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MG MGA - best 1800 / 5 speed combination

Just wondering...If you were to install an MGB 1800 engine mated to a Ford Sierra 5 speed in your MGA, which year engine would you choose and why? Just trying to sort out opinions.
Thanks.......Jerry
Jerry Murphy

Best 1800 engine from MGB is the early 18V models taken from 72'73 cars. These engines have a stronger bottom end and also have larger valves fitted. After that point the heads reverted to the smaller valves of the pre 18V series. The motors you are looking for are likely to have an engine number starting 18V 581 582 or 583 these differences only representing transmission types.
Iain MacKintosh

The later MGB engines with 5-bearing crankshafts are nice engines. I use one and am very pleased with it However, these engines have electronic tachometers. This means a having a Smiths instrument instead of Jaegar on your instrument panel. You would also have the problem of sourcing the correct type depending on whether you are running positive or negative earth.

Steve
Steve Gyles

If you build an engine from an Austin 1800 the rear of the block can be drilled to take the rev counter drive & MGA cam.
Garth.
Garth Bagnall

I have an 18v engine with the Ford 5-speed. I used an old gauge and had it converted to electric so it still has the proper face. I also had the rear of the block machined to fit a dummy tack drive. It looks like the real thing with a lot more power.
JEFF BECKER

I take my hat off to you guys who go to so much trouble to keep the original look. I just keep all the original bits in a box and that satisfies me that I can return the car to originality should I so wish. Mind you, it is now such a big box I reckon I could build another car!

Steve
Steve Gyles

Jerry

On the theme of tachometer drives, the earlier 1800 engines with 3-bearing crankshafts retain the mechanical drive.

An advantage of the 5-bearing engine is the improved rear oil seal arrangement - still no oil drips (from that area) on my mushroom coloured carpeted garage floor!!

Steve
Steve Gyles

I agree; early 18V is the best choice. I recommend Peter Burgess book " How to power tune MGB". Lots of helpful stuff some of which can be applied to MGA's. cheers, Bill
w.g cook

HOOKED UP 3 MAIN B ENGINE TO DATSUN 240Z 5 SPEED TRANSMISSION. THE ONLY MODIFICATIONS MADE WAS TO CUT THE BRACE ACROSS THE TRANSMISSION TUNNEL, AND A FEW WHACKS TO THE TUNNEL AT THE BULKHEAD, ABOUT 1/2". BOUGHT TRANSMISSION AT WRECKING YARD FOR $100, REBUILT THE 3 MAIN. MADE BACKING PLATE FROM 3/8"ALUMINUM. USED 1600 BACKING PLATE AS A PATTERN. CUT THE ALUMINUM ON BAND SAW, AND BORED HOLES WITH DRILL PRESS. HAD TO CUT A HOLE IN THE DATSUN TRANS FOR LUCAS STARTER LOCATION. NOT QUITE COMPLETE ON INSTALLATION, BUT EVERYTHING LOOKS GOOD, AND DOES FIT. I HAD TO TAKE OUT THE PASSENGER FLOORBOARD, AS I HAD TO PUSH THE TRANSMISSION TUNNEL 1/2" TO PASSENGER SIDE TO PROPERLY ALIGN THE TRANNY.
cliff hughes

Cliff! No need to shout! :-)
David Breneman

18V 581 engine with side timing marks (so no more getting on your back with the timing light)
Mk1 MGB backplate and Flywheel.
MGB MK1 4 hole layshaft gearbox (Much stronger)
MGA rear gearbox housing and gearstick remote bolted to above gearbox. Thus not adapting gearbox mounts.
3.9 Diff (if you swap the diff then you don't need a 5 speed and you don't have to play about with tunnel and floor boards)


Bob's your uncle and you still have an MG not a Datsun/Ford.... Not that I mind that stuff I have a Datsun 5 speed in my MGB GT.

Cheers <MARK>
Mark Hester

Mark,

Not sure that the US side of the pond know anything about Bob being your uncle (or Sally being your aunt)!

Dan
Dan Barton

Mark - I think you mean 4 bearing, not 'hole' layshaft, and I agree that it is better than the earlier version, though in street use it doesn't make a lot of difference - unless you happen to be rebuilding it, when you sure wish you had caged rollers instead of loose ones!

I use a 3 main B engine in my Mk 2 coupe - best power of the bunch, and no fuss about tach drives. Yes, the 18V has bigger valves, but so what - it doesn't have more power. If you must, install an 18V head on a 3 main.......

I have left the 4.3 diff in the car as I didn't want to be bothered changing spider gears in my 4.1 to match the coarse spline axles in the Dunlop 4 wheel disc set up, but I may get around to doing up a 4.1 or 3.9 with the correct spiders and swap it in - only really worthwhile if you do a lot of highway work, and even then, I have run this car at 5000 RPM for hours on end on long trips....earplugs help.
Bill Spohn

To All...
I haven't responded to any of the posts on this thread, but am watching all with interest. I hope to upgrade my 1500 this winter and am trying to decide which way to go. I've read from the archives that a 1500 with the 5 speed would be a little underpowered.

Jerry
Jerry Murphy

Jerry,
If you only after a modest increase in power.
Then a 45 DCOE Weber and extractors even on a 1500 is worth at least 10BHP and even if you go down the whole engine swap route then the Webber can just be re-jetted.
Plus working in the engine bay becomes so much easier.

I have just been through this process as my 1500 before it broke the crank on they way back from Brands Hatch. It could overtake many MGF's if you didn't use the middle peddle too much.

5 speeds and overdrive's are OK, but they don't increase the power or take away power for that matter, they just make the driving more pleasurable. But this can be achieved by changing diff ratio's anyway and as MGA's have 15" rims you can then afford to use lower profile tyres witch obviously helps the steering wheel work better.

These days options are endless, so your best bet is to pick one that suits your budget.
I'm not a huge one for originality, but I do prefer to stick to MG parts where possible and Webbers have always been an option.
Have a good weekend all.
Cheers <MARK>
Mark Hester

Keep in mind what you want. I have a 3.9 rear end in my car too. This past weekend as we were coming back from a car show, 6 MGA's went thru a nice mountain range. Another car which also has the 5-speed was able to pull out quicker because he had a 4.3 rear end. I was able to overtake him on the flat lands due to my gearing. We both have an 1800 engine and the 5-speed. I also have a Judson Supercharger to help to. My car is still not tuned in yet as I only got it running again the night before.!!!
JEFF BECKER

This thread was discussed between 10/05/2005 and 20/05/2005

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