2x4 carbs "428"

[saltshaker]

if your running a 2x4 intake on your 428, which carbs are you running? anyone running 1850's (600cfm) or the 450 mech carbs etc?

[Woodz428]

I recently finished a '67 GT500 for a customer and he bought "reproduction" carbs from Carl's. They are vacuum and I don't know the cfm without going to the site, they have the special vacuum tops that link the secondaries together..that's very important for smooth operation of the carbs. The owner claims it has never run as well as it does...and he's had it since 1979.

[acmjg]

I'm running a BT 2 x 4 with Carls reproduction BJ-BK vac secondarys in my Cobra. They run great.

[blykins]

My 428FE had a Dove Tunnel Wedge with two Demon Road Demon Jr. 725cfm carbs on it. They are 1850-sized carbs. Very inexpensive too and come in choice of electric or mechanical choke.

[Barry_R]

I size these setups as if they were a single double pumper carb - ignore the vacuum secondary side. I would personally (this is just an opinion) run nothing smaller than 600s on a stock engine, and 750s on anything modified. The secondary barrels will only come in as airflow demands - they will not "overcarb" the engine, and their opening rate can be adjusted.

Normal universal type carbs will work. Some tweaks are needed for compatability with the reproduction linkage. The repro carbs will work well, but seem to be calibrated extremely rich - no doubt matching Ford's calibration from back in the proverbial day.

[footnfan]

I took the original carbs off of 67 GT500 #1002, and installed twin 450 cfm holley carbs. They were like magic....no leaks.....ran like a scalded dog.

Dan

[eglasius@miljoc]

I'm new here, but I have the 1850 600 vac sec on my 427 Windsor and on the dyno they made more power and torque than the 450's, even at 2500 rpm. I looked at it like Barry R, when you step on it, only the primaries of both open so it's like a 600 DP. You can then adjust the secondaries to come in from there. HTH's

[Clois Harlan]

When I first installed my 2 X 4 set up on my 428 CJ I used a pair of Edelbrock 650 carbs which really didn't work out the best. My best performance came from a pair of Holley 4160 mechanical 450 carbs. Great Power lousy mileage (maybe 5 mpg)

[427 S/O]

Same here with the 450's, mechanical secondaries, no choke. After playing with jets got awesome throttle response. Using your foot to open her up is far better than vacuum assist....imo.

[blykins]

Salt, here's a pic of my 428FE and the Demons. You can see how the quick change vacuum works, and the way you hook them together.

[patrickt]

Originally Posted by blykins

Salt, here's a pic of my 428FE and the Demons. You can see how the quick change vacuum works, and the way you hook them together.

Very nice; I do like the look of twin carbs. Refresh my memory -- were the single four barrels on the race 427s vacuum or mechanical?

[blykins]

Mechanical weren't they?

[Barry_R]

Could be wrong - but every factory 427 FE package I've seen had vaccuum secondaries. Most mechanicals are 4150 style with metering blocks at both ends - no room for those on an FE intake.

[patrickt]

Originally Posted by Barry_R

Could be wrong - but every factory 427 FE package I've seen had vaccuum secondaries. Most mechanicals are 4150 style with metering blocks at both ends - no room for those on an FE intake.

I thought everyone here was in agreement that the 4160 was clearly superior to the 4150, dual quads, BGs, and FI due to its technological leap in handling those pesky secondaries. In fact, adjusting the secondary side of my Holley is almost done by the time I get the hood open.

[Barry_R]

You don't have enough carburetors on that engine....

I have carbs that are vac secondary 4160 yet still will allow use of normal jets....

[undy]

Originally Posted by Barry_R

I have carbs that are vac secondary 4160 yet still will allow use of normal jets....

Yep, got two of them myself..

[tmareina]

I run a Dove Tunnel Wedge intake with two 660 cfm Holley carbs. They work GREAT...No problems in 2 years...have not had to adjust them either. Look in my pics for a view

Tom

[patrickt]

Originally Posted by Barry_R

You don't have enough carburetors on that engine....

At 447 cubes (I'm using the 4.125" SCAT stroker) my FE is one of the smaller sized FEs on this forum. The "relatively small" single 3310 works very, very well along with the old fashioned solid "K" cam (245/.525 at .05, 114LSA). Even with these mild components (compared to some of the mills on this forum, that is) she's traction challenged -- and not just out of the hole, during hard acceleration as well. I'm sure I have untapped horsepower in there, I just don't know if I could tap it if I had it. And if I got a second carb, I'd have to get rid of that beautiful custom Turkey Pan that Bob P. spent months carving out of billet by hand....

[Barry_R]

C'mon - I'm just teasin' ya....

After all - this was a 2x4 carb thread.

[patrickt]

Originally Posted by Barry_R

C'mon - I'm just teasin' ya....

After all - this was a 2x4 carb thread.

The problem is I really do like the look of dual quads. When I was spec'ing the engine out a few years ago I was torn between the single with a TP and the beauty of dual quads. Short of Webers, nothing looks as nice as dual quads. And I'm starting to get a little weary of the TP look and I might be ready for a change....