to prevent frost damage core plugs used to corrode from the inside rapidly because air was allowed into the system for extended periods. Fresh water, regularly, with lots of dissolved air (oxygen) in it did not help either.
To combat this, my Dad used to insist that all the core plugs we replaced were tinned with solder on the inside to protect them. We never had to replace them twice. There was also a secondary advantage if the solder carried on over the edge by improving the seal.

With the use of modern anti-freeze and water which will go 'stale' with prolonged use soldering is not perhaps as important, but for the sake of a few seconds work????????

I would suspect that your 1.39 inches is 1 3/8 (1.375) and 1.55 inches is 1 9/16 (1.5625)
_________________
Quote from my late Dad:- You only need a woman and a car and you have all the problems you
are ever likely to want". Computers had not been invented then!

[ukdave2002]

Morris engines of this era originated from France; Hodgkis I think was the name of the company, so mid is correct to measure in metric. They have metric threads with whitworth sized bolt heads!! very confusing!, I wonder how many mechanics over the years have tried to chase a thread with the wrong size tap!!


Dave

[Jim.Walker]

I have to accept the chastisement! I did not really take in the thread header, taking the first line with "the Morris" as my guide.
My only contact with any Morris of this era was a 15-6? which had melted its big ends and while I must have used Whitworth/BSF spanners because that is all I had in those days (the mid 1950s) I can remember nothing about threads.
Apologies!

However, if the cylinder blocks were machined in this Country is it not likely things like core plugs would be Imperial sizes? And if they were machined to Metric sizes is it not more likely that sizes would be limited to one decimal place for convenience?
_________________
Quote from my late Dad:- You only need a woman and a car and you have all the problems you
are ever likely to want". Computers had not been invented then!

[ukdave2002]

Hi Jim

The engine I have real expirience of is the morris 8 / early post war minor sidevalve. With this unit the engine was made in the UK but they retained all the metric dimensions, mains were 42mm big end 40mm as standard, all the threads are metric and to confuse the situation even more, some have a different pitch to modern metric course or fine threads . But as you say they all have Whitworth/BSF head sizes on the bolts! When I dismantled my 8 engine, I had to bag and lable all the screws and bolts as its such a pain to find a replacement if you mislay one!

Dave

[Nic Jarman]

Oh yes, what a load of fun. My 8 drove me up the wall when I tried to replace some rounded bolts. I got out my box of imperial fixings and the rest you know.