A833 + clutch question : 68 318 engine
Are you suggesting the rotating assembly be balanced every time a p/plate is changed??
If they are out over 40 grams, and you replace that p/plate with one 40 gr - 180* opposite, you'd then have it 90+ gr out of balance , would it not?, rather than a random small imbalance?
inquiring minds want to know.. lol
cheers.
You are correct. That's why changing pressure plates and not fixing balance issues is bad. You just need the flywheel and pressure plate. You measure how far out of balance what you have is (that is piss poor English right there) with the original pressure plate. Then you mark the flywheel position on the mandrel and mount the new pressure plate and test it. You make it the same out of balance as the original was. Then you can bolt it back on.
The will run out of balance by a bunch and may not hurt anything. Had a customer with a BBC in a roadster. Apparently, backing it out of the trailer, he snagged the flywheel (power glide car) and bent the crap out of it. He walks through the pits and borrows one from some dude. Neither one bother to think if they have internal or external balanced cranks. My customer bolts it on and goes. He finished the rest of the season. He probably put another 50-60 runs on it. It came in for a freshen up and some up dates. I thought damn, WTF? Why in the *+#^|€<£¥%#€ing world did I externally balance the front of the crank, and internally balance the rear???? Was I on the crack pipe? This makes no sense. WTF was I thinking? Oh well, it is what it is. I should have pulled his original paperwork.
I get the thing on the balancer and it is shaking like a dog pooping peach seeds. I can barely keep it in the balancer. I double check and all the crap I'm using is what he came in with. I finally went and pulled his file. Sure enough, it was externally balanced on BOTH ends!!!!!
I call the customer and tell him to drop socks and grab his self and get over to the shop. I show him what is happening. Then, and only then, did he tell me what happened. I said, you don't think you should tell me (your engine builder) when something like this happens? You don't think it is important that I know you tore up a part? So after I tongue lashed him until I felt better, I made him drive over and get me the correct part.
Moral of the story is: don't just ASSume because it bolts on its correct. And always tell your engine builder when doo doo occurs. That guy was lucky he didn't spit the crank out, and possibly crash the car.