Carb Selection

[sal37]

Hi
I am hoping some knowledgeable people can help - I am looking for a suitable carb for my '37 project.  The engine is a 350 chev, mild/moderate cam timing, possible air gap intake manifold and I was considering a Barry Grant Road Demon around 650cfm.  They appear to cost more than holleys etc - is the additional cost justified?? that is, are there performance benefits or ease of tuning etc to warrant the cost?
Thanks
Stephen

[wayne petty]

an air gap manifold might be too much for a moderate cam ..

got more info on end use..

drag strip only car..

local street only car..

street and highway cruiser where you expect some MPG..


there are lots of smart people on this forum..

we could use more info on final use.. and on things like expected engine rpm..  or tire size.. gear ratio.. transmission type.. torque converter stall speed..

which heads.. casting number.

stock manifolds or headers..


you have multiple carb types..

quadrajets.. new and used ... new might still be available..

original carter carbs... used and rebuilt..

various edelbrock   avs..  

summit has a summit label version of the holley with a a one piece top cover that is very user friendly.. which is actually a modern version of the autolite 4100 which is the 4 barrel version of the 2100 .. but with holley treatment..

http://www.summitracing.com/parts/SUM-M08600VS/?rtype=10


there is so much in choosing a carb.. or just tossing on one and going from there..

some more info on end use.. will really help with some of the selection issues..

i am not trying to talk you out of a road demon..

[Learpilot]

I have a similar set up with a 350/350 in my '40 Ford. I have tried the 625cfm Road Demon and the 670cfm Holley Street Avenger. They are both Great carbs and work good out of the box. The Demon is easy to polish, if you want that look. Some of the Road Demons have one idle screw, that would be nice. I am currently running a 670 Street Avenger and I love it. The gas mileage is about the same for both. My perfect Carb would be a Street Avenger version of the Holley Spreadbore. It has the small bore on the Primarys just like the Q-jet. I do not like the Q-jet. I had a Q-jet on my '79 Corvette and to keep it from stumbling off idle I had to re-built it every 6 months.

I hope this helps a little.
Rick

[UGLY OLDS]

The Ugly Olds has an engine set-up simular to yours .. A '71 LT1..  (350 /350 horse ) stock heads ..Edelbrock Performer Intake ..Stock LT1 exhaust manifolds ......I use a good ol' 600 CFM Holley ..( List 1850) ... It runs as fast as I want to go ....with 18 MPG on the road with the A/C running .....
I like to think it's a good combination .... 650 CFM on a Air Gap Manifold seems a bit much unless  you plan on running 4000 RPM ++ quite often ..... :?


Bob.....

[sal37]

an air gap manifold might be too much for a moderate cam ..

got more info on end use..

drag strip only car..

local street only car..

street and highway cruiser where you expect some MPG..


there are lots of smart people on this forum..

we could use more info on final use.. and on things like expected engine rpm..  or tire size.. gear ratio.. transmission type.. torque converter stall speed..

which heads.. casting number.

stock manifolds or headers..


you have multiple carb types..

quadrajets.. new and used ... new might still be available..

original carter carbs... used and rebuilt..

various edelbrock   avs..  

summit has a summit label version of the holley with a a one piece top cover that is very user friendly.. which is actually a modern version of the autolite 4100 which is the 4 barrel version of the 2100 .. but with holley treatment..

http://www.summitracing.com/parts/SUM-M08600VS/?rtype=10


there is so much in choosing a carb.. or just tossing on one and going from there..

some more info on end use.. will really help with some of the selection issues..

i am not trying to talk you out of a road demon..

Thanks everyone for your replies.

The car will essentially be a street car but we will use it to go to events so I need to keep fuel consumption in mind.  

What I have in train at the moment is:
350 chev 1987 block - currently standard bore but may require 030 bore
World product s/r cast heads (I have been carting them around for the last 10 years so need to use them)
T700R4 auto
rear end ratio - somewhere around 3.5 - 3.7
Rear tires 28.7" diameter
modified hooker block huggers
Cam choice has not been made but I was considering one of the comp cam range but it is confusing? :?

Stephen

[wayne petty]

in digging into the new demon catalog..

some of the road demon jr's  have the 1 7/16" primary and 1 11/16 secondary bores...

so it is like a 390 cfm primary and a 750 secondary throttle blade...

here is a tidbit of info


http://www.hotrod.com/techarticles/engine/hrdp_0307_road_demon_jr/

don't forget.. you are really looking for MPG not MPH in the traps.. if i read you right..

you might go back and look at some of  C9's posts..  he was able to get great mileage out of his roadster..


higher vacuum readings at cruise equate to less mass of air through the motor... so less fuel is needed to reach the proper air fuel ratio..