Is it worth it removing this smog equipment?

[85Squared]

http://67-72chevytrucks.com/vboard/showthread.php?t=601876

I found this link where another guy had the same questions and the general idea is that it was some sort of heavy duty emissions package. I also watched a video of another guy removing some other smog equipment from a K20 and he mentioned something about a feedback carburetor and potentially Messing up the feedback going to the carburetor by removing certain emissions equipment so now I'm hesitant to touch anything because I really don't feel like changing carburetors in order to avoid that possibility.

 

[87ChevyR10]

Yuck! This just reminds to never buy a cali vehicle!

 

[MikeB]

EFE =Early Fuel Evaporation

I'm not sure if that's what his plumbing and canisters are, but this is info about EFE:

From my 82 Light Truck service manual:

Supplies a source of rapid heat to the induction system during cold “driveaway”. Should “turn off” after engine warm-up.

The Vacuum Servo type uses a valve and vacuum actuator which increases the exhaust gas flow under the intake manifold during cold engine operation. The valve is located in the exhaust and is vacuum operated. It is controlled by a Thermal Vacuum Switch (TVS), or an EFE solenoid controlled by the ECM. When vacuum is applied, the valve closes, causing the intake to heat up.


I also found this when I was trying to determine how all the emission systems worked: http://www.autozone.com/autozone/re...l-Evaporation-EFE-System/_/P-0900c15280055ca7

 

[MikeB]

Regardless of what the system does, if you are concerned about installing headers and breaking bolts (not sure how that happens), then use some OE type cast iron manifolds. The 96-up manifolds will work and don't have any holes that need to be plugged except for one on the driver's side. Stock 85 head pipes will not bolt up because the outlets are not the same as yours, but that's an easy fix for a muffler shop.

 

[Craig 85]

This is all part of the air injection system. The reason this looks different than most is you have factory stainless exhaust manifolds. They use a different looking check valve than the trucks with cast exhaust manifolds. I would not replace these with cast manifolds as the stainless ones are more like headers and probably flow better. What ever you do, try not to damage the air injection tubes if you remove them. They are slowly being discontinued. I just ran into this with my truck. I was re-installing mine and one of the nuts stripped. I was lucky to find an oem piece to replace it, but it was through a vintage parts dealer.

Back in the the early 90's I didn't want to loose power by spinning the smog pump on my '77 K5. Between smog tests, I would remove the smog pump and change the belt to a shorter one. I then tied the air injection pipes together, so I didn't have any exhaust leaks.

 

[Craig 85]

FYI for those following this tread, here's photos of the manifolds he has. They also made them for big blocks too.
Small block
https://www.dormanproducts.com/gsea...K10%20Suburban&origin=YMM&q=stainless exhaust
Big block
http://arts-attic.com/blog/?p=1379

 

[CSFJ]

Weren't these the style that HRPC was looking for?

 

[MikeB]

Seems like some 80s Corvettes, Camaros, and the LT1 Caprice also used stainless manifolds.

 

[HotRodPC]

Weren't these the style that HRPC was looking for?

Yes, I was just going to say, I see in the pic now, those are the exhaust manifolds used for only 2 years on what considered Heavy Duty Small Block 8600lb GVW 3/4 and 1 ton. Used only 2 years. 84 and 85. Yes, I'm still looking for one those manifolds. I have the pipes and mufflers for both sides and they look like they'd breathe like a header. They have massive ports in them.

 

[Craig 85]

Summit Racing carries those Dorman manifolds. $435 for the pair, but the ship date isn't till the end of October!

 

[WFO]

Yes, I was just going to say, I see in the pic now, those are the exhaust manifolds used for only 2 years on what considered Heavy Duty Small Block 8600lb GVW 3/4 and 1 ton. Used only 2 years. 84 and 85. Yes, I'm still looking for one those manifolds. I have the pipes and mufflers for both sides and they look like they'd breathe like a header. They have massive ports in them.

My 86 has those manifolds. Still has original exhaust back to the mufflers. Previous owner put on glass packs and tail pipes.

 

[HotRodPC]

OK, so then it's 85 and 86 instead of 84 and 85 that got those. Pretty certain it was just 2 years.

 

[HotRodPC]

Here's the left side one that I have. Hope to acquire a right one someday. I have the full exhaust system that goes to these manifold. Just that the guy who pulled the engine out of this roller I bought, he left the right manifold bolted to the block he took.

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[Craig 85]

Here's the left side one that I have. Hope to acquire a right one someday. I have the full exhaust system that goes to these manifold. Just that the guy who pulled the engine out of this roller I bought, he left the right manifold bolted to the block he took.

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There's a new one on eBay right now for $130.
https://www.ebay.com/p/Exhaust-Manifold-Right-Dorman-674-530/76466749

 

[HotRodPC]

There's a new one on eBay right now for $130.
https://www.ebay.com/p/Exhaust-Manifold-Right-Dorman-674-530/76466749

That one pretty much stays there. I'm in no hurry so I'm hoping to eventually catch one at a Pull A Part for $15. You see the ports on that left one I pictured? How can that thing not breathe good?