you fabbed up a set of he's thru a cat and then thru a muffler.

hypothetical - if the exhaust read 700 HC & 7.00 CO - what woud it read with cat?

jim

The cat is unlikely to get the CO down, but it would do a reasonably good job on the HCs. The CO you show means the car is running seriously fat, way beyond where it would be running best. If you did install a cat, with CO like that, it probably wouldn't last more than a few hundred miles anyway.

The Cap'n

Oops read the post first

I would lean out the idle system just a bit and retard the timing. That should lower the CO a bit and keep the HC from climbing. Its all a crap shot. Adding a cat would get you to pass ether way... IMO ...

And what's he gonna do about the CO? If he gets the CO down to below the limit for a '72, it's reasonable to assume the HCs will fall as well ................. Besides, the timing is specified, and if he doesn't fall within a degree or 2 of the specification, it's gonna fail.

The Cap'n

It all depends on the testing criteria and If he check the timing.
Lots of guys say they did and don't

i'd expect the high h.c.'s are high due to the high (rich) c.o. mix. lean out the mix (c.o.) as much as the h.c.'s will allow, stop at the low point before the h.c.'s go back up. h.c.'s are basically a misfire/partially burn fuel... either a lean or rich.

i've had cars fail with every component operating 100% except for a lazy cat that would not pass. a new cat does wonders. the big disclaimer here is to have everything else solid.

the air cooled engines i've smogged have to be leaned down so much they sound like shit. the trick is to get the h.c. sweet spot while choking back the mix (c.o.)

get that and a (good) cat

mike

I see you are in Milton DE, just south of where I grew up, in Milford. Left in '65 when the draft was breathing down my neck and have lived on the left coast ever since. I was back there a couple of years ago and don't remember seeing a Porsche, let alone a 914 of all things. I used to race on the dirt speedways that were abundant in the 60's like Georgetown, Little Lincoln, Delmar and several in MD that I forget.

This is for your V8 powered 914, right?

Antique tags?

delaware is 1968 and older : (

looks like i need a 356 to drop a v8 into : ))

i passed two years ago by just taking my air cleaner off for the test, as i had a very restrictive one on at that time. but i would also like to pollute less.

subaru power would be better for the environment.

--

Or you could just do a tuneup ............................. The Cap'n

Or go to fi. even tb fi. you probably wouldn't need a cat. micro squirt tb? or move out in the country.

" but i would also like to pollute less".

Jim,
That train left the station 30 years ago, LOL

Seriously, Your close and if you can run the test without a air cleaner, well that sounds like they don't look to close at anything but what the readings. Retard the timing, tighten up the idle CO and run the idle speed as high as you can. Idle speed / circuit is the hardest area to control emissions running a carb(I'm sure someone will disagree). so raising the idle will help a bunch. I'm sure there's a limit so I would find out what it is.

will it be ready for Hershey this weekend?

the air cooled engines i've smogged have to be leaned down so much they sound like shit. the trick is to get the h.c. sweet spot while choking back the mix (c.o.)

get that and a (good) cat

mike
[/quote]

That was my experience....When I had to have smogging!
retarded and leaned to shit!!...I always asked them to set it back
like it was. when they passed it! relieved I don't have to do it
anymore(75')

a tune up - i am not looking for a common sense solution : ))

thanks

jim

--

If you're looking to pass a smog test, disconnect one of the small vacuum lines and raise the idle and don't let it idle for more than a two minutes before doing the test, it will load up on you. If you're looking to make the emissions go down a bit, you really wont get less than perhaps 3.00 co and 300 hc for a v8. Say for example if you removed the cat from the 99 accord in your og post the readings would be around 70 for hc and .30 for the co. Newer cars with fuel injection just run better.

I know I am jumping in late on this but I don't get it, why can't you just lean it out?
I just had my old RV in to get smog tested and it runs way cleaner than you're showing for yours.
It is a 77 motor home on a 76 Chevy 1 ton van chassis with a 350
It has no cat, no EGR.
It has Air injection & EVAP
The only things non-stock are the MSD ignition and a mild "RV" cam.

Specs as tested a 9:35 this morning:
Idle CO -- 0.65%
Idle HC -- 27ppm
2500rpm CO -- 0.12
2500rpm HC -- 20

California allows 3.0% CO & 300ppm HC at idle and 3.5% CO & 350ppm HC at 2500rpm

What is with your engine that you can't get it idling cleaner?

Good luck

Jim

Jim....alcohol...in the car, not you.
Less than a 1/4 tank of fuel...10 bottles of dry gas (alcohol) and it should pass.
Go directly to a gas station and fill that tank up afterwards.
Rich

Uh oh, you just revealed The Secret. Ignore that post everybody, you didn't hear that here, it doesn't exist, and we can PROVE it!

Actually that fillup after the test is a very important part of Rich's post. Be careful about carb and other fuel parts, especially pre-e85 stuff, because that alcohol will swell some types of rubber and can really screw stuff up. No nasty gases though, just water vapor...

Yes the fill up is key...you gotta dillute it fast.

Rich

hey jim,

find a friend with an infra-red meter (smog machine) and play with your timing and mixture. it's really fun. really. =-)

you'll quickly see that mixture is only part of the equation. timing, compression, vacuum, cat health/saturation, and more can be analyzed and a clearer solution can be found.

i used a complete engine analyzer which also was an oscilloscope and read ignition timing and each individual cylinder firing, condenser health, wires, plugs, and ... other stuff. LOL

but dude, a tune up, a very small retard on timing, and a little alcohol will definately do the trick.
Look at this guys numbers and end result at the bottom of his thread, and see what it can do...
http://www.honda-tech.com/showthread.php?t=2284799

Silly me. I thought you wanted to FIX the problem, not just pass a smog test. I'll say this again...... IF you put a converter on a car running at 7%, it's gonna fail completely within a few hundred miles, thereby wasting the money you spent on the converter and the work. Furthermore, the mode of failure (the monolith is gonna freakion' MELT) is such that it's likely to plug your exhaust system, causing you to spend even MORE money. Since we're all CSOBs here, the very thought of flushing all that cash down the drain is repugnant.

The Cap'n