oldsdale

Well hello again.

I finally installed exhaust manifolds and installed new pipes, mufflers etc as can be seen here:
https://classicoldsmobile.com/forums...tml#post843010

I brought it to inspection and the car failed at emission tests. I am total dumb with emissions and here is the readings:

HC: 1277 ppm(max.1000 allowed)
CO2:7,10%
O2: 10,44%(max 5,00 allowed)

I am not going to drive a hybrid to satisfy the car inspectors, no way. But is there a smart way to reduce the readings above?

Engine is 1972 Oldsmobile 350 v8 gas,
Carburetor: I have no idea what brand is but I have attached a picture.
Notes:
1-It spends a lot of gas no matter how much I try to optimize the mixture.
2-High rpm idle but not when the transmission is shifted.

Thank you all!

oldcutlass

The carb on your car is an Edelbrock. Are you running a vacuum advance? When was the last time it was tuned up? Don't know what state you live in, some states have an exemption for antique cars, have you looked into yours.

joe_padavano

From the angle of the photo, we can't really tell if it is an E-brock carb or an older Carter (E-brock simply restarted production of the Carter carbs under their own brand name). In any case, it is not original and may or may not be jetted properly for your engine. This is your first problem. You need to know what you are starting with.

oldsdale

High fellows. I found out it's a Carter carburetor. I live in Northern Europe.

Yeah it has. Good suggestion and will try. God knows when it was tuned previously.

Can you elaborate more?

What I've done so far is cleaning the carburetor (after taking photo), change distributor cap, sparkplug cables and sparkplugs.

IDLE sounds uneven and shaky. I suspect timing.

I found exhaust leak somewhere near exhaust manifold outlet.

More suggestions are appreciated.

joe_padavano

It's not a factory carb. Someone replaced the original at some time in the past. Those Carter carbs have been out of production since the 1980s. The carb needs to be matched to the needs of the engine in both size (CFM) and jetting. You have no idea what carb this is, what size it is, or how it is configured internally. Without knowing that and ensuring that it is correct for your application, anything else that you do is completely wasted.

oldcutlass

You can look up the number on the carb through the internet to tell what it was when born. It won't however tell you what had been done to it since. I would again suggest going over your settings with someone/place that has an emissions setup to tune it to pass before going to the testing facility. After that set it up to run efficiently.

MDchanic

Going for an emissions test without tuning up your car first is... a recipe for failure.

Have you checked you points and condenser? Set your dwell angle? Checked your ignition timing? Looked at your spark plugs?

- Eric

oldsdale

Thank you all for the suggestions.

I thought they wouldn't care about the emission for 72 model engine

I will do all suggested above including carb and report back.

MDchanic

I don't know of any place in the US that checks emission on engines that old, but I guess things are different where you are.

It should be easy to get your emissions within the requirements that they list if it is properly tuned.

- Eric

oldcutlass

I think California and a few E Coast states still require emissions to be within spec of what year engine you have in your car and/or the year model of the car. Texas has an exemption based on the license plate category.

joe_padavano

Arizona tests back to 1967 in metro areas (Phoenix and Tuscon). This probably makes some sense as the lack of rust keeps older vehicles on the road there. I'm sure there are others.

oldsdale

Oh Jesus! It's a Carter AFB 9635S. Thanks for the heads up!

I will definitely check the distributor, timing and all but do you have a suggestion for a replacement carburetor?

joe_padavano

750 CFM, likely jetted for a larger engine. Can't go wrong with the correct Qjet.

oldcutlass

The Carter AFB 9635S is a 625 cfm carb and should work fine.

joe_padavano

You are correct, sorry about that. I read the Carter web page incorrectly.

Since the Carter is a square bore carb, check for vacuum leaks if there's an adapter to the Qjet intake.

oldsdale

I tested the carb with carburetor cleaner. All good.

Then I sprayed to driver side intake manifold - cylinder head: bingo! Intake manifold leaks

chrisneu68olds

In CA anything from 1975 and older does not require emissions testing.

