Goin' back to old school carb? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

jdhcth · 07-12-2006, 02:47 PM

This may be a no brainer but I was wonderin' if I replaced my Edelbrock intake and 4 barrel Holley 4175 Q-Jet replacement 650cfm carb with the original intake and original Rochester 2 barrel carb on my '67 283 would my gas mileage improve greatly? I have been told the Holley gets pretty good mileage for a 4bbl, but I haven't checked it.

My rebuild of the 283 was not to be a daily driver driver but now it may have to be. So I was thinking of putting the Rochester/OEM manifold back on.

Thanks,
JD

cdowns · 07-12-2006, 03:03 PM

i doubt you'd see an increase might see a decrease due to poorer manifold design

Dick Dale · 07-12-2006, 05:08 PM

2 barrel gets worse mileage. I am also building a 283 and the best advise I got was a 600 cfrm Edelbrock or Holley. Better mileage when tuned right.

*rage'nrat638* · 07-12-2006, 05:36 PM

i had a brand new holley 600 worked for 3 weeks that was it
i bought a nice edelbrock intake with the duel flange design,,fit's both spreadbore and squrebore carbs.. bought a rebuilt rochester 4 barrel from auto zone for 130.00 after a few cold mornings. have the choke adjusted now..my truck has never ran better...

go with the 4 barrel it will get better MPG than the 2 barrel..then if you need the extra power you have it..

get that edelbrock intake...you will never have to change intake's again..
with a adaptor you could even put a 2 barrel on that intake
painted my intake orange..see picture
mark

**yote1234** · 07-12-2006, 05:49 PM

maby i will go dual quads..get great milage...just kidding

**Palf70Step** · 07-12-2006, 06:13 PM

Yeah, keep the edelbrock manifold, but run a different carb than that holley. The rochesters or a small cfm edelbrock would be my choice, like around a 500CFM for that 283.

Longhorn Man · 07-12-2006, 06:15 PM

the old quadra jet will be the best for MPG...assuming you get a good rebuild. I've seen one sold over the counter, it was supposed to be a reman unit, and it was pretty and had new parts tossed on it, but it was junk and it leaked more fuel than it fed the engine...and it fed a LOT into the engien. Took it back, the guy ended up getting into a pretty big argument with the parts jockey, (accused us of trying to return our core as a defective part) finally got the new one and it ran like a top and got pretty good MPG.

jacobs · 07-12-2006, 07:14 PM

If you want even better gas milage with a Quadrajet, get the book "Rochester Carburetors" by Doug Roe & Bill Fisher, published by H.P. Books and follow their advise in "Economy - Driveability & General Performance". I've rejetted several q-jets and have always experienced at least a 10% increase in fuel milage. I highly recommend this book. You can find it on Amazon at http://www.amazon.com/gp/product/091...lance&n=283155

krue · 07-12-2006, 10:49 PM

Quote:

Originally Posted by jacobs

If you want even better gas milage with a Quadrajet, get the book "Rochester Carburetors" by Doug Roe & Bill Fisher, published by H.P. Books and follow their advise in "Economy - Driveability & General Performance".

I happen to have borrowed this book, guess I need to read it.

BTW Mark, which intake is that?

*rage'nrat638* · 07-12-2006, 11:13 PM

Quote:

Originally Posted by krue

BTW Mark, which intake is that?

http://store.summitracing.com/partde...5&autoview=sku

*MisterMan* · 07-13-2006, 12:47 AM

very nice intake,

holley=large primaries and 2nd daries..
stock quad.=small primaries, and large 2nd's.... leather the throttle, ge goo gas.. punch it, you hit the 2nd and SLURP!!! lol.

only reason im keeping the stocker!!!

Gray Ghost · 07-13-2006, 03:06 AM

I am running the new EPS 2701 intake and the stock Q-jet for a total of 12 mpg. I also don't spare any horses along the way....typically hauling over 500 pounds daily back and forth between Terrell and Dallas [30 miles].

krue · 07-13-2006, 10:35 AM

Thanks Mark.

farside847 · 07-13-2006, 11:07 AM

Thats interesting. Its not the first time I have heard that a small 4bb gets better mileage than the 2bb. Has anyone done this swap that could tell me the improvement? During this day and age, every bit helps.

Fred T · 07-13-2006, 11:48 AM

The Edelbrock Performer is a good manifold for a driver. Add to that a tuned Rochester Q-jet, HEI with the right advance curve and the right gearing in the rear.You should be in the 15-20 mpg range if you keep your foot out of the carb.

As for the Holley Q-jet, it should be a good choice for milage, but I have no experience with one. The big advantage of the q-jet is the small primaries.

For an example, dad bought a 63 Chevy wagon. 327 with q-jet and a powerglide tranny. The last time we had the car out on the road we were towing a 68 Dodge Polara with a towbar at 80 mph. Well over 100,000 miles on the wagon and we got over 20 mpg.

