ok, so ive got a 73 vintage 350 in my project. codes came back as a truck motor with a 3 speed behind it.
at some point it was freshened. unknown to what extent. runs good, sounds good, checks out healthy. pretty strong, too.
anyway, i converted it to serpentine accessories. in the process, i discovered that the harmonic balancer has 3 nubs sticking out in addition to the three pully bolt holes. ive never seen this. nor does any of the aftermarket pullies support this. all of them only have the 3 bolt holes. i drilled my serpentine crank pully to account for them, but it now does not run true. dont know why. planning on clearancing the holes a little more, and seeing if i can get it to self align.
makes me wonder just what the balancer is off of.
also, makes me wonder if i can grind those nubs off. make it so i can run an unmodified pully.
what do you small block guys say? im kind of baffled here.
michael
pics, please...
never seen any "nubs" on a balancer on any Chevy V8 engine... the pulley uses the 3 bolts to hold it in place and a lip that centers it on the balancer, with the big bolt and 3/8" thick wahser in the middle installed after the pulley.
some aftermarket balancers have 6 pulley mounting holes for driving a supercharger, but i've never seen an oem one with more than the 3 bolt holes.
best pictures i have. forst pic you can kind of see the nubs on the harmonic balancer.
second pic is of the v-belt pulley i removed with the nub holes, and the non holed serpentine pully matched together.
[URL=http://s54.photobucket.com/user/dusterbd13/media/1964%20elcamino/011_zps75ef2dc3.jpg.html]
[/URL]
[URL=http://s54.photobucket.com/user/dusterbd13/media/1964%20elcamino/010_zps9818afa3.jpg.html]
[/URL]
That doesnt look like any balancer I have ever seen on a smal block chevy. Just get a different one? I dont think they are very expensive.
that's an old 283 balancer, if you can get the casting numbers off the top/driver side rear of the block, bellhousing area we can look up what the block is and see what balancer you'd need
could also be a 307 balancer. they were good for drag racing but in this day & age not much else
i've seen 283's that just have a hub for the pulley to bolt to without the outer ring isolated with rubber. the 1971 307 that's in my pickup doesn't have a balancer like the one you have- it looks just like any of the millions of small blocks built since the late 60's.
i'd just measure the diameter, note where the TDC mark is in relation to the keyway, and spend the $65 or so to get a new balancer for it..
looking at it again, it looks like the timing pointer that's bolted to the timing cover mounting bolts is for an 8" balancer, so you might as well get one that size..
Thats an antique. You could grind the nubs off, as long as there is another method for centering the pulley. That is generally done by a lip on the center hole of the pulley that slips into the center of the damper. If yours is designed to be centered by the nubs,and the center hole is not the correct size, give up and find a newer damper.
get new balancer at parts store for a 350, go at it.
Streetwiseguy wrote:
Thats an antique. You could grind the nubs off, as long as there is another method for centering the pulley. That is generally done by a lip on the center hole of the pulley that slips into the center of the damper. If yours is designed to be centered by the nubs,and the center hole is not the correct size, give up and find a newer damper.
the center hole in the balancer is the same on all small block Chevy balancers- it's about .002" smaller than the snout on the crank for a slight interference fit... so grind the nubs off and bolt the new pulley on...
novaderrik wrote:
Streetwiseguy wrote:
Thats an antique. You could grind the nubs off, as long as there is another method for centering the pulley. That is generally done by a lip on the center hole of the pulley that slips into the center of the damper. If yours is designed to be centered by the nubs,and the center hole is not the correct size, give up and find a newer damper.
the center hole in the balancer is the same on all small block Chevy balancers- it's about .002" smaller than the snout on the crank for a slight interference fit... so grind the nubs off and bolt the new pulley on...
Not the balancer to the crank, the pulley to the balancer. If the front portion of the center hole is an odd size, maybe thats why his pulleys wobble.
Streetwiseguy wrote:
novaderrik wrote:
Streetwiseguy wrote:
Thats an antique. You could grind the nubs off, as long as there is another method for centering the pulley. That is generally done by a lip on the center hole of the pulley that slips into the center of the damper. If yours is designed to be centered by the nubs,and the center hole is not the correct size, give up and find a newer damper.
the center hole in the balancer is the same on all small block Chevy balancers- it's about .002" smaller than the snout on the crank for a slight interference fit... so grind the nubs off and bolt the new pulley on...
Not the balancer to the crank, the pulley to the balancer. If the front portion of the center hole is an odd size, maybe thats why his pulleys wobble.
the bore is the same size all the way thru the balancer- slightly smaller than the snout on the crank. they are all the same in that respect. big blocks have a recess where the washer on the bit center bolt sits, with the pulley going on over that... small blocks don't have this- the pulley goes on, using the bore of the balancer to center it, then the center bolt goes in.
sometimes the pulleys wobble because they get bent or something, and they aren't exactly made to NASA specs so there can be what appears to be a large amount of runout in them...
just to pile on, that's not a 350 balancer.
