Hi, I am fitting a 4 71 to a sbc. I have the blower mounted and I have the bottom pulley all mounted. I have run a straight edge up from the bottom pulley and measured back to the flange on the front of the blower where the snout will mount. I planned to turn the top pulley around so the hollow side closest to the blower if that makes sense? I am unsure how they measure the snouts that you buy? Which measurement do I use when purchasing ? Any advice is greatly appreciated .. Cheers
You need to know the thickness of your upper pulley to find the true length of your snout. You can use the bottom pulley thickness as a guide as they are MOSTLY the same. Not all, but most. Once you have the top pulley face lined up with the rearmost edge of your straightedge, then you can measure the upper pulley inside mounting face to the face of the cover where you have the upper straightedge now. Snouts are sold measured from the front cover mounting face to the top pulley mounting surface. If your upper pulley is 1/2 thick, you would need a 7.5 long snout. Better to be a bit short than long. They make spacers in just about any thickness. -Abone.
Most pulleys are 1/4 -3/8s thick (Unless ful competition) , the snouts are Measure from mounting flange on gear cover to the flange of pulley , being first time running/ setting up you will find you will have assortment of shims & spacers Not even so call bolt on kits rarely are that , modification adjustments required. If Tight clearances become an issue you can always go to an 8 mm pulley and kevlar belt cut down or purchase to 1-1/2 set up , & probably can get away with a 1.00 -1.250 inch belt on 4-71. I have ran 6-71 @ 15 psi on 2 inch close to 700hp 7,000 rpms 8mm & 8mm GT belt/ pulleys
I actually ran a short snout with the pulley facing outwards for a couple years, couple guys at the track are doing the same, but when I went to the 8-71 I got a proper length snout and turned it around.
gary dyer recommends running the pulley opening face inwards, that way the load from the belt is centered over the bearing in the snout but later told me it wasn't absolutely necessary, it's just something he likes to do
^^^ 2 post above , It just depends on what performance level / Balance of parts & combo used there are so many pulley belt offsets just like wheels , most every ones experiences are different, Not all parts made equal, There are different in snouts not just lengths, bearing plates idlers , case , rotor design , intakes Ext ,Most here are street use , but there is parts that are just junk even for that . Including the bell linkages, buy & chose wisely. There are company's that cater to , DB , AFC- D , ProMod Pulling , Not seen / offered in summit & jegs
This is what I have,,,,it’s classed as a 6 inch snout,,,,,( measures around 5 7/8 ),,,,,I’m gonna use it on my Mopar small block,,( Desoto Hemi ),,,,LoL . I’m planning on running the pulley turned to the inside,,,,I purchased a spacer just in case I need it . But,,,you can run the pulley whichever way you choose,,,or need to . Tommy
I get the majority of my stuff through Good Vibrations but Alky Digger is another good one I ordered my custom offset TBS through Jegs because of better pricing with couple discounts I had, it was direct drop shipment from TBS to my house. I called TBS with a couple questions and they said they didn't build it for me, I gave them the order number, they agreed they built it but treated me as a non customer. I really wish I would've went through a different company for that fact alone, not that the product is bad, but when you drop several grand you'd like to be treated a little better.
20ish year ago RCD , BAE AJR & few others was making majority of blower parts for pro teams until most all are doing in house development ,research & manufacturing since early 2000s I was buying hand me down items from GVR they would get from race teams , Now GVR is not like what they where & Now some how they invoiced with Enderle , It was better to deal Direct (Enderle Jim & Kent) then I started buying direct from teams Me personally Im not impressed with TBS stuff , purchase a few items from Alky digger , there also a few manufacturing from Oz good to deal with ,
I’ve been very happy buying from Good Vibrations,,,,,,very polite and courteous sales people. Carry a wide selection of products. I’m not sure what is going on with Blower Drive Service,,,,,,they have quite a bit that is out of stock or discontinued. Good product,,,,,just hard to get anything you need . Oh well,,,,business is business,,,,,,if it seems to be going down,,,,look at the management or owners,,,,,the buck stops there . Tommy
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