C3 Tech/Performance V8 Technical Info, Internal Engine, External Engine, Basic Tech and Maintenance for the C3 Corvette
Sponsored by:
Sponsored by:

Charcoal canister??

Thread Tools
 
Search this Thread
 
Old May 24, 2007 | 10:26 PM
  #1  
rudolph schenker's Avatar
rudolph schenker
Thread Starter
Safety Car
Supporting Lifetime
20 Year Member
Liked
Loved
Community Favorite
 
Joined: Oct 2004
Posts: 4,809
Likes: 237
From: Utah
Default Charcoal canister??

I recently removed my old Crossfire engine and put in a new zz383. My new set up is now carburated. Do I still need the charcoal canister behind the driver grill? If not can I remove it without causing any problems? Also what did this switch do? It was connected to the canister.



Reply
Old May 24, 2007 | 11:25 PM
  #2  
TheSkunkWorks's Avatar
TheSkunkWorks
Le Mans Master
10 Year Member
Liked
Loved
Top Answer: 1
 
Joined: Apr 2007
Posts: 7,353
Likes: 72
From: Graceland in a Not Correctly Restored Stingray
Default

I haven't delved into the evap canister system enough to know about the switch, but I believe keeping the system in good order would be prudent. Properly plumbed (or maybe even improperly), leaving it in shouldn't hurt performance, and taking it out and capping off the lines will require changing the gas cap to a vented type, which will then vent raw vapors.
Reply
Old May 24, 2007 | 11:28 PM
  #3  
sjmaster's Avatar
sjmaster
Racer
15 Year Member
Conversation Starter
All Eyes On Me
Liked
 
Joined: Jul 2006
Posts: 337
Likes: 10
Default

Man, I need to spin some old Michael Schenker Group albums now

That vacuum switch probably controlled purging. I read that cannister purge only happens on start up.

Last edited by sjmaster; May 24, 2007 at 11:30 PM.
Reply
Old May 24, 2007 | 11:30 PM
  #4  
1fastC3's Avatar
1fastC3
Racer
20 Year Member
 
Joined: Mar 2005
Posts: 393
Likes: 3
From: Dallas, TX
Default

i ran the line from the gas tank side of the cannister to a vac. port on the carb and bypassed the cannister all together, no troubles so far. good luck.

-alex
Reply
Old May 25, 2007 | 08:55 AM
  #5  
11Jake's Avatar
11Jake
Racer
 
Joined: Mar 2006
Posts: 313
Likes: 0
From: Fairfield PA
Default

I can't give you an answer on the switch. I didn't have any switch when I removed my canister and lines. I removed all the smog equipment and caped the lines on my 80 and haven’t had any problems with performance or gas smell.
Good luck!
Reply
Old May 25, 2007 | 09:09 AM
  #6  
...Roger...'s Avatar
...Roger...
Race Director
 
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
Default

Originally Posted by TheSkunkWorks
I haven't delved into the evap canister system enough to know about the switch, but I believe keeping the system in good order would be prudent. Properly plumbed (or maybe even improperly), leaving it in shouldn't hurt performance, and taking it out and capping off the lines will require changing the gas cap to a vented type, which will then vent raw vapors.

Your fuel tank is vented through the canister.If you block the lines your tank will not be vented and the engine can starve for fuel and even cause the tank to collapse.
Reply
Old May 25, 2007 | 01:17 PM
  #7  
7t2vette's Avatar
7t2vette
The ORIGINAL and bestest
Supporting Lifetime
20 Year Member
 
Joined: Oct 2000
Posts: 10,009
Likes: 240
From: Toronto Ontario
Toronto Events Coordinator
Default

Originally Posted by TheSkunkWorks
........ and taking it out and capping off the lines will require changing the gas cap to a vented type, which will then vent raw vapors.
If you remove the cannister, you will need to seal off the connections at the tank as well as change to a vented gas cap. The vented gas caps are like one-way valves; they allow air in but not vapors out, they are this way to prevent the fuel pump from collapsing the tank. A properly functioning vapor recovery system will not affect performance in any way.
Reply
Old May 25, 2007 | 01:38 PM
  #8  
rudolph schenker's Avatar
rudolph schenker
Thread Starter
Safety Car
Supporting Lifetime
20 Year Member
Liked
Loved
Community Favorite
 
Joined: Oct 2004
Posts: 4,809
Likes: 237
From: Utah
Default

Originally Posted by 7t2vette
If you remove the cannister, you will need to seal off the connections at the tank as well as change to a vented gas cap. The vented gas caps are like one-way valves; they allow air in but not vapors out, they are this way to prevent the fuel pump from collapsing the tank. A properly functioning vapor recovery system will not affect performance in any way.
I thought I would keep the canister and line from the gas tank connected, but cap off all the other lines to the canister except the one on the bottom of the canister.
Reply
Corvette Stories

The Best of Corvette for Corvette Enthusiasts

story-0

10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years

 Joe Kucinski
story-1

How Much Horsepower Every Corvette Engine "LOST" in 1972

 Joe Kucinski
story-2

Top 10 DOs and DON'Ts for Protecting Your Convertible Top!

