Hey guys; I need to ask the gurus here for their expert opinion/advice on carb selection. I have tried a holley 390, an edelbrock 500, and most recently a Demon Jr 525. Here are the results/thoughts on each:

Holley – easy to tune, good throttle response, lowest WOT power by far of the 3. Easy starting. Just weak in overall power though

Edelbrock – Best WOT power by far, poor throttle response (relatively) Runs much richer at idle to be happy. Used Oil analysis shows much more fuel dilution of oil with this carb then the holley to back up this thought (in addition to fuel smell). Just feels sloppy at mid range throttle settings; its more like on/off for around town driving.

Demon – disaster. Tried changing jets, power valves, squirters, timing, etc and never got it to run right. Took it apart and found all kinds of metal shavings and junk in it, and even after cleaning it out, never got it to be driveable….just terrible. I wont get another demon.

Specs of the car/engine:

56 Sunliner

292/ford-o-matic

Cam – mummert FY-270-3

Duration @.050 – 224/224

Lobe separation – 110 deg

Gross lift - .469/.469

Ignition – later style dist, pertronix, stock coil, initial timing ~15 deg (tried moving up and down); plugs about 4 mos old gapped to stock, wires about a year old.

Vaccuum at idle ~13-14" @500 rpm

Ive talked to Jegs (from whom I got the demon) and they have offered to exchange the demon for any other carb of my choice….so thus the point of this question. What carb would you chose knowing objectives and history? My thought right now is a #4160 holley 600, or morel likely a holley street avenger 570 (even though its dual inlet), although I have some concern over those being too big and losing some throttle response. I know some have recommended the holley truck avenger 470, but im not sure that would be a big enough jump over the 390? Also, anything weird about the truck carb – it specifically says not for use on v8’s.

Preference is for one with elec choke, vac secondaries, and single fuel inlet.

Also, Holley just released a series of carbs with non-adjustable floats (4160 series). Any thoughts on those (pros/cons?)?

THANK YOU in advance for taking the time to read this and for any thoughts/comments!

Ron Grove

Wauconda, IL

As mentioned in previous posts, I'm running a Holley 465, supposedly it's designed for the y-block. The 600 I was running was way to much carb but this 465 does everything I ask of it and more. Starts, excelerates, idles great. A very good carb. Gary

       

Gary, 55 Vicky, St. Germain, Wisconsin

 

I use the 570 and like it a lot. They recommend it for about 300ci, to 5500rpm. My personal opinion is that it eats the Edelbrock 600 I had for lunch. The Holley is the much better carb of the two.

You may not loose throttle response at all. I'm learning that carbs are one of those things that you can get advice on all day long but you just gotta try them.


Lawrenceville, GA

You can buy the quick change spring kit for the holley and that will put more zap into your midrange power using a lighter spring than the silver one that's in it. And changing springs with the kit is a snap. Of course buy the springs too, they do not come with the quick change kit.

-Gary Burnette-

I've got no experience with the Carter / Edelbrock style of carb and probably won't ever buy one (myself). The "Thunder" versions with the tunable air door for the secondary might work for someone with patience. Sounds like your 500 version was just plain over-rich and didn't get better with age.

Holley's (or the Demon derivatives) have always worked out to my liking - tuning parts and knowhow has always been available....and over a 40 year period. If you are dead set against the Demons - Charlie's comments about the Avenger 570 sound right to me - and they have the big bowls and sight windows I believe.

Anything that has "non-adjustable bowls" must be for children.......   

 
 Steve Metzger       Tucson, Arizona

Thanks guys for all the comments thus far!  Im leaning towards the avenger 570 right now, but ill have to do some more reading.  The carb selector on holleys web site recommend either the 390 cfm or the avenger 570.  The 465 never came up; not sure if it was due to cam selected or what?

Gary, on the 465, where did you hear that it was "made for the Y-Block?"  Id never heard that before, so Im curious as to the source.  i wonder what that means, anyways?

Also, with the 570 avenger, do the larger bowls fit ok with the stock coil loc and oil bath air filter?  ( have about a 1/2" spacer under the oil bath to give some more clearance, but the bowls on the dual inlet carbs are huuuugggee compared to the demon jr or holley 390; the oil bath has been gutted, but still looks/is dimensionally stock for appearance)

Thanks!

Ron Grove

Wauconda, IL

Hi Ron

I have been running a 465 Holley R-1848 on my 292 with B manifold for the last 17 years and have always been happy with its performance.

A variant of this carb was fitted to 1960 332 and 352 so it is no great stretch to see that it is probably spot on for a Y Block.

If you want WOT performance go with the 1850 (600) Holley. I am sure you will find these at a local swap meet. I put an 1850 on my 292 when I took it down the strip once and it certainly went better but for general streetability the 1848 is the better choice.

Hope this gives you some more insight.

Regards

Rick - West Australia
Do Y Blocks Downunder run upside down? Gravity Sucks!!

You probably will not be able to mount the coil in the stock orientation but you will be able to mount it close enough that all of your wiring should work. You will probably need a different bracket. Ford Racing part # M-12044-A2 does the job.



I don't have a clue about the oil bath.






Lawrenceville, GA

A reason the 465 cfm is a good fit for the Y-blk is that it has the correct Ford with automatic linkage. And is also roughly the same cfm as the original carbs used on 56 292's & on 312s. As a side note, a buddy in the last year put a new 4160 -600 cfm on his 289 Mustang. He's very unhappy with it. Says it has poor throttle response & lousy mileage. And in Ted's recent 4 Bbl carb tests on a stk headed engine, the 465 scored very well overall. However, it's a street carb not intended for racing. Also for what it's worth, Pony carburetors literature says that a 600cfm on a 300" or less street engine is unsuitable..

Paul

Steve, i too have had more expeirence and results with the holley 4bbl carbs, theres years of learning how to tune them to the parameters of the engines output, not merely adjusting float levels and air bleed screws. I guess its up to the individuals expeirence on any of the carbs. Holleys for me.

  AussieBill            YYYY    Forever Y Block     YYYY

 Down Under, Australia