69 L46 with a Pontiac carb
08-03-2012, 11:31 AM
#1
Intermediate
Thread Starter
Member Since: Jun 2011
Location: Indianapolis IN
Posts: 25
Likes: 0
Received 0 Likes
on
0 Posts
69 L46 with a Pontiac carb
Alright, slowly working through my car. I've got a 1969 L46, running a Quadrajet 7042274, which per Lars paper is for a Pont 72 400 AT FEDERAL.
Any problems with running this set-up? First logical step to me is to make sure carb is set-up per factory specs. Car doesn't run poorly, just want to make sure I'm getting all the performance I can.
These are the stock set-ups per Lars paper, but I'm not smart enough to translate these numbers into part numbers to buy from Napa.
74 47 7029922 CS 2.5659 3.7699
Any problems with running this set-up? First logical step to me is to make sure carb is set-up per factory specs. Car doesn't run poorly, just want to make sure I'm getting all the performance I can.
These are the stock set-ups per Lars paper, but I'm not smart enough to translate these numbers into part numbers to buy from Napa.
74 47 7029922 CS 2.5659 3.7699
08-03-2012, 11:42 AM
#2
Yea...................Bad carb alright. Worthless really....No dollar value so..............I'd throw it away...But make sure when you toss it rap it in news paper soundly, gently place in an ups approved box, And send it to the address below. freight is already paid buddy....
He He.
He He.
08-03-2012, 11:58 AM
#3
Tech Contributor
Member Since: Aug 1999
Location: At my Bar drinking and wrenching in Lafayette Colorado
Posts: 13,652
Received 4,919 Likes
on
1,929 Posts
The Pontiac carb, jetted to the stock specs, will run just fine on the Vette; just as a lot of the Pontiac guys run Vette carbs on their GTOs because they can't find that carb you have on your Vette...
The Pontiac carb has the fuel inlet straight in the front. This will prevent you from running a stock steel fuel line on your car, and will cause interference between your cheap rubber fuel inlet line and the waterneck, in most cases (I'm just assuming and betting someone put a rubber line on the car...). This inlet line system is not good, and is the primary drawback to the Buick/Olds/Pontiac carbs.
The choke system on the Pontiac carb is different from the Chevy, so you cannot run or hook up your stock choke system. If you do, it will operate the choke backwards.
The throttle cable attach point and system is different on the Pontiac. Whereas the Chevy carb for your Vette has 2 cable attach points to allow the Vette to be used at the lower point for full throttle opening, the Pontiac only has 1 attach point, and it is located far up on the lever. This will not allow your Vette to achieve full wide open throttle in most cases, unless the throttle cable bracket has been altered.
There are guys out there willing to kill for that carb, so you might be best off offering it up as a trade for the correct carb for your Vette - specify the carb number(s) you'd be interested in. (try: http://www.gtoforum.com/f50/ ). There are a bunch of crap Q-Jets out there, so if you do that, I'll be more than willing to review the photos of the trade offers you get and give you my opinion.
Let me know if you need all the NAPA rebuild and component part numbers - I have all the numbers if you want to rebuild what you have.
Lars
V8FastCars@msn.com
The Pontiac carb has the fuel inlet straight in the front. This will prevent you from running a stock steel fuel line on your car, and will cause interference between your cheap rubber fuel inlet line and the waterneck, in most cases (I'm just assuming and betting someone put a rubber line on the car...). This inlet line system is not good, and is the primary drawback to the Buick/Olds/Pontiac carbs.
The choke system on the Pontiac carb is different from the Chevy, so you cannot run or hook up your stock choke system. If you do, it will operate the choke backwards.
The throttle cable attach point and system is different on the Pontiac. Whereas the Chevy carb for your Vette has 2 cable attach points to allow the Vette to be used at the lower point for full throttle opening, the Pontiac only has 1 attach point, and it is located far up on the lever. This will not allow your Vette to achieve full wide open throttle in most cases, unless the throttle cable bracket has been altered.
There are guys out there willing to kill for that carb, so you might be best off offering it up as a trade for the correct carb for your Vette - specify the carb number(s) you'd be interested in. (try: http://www.gtoforum.com/f50/ ). There are a bunch of crap Q-Jets out there, so if you do that, I'll be more than willing to review the photos of the trade offers you get and give you my opinion.
Let me know if you need all the NAPA rebuild and component part numbers - I have all the numbers if you want to rebuild what you have.
Lars
V8FastCars@msn.com
08-03-2012, 12:34 PM
#4
Intermediate
Thread Starter
Member Since: Jun 2011
Location: Indianapolis IN
Posts: 25
Likes: 0
Received 0 Likes
on
0 Posts
Thanks for the quick response. Right on the rubber fuel line, they didn't even flare the tube. I added a longer line with a bend and flare to get around that problem temporarily.
Based on pictures of other cars the throttle connector definetely appears modified
Trades make me nervous... a working carb for an unknown. Any reliable places to buy the right carb then sell mine later? With a 6month old I'm leaning toward convience right now vs. cost savings. As spending time with my daughter priority 1.