 Michael S. Palmer
story-3

Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

 Joe Kucinski
story-4

150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

 Joe Kucinski
story-5

8 Coolest Corvette Pace Cars (and Replicas) of All Time

 Verdad Gallardo
story-6

Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)

 Joe Kucinski
story-7

Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!

 Verdad Gallardo
story-8

Top 10 Corvettes Coming to Mecum Indy 2026!

 Brett Foote
story-9

Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!

 Michael S. Palmer
Old May 25, 2007 | 02:11 PM
  #9  
7T1vette's Avatar
7T1vette
Team Owner
15 Year Member
Community Builder
Community Influencer
Top Answer: 5
 
Joined: Jan 2006
Posts: 37,637
Likes: 3,117
From: Crossville TN
Default

If you only leave the line from the tank to the cannister, there will be no "flow" passage for the system to work...it would just be dead-headed. You need to keep the line up to the engine area so the vapors in the tank can get burned by the engine.
Reply
Old May 25, 2007 | 03:08 PM
  #10  
...Roger...'s Avatar
...Roger...
Race Director
 
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
Default

Originally Posted by 7T1vette
If you only leave the line from the tank to the cannister, there will be no "flow" passage for the system to work...it would just be dead-headed. You need to keep the line up to the engine area so the vapors in the tank can get burned by the engine.
but for the sake of discussion when do you think these vapors will form?When the engine is running air should be going from the canister to the tank because the engine is sucking fuel from the tank.In his case and I'm not totally sure about his pump situation he is going to have fuel returning also -churned up by his 1982 crossfire electric pump.This could create some fumes.When the car is shut off and the heat causes some expansion I would say the fumes would go to the canister.On the next start up the engine should evacuate the canister "if" still connected to the engine.
Reply
Old May 25, 2007 | 03:31 PM
  #11  
rudolph schenker's Avatar
rudolph schenker
Thread Starter
Safety Car
Supporting Lifetime
20 Year Member
Liked
Loved
Community Favorite
 
Joined: Oct 2004
Posts: 4,809
Likes: 237
From: Utah
Default

Originally Posted by DWncchs
but for the sake of discussion when do you think these vapors will form?When the engine is running air should be going from the canister to the tank because the engine is sucking fuel from the tank.In his case and I'm not totally sure about his pump situation he is going to have fuel returning also -churned up by his 1982 crossfire electric pump.This could create some fumes.When the car is shut off and the heat causes some expansion I would say the fumes would go to the canister.On the next start up the engine should evacuate the canister "if" still connected to the engine.
Let me clarify my fuel pump set up. Since I'm now carburated I no longer have an in-tank electric pump. I opted to run a mechanical pump, this way I don't need a pressure regulator. I capped off the return line at the tank (gas tank has been newly replaced I also removed the old fuel line and ran a new fuel line). My thoughts were to vent the tank through the existing line up to the charcoal canister, which will be open to air via the bottom hose which tucks up in the frame rale. I thought this would still allow venting of the tank and might help with a potential fuel smell?
Reply
Old May 25, 2007 | 05:23 PM
  #12  
7T1vette's Avatar
7T1vette
Team Owner
15 Year Member
Community Builder
Community Influencer
Top Answer: 5
 
Joined: Jan 2006
Posts: 37,637
Likes: 3,117
From: Crossville TN
Default

Flow through the vapor system is FROM the tank TO the cannister, then INTO the engine. The cannister "collects" the vapors from the tank until the engine is running, then manifold vacuum sucks those collected vapors into the base of the carb so they can be burned off.
Reply
Old May 25, 2007 | 05:35 PM
  #13  
...Roger...'s Avatar
...Roger...
Race Director
 
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
Default

Originally Posted by 7T1vette
Flow through the vapor system is FROM the tank TO the cannister, then INTO the engine. The cannister "collects" the vapors from the tank until the engine is running, then manifold vacuum sucks those collected vapors into the base of the carb so they can be burned off.
Your talking about when the engine is not running -right?
Reply
Old May 27, 2007 | 12:12 AM
  #14  
7T1vette's Avatar
7T1vette
Team Owner
15 Year Member
Community Builder
Community Influencer
Top Answer: 5
 
