C3 Vette Registry - The Best Resource on the Net for C3 Vettes! C3 Vette
Forums -> C3 Fuel, Emission Control, and Exhaust Systems
Not Logged In! Login or Register!  Users Online: 22 / Help 
Features  Find C3 Parts on ebay in only 2 or 3 clicks!  | Add YOUR C3 to the Registry

Supporting Vendors
VetteBookStore.com
Mid America Motorworks
Volunteer Vette Products
CorvetteClothing.com
Bair's Corvettes

C3 of the Month
None Current
Enter Yours Today!
Online C3 Show
13
C3s are Registered

Vanity Plates
MY69VET
glenns
Featured Links
Chevrolet Corvette Restoration Guide


Buy Now
Motor Trend - $5 for 12 issues.
Motor Trend
Only $5 for 12 issues.


Corvette: America's Sports Car Yesterday, Today, Tomorrow (Hardcover)
Corvette: America's Sports Car Yesterday, Today, Tomorrow (Hardcover)


Chevrolet Corvette: 1968 thru 1982, All V8 models (Haynes Manuals) (Paperback)
Chevrolet Corvette: 1968 thru 1982, All V8 models (Haynes Manuals) (Paperback)


How To Rebuild Corvette Rolling Chassis 1963-1982
How To Rebuild Corvette Rolling Chassis 1963-1982



| Hide Signatures and Profile Pics

 New Topic New Topic Post Reply Reply New Poll New Poll Search     Search Page [1]  
8/5/15 12:36pm - Original Message: 'smog removal'
shelly 81
Former Member
- Send Private Message


Saint Charles, MO - USA

Vette(s):
1981 dark blue metalic St.Louis built.

Joined: 11/20/2007
Posts: 4
I want to remove the emission devises and computer from my 81(non ca). I have HEI. I don't know any thing about the connector on the carb and don't want to tear into it till I get info on it. I know that the computer controls metering and timing (every 10 sec., WOW). I have a wiring and vacuum diagram, I just want good advise on how to attack it before I start. As far as eco and mpg, I've had her 9 and a half years and put 5000 miles on her verified 52001.3 total miles. Any help would be great! Thanks!    

____________________________________
 Reply Reply  Quote Reply w/Quote
 
Support C3VR!
Suport our advertisers
8/5/15 1:40pm - Reply: 'Re: smog removal'
johnu
Standard Member
- Send Private Message


Eagan, MN - USA

Vette(s):
1981 Corvette Two-Tone Claret color, 4 spd, C7 Vert

Joined: 5/23/2007
Posts: 507
I'm probably wrong... but why bother for 600 miles a year?  The gains from that low-hp motor might be too small to feel.  I chose to keep my '81 stock and eliminate any headaches trying to reinvent this motor.  Plan A would be to do the full monte like Sarge81 did to his with the proper fuel injected motor.
 
 





|UPDATED|8/5/2015 11:40:08 AM (AZT)|/UPDATED|


____________________________________
      Only 23 years together
 Reply Reply  Quote Reply w/Quote
8/5/15 3:02pm - Reply: 'Re: smog removal'
Sarge81 Lifetime Member
Lifetime Member
- Send Private Message


WEST SENECA, NY - USA

Vette(s):
1981 Blue Ice Met. w/pearl ghost flames TKO500 5speed. LS1 Swap 3.45 Dana 44.

Joined: 12/3/2001
Posts: 2376
If the system is becoming troublesome such as mine originally was. Just yank that engine out and either put some higher compression pistons, heads and a mild cam in it or put a crate engine in it. The stock pistons are only 8.2:1 CR. So no matter what you do with it in stock form you won't get significant power gains. 

I put a GM 350 HO crate engine in it back about 13 years ago. Stripped out ever bit of computer wiring and computer. Went with a non computerized Qjet carb and HEI distributor. There was one green wire that connected near the wiper motor. It was part of the computer wiring. That had to stay otherwise the A/C would't kick on.

