Having just fitted a Sedan injection system to a TR6, the following points
will probably be of use to anybody contemplating the same exercise.
> Anyway, having almost given up on the idea of installing a PI
>unit on my TR6 (mainly because of the difficulty and expense in
>obtaining all the parts), I stumbled across an almost complete setup
>this weekend and decided that I should obtain it whilst I had the
>opportunity. I think the unit is actually of a Triumph 2500PI car,
>since the inlet manifolds are painted red (is this a works car
>installation?). Does anybody know if these units were different from
>those of the TR6?
I guess that the first point to look at is, is your existing head/block
of the recessed sleeve variety. If so then you may as well give up now
or look at changing the motor as well!. The inlet ports on a recessed sleeve
engine are at different spacing to the earlier engines, and all the PI
systems were fitted to the early engines.
So if your engine is ok then every thing will fit, except the linkages.
I found that the rear linkage arm had to be reshaped to clear the
body work around the drivers footwell. The sedan linkages are longer and
at a different angles to the original TR variety but this will only affect
the amount of right foot need to achieve the required performance.
>Anyway, I now have manifolds and linkages, metering
>unit, distributor, injectors, fuel pump, fuel filter and relief valve.
>From current knowledge, I think the main things I'm going to need to
>make it a workable unit is a metering unit drive shaft (I think these
>are quite rare)
I would think that as you have found an almost complete system then you should
be able to find the metering unit drive shaft from a wrecked sedan. The other
problem that you will find is that there is no longer any manifold vacuum to
provide vacuum advance to the distributor, this will not stop the engine from
going but it will not go as well as it could until the distributor is modified
to provide all the advance from the weights.
> and all the return pipework and high pressure lines.
>I also think I might have to obtain a PI fuel tank for the fuel return
>lines.
The easiest way to install the pipework is to start with new steel piping
and feed it from the back to the front. Don't use the sedan plastic piping,
as it runs a little too close to the TR exhaust pipes for safety
You will certainly need a TR PI fuel tank! With the original tank you
will loose fuel pressure (and noise) with any thing less than a half a tank
of fuel on even the most mildest of corners. The piping can be set up
to suit the original tank and it will work if you keep the tank full! I made
a surge tank which fits in the fuel line between the tank and fuel pump, this
seem to have solve all the problems of not having a PI tank, if you need some
details of how this was constructed let me know and I will attempt to describe
the details.
>Anyway, I suppose my main question is: were the Triumph 2500PI
>units different in spec from those of the TR5/6 and if so in what way?
The only differences that I know of is in the calibration of the metering unit,
the unit can be recalibrated simply by adjustments to suit the TR specs if you
can find somebody who has suitably knowledge on PI units.
>I have noticed that the inlet manifolds are slightly different from
>the ones I have seen before, but this might be if it really was a
>"works" unit.
There are some differences between early and late model injector manifolds,
these will not make any differences to your installation. The differences appear
to be mainly in the area of idle air adjustment, to try to improve some early
idle problems.
> Anyway, for those of you who are worried that I might
>decide to instally this unit tomorrow, fear not. I realise that this
>installation is not a trivial matter, and I don't expect to
>contemplate any installation until I've undertaken all the necessary
>checks on the components and have upgraded the rest of the engine to
>suit - I think we are talking about at least a year from now....
Fear not, after having done a conversion, I would expect that it could be easily
achieved in only one days work. (so long as you are reasonable mechanical and
all the bits are in working order.
Mind you, I had a car ten feet away which was a genuine PI car to copy.
> Anyway, any advice would be gratefully received.
> Cheers,
> Paul.
I could wish you good luck, but the job is not that difficult if you are
reasonably organised, Good Luck anyway.
Greg Black
TR4A
TR5 (currently for sale)
gblack@bmr.gov.au
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