[IMG]
[/IMG]
[IMG]
[/IMG]
[IMG]
[/IMG]
Based on pictures of other cars the throttle connector definetely appears modified
Trades make me nervous... a working carb for an unknown. Any reliable places to buy the right carb then sell mine later? With a 6month old I'm leaning toward convience right now vs. cost savings. As spending time with my daughter priority 1.
[IMG]
[/IMG][IMG]
[/IMG][IMG]
[/IMG]
08-03-2012, 04:01 PM
#5
Le Mans Master
Member Since: Oct 2002
Location: Las Vegas - Just stop perpetuating myths please.
Posts: 7,098
Received 373 Likes
on
356 Posts
Trade for Over the Counter Replacement qjet?
Thanks for the quick response. Right on the rubber fuel line, they didn't even flare the tube. I added a longer line with a bend and flare to get around that problem temporarily.
Based on pictures of other cars the throttle connector definetely appears modified
Trades make me nervous... a working carb for an unknown. Any reliable places to buy the right carb then sell mine later? With a 6month old I'm leaning toward convience right now vs. cost savings. As spending time with my daughter priority 1.
Based on pictures of other cars the throttle connector definetely appears modified
Trades make me nervous... a working carb for an unknown. Any reliable places to buy the right carb then sell mine later? With a 6month old I'm leaning toward convience right now vs. cost savings. As spending time with my daughter priority 1.
cardo0
08-03-2012, 06:08 PM
#6
Tech Contributor
Member Since: Aug 1999
Location: At my Bar drinking and wrenching in Lafayette Colorado
Posts: 13,652
Received 4,919 Likes
on
1,929 Posts
69brodus -
Your photos show exactly what I was talking about:
1. That fuel line is frightening...
2. Your choke is hooked up, but it's operating backwards, so it will close as the engine warms up. You need to disconnect it if you intend to keep running that carb.
3. They have altered your throttle cable bracket to accommodate the Pontiac throttle position: That's why the hose clamp is installed on the cable. You're going to have "Bubba Setup" unless you do significant work to the system to accommodate the different carb.
Note that your Pontiac carb has been altered and damaged with the removal and destruction of the bowl vent tube coming out of the top, forward casting housing - somebody did this to be able to fit the Chevy air cleaner onto the Pontiac carb without drilling a hole in the air cleaner base for the Pontiac vent tube. This will limit the value of the Pontiac carb.
The offer from cardo0 is pretty outstanding - I'd jump on that if I were you: He's a stand-up guy that I would trust, but you can also have him send me his carb for test and setup before I send it on to you. That would be a safe, smokin' deal.
Lars
Your photos show exactly what I was talking about:
1. That fuel line is frightening...
2. Your choke is hooked up, but it's operating backwards, so it will close as the engine warms up. You need to disconnect it if you intend to keep running that carb.
3. They have altered your throttle cable bracket to accommodate the Pontiac throttle position: That's why the hose clamp is installed on the cable. You're going to have "Bubba Setup" unless you do significant work to the system to accommodate the different carb.
Note that your Pontiac carb has been altered and damaged with the removal and destruction of the bowl vent tube coming out of the top, forward casting housing - somebody did this to be able to fit the Chevy air cleaner onto the Pontiac carb without drilling a hole in the air cleaner base for the Pontiac vent tube. This will limit the value of the Pontiac carb.
The offer from cardo0 is pretty outstanding - I'd jump on that if I were you: He's a stand-up guy that I would trust, but you can also have him send me his carb for test and setup before I send it on to you. That would be a safe, smokin' deal.
Lars
Last edited by lars; 08-03-2012 at 06:14 PM.
[/IMG]
08-03-2012, 06:57 PM
#8
Tech Contributor
Member Since: Aug 1999
Location: At my Bar drinking and wrenching in Lafayette Colorado
Posts: 13,652
Received 4,919 Likes
on
1,929 Posts
..and I notice that the secondary airvalve lockout lever is still in place: With the choke operating backwards, the lockout lever will never retract, so you have no secondary operation on your car. Is your Vette kinda' slow at wide open throttle - feels like it's "hanging back"...?
08-03-2012, 08:18 PM
#9
Intermediate
Thread Starter
Member Since: Jun 2011
Location: Indianapolis IN
Posts: 25
Likes: 0
Received 0 Likes
on
0 Posts
It's faster than my CJ7...but not much better than my Honda...so yeah.
I was just getting ready to verify pedal was pulling full throttel, Then I was going to hold down the secondary tab to keep them locked to see if made a difference...now I won't bother. Worknig with cardo0 to get a deal in place and a carb shipped to you.
I was just getting ready to verify pedal was pulling full throttel, Then I was going to hold down the secondary tab to keep them locked to see if made a difference...now I won't bother. Worknig with cardo0 to get a deal in place and a carb shipped to you.