Jasonwayne222

So its a fresh crate engine with eddelbrock 1406 600cfm carb it will slightly surge at light throttle cruise. Goin richer doesnt seem to help. Now if i run with the vacuum advance disconnected it goes away. So with more timing the problem exists but i want the vacuum advance hooked up for fuel economy what should i do with this

kenash

Hi,
What do you know about your distributor? New/Used?
What do you know about your timing?
Are you using the "timed" port or full vac port. I think the full time port is on the driver's side, on the Eddy carbs, if I recall.
Are you seeing total advance, if so, at what RPM. What initial timing? You mention "crate". Is this a stock 302 crate?
At the very least, us a vac gauge to set the idle quality. Also, what kind of engine vac are you making?
I think a few more details might help.

Jasonwayne222

Its a new msd HEI ignition initial timing set at 10 on bottom 34 on top vaccum advance set to add 10 extra timing coming in at around 8 inches im using manifold vacuum but it doesnt make any difference at cruise ive hooked a vacuum gauge to both ports just to see and you get the same vacuum at cruise on manifold or ported you just dont get vacuum from ported at idle ive been runnin with no vacuum advance and it runs fine just slight surge at light cruise with advance hooked upim thinkin im still lean in cruise mode. The plugs are a golden brown right now i have the second smallest rod in my carb with orange springs and stock jets

Jasonwayne222

And my timing is all in at 3000

kenash

Hi,
OK, It looks like you got some good stuff going on there.
I mentioned the engine vac test,so as to get a read on the general health of the engine. You want to see a steady needle with a good strong vac signal. I've tuned that same carb, but as a 1405 model, they can run very strong when tuned well. So, without making any other changes, I would go one or two steps richer on the metering rods, only, it's a WAG t this point. Then, do your regular road test, read the plugs. The key to any good tuning procedure is to use the same procedure each time, document each change, and not make a lot of change at once. Through out any testing, keep a log of the changes.
Good Luck!

Jasonwayne222

so i checked and the vacuum advance comes in around 12inches of vacuum but ill check engine vac for you today I just went to the smallest rod 7042 I think with the purpe springs which are taller and its almost perfect good enough to where if you didnt know cars you couldnt tell but I wanna keep tweakin it. My 0-60 is around 8.8 which is a little dissapointing, I am getting a little tire spin and I plan on putting traction bars, its 17x9s in the rear with the stock rear end but Im wondering how to tell if I need to go richer on secondarys Ima do a plug read and do a few more small adjustments.

kenash

Hi,
I very good way to map your AFR is to seek a local chassis Dyno shop. If you have a welded O2 sensor bung welded in your header collector, they can insert an AFR sniffer and you'll get a graph of your AFR. They can collect data about 2500 through 6000 or whatever redline you specify. Obviously, you'll see your RWHP and RWTQ, as well.
You can spend months tuning in the manner your're doing it. The reason I say this is, I did it the same thing. It wasn't until I got on the Dyno that I saw, I needed richer secondary jets. When I was finished, my AFR was 12-8 to low 13s. getting the mid range bog was lessened by playing with the distributor vac and the metering rods. So, I know some of the challenges you're facing.
Good Luck!

Jasonwayne222

I may weld in a bung and install an A/F gauge but ill have to go out of town for a dyno but thats really what i wanna do.

Thanks

kenash

OK, if chassis Dynos are not an easy access venture, you could consider an Innovative built-in gauge package, or, their data logging system. I have one of their systems that will record (data log)the rpm and AFR and can be down loaded to a laptop for review.
I know other vendors have a similar system like "FAST", to name another.
Check these out.....
http://www.innovatemotorsports.com/products/MTS.php

rbowmar

Brilliant! Sure beats checking your plugs!