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So I finally got my new 383 in the car. It looks gorgeous. However, some things I didn’t consider:
Vacuum routing - The port on the base of the carb is for PVC . The manifold port just behind the carb is covered by the carb itself. I found a 1/2 gasket that allowed me to raise the carb enough to get a 90 degree port under it. I am splitting this between the brake booster and trans. The advance can goes to the port on the metering block. That leaves 2 ports on the carb, one timed and one manifold, for the lights and the smaller EVAP line. Will these work for either? Can I dump the EVAP altogether?
Temp sender - For the moment I’ve got a 3/8 sender mounted in the intake between the water neck and heater line. The gauge I’m using is either inaccurate with the stock gauge or my engine is running 15-25 degrees hotter than it should. Is there a 1/2 sender that will work with a stock gauge?
Brawler carb - I can’t seem to get the idle right. I have to set the curb idle at 1200 in order to keep it from stalling when dropped into gear or coming to a stop. Could my creative vacuum routing be the culprit? According to Smeding, the carb is expertly tuned and shouldn’t require ANY adjustment except curb idle. Which is good because I haven’t a clue how to tune this thing. (I felt like I had just started getting a handle on my old Qjet.) So I’m reluctant to start turning adjustment screws if something else could be causing this. The engine was dynoed in Texas and I live in Denver. Could altitude be a factor? I asked that they jet it down to accommodate this but have no way of knowing if they did or not.
All in all I’m really pleased with the engine. It went in without issue. And even though it’s not running as well as it could, it is ridiculously powerful! It will throw you back in your seat any time you tap the gas. I just need to get it dialed in. Any tips or advice on accomplishing this would be greatly appreciated! Anyone in the Denver area willing to help out will be compensated accordingly! Beers or bucks!
Lots of initial timing will boost the vacuum and idle strength. turn the initial timing up to about 20 degrees. Then with the engine warm adjust the 4 corner idle screws to get the highest vacuum. You may need to turn the idle speed screws down. Once you get it to idle better at lower rpm lets say 1000 with your foot on the brake put it in gear and and it should only drop say 200 to like 800 rpm in gear.
Then you have to limit the mechanical advance to say 34-36 degrees total when you rev it to say 3500 rpm with all the advance in. Of course with the vacuum advance plugged
So I finally got my new 383 in the car. It looks gorgeous.
I'm currently in the process of installing a Smeding 383 in my '73. I didn't go with a carb - ended up having them install an Edelbrock Pro Flo 4 XT EFI system. But when I first talked to them about the carb, they said I wouldn't need to adjust the carb at all except for idle and they also said I would not need to make any adjustments to timing. They said they set the timing right where it's needed and there is no need to change it. That said, I think I would contact Smeding and tell them you installed a 1/2" spacer under the carb and ask them about routing the vacuum lines. You may be onto something with your question about creative vacuum routing. Sounds like your setup just needs a few minor tweaks.
Thanks guys. I was hoping there was something I’d missed. Once I start in on the timing and idle screws there’s no turning back... What curb idle should I shoot for? My stock engine idled right at 700. This thing won’t hold idle below 1000 and nothing below 1200 in gear. Man does it sound great though, and on the street this thing is a monster!
I talked to Smeding and they said not to change the timing, idle, or the 4 corner idle adjustments. I disconnected and plugged all vacuum sources on the carb and no change. Still won’t idle below 1000. I even put gaskets on either side of the spacer in case there was a leak there. No change. Getting very frustrated.
I talked to Smeding and they said not to change the timing, idle, or the 4 corner idle adjustments. I disconnected and plugged all vacuum sources on the carb and no change. Still won’t idle below 1000. I even put gaskets on either side of the spacer in case there was a leak there. No change. Getting very frustrated.
Shot in the dark - any chance your throttle cable is in a bind somehow and holding the throttle open?
New Smeding 383 install
