no bypass - A+ engine

[liammonty]

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

[bmcecosse]

Yep - getting tiresome !

[MarkyB]

And irrelevant to everyday Minoring.

[IslipMinor]

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?

[bmcecosse]

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.

[LaughingBoy]

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

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.

[bmcecosse]

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

[IslipMinor]

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.

[les]

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