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Fv433 heat exchanger


Colvyn

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You've opened a right unobtainium can of worms!

As far as I know, there are no spares unless someone is hiding something, but they probably wouldn't be prepared to admit it, let alone sell.

I had mine rebuilt by the OEM, whose name currently escapes me,  but it took them two years as a "when we've got spare time" job.  I had multiple conversations with their technical director as he and his chief fitter are the only people who even remember them, everyone else has left and the assembly jigs are long gone for scrap. They tried to find any remaining spares, even getting the MOD to check what they might have lying around at Bicester, to no avail.  They eventually invented a flushing rig and left the exchanger on it for months until the individual elements were sufficiently clean to allow repair, and even then it was touch and go.  I can't remember what they charged me, but it wasn't cheap and they said it had probably cost them ten times what they actually charged me.

If I had to do this again (and I sincerely hope I don't) I'd take a different approach.  Ditch the hydraulic fans and replace with electric, freeing up space in the pack to possibly fit a modern heat exchanger from another engine although I couldn't say exactly what - space is very tight.

Andy

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Are you missing one or is it damaged?  Is the pack for an FV430 or is it an interesting item on its own?

Andy, was it made by Gallay or something similar?

I am not sure that electric fans would be powerful enough in view of the lack of any ram effect that you would see with a truck.  With the relatively light and gentle use a preserved vehicle will experience there are three options:

1. Don't have an oil cooler but have a temp gauge and poss thermostat and warning light.

2. Fit an oil cooler radiator in a good position on the pack, again with temp gauge and T stat.

3. Make a new heat exchanger from scratch.

If you are not going to use it on road run or continuously cross country, it may be surprising how long you could run on option 1 without the oil getting too hot.

I will have a look at a pack tomorrow to remind myself what it looks like.

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The original heat exchanger was made by BI Engineering in Wellingborough (I've just reminded myself of their name).  It's different to that used on the rest of the FV430s because the Abbot pack is completely different due to the lower profile of the Abbot.  It is, however, similarly complicated with four separate sections - engine, gearbox, steering box and hydraulic fans. 

The usual problem that affects all the FV430s (including the Abbot) is leakage of cooling water into the gearbox element of the heat exchanger, demonstrated by emulsified oil on the gearbox dipstick.  My theory is that someone got the specification wrong in terms of pressure requirement for that particular section.  I think that the Abbot heat exchanger is also more highly stressed as it's almost half the size of the usual FV430 variant but still asked to do the same job.

It's a ridiculously tight fit in the Abbot pack, requiring a fleet of crowsfoot spanners to tighten unions that have virtually no clearance between themselves and the pack frame.   It would have helped considerably if someone had decided to attach the heat exchanger to the engine rather than the pack frame as that would have avoided a mass of junctions between steel pipes and flexible hoses.

I've attached the relevant image from the ISPL and a photo of mine before it departed for rebuild.

Andy

IMG_3761aw.jpg

Figure A50.pdf

Edited by andym
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I have managed to get a Abbot heat exchanger, now to send it off to get it rebuilt the cost quoted is about £800.00 subject to inspection with a years warranty. Yay

ps includes carriage 

Edited by Colvyn
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I'm sure the heat exchanger is only really needed under harsh running conditions e.g. Fields and muddy conditions, under normal road conditions it's not really needed, so, if mine started leaking water into the engine oil I would look at bypassing it, and maybe putting cooling fan in front of the radiator. Looking at the size of the heat exchanger, yes it will help cool water, oil, but not that much to make a big difference, that just my thoughts.

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I wouldn't be too sure of that - the Abbot is generally undercooled compared to the FV432, which is why it has uprated fan motors and pump.  Don't forget it isn't usually the engine section that leaks, it's the gearbox section.

Andy

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3 hours ago, Colvyn said:

Mine was leaking into the steering box, I uncoupled it and connected male and female into a loop to get me out of trouble.

That's exactly what I'd do, will be fine doing that I'd have thought. There even room to connect it up to a oil cooler radiator in the abbot!

Edited by diesel1
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  • 4 weeks later...

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