Just going through some info and came across a statement that has me wondering (yeah I know, happens all the time..LOL ). Anyway, in the Doug Roe book "Rochester Carburetors" he says three hangers are available from Roe, Inc and says .520 lean, .570 avg, .615 rich when describing the distance from the hole to the surface where the hanger sits. Dimension "h" Page 133. Now maybe I'm missing something, but wouldn't a shorter distance actually hold the secondary rod out out of the orifice further to start, enriching faster upon the secondaries opening? Or does he mean those hanger specs are meant for leaner or richer rods? Thanks for any info..
I think the actual secondary rod taper and tip length are going to be more of an influence than hanger hole position. Some hangers may work better or worse with certain rods.
For sure but it just seemed like the statement made in that book is backwards. Its a curiosity thing more than anything else...
"I think the actual secondary rod taper and tip length are going to be more of an influence than hanger hole position. Some hangers may work better or worse with certain rods." +1 We build a lot of q-jets for Stock Eliminator, Super Stock, Pure Stock and FAST cars. For these racers we supply a full set of machined metering rods from the same cores with the same tip length, included angle, etc. Typically in .002-.003" incriments for the set. I've seen folks tune with different metering rods and hangers, and the results can end up all over the place. We found this out on the dyno several years ago when swapping in tiny tipped metering rods with shorter tips and larger upper section, and went LEAN vs a rich taper longer/fatter tipped rod they replaced. Rather that mess with hangers and different types of metering rods, we've found that tuning is more accurate finding the right hanger with a specific metering rod, then changing to the exact same rod with only the tip diameter being different.....Cliff
This all started because I was cataloging what I have here for parts and spares....with the cars have a total of 11 carbs from 71 stage 1, 71 455, 70 455, to 72 455 (x2), 72 350, 75 455's (x2), one 76 455, 1981 4 speed manual corvette electronic etc plus mid 80's chevy truck 350 and lots of rods and jets and primary rods as well. I was looking at them and almost all the hangers are different (even on same carbs) so started looking into that which is where I stumbled across the reference on page 133 which made me wonder so I put up this post. Lots of good info here, thanks for the replies :TU:
