Bracket Talk
Mandrel wobbles

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August 01, 2019, 07:23 PM
421philt
Mandrel wobbles
My new APD drive mandrel has a slight wobble at idle . It's a BBC with an ATI balancer and msd crank trigger. I know some crank trigger wheels came with centering rings but this one didn't. Will this wobble be a problem ?
August 01, 2019, 07:57 PM
green1
I personally wouldn’t run it, that is going to get worse at rpms I would think.
August 01, 2019, 08:05 PM
Bucky
How much run out is there?


Foxtrot Juliet Bravo
August 01, 2019, 08:53 PM
Cashflow
Fix it!


Clowns to the left of me, Jokers to the right. Here I am.......
August 01, 2019, 09:16 PM
421philt
There's no run out or wobble with the trigger wheel, it's just the mandrel . I'm not sure of the run out but its not much . Using it to run vacuum pump and alternator.
August 01, 2019, 10:40 PM
Alaskaracer
I have a brand new Ron's injection mandrel I don't need if you're interested for bbc


Mark Goulette
Owner/Driver of the Livin' The Dream Racing dragster
www.livinthedreamracing.com
"Speed kills but it's better than going slow!"
Authorized Amsoil Retailer
August 02, 2019, 08:25 AM
Bucky
To be quite technical about it: Nothing is perfect. All mandrels have some run out. Too much is a problem


Foxtrot Juliet Bravo
August 02, 2019, 11:21 AM
Cashflow
If you can see it wobble it's too much!


Clowns to the left of me, Jokers to the right. Here I am.......
August 02, 2019, 11:29 AM
TomR
If you are you using the 3 bolts to locate it then thats the problem. We put my crank trigger wheel in a lathe and machined a recess to locate the mandrel so it spins true. The bolts just hold it to the balancer.


72 Nova "Hooptie"
August 02, 2019, 02:32 PM
BJs Wild Ride
A little at idle doesn’t bother me. My wife’s car has a 3 bolt with a register. It has a barely perceptible wobble at idle but goes away as soon as you rev it. Not the first time I’ve seen that. Now if you crank it up to 4K and it’s still wobbling, then ya, I’d fix that.
August 03, 2019, 07:30 PM
Bad News
quote:
Originally posted by BJs Wild Ride:
A little at idle doesn’t bother me. My wife’s car has a 3 bolt with a register. It has a barely perceptible wobble at idle but goes away as soon as you rev it. Not the first time I’ve seen that. Now if you crank it up to 4K and it’s still wobbling, then ya, I’d fix that.


The only difference between idle and 4000 rpm is you cant see it wobble at 4000.
But it still is wobbling. Fix it.
Put a timing light on it at 4000, you will see the bi tch dancing.