Quadrajet Problem Solving > Dialing in your rebuilt Quadrajet carburetor

Seconary rod suggestion?

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55 Tony:
I have a 17084226 on a 454 with a Comp "hot street machine" 11-450-8 cam and compression ratio is somewhere above 10:1, (I didn't know about CCing the heads till after it was together.)  Cranking compression is 210psi in all cylinders.  The cam actually calls for only 9.5:1.  It runs pretty darn good.  I can't find my notes on what the current primary jets and rods are, but the primary is pretty good according the the A/F gauge.  At WOT it's about 13.5:1 - 14:1 and I'd like to get that closer to 12.5:1  Also, it has old iron 781 heads.  I don't know how/if the higher compression effects target A/F ratio.  If it matters, I have headers and an Edlebrock manifold.
The current secondary rods are DP's.  A bit fat but I guess the short power tips are helping at WOT.  So I'd like a suggestion on what rods to try to get richer.  Laying around I have sets of:
CE, DH, CK, and CC's.  The hanger is a J but who knows if it's been bent.  I have a few other hangers, I know I bent one so I'd be willing to bend it to what ever is needed.
I won't be able to test this real soon because the rear is out to get new ends on it to get rid of the C-clips, and I'm changing from 3.42 to 4.10 gears.  I'm real excited about trying those gears out! :)  I bought some slicks and have been to a local track that was just re-opened after being closed for years.  They don't even have a tree or anything to time you at the moment, but it's only $20 to get in and it's good for a rookie like me who has never drag raced before.  When I took the rear apart I found that I had twisted an axle, they are only 30 spline but I've been told by quite a few people that I must have had bad axles.  The other axle wore where the bearing rode on it.
Sorry for the lost post, just tried to give all the info you may need.
Tony

Cliff Ruggles:
I'd try the CE metering rods, they are smaller than the DP's and will fatten it up a bit at full throttle.  Also make sure that you are using a high flow N/S assembly and adequate fuel delivery to the carb or the results may not be as expected.......Cliff

55 Tony:
Thanks Cliff, I'll do that.  I have the large needle and seat so all is OK there.  Otherwise the carb is pretty good, I can always go from idle to full throttle without the slightest bog and it's not too slow to open either.

When I rebuilt the motor, the guy helping me got me to advance the cam 2 degree's.  I asked some if I should change it to straight up and they said no, by now the chain has stretched so it probably is straight up.  I'd appreciate your thoughts on this.  As I mentioned, the cranking compression is real close to 210psi in all cylinders.  I don't suppose you can guesstimate by looks how many CC's these 781 heads are?  It also appears that it's been decked also, but again I didn't know to measure that until AFTER it was together and in the car.

73ss:
I've seen online anywhere between 119~122cc for 781 & 049 heads. I'm running a set of 781's and when I had them done I had the shop check them and they came out at 114. This is after I had them cut. They may also have been cut before I got them.

210 psi seems quite high. Does it rattle or ping? I'm assuming having the cam advanced is causing some of it. What cc dome on your pistons? You can look up the part number and find out.

I have a 20cc dome and a .024" head gasket and mine comes out to 9.8:1 compression using one of the compression calculators. I've got around 165 psi cranking compression. The piston is 20 in the hole. This is before I knew any better.

Cliff Ruggles:
210 cranking pressure seems very high for that cam in a 454 with 10 to 1 compression. 

Was the cam just advanced 2 degrees from straight up, or advanced after it was degrees 2 more degrees?

Comp specs out the cam at 290 degrees seat timing with 232 @ .050" on a 110LSA. 

In a 454CID engine at 10 to 1 or a tad higher compression I'd expect around 170-180psi cranking pressure based on the engine builds I've done here with similar parts......Cliff

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