*MisterMan* · 07-13-2006, 05:59 PM

Quote:

Originally Posted by Fred T

The Edelbrock Performer is a good manifold for a driver. Add to that a tuned Rochester Q-jet, HEI with the right advance curve and the right gearing in the rear.You should be in the 15-20 mpg range if you keep your foot out of the carb.

As for the Holley Q-jet, it should be a good choice for milage, but I have no experience with one. The big advantage of the q-jet is the small primaries.

For an example, dad bought a 63 Chevy wagon. 327 with q-jet and a powerglide tranny. The last time we had the car out on the road we were towing a 68 Dodge Polara with a towbar at 80 mph. Well over 100,000 miles on the wagon and we got over 20 mpg.

was it down hill!!!!!!!!!!!!?????????

JameslovesJammie · 07-13-2006, 07:54 PM

My grandfather was the Shop Foreman at Chevy garage in my hometown growing up. He knows how to tune a carb. He has a 1972 350/350 4x4. He took off the quadrajet and put on a 2 barrel and tuned it as best as he could. Mileage was 2 mpg worse and had now power when towing a load up a hill.

farside847 · 07-13-2006, 09:00 PM

Do you think a quadrajet would work on a 307?

jacobs · 07-13-2006, 09:47 PM

Quote:

Originally Posted by farside847

Do you think a quadrajet would work on a 307?

Yes! Pontiac installed the q-jet on their OHC 6 cylinder engines in the mid 1960's. It's an amazing carb as it works well on small or large engines.

07-12-2006, 02:47 PM	#1
jdhcth Registered User Join Date: Dec 2005 Location: Houston, TX Posts: 51	Goin' back to old school carb? This may be a no brainer but I was wonderin' if I replaced my Edelbrock intake and 4 barrel Holley 4175 Q-Jet replacement 650cfm carb with the original intake and original Rochester 2 barrel carb on my '67 283 would my gas mileage improve greatly? I have been told the Holley gets pretty good mileage for a 4bbl, but I haven't checked it. My rebuild of the 283 was not to be a daily driver driver but now it may have to be. So I was thinking of putting the Rochester/OEM manifold back on. Thanks, JD

07-12-2006, 03:03 PM	#2
cdowns Senior Member Join Date: Jan 2003 Location: daytonabeach Posts: 22,956	Re: Goin' back to old school carb? i doubt you'd see an increase might see a decrease due to poorer manifold design __________________ 71c-10 350/2004r/4:11 lowered3/4 longbed/dead by hurricane MEANING OF DEATH::::: SOMEBODY ELSE GETS YOUR STUFF DONT BELIEVE EVERYTHING YOU THINK TAKE MY ADVISE;I DON'T USE IT ANYWAY

07-12-2006, 05:08 PM	#3
Dick Dale Excelsior, You Fathead. Join Date: Jun 2004 Location: Valparaiso, In Posts: 937	Re: Goin' back to old school carb? 2 barrel gets worse mileage. I am also building a 283 and the best advise I got was a 600 cfrm Edelbrock or Holley. Better mileage when tuned right. __________________ Go Navy. The Sea Is Ours. Budget 350 Build http://67-72chevytrucks.com/vboard/s...38#post2264638

07-12-2006, 05:36 PM	#4
rage'nrat638 Account Suspended Join Date: Mar 2003 Location: THE FALL GUY CHICAGO IL Posts: 5,883	Re: Goin' back to old school carb? i had a brand new holley 600 worked for 3 weeks that was it i bought a nice edelbrock intake with the duel flange design,,fit's both spreadbore and squrebore carbs.. bought a rebuilt rochester 4 barrel from auto zone for 130.00 after a few cold mornings. have the choke adjusted now..my truck has never ran better... go with the 4 barrel it will get better MPG than the 2 barrel..then if you need the extra power you have it.. get that edelbrock intake...you will never have to change intake's again.. with a adaptor you could even put a 2 barrel on that intake painted my intake orange..see picture mark Last edited by rage'nrat638; 07-12-2007 at 07:02 AM.

07-12-2006, 05:49 PM	#5
yote1234 Senior Member Join Date: Feb 2003 Location: Gold Canyon Arizona Posts: 4,330	Re: Goin' back to old school carb? maby i will go dual quads..get great milage...just kidding __________________ 1971 K5 CST Blazer 1965 Chevelle Malibu 283 (sadly sold) 1968 Camaro 327 1968 Honda mini-trail z50a #377 1966 uh 1-D Huey

07-12-2006, 06:13 PM	#6
Palf70Step State of Confusion! Join Date: Jul 2002 Location: Gulfport, MS USA Posts: 46,819	Re: Goin' back to old school carb? Yeah, keep the edelbrock manifold, but run a different carb than that holley. The rochesters or a small cfm edelbrock would be my choice, like around a 500CFM for that 283. __________________ Bill 1970 Chevy Custom/10 LWB Fleetside 2010 Toyota Tacoma PreRunner SR5 Double Cab - DD Member of Louisiana Classic Truck Club (LCTC) Bill's Gallery Life isn't tied with a bow, but it's still a gift. Live simply. Love generously. Care deeply. Speak kindly. Leave the rest to God!

