Mazda Rotary Club

Cars by Model Type => 2nd generation RX-7's => Topic started by: B.Martin on October 19, 2011, 08:49:05 PM

Title: Dual alt pulley?
Post by: B.Martin on October 19, 2011, 08:49:05 PM
Do you not need 2 pulleys for this or is it just the one? I only got one is that right or should I have 2?
Title: Dual alt pulley?
Post by: Grant Monkhouse on October 19, 2011, 09:02:09 PM
Do you have 2 alternators? I always thought the dual
Pulley was off the eshaft?
Title: Dual alt pulley?
Post by: monterx7 on October 19, 2011, 09:08:13 PM
i added a dual alt pulley when i got rid of my air pump...if you take off the air pump belt, then there is very little belt-to-pulley contact on the water pump pulley, so thats why i doubled up.  
 
so now i have 2 belts with little belt-to-pulley contact haha
Title: Dual alt pulley?
Post by: Grant Monkhouse on October 19, 2011, 09:13:34 PM
Shouldn\'t you use an under drive kit then?
Title: Dual alt pulley?
Post by: m1tch on October 19, 2011, 09:25:14 PM
Quote from: Grant Monkhouse;795366Shouldn\'t you use an under drive kit then?

The issue is that the single belt will slip between the alt, water pump and main pulley if there is only 1 belt. I have fitted a dual alt pulley as my mechanical air pump has gone, gives more contact meaning that the water pump is correctly driven. You don\'t want to fit an underdrive kit as that would reduce the flow, they are ok if the car is for track only.

The other options are fitting an idler pulley or a shiny Gilmer kit
Title: Dual alt pulley?
Post by: L18M on October 19, 2011, 10:09:02 PM
its just one block with 2 groves that fits a belt into each one.

(http://t1.gstatic.com/images?q=tbn:ANd9GcRcDz1Q0BjBsHA0RwBJNMimrdN70lmj0EOzK-ysZpgXWQMe9-ZP)
Title: Dual alt pulley?
Post by: B.Martin on October 19, 2011, 11:10:28 PM
Oh that\'s okay then, cheers Liam. Oh by the way I finally got the leads today, great stuff! Just need the air pump removal blanky things and the belts now and I can get that done, oh Liam... I need an induction kit :Giggle
Title: Dual alt pulley?
Post by: Prof on October 20, 2011, 07:44:37 AM
Yep - the location of the water pump pulley means that with a single alternator belt, there is only a small contact area (about 2" of circumference on the water pulley, and at a slight angle).  Normally that pulley is also driven by another belt going around the air pump and has about another 3" of contact.
Title: Dual alt pulley?
Post by: B.Martin on October 20, 2011, 08:05:51 AM
Oh well thats fine then, if anyone is kind enough to live near a halfords and fancy picking me the belts i need up and shipping them to me i\'d be more than happy to pay the costs plus and extra €10 in beer tokens for your trouble. As frankly Cyprus is a poor attempt of a country when i comes to car bits!
Title: Dual alt pulley?
Post by: L18M on October 20, 2011, 11:54:15 AM
re-a filter? lol

i can pop to halfords for u for when i post out coilovers to you lol

blanking plates.. (doesnt say if tis fd or fc though.)
http://www.racingbeateurope.com/b-blanking-plate-kitb-741-p.asp
Title: Dual alt pulley?
Post by: grinder on October 20, 2011, 12:32:39 PM
what belts are you putting on ??

i need to know if i ever use the dual alt pulley i bought 6 yrs ago :D

Im sure you can use some old mini belts ?
Title: Dual alt pulley?
Post by: B.Martin on October 20, 2011, 01:45:04 PM
Quote from: L18M;795425re-a filter? lol

i can pop to halfords for u for when i post out coilovers to you lol

blanking plates.. (doesnt say if tis fd or fc though.)
http://www.racingbeateurope.com/b-blanking-plate-kitb-741-p.asp

Re-A filter is rather pricey is it not? Good one with the coilovers ;)

Re- the racing beat blanks, its for the FD.

