BXProject

David wrote:Not quite. A 405 with air has an amusing setup with the pas pump above the alternator and a eleventy-billion mile long serpantine belt driving it all.

Ahh yes, I had rather forgotten that 405's had PAS pumps
Although I haven't looked at much in the way of cars apart from Cit's for ages so..... thats my feeble excuse!
I think I best go look at the kit I have and see what I do and dont have since I know it isn't completely complete, and it's been, oh, I dunno, 8 years or so since I actually did look at it

So I couldn't find the tensioning roller - even though I know I've seen it quite recently and put it somewhere 'safe'........so I fiited on of the rollers from the Xantia set-up. Ah yes, it was the one David said was pointless..................and indeed it is. Not that I doubted you DR but I was any port in a storm. Anyway's, I've bolted a Xantia cambelt idler roller onto a spare threaded hole on the bracket that holds the useless roller and it provides a reasonable bend in the belt.

I intend to use the alternator tensioner to tension the belt - can anyone see a problem with this. All the pulleys look in line.
I've cut the old belt and removed about 185mm so I'm looking roughly for a 5PK1045 to a 5PK1025 as measured without tension. 5PK1015 I hope should do it.........
Fingers crossed tomorrow I'll get the system charged and I'll be A/C away

Bx Bandit wrote:I intend to use the alternator tensioner to tension the belt - can anyone see a problem with this. All the pulleys look in line.

Now put a straightedge across various pulley faces and check them. I will almost guarantee the alternator is about 5-10 mm too far towards the nearside of the car. You have two options. Either space the pulley out with a couple of washers (I've done this before) or fit a different mounting (a fixed one which is used with 5pk belts and a tensioner)

Will do squire. The odd thing is that the car obviously came with the correct mounting, but I had to fit the 'normal' one when I broke the bearing. I hope I didn't give it away on J Dyanes engine - don't think I did. Isn't the position of the alt determined by the bottom cast mount that bolts to the block?

It's become a little academic right now anyway as my a/c bloke can't do it about for a week. He want's £60 for a drop in (R413a I think he said). I rang round and the next price I got was £120!

Oh Vanny, with the Xantia alt mount did the alt hit the rad fan cooling switch? It would seem to drop the alt by about 45mm compared to the std BX alt mount.

It's the bracket that bolts onto the engine that determines the alternator location. Adjustable alternators were designed to be used "on their own", IE without anything else on that end of the engine, and as such were designed with a 4pk belt, 4-rib crank pulley, and were generally a fair bit tighter to the engine than the 5pk setups.

R413a is what I ran around with in my 405 AC for a fair while. Worked very well, but I had to disable one of my pressure switches as the pressures for R413a are not identical to R12.

Managed to get the air out of the vents down to -5 at one point... with an outside temperature of 30. I thought that was quite effective!

David wrote:Managed to get the air out of the vents down to -5 at one point

Is that with the standard controller? I thought it was meant to back the compressor off at around 0c on the evap, giving 3c on the vents.

Bx Bandit wrote:Oh Vanny, with the Xantia alt mount did the alt hit the rad fan cooling switch? It would seem to drop the alt by about 45mm compared to the std BX alt mount.

That was using the Xantia mounting bracket. Initially it did hit the fan cooling switch, but i converted to a 309 DTurbo rad which has the switch at the other end.

David wrote:the pressures for R413a are not identical to R12.

I think Bandit was going down the R134a route? And changing the oil? Though if the project takes long enough i'd reckomend using oil suitable for R1234yf.

Isn't R12 the one that's banned now due to something about a small hole in something called the Ozone layer?

R12 is a CFC, R134a (and i guess R413a) are HFC, they both do some damage and hence come the 4th of July a big box of regulations come into place about who can use/handle/store R134. R134a does a stack load less (factors of tens) compared to R12.

The hole is caused by the sun, but is occurs due to thining of the ozone layer. My reckoning is that it would naturally happen over time anyways.

Vanny wrote: The hole is caused by the sun, but is occurs due to thining of the ozone layer. My reckoning is that it would naturally happen over time anyways.

I blame the cow farts...

I blame all those Chinese for breathing out too much.

David wrote:It's the bracket that bolts onto the engine that determines the alternator location. Adjustable alternators were designed to be used "on their own", IE without anything else on that end of the engine, and as such were designed with a 4pk belt, 4-rib crank pulley, and were generally a fair bit tighter to the engine than the 5pk setups.

R413a is what I ran around with in my 405 AC for a fair while. Worked very well, but I had to disable one of my pressure switches as the pressures for R413a are not identical to R12.

Managed to get the air out of the vents down to -5 at one point... with an outside temperature of 30. I thought that was quite effective!

I did have a look and a measure with a straight edge - were your ears burning today? Cos the way I was cursing you, your ears should now be nicely charred!!!!!!!!
The a/c pump was 2.5mm to the n/s of the crank pulley and the alternator 1mm. It's likely that the bracket I used was the one that came with the car when I bought it from you. I packed out the pump and it's spot on, but I've left the alternator as is.

Vanny - I was undecided for a while but I have decided to go for the R413a. It's my cheapest option combined with the least hassle. Interesting about the pressure switch David - I may need to bend your ear about that when the time comes. I'll settle for -5!!!! My Dad's XM often has vapour trails coming out the vents! totally cool!

Interesting too about the 306 rad - was that a bolt in swap?

309 not 306, very very rare, but brand new was only 90 quid! Pretty much drop in, slight mod to the top panel, the lugs are in slightly different places. Bottom lugs are the same. Not sure how well it would work with a condensor as well though. I still have it, planning to flog it whan i get my arse into gear.