madball

iTrader: (2)

I am in the process of installing an F1A, EPP Cog Drive w/ATI blower sprag pulley, and a ATI 918853 Damper. I am pinning the crank with the ATI (Transmission/Damper company) side pinning kit which I allready have. I did not like the idea of the front pinning kit that comes from ATI(supercharger company) and drilling into the front of the hub. At first I drilled a hole for the pin but for whatever reason, even though I used the correct size pin and marked the drill bit like they instructed, the bit went all the way through the crank so that hole was uselless. I then drilled a shallower second hole roughly 180* from the other. The thing is I am just unsure if that will be enough to hold the hub especially considering I will be running a 50mm Cog Belt. I called ATI(tranny co) and they said I could send the hub back to them so they can machine a second keyway at 180* for $40. ATI(tranny co) basically said it was my call and that one should work but of course two would be better. Also I will then need to drill two more holes at 90* from the two that I allready drilled. I just don't know if the two pins are really necessary or not. I don't know why they don't just machine two keyways in the hub in the first place. This is going on a stock LS1 and I only plan on running about 8#'s of boost by restricting the inlet side of the blower and using a 7.00" crank cog and the 4.5" sprag cog. Once I get the car sorted out I plan on putting in a forged stroker with a keyed crank so I can crank up the boost.

Has anyone here ever used a 50mm cog drive with the single side mount pin and had problems???? Any suggestions????

93formto98T/A

iTrader: (28)

I sheared a keyway on my lunati crank with the 50mm cog. Definietly go dual keyway. Believe me, it ain't worth it to have to pull and rebuild a motor when pins or a single key shear.

madball

iTrader: (2)

You don't think it will be a problem to have four holes drilled in the crank?

93formto98T/A

iTrader: (28)

The more you remove from the crank the weaker it becomes. But conversely the less surface area you have via pin or key the more likely it is to shear off under load. I wouldn't recommend 4 pins. Dual keys FTW.

madball

iTrader: (2)

I don't mean 4 pins. I allready drilled two holes but the one is useless because it went right through the crank and it also isn't a perfect 180* from the other. I plan on drilling the two new holes at a 90* from the other two. I dont' think the other two should affect it much and I plan on putting pins in there and just grinding them down to take up the space. You think that would be ok???? Dual keys will be done when I build a motor so I guess I am best off now to just have the hub machined and run two keys. That's the thing I know that these two unneeded holes weakened the end of the crank a little but I don't know which is worse, to have four holes with two pins or two holes with only one pin?

Part of me also thinks that the stock motor will go boom before I have a chance to spin the balancer/shear the single key anyways.

Also for the price of the ATI damper and the pinning kit you would think that it would allready come with two keyways cut. You would also think that it wouldn't of been so easy to drill through the crank and the pinning kit would somehow prevent this, besides putting a piece of electrical tape on the bit.

madball

iTrader: (2)

Shipped the hub out to ATI. Dual pin it is.