Emission crud

[Pav8427]

I have a California 79 H/O that is still equipped with all original emissions parts. All are still hooked up except EGR. As far as I can tell, operational. It runs pretty decent.
Is there any tricks to tuning this set-up that you wouldnt normally use on a non emissions rig?
Would I be better off adding a few more feet of vacuum lines and bypassing. Setting it up old school with only VA, PCV and only the basics?
As far as I have figured it is box stock.
I did do a good rebuild on the original 17059553 carb with Cliffs parts. And have been playin with the timing curve.
Ant suggestions would be greatly appreciated.

Thanks. Doug

[Cliff Ruggles]

At heavy and WOT emissions stuff really isn't playing a big role in hurting engine power aside from the restriction of the CAT, if the engine sees it as one.

For "normal" driving all those devices were in place to meet EPA standards at the time the vehicle was sold. 

The absolute WORST thing you can do is to install an aftermarket HEI recurve "kit", they are absolute junk and no performance improvement waiting for you there.

I get so many HEI's in here with that garbage in them I'm ran out of cores from stripping them for OEM parts to put back in them.

The factory HEI timing curves really aren't that bad on those units, and provide a smooth/steady timing curve starting right off idle and all in around 2800-3400rpms just like they should be.   When you don't see those numbers most just need taken completely apart and a good cleaning and fresh grease on the moving parts.......Cliff

[Pav8427]

Did a little digging. Found VA line to TVS was giving manifold vacuum at idle. To check things out I bypassed everything and ran VA direct to ported vacuum. Prior to this I had 14*initial. 35*in at around 2300. With 24* VA connected.  I have a 10* VA can installed to limit total. Since total came in early, I swapped in a couple factory springs that seemed a little stiffer. After bypassing, I still have 14* initial, 35* all in right at 3000. (Just a few more with a blip of throttle) Interestingly, there is no timing added till about 1700. Guessing that is mechanical starting. Gonna try one of the lighter springs to see what happens there. Not sure what happened to VA.

Gonna try for mechanical to come in around 1000, give or take.
With a 'stock' car like this. Is it best to see VA start just below cruise vacuum? Sooner? Later?

California cars have 2.56 gears and forgot to mention, installed 'factory' CAT bypass. (Removed it)

Thanks. Doug

[Cliff Ruggles]

When they are working correctly mechanical will start right off idle. 

Might be time to take the HEI apart and clean it up and new grease, etc.

I do not use or like light springs on them.  Without a positive stop added they will continue to add advance at high RPM.

They used a lot of vacuum advance timing on later emission engines to effectively burn lean mixtures and meet emission standards in place at that time.....Cliff

[Pav8427]

Pulled dizzy and did a quick clean up, relube, and shimmed to bout .018. Thinkin this must be a reman as springs were heavier than all stock ones I have. Did a re tune on idle and timing. Still have 14* initial, 35* in at 3000 w/10* added from VA. Runs much cleaner considering it has a whopping 170HP. One thing I did see was that mighty vac showed VA started around 8in, was all in by 11in. Ported vacuum port shows that I dont have that kind of vacuum till around 1600-1700 rpms. That sound about right? Any reason to bring that in sooner? Any thing on the carb end of things you can change to get that?
Anything that could be messed up or out of adjustment?

Thanks. Doug

[Cliff Ruggles]

Test the VA with a vacuum pump.  It should start around 7-9" and all in by 11-13" or close to it.  If not get a different unit.
No need to limit it to 10 degrees, those pathetically "low" compression engines with tiny retarded emission cams like a LOT more than that at light load.

I use one here that's perfect for HEI's. They aren't on the website but we sell them separate from doing a distributor build........Cliff

[Pav8427]

Thanks Cliff. I will call the shop when I get a chance. I appreciate all the good advise.

Doug