Quote from: grinder;795428what belts are you putting on ??

i need to know if i ever use the dual alt pulley i bought 6 yrs ago :D

Im sure you can use some old mini belts ?

I heard this too, i\'m sure someone can clarify.
Title: Dual alt pulley?
Post by: L18M on October 20, 2011, 05:04:37 PM
just use a normal fc alt belt.
i thought the mini belt was for the \'yoohoo\' belt?
im just using normal alt belt, so have 2 of them on the engine :)
Title: Dual alt pulley?
Post by: grinder on October 20, 2011, 06:41:28 PM
cool

anyone got a halfrauds part number ?
Title: Dual alt pulley?
Post by: Prof on October 20, 2011, 07:15:32 PM
Well the belts are AVX10 x 800La (Gates 6212MC) - so HB800a should be about right me thinks ?
Title: Dual alt pulley?
Post by: m1tch on October 20, 2011, 10:37:54 PM
I got 2x Halfords HB800s, they fitted fine when Prof and I fitted the dual alt pulley to my FC on Tuesday :)
Title: Dual alt pulley?
Post by: grinder on October 21, 2011, 12:41:25 PM
how easy is it remove the nut on the alt ??
Title: Dual alt pulley?
Post by: Prof on October 21, 2011, 12:46:19 PM
easy with a leccy torque gun or an air gun - otherwise foget it ;)
 
On m1tch\'s car the stock fan is still on, so we had to take the alternator off the car to remove the pulley as you couldn\'t get any tool in there with the fan and shroud still on.  With electric fan mod it\'s much easier and could be replaced in situ.
Title: Dual alt pulley?
Post by: L18M on October 21, 2011, 02:19:22 PM
i took my alt off and took to local friendly garage n they undid it for me and put the twin pulley on :)
Title: Dual alt pulley?
Post by: m1tch on October 21, 2011, 06:11:32 PM
My dual alt pulley is SHIIIINY :D
Title: Dual alt pulley?
Post by: B.Martin on October 21, 2011, 08:21:15 PM
Mine is as well, got a few scratches on though.
Title: Dual alt pulley?
Post by: papercutout on October 25, 2011, 05:02:39 AM
This is old, but I\'ve not been on here for a while.


Halfrauds part number - HB800a. That means it\'s an 800mm belt Ben, just make sure you find 2 matching new ones of the correct width and it\'ll be easy for you. You MUST be able to source 800mm belts in Cyprus!

To get the nut off, I stuck a flat head screwdriver through the vent holes in the alternator (front to back) as far as possible, and undid it fine. Be careful though - I also had to bend the fins back slightly, and this isn\'t easy, because 1 caught after.

I know someone who can make blanking plates for a reasonable price if you still need some. They\'re what I\'m running on my rex, and I did a thread a while back showing pics of them. They are really, really top notch work.
Title: Dual alt pulley?
Post by: B.Martin on October 25, 2011, 07:28:40 AM
Right well i\'ll probably just buy the belts of halfrauds online and have them sent to my mums address and she can ship them to me. Probably try and find someone with a decent drill to remove the airpump, i\'ll have a search for your for sale thread when i get a chance mate. Are they good quality and good price then, obviously you know how us FC lot roll ;)
Title: Dual alt pulley?
Post by: papercutout on October 25, 2011, 02:34:23 PM
I\'ve just texted him about the blanking plates, will let you know when he lets me know.

You don\'t watch a drill, you want a ratchet gun!

For sale thread with photo of blanking plates and photo\'s of the turbo he did:
http://www.mazdarotaryclub.com/forums/showthread.php?t=71491
Title: Dual alt pulley?
Post by: B.Martin on October 25, 2011, 03:04:19 PM
Okay let me know about the blanking plates.