07-12-2006, 06:15 PM	#7
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: Goin' back to old school carb? the old quadra jet will be the best for MPG...assuming you get a good rebuild. I've seen one sold over the counter, it was supposed to be a reman unit, and it was pretty and had new parts tossed on it, but it was junk and it leaked more fuel than it fed the engine...and it fed a LOT into the engien. Took it back, the guy ended up getting into a pretty big argument with the parts jockey, (accused us of trying to return our core as a defective part) finally got the new one and it ran like a top and got pretty good MPG.

07-12-2006, 07:14 PM	#8
jacobs Registered User Join Date: Sep 2005 Location: 9000' Mountain Man Posts: 326	Re: Goin' back to old school carb? If you want even better gas milage with a Quadrajet, get the book "Rochester Carburetors" by Doug Roe & Bill Fisher, published by H.P. Books and follow their advise in "Economy - Driveability & General Performance". I've rejetted several q-jets and have always experienced at least a 10% increase in fuel milage. I highly recommend this book. You can find it on Amazon at http://www.amazon.com/gp/product/091...lance&n=283155

07-13-2006, 12:47 AM	#11
MisterMan Account Suspended Join Date: Jan 2006 Location: Visalia, California Posts: 286	Re: Goin' back to old school carb? very nice intake, holley=large primaries and 2nd daries.. stock quad.=small primaries, and large 2nd's.... leather the throttle, ge goo gas.. punch it, you hit the 2nd and SLURP!!! lol. only reason im keeping the stocker!!!

07-13-2006, 03:06 AM	#12
Gray Ghost Senior Member Join Date: Sep 2004 Location: Terrell, TX Posts: 1,967	Re: Goin' back to old school carb? I am running the new EPS 2701 intake and the stock Q-jet for a total of 12 mpg. I also don't spare any horses along the way....typically hauling over 500 pounds daily back and forth between Terrell and Dallas [30 miles]. __________________ Kelly '05 GMC Sierra SLE Z71 Bone stock except for new bed rail caps.

07-13-2006, 10:35 AM	#13
krue Designated A-hole! Join Date: Mar 2003 Location: South Mississippi Posts: 36,450	Re: Goin' back to old school carb? Thanks Mark. __________________ "If it ain't broke, fix it 'til it is!" Being stupid ain't illegal. We're Still Debt Free Except for the House!!! www.daveramsey.com 70 GMC SWB Stepside project "Green Booger" soon to be 6.0l/4l80e 93 S-10 "Poppaw's Truck"

07-13-2006, 11:07 AM	#14
farside847 Registered User Join Date: Feb 2005 Location: Bay Area, California Posts: 995	Re: Goin' back to old school carb? Thats interesting. Its not the first time I have heard that a small 4bb gets better mileage than the 2bb. Has anyone done this swap that could tell me the improvement? During this day and age, every bit helps. __________________ 1971 Chevy C10 Shortbed Stepside, 307v8 3-on-the-tree

07-13-2006, 11:48 AM	#15
Fred T Cantankerous Geezer Join Date: Aug 2002 Location: Bel Aire, KS Posts: 6,264	Re: Goin' back to old school carb? The Edelbrock Performer is a good manifold for a driver. Add to that a tuned Rochester Q-jet, HEI with the right advance curve and the right gearing in the rear.You should be in the 15-20 mpg range if you keep your foot out of the carb. As for the Holley Q-jet, it should be a good choice for milage, but I have no experience with one. The big advantage of the q-jet is the small primaries. For an example, dad bought a 63 Chevy wagon. 327 with q-jet and a powerglide tranny. The last time we had the car out on the road we were towing a 68 Dodge Polara with a towbar at 80 mph. Well over 100,000 miles on the wagon and we got over 20 mpg. __________________ Fred There is no such thing as too much cam...just not enough engine.

07-13-2006, 07:54 PM	#17
JameslovesJammie God Bless Mr. T Join Date: Apr 2004 Location: Minot, ND Posts: 348	Re: Goin' back to old school carb? My grandfather was the Shop Foreman at Chevy garage in my hometown growing up. He knows how to tune a carb. He has a 1972 350/350 4x4. He took off the quadrajet and put on a 2 barrel and tuned it as best as he could. Mileage was 2 mpg worse and had now power when towing a load up a hill. __________________ Like a midget at a urinal...sometimes you must stay on your toes.

07-13-2006, 09:00 PM	#18
farside847 Registered User Join Date: Feb 2005 Location: Bay Area, California Posts: 995	Re: Goin' back to old school carb? Do you think a quadrajet would work on a 307? __________________ 1971 Chevy C10 Shortbed Stepside, 307v8 3-on-the-tree



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