Wrong carb on California Emissions six?

[kuhlou]

Reading a recent post led me to see which carb is mounted on my Califormia Emissions equipped 1966 mustang six. It is the autolite 1100 with SCV. I believe I read earlier that the CA six distributor should NOT have the SCV equipped carb?

What effect would this have on performance? I have problems cutting out at lower speeds, accelerates fine.

Can I modify the carb, simply take out the SCV?

thanks.

 

[page62]

What kind of distributor do you have? Load-o-matic or non-Load-o? To check, pull off the distributor cap. If you see springs in there, it's an LOM. If there are no springs, it's a mechanical advance (conventional) unit.

The SCV works in conjunction with the LOM distributor as a matched set. A carb with an SCV will not provide the correct vacuum signal to a conventional (non-LOM) distributor. Simply removing the SCV does not work. Instead, you must use ported or manifold vacuum for use with a conventional distributor. Or change carbs to a non-SCV unit.

 

[kuhlou]

There are no spring, so it's a non-LOM distributor.

So, I can just change to vacuum line to come off the intake manifold, if I understand you correctly?

Trouble is, I took the last available port off the intake vacuum block for my disc brake booster, one goes to the smog system, the other to the auto transmission.

Can I swap one of the manifold vacuum lines to the carb, so I can hook the distributor vacuum to the manifold?

 

[kuhlou]

I've kept the smog stuff on because this is a really nice original CA mustang convertible, so I've wanted to try and keep it original. I'm in MN, so all that CA stuff is cool. What might be the best way to find the correct carb? My local shop "sent out" the original for a carb tune up, and I wonder if I got the same one back.

 

[Bort62]

Just use a T in the Vac Line.

 

[kuhlou]

Does it matter it comes off the vac line for the trans, brake booster or smog stuff, or any of them?

Assume I need to plug the vac port in the carb as well?

thanks, fellows, the help is most appreciated.

 

[kuhlou]

one more thing. I don't have to worry about plugging the scv then, correct, since won't be using any vacuum off the carb?

 

[Bort62]

You should cap the SCV port off or you will have a vacuum leak.

 

[Bort62]

There are basically two sources of Vacuum on an engine. The first is Manifold vacuum, which is sourced below the throttle plate and is at it's peak @ idle. The second is ported vacuum which is sourced above the throttle plate and is 0 at idle, but approximately equals manifold at part throttle.

Both sources are 0 at WOT or near WOT.

IMO you want to use manifold vacuum for the advance.

 

[kuhlou]

got it, do I need to cap off the cap off the vacuum on the carb as well? What is best method to cap off scv? It looks like the scv will unscrew from it's port? Thanks.

If I were looking to upgrade the carb, since I have the mismatch, what would your advice be? I see a brand new holley 2300 350 cfm on ebay for around $80 shipped to me. ??

 

[page62]

I think you're okay just to plug the vacuum (SCV) port on the carb, and leave the valve alone. However, I built a custom SCV plug by taking an old SCV valve, removing the internals, and gluing a nickel in there using JB Weld. While I was at it, I also plugged the other end of the valve. Don't know if I need it or not, but it looks cool! 8)

 

[ludwig]

Call Pony Carburetor and ask for their tech desk. Tell them what you have and what you want to do. They can point you in the right direction. You might be able to work out a replacement or a rebuild of what you currently have.

Disclaimer:
- their carbs are relatively expensive (but I have found them reliable)
- you will get NO help for anything other than a STOCK application.
- one or two members have REALLY strong opinions about Pony Carbs. Gird yourself (as I do).

 

[kuhlou]

okay, finally got to work on the stang. I swapped the dist vacuum line to the manifold, and put the smog system vacuum line on the carb vacuum port. The 200 runs better, very little hesitation at low speed, and accelerates smoothly, as long as I don't tromp the pedal. If going up a good size hill, or giving it more more I get quite a bit of detonation sound from the engine. So, not everything is working right for sure.

I will tee the smog stuff back into the manifold, plug off the carb vacuum and plug the scv valve as described earlier. I also replaced plugs and wires for good measure.

Finally, if stay with the stock non-LOM distributor, what would a good carb choice be (an upgrade). Or, if I make the switch to DSII, how about a good carb choice to go along with that setup?

Thanks everyone for your contributions. We are good enough to cruise around a little for now, but want to get it really running right.

 

[kuhlou]

Been reading the carb related posts. Given my situation, wrong scv value autolite 1100 carb for non-LOM distributor, would a reasonable fix be to swap the "wrong" autolite carb out for a HW5200 ? I plan to go to a DSII ignition setup sometime this summer. would a switch to that carb be a step in the right direction now, prior to installing the DSII? Then, I'd have a newly overhauled autolite 1100 scv to peddle.

 

[Bort62]

If the HW satisfies your long term goals, then yes - I think it would be a good choice to upgrade now.

Try backing off your initial timing a few degrees to get rid of the detonation.

 

[kuhlou]

going the DuraSpark route seems close to a no-brainer. The rebuilt autolites are expensive, so it makes the HW or Holley 2300's seem reasonable, unless there is something I don't understand, on top of the refitting the non stock carb to the available space.

Is it possible to fabricate the stock air cleaner on a 66 mustang to fit on top of the HW or Holley? Anybody tried this? Thanks.