Last year I went the "full monte" as John mentioned. I shoehorned a Gen III LS engine into my car. Basically its built to a '02-'04 spec Z06 engine with a step over stock on the cam. Runs like a modern vette now.

Is your car a automatic or manual transmission?


____________________________________

GEN III 5.7L "LS6" Engine swap
TKO500 5 spd.
3.54 Dana 44
'69 "N11" Sidepipes
Borgeson Steering Box
Born 8/1981
Sequence #3975




Click here to see more pics of my Vette on CarDomain.


Lifetime Member #26
 Reply Reply  Quote Reply w/Quote
8/5/15 3:33pm - Reply: 'Re: smog removal'
kstyer Lifetime Member
Lifetime Member
Moderator
- Send Private Message


CUYAHOGA FALLS, OH - USA

Vette(s):
1975 C3 Red, T-Tops, Black Interior. All I need is time and money! Getting there!

Joined: 12/2/2003
Posts: 6410
If the car is not causing problems, I agree, why bother?  BUT if you still wish to do so, it's really easy.
 
Replace the carb with a non electronic controlled qudrajet carb.  The hook ups will be the same minus wiring connections.   Replace the distributor with a standard HEI from 80 or older, and connect the vacuum line, tach lead, and power lead.  Unplug the ECM.
 
Done.
 
If you want to you can also disconnect the EGR, but you may have some pinging problems.  You can disconnect the AIR (air pump) system simply by removing it, and pluging the lines into the exhaust manifold.  The EFE, Early Fuel Evaporation, is a vacuum controlled heat riser.  If it's not causing a problem, leave it alone.  It will help the engine warm up faster.


|UPDATED|8/5/2015 1:33:28 PM (AZT)|/UPDATED|


____________________________________
On the "Tail of the Dragon"
(some day, no strike that, October 2008 it turned red, still in progress!)

(click either image to see a bigger version)
 Reply Reply  Quote Reply w/Quote
8/6/15 9:09am - Reply: 'Re: smog removal'
shelly 81
Former Member
- Send Private Message


Saint Charles, MO - USA

Vette(s):
1981 dark blue metalic St.Louis built.

Joined: 11/20/2007
Posts: 4
Great responses. The reason I even thought about it is that I need to rebuild the carb and was going to tear out the smog crap. So i'm going to leave her alone and just fix the q jet. I've rebuilt q-jets before but it's been a while so any tips on that would be appreciated! I've also purchased an aluminum radiator for the old girl and plan to use Water Wetter. I've heard two bottles is best, but what about the coolant? Is there a better than recommended product to help cool her? Again, great advise! Might put 700 miles on her this year.

 SAVE THE WAVE!Big smile


____________________________________
 Reply Reply  Quote Reply w/Quote
 New Topic New Topic Post Reply Reply New Poll New Poll Search     Search Page [1]  
 Forums -> C3 Fuel, Emission Control, and Exhaust Systems
(Moderator: Adam Wartell, Norsky, Adams' Apple, kstyer)
 

 
Official C3 Vette Registry Community:
Home | Forums | Email | Who's Online | Clubs | Events | Member Stats

Other Official C3 Vette Registry Areas:
Members | Research | Shop | My Account | About C3VR
 

Corvette is a registered trademark of the General Motors Corporation(GM) & Chevrolet Motor Division. Vette Registries, LLC is responsible for all site content (except for member submitted content or where otherwise noted) and does not claim or imply that Chevrolet or GM is responsible for Official C3 Vette Registry content. Vette Registries, LLC is independent from GM and is not affiliated with, sponsored or supported by GM.  Copyright/trademark/sales mark infringements are not intended, or implied and are in fact used to support GM, Chevrolet and Corvette

Official C3 Vette Registry content is Copyright 2001-2017, Vette Registries, LLC. Content may not be reused without written consent. All Rights Reserved. NS

Corvette (Vette) Model Years on this site: 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 30