Vacuum connections without Smog

[BroadwayBlue]

My new 289 has a distributor I want to remove and go back to the original.

This car has had the smog equipment removed.
My 302 has the smog equipment on it.

I found some diagrams with the smog equipment.

Anyone have diagrams of the connections without smog. Does it matter?
Or any recommendations?

I'm planing on going with a dual vacuum distributor.
Will that work without the smog setup?

Thanks!
Rich

 

[CougarCJ]

From my learnings, the dual vacuum advance on the distributors were for emissions.
I would stay with a single advance, with the vacuum line coming straight from ported vacuum off the carburetor.

The vacuum tree on the thermostat water inlet is also for emissions.

Are you saving your smog parts? I may be interested in another 1968 thermactor system.

 

[BroadwayBlue]

Thanks for the info.
So you're recommending switching to a single advance?

My 289 does not have smog but had a dual advance before the previous owner switched to an HEI distributor.

My 302 has the smog and also has the dual advance.

The 289 is the one I'm planning on going back to the original distributor, which the previous owner gave me.

I don't have the smog for the 289 at all and no plans to remove it from the 302 at this time. If anything changes I will let you know.

Thanks!

 

[GTCSMustang]

The 302 has smog because it's a manual transmission car. And the 289 does not have smog because it's an automatic transmission car. No 1968 Mustangs with automatic transmissions came from the factory with smog. It is a common belief that California Mustangs had smog and other state cars did not. Not true...there is no such thing as a "California Emission" car in 1968. But there was in 1967.

Scott

 

[BroadwayBlue]

The 302 has smog because it's a manual transmission car. And the 289 does not have smog because it's an automatic transmission car. No 1968 Mustangs with automatic transmissions came from the factory with smog. It is a common belief that California Mustangs had smog and other state cars did not. Not true...there is no such thing as a "California Emission" car in 1968. But there was in 1967.

Scott

Hi Scott,
That's what I always thought was the case, but recently I read somewhere that all 68 cars had emissions on them.
Now I need to figured out where I read that.

But Dual is correct still without the smog?
I'm so confused now :grin:

I thought a Thermactor and IMCO were both smog/emissions equipment. Am I misunderstanding that?

According to MCA rules:
Emission System: [FONT=Arial,Arial]PCV, smog pump, pulleys and attaching parts or IMCO system. Correct style, finish and design for year. [/FONT]
67: [FONT=Arial,Arial]All 71 & 72 DSO - thermactor system except K engines delivered to California before mid-April. All other DSOs - no thermactor. Some late cars used IMCO. [/FONT]
68: [FONT=Arial,Arial]All US DSO - thermactor systems on all manual transmission equipped cars and all 390 4V’s and 428CJ. IMCO systems on all others. [/FONT]

[FONT=Arial,Arial][/FONT]
[FONT=Arial,Arial]Is IMCO not a smog setup?[/FONT]
[FONT=Arial,Arial]Sorry for the questions - just trying to understand the correct setup for the distributor and all.[/FONT]

 

[GTCSMustang]

Rich,

If you have a 289/2V Automatic, your car should have a dual-diaphram vacuum advance. The only 1968 Mustang that came from the factory with a single-diaphram vacuum advance was a 302/4V Automatic (with and without air).

Scott

 

[Mosesatm]

Rich, IMCO is a version of smog control but when most people talk about a car with smog they are talking about the smog pump system (thermactor).

 

[teamlo]

If you want the "bible" on the small-block Ford V8, I'd suggest Bob Mannel's excellent book, "Ford Small Block V8, 1962-1969". Well worth it's weight in gold.

