Morris Minor Owners Club

I'm getting a sense of deja vu here... I think I might have heard this argument before!

Yep - getting tiresome !

And irrelevant to everyday Minoring.

Extremely tiresome indeed. The only relevant point to me is that BMC never had an A-Series engined car without a by-pass circuit. Yes you might get away without, but it is clear that problems are not too far away, so why do it?

But I did (1340) - and do even now (modified 1098) - have a car with no bypass as such - just the heater valve open! Both engines no problems - and great heater action. And many many Mini folks do the same. Some advise holes in stat - and if nervous, I see no harm in doing so.

Only just revisited this thread - bmc's initial answer had put my mind at rest.

Interesting to read all the info and opinions. At risk of more tedium and re-opening a can of worms

IslipMinor wrote:The only relevant point to me is that BMC never had an A-Series engined car without a by-pass circuit. Yes you might get away without, but it is clear that problems are not too far away, so why do it?

I may be wrong but what about the Ital A+ engine? I don't think it had a bypass hose nor the Metro-style thermostat housing with the sandwich plate bypass. It had the heater outlet (permanently open I think) near no. 4 cylinder, which provides an effective bypass and more effective cooling of no 4 cylinder than on the Metro (which has the sandwich plate instead of the heater tapping).

So I'm not going to worry - just need to keep the heater tap open at all times. I've had this system for many years (1310cc modified engine) and not had any problems with no 1 cylinder overheating, valves sticking etc.

One improvement might be to install a 'T' valve by the heater outlet so that circulation to interior of car in summer can be turned off whilst maintaining flow back via inlet manifold to bottom hose.

Just leave the heater valve open - it WILL be fine, and working much better too!

what about the Ital A+ engine?

The answer from the Marina/Ital forum is that the 1275 A+ engine in the later Itals (1980 on) retained the pump to head by-pass hose.

Original s heads had steel guides as standard, special tuning offered phosphor bronze to replace if required.