Wrong engine, right?

[Xephe]

As I continue on my voyage of Marina discover it’s suddenly all fallen into place. My car has completely the wrong engine. I think.

As far as I can work out I should have a 1700 O series, not the 1800 B series. I did wonder but thought it might be some odd NZ variation but looking at the information 1982 should be an O and the listed engine number starts with 17v not 18v as I think it would have. The engine in there has no identification, possibly deliberate when it was swapped, who knows. The decals (or what’s left of them) look pretty old school too so I reckon it’s a much earlier B series at that.

So, the question is, what to do? Rebuild this engine or try and get another one? I’d like it to be as original as possible and not sure how this all effects my ability to re-register it etc. how available are O series engines in NZ and do I need lots of other bits, not sure. Will need to investigate. I might of course be wrong and it is correct.

[locost_bryan]

Kilroy in Christchurch would be your best bet for sourcing an O-series engine. The 1700 was never offered in anything else in NZ, the Princess only got the 2000 version, and neither car were big sellers.

I've heard of a few other Marinas that have had the 1700 replaced with an 1800, probably because they were more plentiful and mechanics were more familiar with them.

I don't think it should hinder getting it re-vinned, as the power is within 20% of the original engine, so won't need a cert and uses the manufacturers original hardware.

[Xephe]

Ah, great info on the cert aspect. I guess if it’s no big deal to get it back on the road then the old B might not be a bad idea given the better availability of parts etc. It would be nice to have an O but I’ll press on with the rebuild in the existing lump and see what’s out there.

[Kilroy]

I have the correct airfilter housing for your twin carbs should you need it.

[Xephe]

Hi Kilroy, thanks for the offer. The housing is in the back of the car. I’ll need to check if there is actually a filter in there. There’s definitely some other bits and pieces missing. If you look closely you might be able to see that the throttle cable is attached to the carbs with an electrical connector block. An innovative solution I thought.

[Kilroy]

There is a very good chance that your engine and carb setup were lifted straight from a Mk2 Marina HL, as that is what they used. If so you will also have an MGB exhaust manifold which makes one of the best sounds out there.
I do have spare O series engines, but there is a lot of work involved in swapping everything over so easiest to stay as you are, and as you note, most wof people would not know the difference.
The O series engine is lighter and more fuel efficient, but not well understood in NZ.
They have the potential to outperform the B series if given the same treatment I feel, and that has always been my aim.
Just because...

[Xephe]

I suppose then my best bet is to rebuild the B I have and get that car back on the road as the first order of business. I would still be keen to O series it at some point for originality but that’s a secondary consideration. That said, If you have a spare O series I would be happy to chat about taking it off you hands if you were interested. It’s all coming out either way.

[drinud]

Just seen this: https://www.ebay.co.uk/itm/Morris-Marin ... SwMjBdLd6p

[MarinaCoupe]

True, but Xephe is in NewZealand.

[Xephe]

There is a very good chance that your engine and carb setup were lifted straight from a Mk2 Marina HL, as that is what they used. If so you will also have an MGB exhaust manifold which makes one of the best sounds out there.
I do have spare O series engines, but there is a lot of work involved in swapping everything over so easiest to stay as you are, and as you note, most wof people would not know the difference.
The O series engine is lighter and more fuel efficient, but not well understood in NZ.
They have the potential to outperform the B series if given the same treatment I feel, and that has always been my aim.
Just because...

I PM’d you around the O series. I am still keen to have the car as original as possible but thinking on this a little more my immediate goal is to get it back up and running as quickly as I can so sticking with a B series would be the way to do that. Mine needs a rebuild badly so if I can find a working B series to drop in that would be the ideal scenario. Rebuilding the B series would take me a very long time.

I just need to find one now.

[locost_bryan]

MGB GT engine in Wellington, current bid $200.

[Xephe]

Ideal. Thanks Bryan. I looked this morning but missed that somehow.

Are there any fundamental differences to be aware of between the Marina and MGB GT engines? That’s a 1970 engine apparently. A quick look suggests the fuel pump is somewhere different at any rate. Might not be a show stopper but I’ll need to use my current ancillaries so want to check they will go on.

[locost_bryan]

Electric fuel pump on the MGB, have to check if the cam has the lobe to run the mechanical pump.

Most of the other differences are in the ancillaries, like the backplate, that you can just swap over from you current engine.

Chris will fill you in on any fish hooks. :-)

[MarinaCoupe]

Bryan has it right. Use the Marina carbs, inlet, exhaust manifold. If you use the Marina fuel pump, assuming the fuel pump lobe is on the camshaft, then there will be minimal transition, although I would use the distributor from the replacement engine as it will have a better advance curve (I used one on my tuned B series), than the Marina one - but try both and see what you prefer.

The only possible engine difference will be whether it’s a 3 bearing or 5 bearing crankshaft. If the engine number starts GC/GD/GE/GF/GG/GH & 18Vxxxxxxx then it’s a 5 bearing crank, if it starts GA or GB then it’s a three bearing crankshaft which were fitted to early 1960s MGBs.

[Xephe]

Great information!

Looks like a GG motor so 5 bearing. There is no mechanical fuel pump fitting on the block at all that I can see in the location I have one. May be located elsewhere but it’s difficult to see from the pictures. I might see if I can go take a look.

Edit: Apparently, its possible to buy a fuel pump ‘blanking plate’ for an MG B series from ‘72-8*’ I wonder if a new block was introduced in 72 with a mech fuel pump boss that was simply blanked off on MG’s after that. Surely there were other b series applications that had mechanical pumps before ‘72 though. I shall keep researching