Sq 4 technical / supplier advice please

[Andrew.rogers]

I've recently inherited a 1954 Mk II Square Four. From the (very) little I know I understand that they suffer from oil feed issues and con rod issues / failure. If I am to spend some money on getting the bike running well what should be on the parts / job list? Can anyone recommend an engine / bike builder to carry out the work?

[brenton.roy]

Hi Andrew, welcome to the forum. You're a lucky man!
There may be several things to do, but in terms of reliability, the main thing is to have the crankshaft oilways cleaned, with wire, not just with air.
This will mean splitting the bottom end.
While a mechanic is there, they can measure up the big ends, mains etc.
A number of owners fit Morgo oil pumps. An oil filter is a good idea.
New con rods are available through the club and Draganfly.
As for a mechanic, we'd need to know which country you live in.
Brenton

[nevhunter]

people who work on very modern machines. ( they mostly don't get rebuilt, they just get another engine) have a totally different concept of clearances/material etc. Your engine ran just fine when new, in most cases. IF someone wants to modify it make sure the mod is necessary. If you want to increase the performance of it remember that everything in it is not new. Cases become brittle/ corroded/distorted. Shafts get fatigued /cracked.gunked up with sludge. Alloy rods have a limited life. Mostly all you have to do is check fits, alignment, crack test parts where applicable, clearances and don't run modern piston clearances. Keep to the original ones..
The Sq4 cylinder head can absorb a few $'s, and needs to be done well if it is going to run well and reliably. It's not rocket science but you need to find a suitable engine builder rather than a "mechanic" Nev

[Andrew.rogers]

Thanks for the advice. I'm based in the midlands in the UK so if you've heard about a good engine build in this area (or elsewhere in the UK) then please let me know