F1 cog belt questions
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'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.






