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MG MGB Technical - 'O Series' Oil pressure

I've just finished fitting an 'O Series' engine to mt B GT. Every thing runs fine, lot's more power.

BUT

The Oil pressure at idle is about 20 psi and between 40 and 60 psi when running.

The engine's from a Rover SD1 and the manual say's 40 to 60 psi at idle, 60 to 90 psi running.

When I rebuilt the engine crankshaft was reground and new bearings fitted. The only thing I didn't check was the oil pump. Would have been reaonably happy with pressure in B, but now concerned after reading Rover Manual.

Has anyone any comments, am I worrying unduly?

Steve
Steve Williams

Steve,
Donīt have a clue about oilpressure on the o-series SD1 engine. The only thing I can come up with is to doubblecheck with an external oilpressure meter.

Now to the real question on my behalf. A friend of mine has a SD1 o-series sitting in his garage and heīs trying to talk me in to an engineswap. Itīs a 2 litre 2xHIF6 carb engine. The gearbox is aimed for his V8 project. I have seen your previous postings claiming it to be a pretty straight forward conversion. I have a US-spec 79 tourer so I donīt have to change the motormounts but I foresee problems on the behalf of the directacting brakeservo. I really donīt want to rid myself of powerbrakes and wonder just how much room you have between the rear carburettor and the inner wing.

Hope to hear from you

Cheers
Erik
Erik

Steve. The last I heard, Roger Parker was still on the staff of the technical assistance section of the MG Owner's Club. Roger is very knowledgable and, if memory serves correctly, has done this conversion himself. A phone call or, if you have his work e-mail, an note, might be in order for a definitive answer. We do not see much of the O series engine here in the US. Les
Les Bengtson

Erik

The biggest problem I had with the engine was fittng the modified exhaust manifold. I used the top section from the Rover and fabricated the bottom to mate to standard MGB exhaust. The pipes from the manifold run side-by-side down between engine and chassis leg, with very little clearance. I think your biggest problem might be the steering coloumn on a left hand drive car, unless you can get the pipes to run one behind the other. Used the SD1 alloy inlet box with K&N type air filter at the front. I'll check tonight to see if the servo would go passed it.


I have fitted dual circuit brakes so will be able to compare left and right side for a later car.


I've also sent you an E-Mail with some photo's and a brief description of the problems I had.

Steve
Steve Williams

Steve,
What sort of power should your new engine be putting out ? And does the car feel quicker. I guess what I really want to know is 'is the end result worth the time and effort involved in the engine swap ?

If you have some pictures of the 'swap' and some more details, I for one would be interested in hearing more about it.

Regards, Charlie.
Charles Goozee

Steve,
Thanks, I will study the e-mail and pictures as soon as I get home tonight. I kind of hope that this will be a possible route to go. Our MOT is not so keen on substantial engine upgrades, so the o-series might be "it".

Cheers
Erik
Erik

Charles

Not aware of the actual power output, I've only been running it since the weekend and cretainly noticed an improvement.

Enjoying MG did an article on a similar engine mid 2000 (August - Octoberish). I think it takes the bhp to over the 100 mark. What I have noticed is how quite it is compared to 'B' Series - no tappet noise, infact come to a stanstill a few times and tried to restart the engine - hadn't stopped.

Personally I would do it again, I do about 10-12000 miles a year in it and think the improvements great. From choice I would choose a R/B or fit R/B crossmember and steering, this would have made life easier.

Also the gear lever linkage is a bit stiff (loosening now) and on quite a few occasions started off in third gear by mistake - first is almost redundant.

Still fine tuning and not got the best out of the HIF6 carbs. yet, so should get even better.

I'll E-Mail you and attach some photo's, about 8meg in two zipped files.

Erik

Sent you an email and first zip but your mail box is now full, send the rest tomorrow.

Steve
Steve Williams

Steve

Check pressure relief valve - you might have some swarf trapped in there. Not sure where it sits on O series, but may be worth replacing plunger and spring anyway. It's an inexpensive first shot.

Dave
Dave Wellings

Steve,
Thanks a lot for your mail. Got the letter and one Zip. E-box is emtied.

Cheers
Erik
Erik

Dave

Yes thought of that myself, but seemed alright when I overhauled engine, probalby do as you suggest and change valve and spring. Although, oil pump sits at front of engine, and contains relief valve, may also consider changing the whole assy.

Erik

Sent you the rest of the photo's.

Looked last night at exhaust side of engine, feel it's a wee bit tight for steering column to pass down side of manifold (maybe a redesign of manifold would get round it).

Steve
Steve Williams

Steve,
Watched your photos last night and it seems that it is a tight fit on everything on the carburettor side. It is possible to redesign my tubular extractor from the B-series. The biggest worry is still the measurement from the rear carburettor to the inner wing. In my case, to the brake booster setup. Your memory served you right. The article in Enjoying MG was in Aug 2000. The tight fit on the induction side could have been one of the reasons, why fuel injection was considered for the US market. Well it means that, I "just" have to remove the B-series and slip in the O-series. Nice winter project. From wathing your pictures, I have to agree that it seems to be easier to convert a RB than a CB. Nice dash board!!

Thanks again and Iīll keep you posted.

Cheers
Erik
Erik

Steve,
Thanks for the information and pictures. It would be interesting once you've sorted everything out to your satisfaction to have it rolling road tuned. To see what your's is producing compared with a good MGB engine.

Charlie.
Charles Goozee

After running the car this week I've noticed a number of required improvements.

1. The adjuster I made for the Alternator needs to be longer. I placed alternator low down to reduce the size of the fan belt, but now find it difficult to adjust the fan belt.

2. Much better to use R/B crossmember and possibly steering rack/column. The movement on the engine, now the mounts have settled down, is causing bottom of engine to knock on top of crossmember. This only happens when cold starting, freezing here this morning. May get round this with engine steady bar, but prefer to fit R/B crossmember.

Steve
Steve Williams

Steve,
What about trying some of the hardened V8 mounts? You may get a bit more vibration transfered to the cabin but it could save the hassle and expense of changing steering/x-member??

Just a thought,
Ian
Ian Johnston

This thread was discussed between 14/10/2002 and 17/10/2002

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