Fun71

It's not so much that as decades ago the dip$h!t legislators wrote the law using a hard 20 year age (1967) as a "20 year old" vehicle instead of putting in a rolling 20 year condition. Heck, California didn't even do that. Now we're stuck with the AZDEQ and US EPA having to review and approve any changes to the emissions laws.

oldsdale

Wow... Yes my car is registered 1978, that's why they do the emission test. No matter how old is the engine, they will count the car's age. Stupidest thing I have ever heard. Welcome to EU my friends.

joe_padavano

Actually, testing is SUPPOSED to go by the age of the car. If it didn't, there would be nothing preventing you from buying a brand new car and installing a 1960s motor in it, which defeats any emissions requirements on the new car. Alternately, if you had a 1960s vehicle and put a brand new LS motor in it, should it be tested to 2015 standards?

One can argue the value of emissions testing on cars over 25 years old, and whether there are enough of those still on the road to matter, but testing needs to go by the year of the vehicle to make any sense.

MDchanic

Oh. It's a 1978 car?

You may have trouble hitting the required numbers, as the '78s had catalytic converters.

I would strongly recommend scrounging up an old exhaust gas analyzer (they used to be fairly common and not expensive), so that you can tune it for the test - it may require some playing around.

- Eirc

olds 307 and 403

A Quadrajet is what you want from a similar sized engine and rebuild it. You might pass or be close after you replace the intake gasket.

joe_padavano

The OP has a 1978 Chevy pickup that originally had an Olds 350 diesel and now has a 350 gas engine. The 78 diesel truck had no emissions controls required, and I don't even think that the 78 gas pickups needed cats in the U.S. Keep in mind that trucks have always had looser emissions requirements than cars. I don't know how the truck is being tested, however. In most states in the U.S., the VIN would show that the truck is a diesel and testing would not be required anywhere.

MDchanic

Absolutely true on both counts - I hadn't realized he had a truck.

I agree that a diesel truck should be subject to no emissions testing - a gasoline engine in a diesel truck of that era should improve its emissions no matter what.

I really don't remember the older emissions standards, but the standards he posted initially looked vaguely to me like the ones that NYS used to test for on my '70 Chevelle - if that's the case, they should be looking for a pre-cat standard, since this truck would have never had a cat (and, note that in this era, European cars did not have cats either - their US models had to be re-engineered for emissions before they were exported), so a good tune-up should do the job.

If they're going to sniff your pipe every year, though, picking up a used emissions tester still wouldn't be a bad idea...

- Eric

oldsdale

Intake manifold gasket, exhaust port was leaking. I assume this has some impact on emission. Ordered new gaskets and waiting for it to arrive. It's a steel gasket with silicone seal. I have never installed a steel gasket before

Anyway, you guys are awesome! Thank you all for the quality conversation. I will report back soon.

I'm done with this car after the inspection. I look forward to visit the states, buy couple of 50's ,60's vehicles (1 cutlass, 1 chevy apache etc), get a container and ship them to europe. I am also looking forward to meet with people who could send me vehicles.

joe_padavano

Search this site for threads on the "turkey tray" gasket. There is a technique to proper installation, as described in the Chassis Service Manual Failure to follow this procedure will lead to more leaks.

oldsdale

Hello again,

I feel like this is worth sharing. One of the bolts was not same size and it was tighter than others. Vacuum leak was exactly around this bolt.

I bought new bolts.
Check the one in the left in attachment.

Update 2: I called the previous owner and I gently asked about it. He said his wife did the intake gasket job. They also used the rubber gaskets for the front and rear instead of sealer (there was no oil nor coolant leak though).
Update 3: Previous owners tightened the bolts with Chevrolet 350 "X sequence" starting from center to out.

I couldn't yell at the phone because the owners are associated with an MC gang

Right on. I found this for the torque and the sequence:

http://torquespecs.tripod.com/oldsfs...8.htm#Note%201

I would be very glad if you confirm it's correct.

Should I apply multiple stage torque? I mean 1st X lbs then, xx lbs and wait approximately 24 hours for the sealer, drive it couple days and check the torques once again.

MDchanic

Yes, that look like the same sequence as in the CSM.



And, yes, I always torque everything in stages.

- Eric