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Re: Engine choice

To: Barney Gaylord <barneymg@ntsource.com>, "Jack Levy" <jack@cocoinc.com>
Subject: Re: Engine choice
From: Bob Shaw <shaws@mlcltd.com>
Date: Mon, 7 Aug 2000 19:20:52 -0500
At 1:30 PM -0500 8/7/00, Barney Gaylord wrote:
>At 11:24 PM 8/6/2000 -0400, Jack Levy wrote:
>>Leaving the obvious originality issues aside, what are the disadvantages
>and advantages of putting a 69 MGB GT 1800 in a 57 MGA?
>
>Advantage: a little more grunt.  Disadvantage: a little work in the
>conversion, but still a bolt-in with the right parts.  Otherwise not mech
>of either, but quite a few MGA 1800 already on the road.

Absolutely concur!

>  >.... what do I need from the GT?
>
>Just the engine, and a water pump with the pulley mounting flange in the
>right place.  Use the MGA engine mounts,

The A mounts and the mounts from a '69 B should be the same.

>  water pump pulley,

The A pulley may not fit. I ended up using the B pulley in order to 
make everything line up correctly on my 57 conversion

>  thermostat
>cover, and engine rear plate (and maybe the MGA crankshaft pulley).

Keep the B crankshaft pulley. You will also need the tach from a '65 
through '67 B, and you will need to splice the loop on the back of 
the tach into the wire from the switch to the coil.


>   Have
>the MGA rear plate bored out to accept the MGB rear crankshaft seal.  You
>need an adapter bushing for the rear end of the crankshaft to accept the
>(smaller) pilot nose of the MGA gearbox input shaft.

Moss carries it, but I can't recall the number

>Otherwise you could
>install the MGB input gear into the MGA gearbox.  Use the clutch disk that
>mates with the splines on whatever gearbox input shaft you have.
>
>To mate the 5-main engine to the 3-syncro gearbox (small bellhousing) you
>need a flywheel from a '65-'67 MGB 18GB engine.  To use the MGA clutch
>pressure plate with the MGB flywheel you need to remove two of the three
>locating pins and install another one (machining required) to give it two
>pins @ 180 degrees.  To use the MGB pressure plate you need to also use the
>MGB clutch release bearing, release arm, and the gearbox front cover from a
>MGB 3-syncro gearbox.  These last bits are required because the MGB
>pressure plate is thinner and the release bearing has to be relocated
>farther forward.

Another option is to convert to a B fully synchronous transmission. 
You will have to fabricate a new rear motor mount to fit the 
transmission ( I formerly marketed one, but stopped. I would make 
another run with 5 orders. The parts from me cost $100. If you are 
mechanical, can weld, and are creative you can make your own for less 
than that.) You will also have to relocate the shifter bubble or the 
hole in the shifter bubble on your transmission tunnel. You will also 
want to use an overdrive cable and the B starter on this application. 
Iaf you want to use an overdrive transmission you will need to modify 
the frame and the tunnel. In either case you will want to extend the 
length of the drive shaft 2.25 inches. My A with overdrive is a very 
pleasant car to travel in.
>
>Barney Gaylord
>1958 MGA with an attitude
>     http://www.ntsource.com/~barneymg

-- 
Bob Shaw
Check out Shaw's Garage at http://www.mlcltd.com/shawsgarage/
My British Car is NOT leaky - it's merely marking its territory.

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