Ray,
I have 2x4 WCFBs on my 56 Dodge 315 Hemi. I am also very happy with them.
There are several things to consider when running dual quads on the street:
1. The carbs must be in good operating condition and properly tuned. They
should be matched as a dual quad pair.
2. Progressive linkage is preferred. Mine is so smooth, I don?t even feel
any transition points as the second carb begins to open. Much smoother than
a modern single 4bbl with big secondaries.
3. Vacuum secondaries are very preferred. This prevents too much airflow.
The secondaries will open automatically only when the engine needs them.
4. Many modern engines running dual quads are full race, and are therefore
not suitable for the street. This may be why you have heard duals are not
good on the street.
5. Back in the 50s, single 4 bbl carbs were much smaller than today.
Starting in 1955, 2x4 and 3x2 carb systems were common factory options in
performance packages. The Carter WCFBs used in 57 for example, were only 340
cfm. Much too small to allow a Hemi to live up to its real potential, even a
315 Dodge. You need 2 WCFBs to provide 680 cfm, which is still less than a
typical late 60s single 4 bbl.
6. The size of your carburetion greatly depends on the size of your engine
and the horsepower potential. If you run factory original 2x4s, you should
have no problem. If you plan to use modern carbs and unless you plan on BIG
horsepower, look for the smallest 4 bbls you can find, probably 500 cfm
AFBs. Even a pair of 500 cfms may be too much for anything smaller than a
hot 354/392.
7. Dual quads usually run on a single plane intake manifold, with one large
plenum under both carbs. On the street, single 4 bbls usually run a dual
plane intake manifold. The dual plane intake with equal carb size will give
a little better performance from idle to 3000 or 4000 rpm. Above 4000 rpm,
the single plane works better.
8. A single modern 4 bbl carb of the proper size will probably give as good
or better performance and is much easier to tune. It just doesn?t look as
cool as dual quads!
I?m not sure why that one city police force frowned on Hemis. I think they
are not any different in reliability than a non-Hemi. They had a reputation
for ruggedness and long life. The only major difference is the heads, and
they are just as reliable as any other type. They just make more horsepower.
The only drawback on some of the high output Hemis is that they had dual
quads and solid lifter cams, which require adjusting. The other minor
drawback is that they make so much more power, they might break something
when driven by cops who like to frequently step hard on the go pedal of a
car they don?t own and have fun.
What size Hemi do you have and what carb system are you planning on?
Dave Homstad
56 Dodge D500
-----Original Message-----
From: Forward Look Mopar Discussion List
[mailto:L-FORWARDLOOK@xxxxxxxxxxxxx]On Behalf Of Angela Underwood
Sent: Thursday, November 01, 2001 8:10 PM
To: L-FORWARDLOOK@xxxxxxxxxxxxx
Subject: [FWDLK] 2x4 engines
Hello everyone. I have had several people tell me that it is practically
impossible to run 2 4bbls on the street on any kind of regular basis.
Knowing that many of you on the list run multi-carb engines of several
different varieties,what are some of your experiences with this?
I also read in a police car collectors' manual that one of the buying
restrictions for a certain major city in the mid fifties was up to an
including the 383(even with multi carbs) but to exclude hemis of all
dimensions based on their labor intensive upkeep. Any thoughts on this? I
plan to drive my hemi with 2x4s, probably not everyday but quite often. The
commute to work is less than 10 miles round trip.
Thanks for any input.
Ray
|
|
Back to the Home of the Forward Look Network