Originally posted by Shayd
Anyone ever have the problem where no matter how tight you tighten down the motor clamp/heatsink the motor remains loose enough that under power it eventually pulls away from the spur giving you that really nice grinding sound?
I had that problem on Saturday. No matter what I did it wouldn't keep the motor from pulling away. I mic'd the motor cam and it was round and .870. Checked against a brand new one and exactly the same diameter. Had the original motor clamp/heatsink so spent the cash and bought the FT one with the larger fins. Same exact problem. DNF first qual, had to run to pit in second qual to reset pinion and finished fast enough to get 3rd position in B main. Then in B-main happened again just after I took the lead, and I just walked off totally frustrated.
After I got home and chilled out here is what I did to fix it so that it clamps the motor. After I had time to sit down at home and look at it without getting all frustrated again(like at the track that night.)
On the spring side I took a flat file and basically filed down that little ridge where the screw goes into the chassis, and then took it down a bit further. Now the motor stays in place.
Anyone else EVER have this happen?
Just out of curiosity, do you race in very hot weather?
Were you running modified?
Was your motor overgeared at anytime in the life of your chassis?
When your motor is HOT, it heats up the Cam on the motor. As this is hot, it could start to liquify that section of your chassis, causing the Cam to "sink" in the chassis. Giving more "play" between the cam and the motor clamp.