Upgrades4MGs
Get more from your B...
Engine Upgrades
An O2 Series MGB
This car belongs to Karsten Mikkelsen in Denmark. Karsten contacted me with photos of his modified sump when he first saw the web pages a few years ago. Since then he has kept in regular touch and has completed his conversion.
Firstly, though, the regulations in Denmark are quite strict and apparently Karsten was limited to a SOHC 2L engine, so he opted for the O2 Series. owing to the tax system and the fact that the legal maximum is an increase of 20% HP, everything over gives you a penalty of paying new registration tax of 180% of the Estimated value of the car after conversion, therefore, VERY expensive.
The O2 Series engines were a little more complex with EFI and the distributor on the end of the camshaft. For some strange reason the inlet and exhaust moved to the opposite side of the engine.
To begin with, the sump is the first problem. A Sherpa sump will fit but failing that it is necessary to cut a sump to suit and in this case Karsten used a B Series sump welded to the frame of a Marina sump, which fits perfectly. The Sherpa sumps can still be found but they are becoming more difficult to source. If you can source one then also aim to get the oil pick up pipe. These will point to the lower part of the sump correctly. If you can't then a little heat and re-brazing will allow the existing pipe to be modified.
The water pump has to be modified to fit. It is necessary to turn the outlet slightly.
Kartsen also fitted an e
Karsten then moved the Ignition distributor to the front of the cambelt cover, and reinforced the cover accordingly.
The oil pump was next. As seen on Keith Dale's and Roger Parker's cars the work around is to cut the cross-member to make room for the oil filter and sump. However, many fear doing this as it weakens the cross-member substantially despite any attempts to redress the lost strength.
The O1 Series oil pump will fit O2 engines to no. 20HAxxxx but will not fit the O2 20HB or 20HC and newer later owing to the different diameters of the later crankshafts. The crank of the O1/ O2 20HA is longer in the "nose" and so are the camshafts, this is because the early engines have different cambelts and fan belts.
Karsten has come up with a very professional looking modification for the oil pump which will also work with the M/T16 engines.
This is the standard oil pump and filter head. Even with a Mocal adaptor for hoses to use a remote filter, there is still insufficient clearance with the cross-member.
And this is it modified. It does mean using a remote filter housing but that is an advantage in my view, along with an oil cooler if necessary.
Here's some detail on the EFI:
The mileage has also improved over the old 1800cc engine: over a distance of 180km with varying normal driving (town @ 80km/h) the fuel consumption is approx 13km/litre (UK 35mpg). The old engine was difficult to get better than 10-11 km/litre (UK 29mpg).
O Series Power