I have a SMALL engine issue.

[alackofspeed]

Originally Posted by grant620

Anyhow - I'd recommend for ease:
1.8K
R65 box
1.6 clutch and flywheel
1.6 head (ported and flowed - even better with big valves!)

Is the Rover ECU easily remapped? How would one take adavantage of the 1.8 mated to the 1.6 ported head?

To get back on topic, if doing all this work, then one might as well be repairing the currently defunct 1.6...... and it's cheaper to buy another engine, and drop that in... and a 1.8vvc with pg1 would be easy enough to drop in.....?

[grant620]

I disagree
He alredy has all the 1.6 parts, so putting a 1.8 in from the point of view of a bottom end is a good thing. No need to buy new ECU, box. clutch etc.
ECU will deal with it easily. It runs on a mass air flow structure, so will see the pressure and temperature and deal with air flow accordingly.
MEMS is nigh on impossible to remap.

[Ex-Biker]

If I do go ahead with this, it will not be me building the engine.

It will be a reputable builder

[alackofspeed]

If you've a good block, and a good head, mating the two together is easy.

As for the ECU side of things, I don't see how a 1.8 will work properly with the 1.6 ECU, maf or not. Surely the calculated load will be incorect (as the engine will be breathing more deeply for a given throttle opening), and correspondingly the ignition timing will be wrong?

[grant620]

Originally Posted by alackofspeed

If you've a good block, and a good head, mating the two together is easy.

As for the ECU side of things, I don't see how a 1.8 will work properly with the 1.6 ECU, maf or not. Surely the calculated load will be incorect (as the engine will be breathing more deeply for a given throttle opening), and correspondingly the ignition timing will be wrong?

Rover mapped the ECU's very very very conservatively.
so much so that you can *just* get away with a 1.4ECU on a 1.8!!!

It will KNOW how much airflow there is as a result of air pressure and temperature. ECU doesn't care how big the stroke is.

It doesn't have a MAF by the way - it has a MAP sensor and air temp sensor.
It's a simple calbulation that to make an air-fuel mixture (ratio) you need x parts of fuel to y parts of air, so if it knows what air you have, it can put in the right fuel (whatever engine size).
The only issue is ifyou go outside the ECU's parameters (nearly impossible up to 170-175hp)

[alackofspeed]

This is going off topic, but I'm confused...

I'd have thought the MAP sensor is harder to work with than the MAF, as there's no volumetric flow rate known. A 1.4 ecu, would see, for example atmospheric pressure at full throttle (for arguments sake), and would know that this requires a fuel flow of X to burn with the air, in open loop fuelling strategy. The problem then comes, that when the 1.8 MAP sensor is seeing atmospheric pressure, the engine is actually drawing in about 30% more air than the ecu believes is the case, so to run at the same afr it needs 30% more fuel (roughly) than the ecu will be providing, but the ecu looks up 1 bar of air pressure, and only fuels for a 1.4.

Does the ecu get by the potential open loop fuelling problems, by noting the need for a massive fuel trim in closed loop, and applying the same offset on the open loop map?

The above obviously assumes the same injectors are used in the two engines, but if the injectors are proportionally matched to the engine, I can see a 1.4 ecu would run a 1.8 far more easily.

Just curious, that's all.

John.