The V8 Owners Forum -

As far as tensioners go. One tensioner per belt is sufficient.

Idlers. IMO you need as much belt wrap as possible around the drive pulleys to prevent slip.
You also need sufficient idlers so there are no long unsupported sections of belt where it can start to orbit ( wobble )

belt control and alignment is critical.

As for breathers. I always just vent as many breathers as possible into a well designed catch can ( with adequate venting of course )

ideally this will be designed to recirculate any caught fluids, back into the sump, below the level of oil in the sump. So its a fully closed loop system, and should be maintenance free.

Cheers stevie,
none of the breathers return back to the engine then????

Measured the bottom pulley this evening, bit dark and awkward, SO hopefully i have got it right,
i got 6-3/4" across the bottom pulley if any one has a serp crank pulley to hand which they can measure it would be a help as mines sat on the engine in the car .

i think its too big, and im going to have to run a seperate belt and pulley for the charger
which is going to make more fooking work

I recon that works out at a 5" pully on the supercharger to give you 38000 on the compressor at 6500 revs on the engine (no allowance for belt slipage) I would think a nice big supercharger drive pully would be a good thing as it will reduce belt slipage surely?? With max revs for the pully at about 8600, it will need a ballance, but only to about +-2gram or so.
Best regards
Mike

Recirculating breathers to the intake is to keep the tree huggers happy ( and MOT man )

With adequate oil/air seperation you can retain this feature if you like. Far handier just to vent to atmos.

As for pulley, belt wrap is good. If this means big pulleys, all the better. Far less chance of slip.

cheers stevie,
looks like im going to have to get one made then for the charger, doubt thats going to be cheap

this sort of thing for the breathers?
http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... SS:GB:1123

If you're lucky, you could maybe do a dodgy improvise with say a PAS pulley off something.

But obviously the more metal required for the pulley, the dearer it might be. But 5" and only 6 rib shouldnt be too bad.

It will likely be sub £150

will have a look about the weekend for a 6 ribbed, or is the rv8 serp 7 rib?
anyway will look for a 5" pulley,

Tony are you looking for a 6-rib pulley? what size? I got a few metal and composite ones at work that you might be able to get drilled to fit.

hi mate,
well if i use the serp o/e set up and run a single belt, i need a 7rib 5" pulley,
if i run a second belt for the charger, i need to get a pulley made to bolt on the front of the original crank pulley some how, and one for the charger also,
But then the sizes depend on what size crank one i get made etc,

That sounds like custom pulley job. I'll check. I know we keep a few metal and composite 6-rib pulleys, not sure if we got any 7s. Will look tomorrow.

if i have to run a seperate belt then can be what ever rib mate,
6 or 7.

been looking around and 5" seems to be a popular size for powersteering pumps,
i need to make an adaptor to fit the crank so could i not use one of these pulleys with a slight bit of modification??

only prob is so far i can only find a charger pulley up to 3.75"
which at 6.5k rpm it will give a charger rpm of 38.134rpm.
134rpm above recomended max revs,
as the engine will rarely hit 6.5 and mostly be gear changed around 6k,
BUT at 6k the above pulleys give a charger rpm of 35.200rpm

will this be ok? (Mike )

bottom pulley pics you wanted Marki,, sorry not that good mate, bit tight to get camera in







and the powersteering one on my engine which could vbe adapted for crank pulley for charger?

will this be ok? (Mike )
Yes
Mike

kiwicar wrote:will this be ok? (Mike )
Yes
Mike

cheers mate,
looks like may have a pulley combo to work to now, 5" crank (possible modded PS pulley) and a 3.75" charger pulley,

summit have that 3.75 charger drive, its 6 rib, ally pulley $37.95,
with taxes taxes and taxes works out about £80ish when it gets ere if i we got it right.