General Category > Quadrajet Carb Talk and Tips

help with 17082224

(1/9) > >>

bruno:

i’m looking for some guidance in getting this carb and my ignition set up correctly.
carb-17082224, rebuilt by me with cliffs kit, about 7-8 years ago. finally getting time to fire it up. idle tubes are .036, DCR .055, discharge holes are .086, UIAB=.068, LIAB=.077. primary jets are 73 with 51M rods.
engine is ‘68, 396(325hp) with stock pistons and 215 heads. engine has been freshened up with new rings and bearings, and fel pro head gaskets that came in the kit. also an unknown cam, which i attempted to measure today, and came up with 205/215@.050”and 274/293 lift. i’m not entirely sure of the ICL or lobe separation, but i do have the opening and closing point of both valves if that helps. i just not sure how to interpret the numbers.

Th400, with 3.31 gears. just want to be able to cruise, no racing or daily driver.
distributor is 1111196, dwell is at 30,
just working on the vacuum advance, as i was only getting 5 degrees. then i discovered it was adjustable, but haven’t got to fit it back up yet. haven’t checked centrifugal yet. base timing calls for 4, i had it set at 8. seemed to work okay.
questions:
looking for timing recommendations, high idle rpm’s and then i can start trying to tune carb. i have cliffs book, and will read it again, but want to get distributor set up first.
i haven’t tried driving yet, just running in garage.
any more info that will help, let me know.

bruno:
possibly an XE 250 cam? only thing i know is it was bought from performance auto warehouse in the 80s. the bill just lists it as CHE 396.

Cliff Ruggles:
Not sure if they made XE cams that far back.  Most of the Comp stuff used to be single pattern and nearly if not all of it on 110LSA's.  Far from ideal but they did that to put enough overlap in the deal so your engine had some "attitude" at idle when you went to a car show or cruise in.

The XE256 specifically would be a very poor choice for a 396 unless is was very low compression.  a cam like that wouldn't even come close to taking advantage of good flowing heads used on most big block Chevy engines from that period.

My cam of choice for most of those builds is the GM Marine cam or Melling 22216.  It's pretty much identical to the original 396 and 427 cams from the late 1960's used in the lower performance engines.  Ground on a 115LSA it idles well and produces a very broad/smooth/flat power curve which really helps manage pump fuel at the higher compression ratios many of those engines used.....

bruno:
well i must have measured something wrong, cause i’m getting an LSA of 133 degrees. will look at my numbers again, but i came up with an ICL of 104, and an exhaust ICL of 237 degrees.
keep in mind i was using a dial indicator on the end of a pushrod, so definitely could have gotten skewed!

bruno:
and i should mention i’m running the factory iron manifolds.

Navigation

[0] Message Index

[#] Next page