Register or Log In To remove these advertisements. |
|
|
|
Thread Tools | Display Modes |
12-16-2020, 12:58 PM | #1 |
Registered User
Join Date: Sep 2011
Location: South West
Posts: 431
|
Which carburetor to use, Rochester or Carter?
Hello all. Currently I have a 283 with a stock manifold and Holley carb. When tuned correctly it runs good, but I am tired of constantly having to mess with the primary/secondary float adjustments on this thing; seems as though I am doing it monthly. Having to use an adapter to mate the carb to my stock manifold, I just think it best to go back to a period correct carb. I know back in the day they used both Rochester 4GC's and Carter WCFB's. Searching the inter-web yields more Rochester's available than Carter's. Is one better than the other? Thanks
|
12-16-2020, 01:38 PM | #2 |
Registered User
Join Date: Aug 2009
Location: Bowser
Posts: 13,516
|
Re: Which carburetor to use, Rochester or Carter?
Shouldn’t need constant adjustments.
Might be a fuel pressure problem or level setting. Changing to either new carb might not help. I think either one needs a max of 5psi. Have you tried setting fuel level about 1/8 inch lower? Where in the sw are you located? |
12-16-2020, 02:07 PM | #3 | |
Registered User
Join Date: Sep 2011
Location: South West
Posts: 431
|
Re: Which carburetor to use, Rochester or Carter?
Quote:
|
|
12-16-2020, 04:21 PM | #4 |
Registered User
Join Date: Aug 2009
Location: Bowser
Posts: 13,516
|
Re: Which carburetor to use, Rochester or Carter?
Plenty good pressure could be too much.
Level setting is float level. Normally I set it lower than the factory says. About 1/8 inch lower. You have center hung floats. They do flood when stopping hard. Side hung are better. Can’t see your adaptor for the carb to intake. Looks like you have a fuel pressure gauge. What’s the pressure at? |
12-16-2020, 04:36 PM | #5 | |
Registered User
Join Date: Sep 2011
Location: South West
Posts: 431
|
Re: Which carburetor to use, Rochester or Carter?
Quote:
|
|
12-16-2020, 04:48 PM | #6 |
Registered User
Join Date: Aug 2009
Location: Bowser
Posts: 13,516
|
Re: Which carburetor to use, Rochester or Carter?
Put a fuel regulator on it.
No carb needs more than 5psi. |
12-16-2020, 05:55 PM | #7 |
Registered User
Join Date: Sep 2011
Location: South West
Posts: 431
|
Re: Which carburetor to use, Rochester or Carter?
Thanks for the info. I am already sourcing one as we speak, I also think I have one somewhere at home. I guess my question is, what did they do back in the old days? It is a stock mechanical fuel pump, the same used back in the day.....
|
12-16-2020, 06:07 PM | #8 |
driving is in my blood
Join Date: Dec 1999
Location: Mesa AZ
Posts: 5,694
|
Re: Which carburetor to use, Rochester or Carter?
I agree something is off. I've had to reset float level exactly zero times in my life driving here in Phoenix.
__________________
-78 c10 short/step: 388cid, M20, 5/5 drop, lots more. Playtoy and first vehicle. -98 c1500 x-cab: 5.7L, 17" rims, 5/6 drop, flowmaster, helper bags,NBS rear disk brakes. -02 Suburban 4x4: leveled front -CBR600F4i, CBR600RR, CBR1000RR, and standup skis DISCLAIMER: I cant spell for the life of me. |
12-16-2020, 06:43 PM | #9 |
Registered User
Join Date: Aug 2012
Location: Oklahoma City, OK
Posts: 2,486
|
Re: Which carburetor to use, Rochester or Carter?
They just ran the pump straight into the carb. Pretty sure QA was better then. Seems a fair percentage of the newer pumps put out too much pressure.
|
12-17-2020, 07:40 AM | #10 |
Registered User
Join Date: Oct 2013
Location: Maine
Posts: 2,340
|
Re: Which carburetor to use, Rochester or Carter?
I don't know where you guys get those high pressure fuel pumps. Every one I buy only puts out 5 psi. I would get a Qjet off a 305 and be done with it. The Holly does look cooler though.
__________________
76 Chevy K20 76 GMC K15 77 Chevy C10 77 Chevy K10 |
12-17-2020, 10:27 AM | #11 |
Registered User
Join Date: Sep 2011
Location: South West
Posts: 431
|
Re: Which carburetor to use, Rochester or Carter?
Hi all, thanks for the responses. So after work yesterday, I did a little fiddling on the carb. First thing is I found another pressure gauge, removed the current and installed the new one. Fired her up and fuel pressure was just under 6psi, so it seems my pressure is good and the last gauge was bad. I then let her warm up and pulled the sight plugs, the front float was level and once again the back float was high! Adjusted that and the engine runs better. Why does the float keep going out of adjustment?
|
12-17-2020, 10:30 AM | #12 |
Registered User
Join Date: Sep 2011
Location: South West
Posts: 431
|
Re: Which carburetor to use, Rochester or Carter?
Regardless, I still want to go back to a period correct carburetor for my 1959 1/2 ton. So which one is better, Rochester 4GC or Carter WCFB, does one have an advantage over the other? Thanks
|
12-17-2020, 11:20 AM | #13 |
Registered User
Join Date: Jan 2013
Location: Calgary Alberta
Posts: 1,164
|
Re: Which carburetor to use, Rochester or Carter?
