Tuning a 3310

Posted By: Von

Tuning a 3310 - 02/11/12 10:02 AM

Im gonna tackle tuning a 3310 with an O2 sensor....Need to get it as lean as it will allow at cruise

I plan on either drilling/tapping the PVCRs on the primary side or getting an aftermarket front block that is tuneable on the PVCRs...

But, Im not sure whether to get a tuneable rear metering block or use one of the plates like QF sells that allows jets to be used??

Posted By: Kevins493

Re: Tuning a 3310 - 02/11/12 06:06 PM

Just get a jettable rear metering block. It turns out to be cheaper to tune in the long run since you already have a jet kit (for the front) and jets are A LOT cheaper than replaceable plates.

Posted By: DavidDean

Re: Tuning a 3310 - 02/11/12 06:45 PM

I had a 3310-1 w/jet plate that I raced for many years. I had to drill the primary throttle plates to achive a good idle quality w/ a mild roller.I used a PV but didnt do any work to the PVCR. I did try some small wire to lean the idle curcit but finally pulled it and drilled the primary throttle plates. I think the hole size was about 1/8" but I'm not for sure.

Posted By: Von

Re: Tuning a 3310 - 02/11/12 07:46 PM

Quote:

Just get a jettable rear metering block. It turns out to be cheaper to tune in the long run since you already have a jet kit (for the front) and jets are A LOT cheaper than replaceable plates.

Is there an advantage of a metering block over a jetable plate, such as this:http://www.quickfueltechnology.com/metering-blocks-and-parts/billet-metering-plate-kit-vacuum-secondary.html

Posted By: Crizila

Re: Tuning a 3310 - 02/11/12 08:37 PM

I don't think so. I went with the jet plate. Worked good. You might consider cutting off the choke housing and smoothing any sharp edges leading in to the venturi's. I did this and I believe it improved fuel distribution. Definitely improved flow ( good for about 1/2 a tenth with my set up). It's a great carb and easy to tune. Have fun!

Posted By: DaveRS23

Re: Tuning a 3310 - 02/12/12 03:33 AM

I have found that the secondaries are fairly close on the 3310. It might be prudent to wait and see how close the WOT is before you drop the coin for the secondary block.

The primaries are another matter. The PVCRs are way small, which puts the mains way big. Depending on a lot of factors ( gearing, cam, intake, converter, weight, speed, etc, etc.) the carb may cruise on the idle circuit or on the main circuit.

I would suggest that you drive the car with the O2 awhile and see what needs tweeked. I usually need to step down the mains 4 sizes or so and open the PVCRs an equivalent amount, then go to a much earlier opening PV to cover the more distinct transition from the mains to the PVCRs. Something in the 9.5 or 10.5 range.

The WOT on the carbs are usually pretty close, it's the transitions that need the work.

Don't forget to dial the ignition curve in. If this is a big block, I have had the best luck idling with as much advance as possible and then getting the rest of the advance in as quick as possible.

I have used a lot of 3310s. They are the best bang-for-the-buck-carb out there.

Oh, and don't forget the secondary spring kit to tune their opening point. And a quick change cover is nice, but not necessary.

Posted By: Cappy572

Re: Tuning a 3310 - 02/12/12 08:28 PM

I have a sec block for your 3310 you can have. I also have some ideas on how you can tune these carbs. Pm me and i will give you my number.

Posted By: topbrent

Re: Tuning a 3310 - 02/12/12 10:50 PM

If you are tuning for cruise efficiency, pay attention to the transfer slot opening. .020 or less is good, idle feed restrictor mods, ect

Here are some good links to read:

http://www.carcraft.com/howto/ccrp_0507_carb_tuning_tips_tricks/viewall.html

http://www.carcraft.com/howto/116_0501_carbs_tips_tricks_cheap/viewall.html

http://www.chevyhiperformance.com/tech/e...eage/index.html

Posted By: dvw

Re: Tuning a 3310 - 02/13/12 02:12 AM

Quote:

I have found that the secondaries are fairly close on the 3310. It might be prudent to wait and see how close the WOT is before you drop the coin for the secondary block.

The primaries are another matter. The PVCRs are way small, which puts the mains way big. Depending on a lot of factors ( gearing, cam, intake, converter, weight, speed, etc, etc.) the carb may cruise on the idle circuit or on the main circuit.

I would suggest that you drive the car with the O2 awhile and see what needs tweeked. I usually need to step down the mains 4 sizes or so and open the PVCRs an equivalent amount, then go to a much earlier opening PV to cover the more distinct transition from the mains to the PVCRs. Something in the 9.5 or 10.5 range.

The WOT on the carbs are usually pretty close, it's the transitions that need the work.

Don't forget to dial the ignition curve in. If this is a big block, I have had the best luck idling with as much advance as possible and then getting the rest of the advance in as quick as possible.

I have used a lot of 3310s. They are the best bang-for-the-buck-carb out there.

Oh, and don't forget the secondary spring kit to tune their opening point. And a quick change cover is nice, but not necessary.

I agree. Jet for power,then jet for cruise. Go back and drill the PVRC to make up the difference. I was able to lean the primary jets 4 sizes.
Doug