Serpentine Conversion 13BT
 

Alright, Here is the Low down, I am looking to convert my remaining pulley system to a serpentine system, to avoid having differential tension applied to the crank shaft.

Please do not tell me why the v-belt is fine, or this is a waste of time, we will never agree.

Instead help me figure out whether or not this can be done.

So I have a S5 13BT
No power Steering, or Mechanical Water Pump
So that leaves me an FD Alternator
Aircon Pump
and the Crank of course to run.
my understanding is that the alternator, and the crank line up perfectly, so this is not an issue.

Now what is an issue is getting the Aircon Compressor to fit into the equation.
Does it line up true to the crank, and alternator?
Do the FD use the same compressor as we do? Can the pulley be replaced? Or do I need to convert to the FD Aircon Pump?
Now finally if I need to convert to the aircon Pump, do I need to use the FD accessory Bracket as well? (modification required I know)

I am not afraid of fabrication, but I do not have the means to machine a custom pulley set, therefore, I am attempting to piece one together.

I know mazdaracing used to produce one back in the day. However at that time I did not see a need for it, and did not purchase one, and they are no longer around.

You wouldnt believe it but i was just wondering about this again just now. I want to run multi-vee on my 12a front cover 13bt (i believe same pulleys as 13bt?)
Mine's just the alternator and water pump, and can switch to an FD (equivalent) alternator if necessary, so really just wondering if the water pump and crank pulleys are interchangeable with FD.
Sorry for thread bombing, will be watching with interest.

the FD and Rx8 run 2 belts, one for the alternator, and water pump and the other does the AC and PS

so the main pulley has two belt locations. the FD ac compressor and bracket will fit, you'd need to adapt the FD compressor to the FC hoses. or possibly there is some car that used the same basic compressor as the FC, but with a serpentine pulley.

the compressor pulleys do come off, and there is some interchangeability

the FD and Rx8 water pump pulleys are much shallower than the earlier engines, so they don't work. atkins, and KSP make kits to run a serpentine belt... or there is the 13B Cosmo water pump pulley that does work

Ok so I'm going to pull this out my memory banks . The pulley set I have is from a Cosmo . Now from what I remember , they have a serp and v belt setup . V belt being on the ac compressor . Now if I remember right and I could be wrong . The Cosmo compressor was the as as the fc . I just think the brackets are a lil different . Look for Cosmo parts is all I can say .
Here's a couple pics of my setup. I polished the pulleys and Taurus alt . S4 6port turbo
https://cimg6.ibsrv.net/gimg/www.rx7...fee5bfbf3.jpeg


https://cimg7.ibsrv.net/gimg/www.rx7...476fd0844.jpeg


https://cimg8.ibsrv.net/gimg/www.rx7...25b9ce126.jpeg

Thats awesome. Exactly what i was looking for. Cheers guys.



I wonder if this will work? http://atkinsrotary.com/store/74-92-...ulley-Kit.html

I'm sure I picked up that kit and it is sitting in my shed..

Just make sure you keep the og crank pulley for the timing marks just in case .

Dude, can you check your Atkins pulley set? Are they steel or aluminum or something else?

I also used cosmo pulleys
Fd alternator
Fd ac compressor mounted to a factory s4 ps delete ac bracket
Had to weld some mounting tabs, i think 2? On the bracket to get the fd compressor in the right spot because the alighment is not right as-is.
I dont know if another compressor would work or if you can swap the clutch and pulley from a fd to a fc compressor

Lines were simple i cut the end of the fd lines off and welded them to an adapters hose shop made the hoses. Very simple

All much easier to figure out with the engine out of the car

Btw i would classify this as more of a ribbed pulley swap not a serpentine swap.

Thanks guys for the input, a little more than I had;

Now the way I understand this is that the AC will need to be shifted forward the with of a belt plus a Rib.
The serpentine portion of this will be mine to incorporate 1 iddler pulley to ensure that there is sufficient contact with the crank pulley, and a tensioner between the pulley and the alternator to ensure efficient belt routing, and constant tension on the whole assembly. Hopefully this will ensure ease of maintenance, and lower wear on the main front stationary bearing.

When I get all the parts and spacing sorted out I will revisit this exact thread and impart my experience with the community.

You just reminded me of the last piece, i used a fd ac tensioner it bolted right to the s4 bracket

Where do you intend to install a single tensioner?

I am looking at installing it after the AC compressor, to keep the belt tight and to keep it out of the way of the Vmount Intercooler Piping. So it would be just a little above the horizontal line of the top of the a/c compressor, then the belt would go up to the alternator, then back to the main crank pulley.

Hopefully that makes sense.

you thinking a self adjusting tensioner or something you will set?

Nope self adjusting tensioner, that way it will keep constant tension on the belt as it stretches without undue stress on the front main bearing!