I have bought an alternator from a Kia Pride, it is about the same size as a grapefruit. I have now refitted my engine and tried the alternator, but the only place it will fit is high up above the chassis rails. This will make the tensioning pivot difficult, and the v belt will only be in contact with about 45°'s of the water pump pully - is this a problem?

Secondly, I have a cunning idea. Can anyone think of a reason why I could not use a cambelt tensioner from a pinto to tension the fan belt and increase the contact area on the water pump?

Thirdly, has anyone tried the Renault 5, Peugeot 309 90° fanbelt idea? Probably a bit of faffing around but really zainy!

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Originally posted by Mark Allanson
Thirdly, has anyone tried the Renault 5, Peugeot 309 90° fanbelt idea? Probably a bit of faffing around but really zainy!

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The fan belts were about 2 metres long and ran from the front pulley to a pair of idler pulleys which changed the direction of the belt by 90° to the alternator.

Anyone any ideas on tensioning the back of a V belt?

Mark

I have used a Bedford Rascal/suzuki jeep alternator,Conrod popped round and welded me up a new mount and the top mount had to be re-hashed.
It was just a case of searching through an old box of belts till the right one came up,ended up with an 864mm V belt.

This was on a pinto lump though.

I would definitely look for an alternative that gives more than a 45deg wrap to the water pump pulley. At max RPM a waterpump can sink 10-15hp without much effort, and a very limited belt contact patch is very unlikely to support that without significant slippage. I would look for at least 90deg and more if possible.

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Originally posted by crbrlfrost
I would definitely look for an alternative that gives more than a 45deg wrap to the water pump pulley. At max RPM a waterpump can sink 10-15hp without much effort, and a very limited belt contact patch is very unlikely to support that without significant slippage. I would look for at least 90deg and more if possible.

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as a gif
Rescued attachment Pulleys.GIF

Mark

I dont see why the tensioner wouldnt work,but then again i've seen alternators sitting up pretty high on book chassis with pinto's in as well.

Maybe the angle isnt such a big deal.

It would also help that the alternator could be fixed, and not pivoting to provide the tension

Mark

Got to admit there still isnt much room on mine between eng and shasis rail,i'll take a pic a post it tomorow.

Mine pivots like normal but its held in place on the top mount with a very crude modifications that is one of my best designs and took me all of my technical drawing skills to achieve. ( honest)

If I put my alt in its natural position, it doesn't need bolts or brackets - it's just wedged between the chassis, engine, and steering column!

Mark

Here's some pics of mine in situ,might just be able to see the main bracket at the botom pivot.

top bracket is just as crude but it works fine,also gave me something to bolt the hose from astra bottle too as it tended to move a bit when hot.
Rescued attachment Dscn0152.jpg

And from the front
Rescued attachment Dscn0151.jpg

Another from the front
Rescued attachment Dscn0150.jpg

One of the primary reasons for the switch to serpentine belts is their ability to run as many accessories as you wish, via use of tensioners on the back side. I'm not a specific belt expert, so take this as only something to look into, but V-belts have been known to turn themselves inside out on high performance engines due to the types of strain they incur, and I'm thinking that a backside mounted tensioner might contribute to this problem. Probably why they used to use multiple belts rather than snake them through a series of pulleys and tensioners. Just a couple of thoughts in case they may be worth something. Cheers!

could allways do away with the water pump and fit an electric one instead, or how about driving the alternator off of the propshaft??

Do you have enough room in front of the engine, to mount the alternator backward(facing the engine)?

I know Ferrari does this on some of their engines.

[Edited on 13/7/04 by The Shootist]

I looking about all the alternatives, I think there is more room in a MK, but I will try again, or mount it higher, or facing the engine (looong mounts?)

Are alternators directional,i mean if you turn it round will it still produce current ?

Just a thought

The alt produces AC and 9 diodes bring it back to DC, its the bearings and general construction is my only concern about spinning it backwards

and the cooling fan

Surely suck is as good as blow as far as the alt is concerned?

It'll blow either way. (actually it sucks from the backside) Most CF type fans work just as well backwards as they do front ways. In industrial fans the forward or rearward tilt of the blades is designed to prevent stalling in a particular application.

Just moving air as in an Alternator should not be any problem.

Some Alti's don't even have a fan.

[Edited on 14/7/04 by The Shootist]

Spinning 'backwards

Ther should be no problem with the power generation but there may be an issue with the existing wear pattern on the brushes. This could result in arcing and accellerated wear. Might be a good idea to fit new brushes if you decide to go this route.

Mick