 

[franklinair]

I owned an original '68 289: P/S, P/B, A/T, Factory A/C. It had the dual vacuum advance unit using the vacuum tree. My understanding was that of a different vacuum when the engine was warm versus cold. That's why the tree was mounted on the intake, to sense coolant temperature. See 1968 Shop Manual, page 9-16. If my memory is correct, manifold pressure went to the upper connection, and the center & lower connections controlled the distributer vacuum advance, based on engine operating temperature. See Shop Manual page 9-24. Hope this helps.
Neil Hoppe

 

[J_Speegle]

............ No 1968 Mustangs with automatic transmissions came from the factory with smog. ......

Might want to clarify .... no small block or 6 cylinder 68 Mustang with an automatic came with a Thermactor smog system

 

[GTCSMustang]

Oops. That's what I meant. Small block. Thanks.

Scott

 

[BroadwayBlue]

Thanks to all for the info!

 

[6t8-390gt]

If you want the "bible" on the small-block Ford V8, I'd suggest Bob Mannel's excellent book, "Ford Small Block V8, 1962-1969". Well worth it's weight in gold.

I agree!

Two smog control systems were used in 1968 IMCO (IMproved COmbustion control) consisted of a "finely tuned distributor and carburetor calibrations." Bob Mannel explains the system in detail in his book, he also illustrates the 11 different vacuum hose systems. According to Bob the specific hose system used was dependent on type of vehicle, date of manufacture, transmission, and whether A/C was or was not included.

The other smog system was the T/E, otherwise known as the thermactor emissions control.

 

[BroadwayBlue]

Great info as always - Thanks!!

I just ordered the book based on the recommendations here and reviews on the book's website.

Thanks again!

 

[nfrntau]

Rich,
I'll be looking for an electronic igniton for my 289 when I get to that point. Is the distributor your removing electronic? Anyone have a used one they want to get rid of?
Just to be up front, I'm keeping all the original bits and pieces in case I ever want to put them back on.

Bill

 

[BroadwayBlue]

Rich,
I'll be looking for an electronic igniton for my 289 when I get to that point. Is the distributor your removing electronic? Anyone have a used one they want to get rid of?
Just to be up front, I'm keeping all the original bits and pieces in case I ever want to put them back on.

Bill

Hi Bill,

Yes it is electronic. It's an HEI Distributor. Personally I wasn't crazy about the look of it but that's just a personal preference.

Attached is a picture of how it looks mounted. The PO (previous owner) also put on very small air filter as well. I haven't tried it, but I'm not sure the original air filter housing will fit over this unit. The original air cleaner cover and distributor were in the trunk when I got the car. I'll be going back to both.

The picture is deceiving, the Air Filter might look regular size, but it's not. It's similar to what you would see on a multi-carb car. The air cleaner is about half the size of the original air filter. Maybe less than half. Put it this way - the one on the car could fit inside the original air filter.

Let me know if you're interested. I can check if the original air cleaner would fit over this.

Maybe someone else is familiar with this size air cleaner - it was a first for me.
Reminds me of a tri-power GTO filter but larger than that.

 

[CougarCJ]

Rich, be very wary of that style of fuel filter.

 

[nfrntau]

Wow,
That suckers BIG. I'm not sure, but I'd guess that would interfere with a monte carlo bar also. I agree with not being crazy about the look. I hope I won't hurt your feelings but I'm going to pass and keep searching for something a little smaller. Thanks a bunch for the photo, they truely say a thousand words.
Cheers
Bill

 

[BroadwayBlue]

Rich, be very wary of that style of fuel filter.

I assume you meant air filter right? I'm putting back the original as soon as I swap the distributor's

R

 

[BroadwayBlue]

Wow,
That suckers BIG. I'm not sure, but I'd guess that would interfere with a monte carlo bar also. I agree with not being crazy about the look. I hope I won't hurt your feelings but I'm going to pass and keep searching for something a little smaller. Thanks a bunch for the photo, they truely say a thousand words.
Cheers
Bill

You won't hurt my feelings at all.
Hopefully I'm not hurting any one else's feelings because I'm taking it out.
Just personal preference and want to go back to the original setup.