I don't think you're going to find too many old timers here that would have had experience with both carbs from back in the fifties and sixties to give an accurate comparison.
Personal bias for me would be to go for the Carter. I have a 2 barrel WCD that I like a lot. Those old WCFB's and 4GC's sure are expensive on EBay. |
12-17-2020, 11:56 AM | #14 |
Registered User
Join Date: Aug 2012
Location: Oklahoma City, OK
Posts: 2,486
|
Re: Which carburetor to use, Rochester or Carter?
Might look at this: https://www.edelbrock.com/performer-...-egr-1404.html
The 14xx family is based on the Carter AFB which is period correct for your vehicle. It would have the advantage of lots of parts support. |
12-17-2020, 12:39 PM | #15 |
Registered User
Join Date: Aug 2009
Location: Bowser
Posts: 13,516
|
Re: Which carburetor to use, Rochester or Carter?
Choice of carb depends on what year intake you have.
You’ll need to pull the carb off and measure the carb mounting bolt pattern. There were some pattern changes around 1960. And the throttle bore spacing changed as well. |
12-19-2020, 11:14 AM | #16 |
Registered User
Join Date: Sep 2011
Location: South West
Posts: 431
|
Re: Which carburetor to use, Rochester or Carter?
Did some more fiddling and got some advice from my hotrod buddy yesterday. He said it sounds like the 0-ring has has gone bad and fuel is probably getting passed the needle valve. Sure enough, pulled the needle valve and the o-ring crumbled in my hand. Installed two new needle valve and will adjust sometime this weekend.
|
12-24-2020, 02:18 PM | #17 |
Registered User
Join Date: Sep 2011
Location: South West
Posts: 431
|
Re: Which carburetor to use, Rochester or Carter?
What brand/model fuel pump are you using? I just bought a Carter M4172 and it is rated at 5.5 to 6.5 psi max pressure
|
01-20-2021, 06:47 PM | #18 |
Senior Member
Join Date: Dec 2011
Location: Moraga, CA
Posts: 804
|
Re: Which carburetor to use, Rochester or Carter?
Not to nitpick, but normally you just set the float level and leave it.
Then you adjust the idle mixture screws to keep it from dying and to make it idle smoothly. I skimmed through the post kind of quickly, so I may have missed the part where you said you were adjusting your idle mixture screws. But also, I appreciate the part where you said you wanted to get it as stock as possible. Stock is stock and easier to adjust and specify parts for. Nothing to remember, other than the word "stock." ;-)
__________________
(Very) Slow-Going Build Thread: Stock 1970 Short Step with Stock 1970 LT-1 http://67-72chevytrucks.com/vboard/s...d.php?t=567340 |
01-21-2021, 12:19 PM | #19 | |
Moderator
Join Date: Jun 2017
Location: Cherryville, NC
Posts: 2,158
|
Re: Which carburetor to use, Rochester or Carter?
Quote:
__________________
Family and country before all others... 2006 Chevy Silverado (Daily Driver) 2012 Chevy Equinox |
|
01-21-2021, 03:08 PM | #20 | |
Registered User
Join Date: Sep 2011
Location: Ark City, Kansas
Posts: 3,284
|
Re: Which carburetor to use, Rochester or Carter?
Quote:
|
|
01-23-2021, 09:39 PM | #21 |
Registered User
Join Date: Mar 2007
Location: San Pedro River, SE Arizona
Posts: 734
|
Re: Which carburetor to use, Rochester or Carter?
I have been running both types of carbs, for quite a while. The Qjet seems more complex and not as easy to rebuild, but when it is properly rebuilt and working right, it seems somewhat more flexible - little bit better mileage and good power performance. But, the Carter is easier for me to deal with and I like the set-it-and-forget-it aspect on most of these engines.
For these carbs, those comments about problems with fuel pressure over 5 psi are on the mark. I have learned to look at the pump specs before buying.
__________________
CCCC 67 Sting Ray Coupe 327 4sp; 68 K10 Suburban 327 4sp; 69 K20 Lifted 383 4sp; 69 C80 Fire Truck 478 V6 5sp/2sp; 69 C20 Longhorn 327 4sp; 70 C30 Wrecker 350 4sp; 70 C30 Flat Bed 350 4sp; 71 C20 LWB 350 4sp; 72 K5 Blazer 350 4sp; 72 C30 Flat Bed Gooseneck Hauler with sleeper 350/TH400; 72 C20 Longhorn 402 4sp; 52 Mack LTL Supercharged Cummins 5sp x 3sp; 01 Dodge 5.9 HO Cummins 6spd; 02 Safari Trek 2430 8.1 Vortec on Workhorse Chassis; 03 Silverado 2500 HD 4wd Duramax/Allison Moved but still in the family 70 C20 Custom Camper 350/TH350; 72 K5 Blazer CST Highlander 350/TH350 Recently sent to new homes 72 C30 MoHome 402 4sp; 72 K5 Blazer Conv 350 4sp; 75 GMC 6000 Aerial 350 w Allison; 72 GMC 3500 Utility 350 4sp; 70 GMC 3500, 350 4sp |
Bookmarks |
|
|