T-Bone028

swa240z, I had a similar flat spot/bog when first getting into the throttle at low speeds or suddenly off idle. Mostly got rid of it by switching out the pump exhaust valve (its a screw at the bottom/inside the fuel reservoir for each carb) to a "closed" valve. My reasoning was that the accel pump needed to spit out more fuel for initial tip in. At $5/each, its a lot cheaper to test with and theres only 3 that you need to buy instead of 6. Probably not the "correct" way to tune a DCOE, but it worked for me.

Glad to see this build still going. Really looking forward to seeing dyno results between the 40 and 45's, along with the change in venturis. Maybe this is already widely known...but one thing I found was that there is an ebay seller that doesnt say it's Pierce Manifolds out of California, but I'm pretty sure they are based on the shipping label. The price difference between the pierce manifolds website and the ebay store were close to 30-40% less. Havent checked ebay lately, but might be worth poking around if you want to buy a couple of different main venturi sizes. At ~$25/per, it gets expensive!

If the car pictured is being sold as a 2002, then thats not a 2002...looks 2005? Most of the same issues listed above though still apply. Otherwise though, the 2002 SER Spec-V was a fun car. Helical LSD with a fairly torquey 4 cylinder? That thing was a blast. My spare tire wheel rusted out after 8 years though, the headgasket went after 80k miles, AC never worked, and burned a quart of oil a month after 100k . On a plus note: the wheels are 4 x 114.3...which means the brake rotors are the same pattern...and the brakes on that car were pretty good. Always wondered if a brake conversion could be possible on an S30.

I'm assuming no return? Some people advocate putting the regulator AFTER the carbs. I run my system with a return, and my regulator is after the carbs (3.25 psi). Tank - filter - fuel pump - carb carb carb - regulator - filter - return to tank. Anyways, after watching the video, its kinda hard to determine what/where that noise is...have you taken off the air filters yet? Might make it easier to determine which throat is making the most noise. Any fuel leaking out the horns? When was the last time you checked floats and synch'd the carbs?

For anyone thinking of picking one of these up...it made converting to cable incredibly easy and reversible. If you search my posts, you should find an off the shelf parts list and how I set it up. Part came quickly and shipped the day after I sent paypal. Definitely recommend!

To the OP, if it helps, I measured a spare intake to carb gasket, and it measured 40-41mm-ish. I recall when I installed my carbs, the gasket fit closely for both intake and carb diameters. So if your intake manifold measures 46mm (4.6cm), I would assume yes, it was meant for a 45 DCOE. Interestingly, I had always thought that there was not a 45 dcoe specific manifold for the L-series, and that it was expected that the owner would port match accordingly. Where did you get the manifold from?

325hp at the wheels with what looks like a stock exhaust manifold and weber DGV's? Yes, I would be suspicious... Check block and head identification. $800 is a lot for something unknown. I would say $400 is fair for a good running motor if it something you want to build up.

Steve, any headwork? What head? What cam? Estimated compression ratio? Side-note: still have those 34mm venturis? Let me know if you want to sell them...

You can just leave vacuum advance disconnected, and set timing at all in. Have a friend with a timing light help you and set it at like 30-34ish total advance (depends on your CR and gas, pinging, etc). Just let initial timing fall where it may. I've been running fine for a year this way. OR...check out 123ignition!!!! That's on my Christmas list.

I think stock distributor should only have like 17-18 degrees of mechanical advance, so like 14 degrees initial ends up with 32 total...have a buddy help with a timing light and measure/set full advance to where you want it, and let initial fall where ever it does. I run 32 degrees all in with vacuum plugged (I didn't permanently disable vacuum advance with the bead thing). I will likely buy the new dizzy from 123ignition. Check the threads on here and on classiczcars...seems like a pretty easy way to get full timing control. p.s. you should write up your carb trouble shooting and post it! Someone might be in the same boat as you and looking for help too! Just saying. Sounds like you're going in the right direction.

Get the rebuild kits with needle valves included. I think they're like $30/each. 175 needle valve is the standard size for 40 dcoe 18's. or you can try to clean the needle valve with carb cleaner...I say replace it though.

Also, be careful when removing the pin that holds the float in place. The float pin arms can be rather delicate...I broke one of mine!!!

Standard float settings for 40 dcoe 18's is 8.5 mm from the carb top (before dpressing the needle valve, as measured with gasket in place) and 15mm at full drop. I made a small L shaped "ruler" out of heavy cardboard stock. 8.5mm on one end, 15mm on the other. Just be mindful of the seam in the float. Measurement should be taken without the seam. If you search for the YouTube video, it will explain the process better.

Sorry, wrote my response without refreshing the page on my iPhone. 27mm main Venturi is pretty small...I would guess 30-32 would be a better size. I have spare 30's if you want to buy them. 2.25 sounds like your needle valve, not float setting. Buy 3 rebuild kits from piercemanifolds with needle valves. I believe 18's come with 1.75's normally. Float setting is actually 2 measurements. Full drop and right before depressing the needle valve to get more fuel. There is a tutorial on how to properly measure and adjust floats on YouTube. After doing that, you can measure the fuel level in the well with the main jet assembly removed. Research Keith Franck method. Floats MUST be properly set before attempting any additional tuning.

Accelerator pump jet isn't going to cause that. When in neutral and you rev, does it die? What does your AF gauge read? Do all throttle plates operate nicely? Binding in your linkage? What's your full jetting? Where is your throttle plate in relation to the first progression hole? Before doing any trouble shooting you should really check and set your floats. Here's what you need to find out: Carb model (ex: 40 dcoe 18) Main Venturi Aux Venturi Idle jet Main jet Air corrector Emulsion tube Pump jet Exhaust/bleed-back jet And AFTER setting floats to spec, set throttle plates to all 3 carbs to just before the first progression hole, then measure how many turns from fully seated your idle jet screws are ( early carbs are usually between 1-1.5 turns, later I think is 2.5-3), ensure no binding of the linkage, and THEN measure airflow bringing the highest flowing barrel to the lowest. Use best lean idle method for adjusting idle screw. Keep Measuring w sychrometer and monitor AF ratio. Obviously, this is a challenge to tune over the Internet and I could be speaking out my butt.