I tore down my Holley 3310-2 for a rebuild. My accelerator pump was leaking, and I was having issues getting it to start. My primary jets are blackened probably from backfiring trying to get the car started, but that was just the beginning of my confusion. ALL my jets are different. I would have thought the front would have been one number, the rears be something different...say 63s for the front, 67s for the rear. This was more like 63,64 for the front, and say 65,67 for the rear. Is there ANY reason for this kind of jetting? This was a friends carb that was put on the car 10 years ago, and I can't get ahold of him to find out what it's for.

Any ideas?

j

 

http://holley.com/data/TechService/T...%20Listing.pdf

they have your carb on there but im unfamiliar with the numbers they used for the jets. but the front ones should be the same and the rear ones should be the same but a different size. maybe it was on a car that for some reason was running rich off one bank so they leaned it up a bit or vice versa

 

Thanks for the reply. I haven't been out at the car yet to check the numbers on the jets, I just remember it being curious that they were all different. Given the following information, what size jets would you suggest I replace them, if I need to?

340
9.5 Compression
mild work on the heads
MP 284/484 cam
??? Centerline...probably the less streetable one
Edelbrock LD340 Intake
Hooker Competition headers, 2.5" Exhaust with flowmaster knock offs, and turn downs after
8 3/4 rear, 3.23 open rear, 295-50/15 tires
Electronic ignition
Autolite 63 spark plugs
...

Anything else that would help with the jetting without examining the spark plugs?

j

 

not sure on that im trying to figure out a jetting issue myself

 

go with what they say on the holley page.

 

The secondary side calls for a metering plate, not a metering block. I dunno...hmmm...

j

 

Yeah the 3310 is a vacuum secondary carb with a metering plate instead of jets on the secon. side.

There are different plates you can get and of course the primary jets can be changed.

you could use an 02 sensor and a voltmeter to check the jets [500-700mv]
Or; buy one of the 02 meters from maybe Summit {edelbrock meter?}
Usually the engine will 'surge' when it starts to get too lean on a cruise rpm in high gear [45+ mph].
\Too rich is hard to tell with out reading plugs.
I'd start with the originally installed jets and work from that point.

 

ok, so I checked the carb today ( after I changed the truck PS Pressure hose ) and found the front are 70 and 75 ( I think...this one was hard to read ) and the rear are 73 and 77.

Having the secondary metering block instead of the stock metering plate that comes with the 4160 makes it hard to use the jets listed on that PDF. Should I just use the FRONT jets listed, and fudge the secondary side just to get it running?

j

 

I posted the same question over at FABO, and a guy posted back that it was common with the LD340 to grind out the center devider and stagger the jets to get better coverage. I lost my keys, so my trip to the parts store is on hold for the moment. I still need the secondary metering block gasket to get my Holley finished. I am hoping to find one soon...

j