I am working on a car with a F1D mounted on a SchoneckComposites bracket cog kit as seen here: http://www.yellowbullet.com/forum/sh...d.php?t=372769
What combination pulleys is anyone with this setup running? Right now this car has 83/42 pulleys and the crank pulley was so close to the main plate that bolts to the front of the block that it rubbed under boost, and after the plate was clearanced the crank pulley rubbed the idler pulley as you can see in the pics. The shoulders on the idler pulley have now been turned down to clear. I believe its the crank/pulley flexing and not the bracket moving. Also how tight do you run the cogged belt? This was so tight it took 2 full turns of the tensioner bolt just to slack the belt 1/16.

 

I am running 83 crank 44 blower with this belt http://www.mcmaster.com/#6486K32

 

Stock crank?

 

Callies crank. JJcamaro do you have the same mount? And if so do you have the same tight clearance? We aren't even able to remove the belt without taking the blower or the crank pulley off its so close.

 

Probably should move down on the crank pulley. Also the belt doesn't need to be that tight. I get mine to where I can just barely twist it 90* and call it good. Never had a problem.

I'll tell you a weird story about crank flex. I run a cog set up on my ls, but use an msd flying magnet wheel on the front for a crank trigger. I had the gap set at .045" and noticed the wheel started getting rub marks on it. Well when I tore it down, the sensor was obviously touching down on the wheel. There is nothing on the crank sensor bracket, and it it billet so pretty rigid. I told my engine builder and he agreed with me that if the crank snout was moving .045", that it was broke in half. The crank is fine and the front main bearing was fine. We can only guess that it is bending the crank, which to me is crazy. But no other way to explain it.

Here is a pic of my trigger set up. For the crank to flex that much from the front main bearing to the wheel (only a few inches) and not break, blows my mind.

 

Thanks, the belt is definitely going back on looser. I have a lot of experience with 671/871 blowers and run those belts with almost a full inch of slack when cold, but when the motor heats up it will take all the slack out of the belt. The rear gear is being changed today, and will reassemble everything else and going to be re-tuned tomorrow. Will have to see where we are with the rpm after that, right now shifting at 6500 the blower is sinning at 70,200 and the car doesn't pull hard after 5500.

 

Crank too bracket clearance is tight but i pull the belt toward the pass side and have just enough room to slide it off the pulley. I don't have to take any pulleys off to change belts.