scrach building a crank damper

[redrocco]

I need to convert to 8mm htd belt drive to solve the low boost and belt slipage problems I am haveing with my whipple supercharger. The last problem in my way is the harmonic damper. I have a 54 tooth aluminum pulley for the crank but how do I attach it? As far as I have found I have 3 options. I could turn the od of the stock damper down and open up the id of the new pulley and press it on. This would only leave about .100" of stock damper material around the rubber in the damper.

I could also make a new solid hub for the pulley (aka no damper) or make a new hub that's od is .400" smaller than the id of the new pulley and pour it full of rubber and make it into a damper?

Any input would be ausome.

 

[cribbj]

Talk to Endevour Engineering in NZ. They'll fit an HTD drive onto your existing dampner, plus provide a complete set of HTD pulleys to replace your existing serp drive. I sent them a brand new dampner, as I didn't want to risk having a very expensive and custom fit HTD pulley separating from, and spinning off a 20 year old dampner.

Mine was the first one they did for the A/C and P/S, but I think it turned out well (although the engine isn't running yet).

Some more details here, starting at post 660, with pics of the pulleys around 665:

http://www.lextreme.com/forums/showpost.php?p=110064&postcount=660

 

[redrocco]

there pulleys look nice but I don't have the time or money to spend on shipping back and forth around the world. I have some of the new pulleys that i plan on using already.

I have a 3" wide aluminum 54 tooth, a 30mm wide steel 22 tooth and a 30mm wide steel 24 tooth. The 22 tooth is for the alt and the 24 is for the blower. I would be getting a aluminum 50 tooth for the PS and was seriously considering making a new aluminum 24 tooth blower pulley. 24 tooth pulleys can be made without the use of a cnc machine cause its a even deg tooth count (360/24 = 15). a 8mm ball endmill cut every 15 deg in the bridgeport with my spin indexer will work just fine.

My only remaining questions are is 30mm wide enough or should i go to 50mm requires re-buying a 22t pulley for the alt. And how to attach the 54 tooth to the crank. The options are solid hub, slip fit onto the stock pulley however very little material will be left between the rubber in the damper and the od of stock pulley (about .100" per side) or I can make a whole new damper useing a custom inner hub and bond it to the 54 tooth pulley with some 80 duro pourable rubber.

 

[redrocco]

After talking to one of the hodrod guys at work looks like the simplest way is to add a HTD pulley to the front of the crank pulley and run a deadacated belt just for the whipple. I have finished drawing up a hub/puck that will bolt the new HTD pulley to the inside ring of the stock damper. A new pulley for the whipple and a pair of idlers up top and it should be good. But now ile need to find a new 6 rib alt pulley to over drive the alt a tad.

 

[spf_lexus]

Since your running low boost, you would really benefit from a brace for your belt tensioner. My procharger pulls all the slack out of it the second I mash the pedal. Its just a plate the bolts up to the 12mm bolts above the tensioner that has a nut welded to it with a threaded bolt holding the tensioner down. Also, if you can get a pulley for the whipple tha has holes drileld at the bottom of the belt "V" to keep air from getting trapped under the belt it would help.

 

[redrocco]

I have now finished the add on pulley for the crank and a new drive mandrel for the Whipple. The add on is attached to the stock crank pulley using a custom hub. The Whipple drive mandrel is a standard 1 inch so as to be compatible with pulleys of varying tooth count. The crank is a 54 tooth and the Whipple is a 25 tooth for a ratio of 2.16. That will make the Whipple max out at about 8400 rpm at the crank.

 

[Madgem4ltr]

nice adapter redrocco any chance of you making another 1

 

[redrocco]

I can make another one. However I also machined the inside diameter of the stock damper just enough to true it up. If you have some way to do that and tell me its new finnished ID I could make you the properly sized adapter.