Joined: Jan 2006
Posts: 37,637
Likes: 3,117
From: Crossville TN
Default

Any vapors in the tank can only go one way...toward the cannister. If there is some positive pressure for vapors to release [engine OFF], they go to the cannister and get "held" by the charcoal stuff. Then, with engine ON, the engine vacuum sucks the vapors back out of the activated charcoal through the base of the carb and then get burned by the engine. The cannister gets enough air flow through it to purge it before you shut it off again.
Reply
Old May 27, 2007 | 06:28 AM
  #15  
Rotonda's Avatar
Rotonda
Burning Brakes
15 Year Member
 
Joined: Sep 2006
Posts: 1,071
Likes: 86
From: Rotonda FL
Default

If you remove the canister and leave the line, it will vent the tank. As you fill the tank or the fuel in the tank heats and expands, fuel vapor will be expelled. As you pump fuel out for use ,or when the fuel cools and contracts, air will be drawn into the tank to equaloze the pressure.

Question - Why did you remove your fuel return line? The return assures that you will always be supplying cool(er) fuel to the carb, giving you more consistant mixture/performance and also go far towards preventing vapor lock.
Reply
Old May 27, 2007 | 07:12 AM
  #16  
...Roger...'s Avatar
...Roger...
Race Director
 
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
Default

Originally Posted by 7T1vette
Any vapors in the tank can only go one way...toward the cannister. If there is some positive pressure for vapors to release [engine OFF], they go to the cannister and get "held" by the charcoal stuff. Then, with engine ON, the engine vacuum sucks the vapors back out of the activated charcoal through the base of the carb and then get burned by the engine. The cannister gets enough air flow through it to purge it before you shut it off again.
Yes "but" when the engine is running the flow path is reversed.This same line allows air to flow from the canister to the tank as fuel is being removed from the tank to feed the engine.So your statement of one way flow from TANK to CANISTER is not correct.
Reply
Old May 27, 2007 | 03:49 PM
  #17  
7T1vette's Avatar
7T1vette
Team Owner
15 Year Member
Community Builder
Community Influencer
Top Answer: 5
 
Joined: Jan 2006
Posts: 37,637
Likes: 3,117
From: Crossville TN
Default

I guess that I'm not certain about that one. There is a "fuel separator" on the left side of the fuel tank and I'm not sure of its involvement with pressure equalization of the fuel tank when running.
Reply

Get notified of new replies

To Charcoal canister??





All times are GMT -4. The time now is 11:57 AM.

story-0
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years

Slideshow: 10 reasons why the C6 Z06 is still a performance benchmark after 20 years.

By Joe Kucinski | 2026-05-27 17:20:09


VIEW MORE
story-1
How Much Horsepower Every Corvette Engine "LOST" in 1972

Slideshow: How much horsepower every Corvette engine lost in 1972.

By Joe Kucinski | 2026-05-27 16:54:53


VIEW MORE
story-2
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!

Slideshow: How to Protect A Convertible Top: 10 DOs & DON'Ts

By Michael S. Palmer | 2026-04-03 00:00:00


VIEW MORE
story-3
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

Slideshow: The 10 most explosive Corvettes ever built based on power-to-weight ratio.

By Joe Kucinski | 2026-05-20 07:23:03


VIEW MORE
story-4
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

Slideshow: From C1 to C8 we compare every Corvette generation by the numbers.

By Joe Kucinski | 2026-05-12 16:54:12


VIEW MORE
story-5
8 Coolest Corvette Pace Cars (and Replicas) of All Time

Slideshow: Some Corvette pace cars became collectible legends, while others perfectly captured the look and attitude of their era.

By Verdad Gallardo | 2026-05-11 09:50:51


VIEW MORE
story-6
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)

Slideshow: Ranking the top 10 Corvette engines by torque output.

By Joe Kucinski | 2026-05-05 11:58:09


VIEW MORE
story-7
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!

Slideshow: A Corvette pace car nearly matching IndyCar speeds sounds exaggerated, until you look at the numbers.

By Verdad Gallardo | 2026-05-04 20:03:36


VIEW MORE
story-8
Top 10 Corvettes Coming to Mecum Indy 2026!

Among a rather large group of them.

By Brett Foote | 2026-05-04 13:56:44


VIEW MORE
story-9
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!

Slideshow: the top 10 things Corvette owners want in the C9 Corvette

By Michael S. Palmer | 2026-04-30 12:41:15


VIEW MORE