Modified Stag has Vibration Problems with Ford V6 Engine

[Mike Parry <mike@domain.elided>]

Can any one help please?

I have recently purchased a 1973 Stag Auto with no rust, that has not
been used in over 9 years.  The car has had an engine transplant back in
1980 when the FORD 3.1 V6 Essex Engine was fitted.  This was supplied
and fitted by a company called Specialised Engines of Grays in Essex; it
has a stage two conversion with new Cam, Webber Carb, gas flowed head,
enlarged valves and balanced crank and pistons etc. According to the
paperwork it is supposed to develop 195+ BHP.,  (often used in Ford
Capri's).  I am lead to believe that Specialised Engines carried out
many of these conversions

All this sounds fine but here are the problems: -

1 I have been told that the torque converter and flex plate fitted are
the ones originally supplied with the Stag , and these will be wrong for
the auto box as fitted (BW 35), the power curves for the two engines are
not the same.  Does any one have any experience of this engine
transplant with an auto, and if so can you advise me if the torque
converter should be changed, and to what?.

2 I have a vibration that feels as if it is under the floor and comes in
at about 65mph.  It clears again above 80 with the peek at 70.  The
amplitude of the vibration pulses at about 1 - 1.5c/s and is worse when
power is applied.  If I try to balance neutral power, the vibration is
considerably reduced.

To try to remedy the problem I have fitted new U/J's on the Prop-Shaft
and on both Half-Shaft (6 in all, one on each was seezed) as well as
fitting new rear wheel bearings and Engine mounts.  These actions have
made some improvements but the basic problem is still there.  

Although the engine is supposed to be balanced, I understand that the
Ford flex plate carried a large balance weight.  As I have the Stag flex
plate fitted, could my engine be out of balance? but wouldent the
original owner have noticed and done something about it? I cant ask him
as he has been dead for nine years. 

I would welcome any advice or suggestions from any one as to what the
problem might be.

I would like to here from anyone who has a similar modified Stag who has
none of these problems just so I can convince myself that it possible to
fix.  In the long term I will try to find an original V8 engine to put
it back as it should be, but for the time being I must put up with the
Ford engine and try to fix the problems.

Sorry this is such a long communication but I do not know how I could
make it much shorter.  

Thanks 


Mike Parry
Suffolk UK   

-- 
Mike Parry