loose dissy weights
Thread Starter
Melting Slicks
Joined: Oct 2010
Posts: 2,276
Likes: 337
From: "ɹǝpunuʍop", Adelaide, South Australia
loose dissy weights
with all this talk on other threads about timing lately, i thought i'd have a look at mine.
popped the cap on the dissy,
whilst looking at the advance weights in the dissy, they seem very sloppy on the pins...
how loose should they be?
can someone please measure the pin and the advance weight hole diameter for me on a good set.
would they wear the hole/pin over time?
being loose, would that affect the advance curve much by flopping around?
will measure mine when i get home tonight and report back, at work at the moment
popped the cap on the dissy,
whilst looking at the advance weights in the dissy, they seem very sloppy on the pins...
how loose should they be?
can someone please measure the pin and the advance weight hole diameter for me on a good set.
would they wear the hole/pin over time?
being loose, would that affect the advance curve much by flopping around?
will measure mine when i get home tonight and report back, at work at the moment
Last edited by riverracer au; Jul 27, 2014 at 10:32 PM.
Thread Starter
Melting Slicks
Joined: Oct 2010
Posts: 2,276
Likes: 337
From: "ɹǝpunuʍop", Adelaide, South Australia
i realise the springs hold them from coming off, it's just they seem to flop up n down a lot
the holes in the original weights measure 0.191" - 0.195" (it's worn oval) and the pin is 0.183"
is that too sloppy?
or am i just over thinking things?
the holes in the original weights measure 0.191" - 0.195" (it's worn oval) and the pin is 0.183"
is that too sloppy?
or am i just over thinking things?
Last edited by riverracer au; Jul 28, 2014 at 05:30 PM.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,114
From: Crossville TN
Flopping "up and down" is not an issue when the distributor is turning. There is only rotational motion, so there is no force trying to 'lift' the weights. Centripital force tends to throw them 'out', with the spring force trying to resist that movement. The higher the RPM, the further the weights move out and the more the advance plate is turned.
Put just a little wipe of white lithium grease on the little raised area under each weight; that will lube them so that they won't be "sticky" during operation. When you 'time' the engine, the movement of the timing mark image as the engine is revved up should be smooth...not jerky. If jerky, the dizzy advance system is binding up in spots.
Put just a little wipe of white lithium grease on the little raised area under each weight; that will lube them so that they won't be "sticky" during operation. When you 'time' the engine, the movement of the timing mark image as the engine is revved up should be smooth...not jerky. If jerky, the dizzy advance system is binding up in spots.
Thread Starter
Melting Slicks
Joined: Oct 2010
Posts: 2,276
Likes: 337
From: "ɹǝpunuʍop", Adelaide, South Australia
it felt free and moved easily b4 it was installed in the motor.
but the timing mark jumps around, moves back n forth, when revving up trying to get to 36deg @ around 2500rpm.
Le Mans Master
Joined: Dec 2009
Posts: 6,397
Likes: 649
From: Saskatoon Saskatchewan
I checked my timing a few weeks ago and it was at 2 BTDC. I tried to set it to 12 BTDC @ 900 rpm and the timing would jump to 18, I'd turn the distributer the other way a bit, it'd drop to 4 and so on. Eventually by turning the distributer, adjusting the idle speed (and repeat, repeat, repeat) I got it to hold somewhat steady at about 13 BTDC @ 900 rpm. Pulled the distributor cap and rotor and found the same thing you did, the weights on the centrifugal advance were sloppy. Bought a recurve kit with new weights and bushings, turns out the original bushings on my original weights were virtually gone and letting the weights flop around and make the timing erratic. The new weights, bushings, and springs solved that:
http://forums.corvetteforum.com/c3-t...curve-kit.html
http://forums.corvetteforum.com/c3-t...curve-kit.html
Last edited by Priya; Jul 30, 2014 at 01:25 PM.
