345 power possibitlities
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- Posts: 3
- Joined: Sun Sep 03, 2006 8:02 pm
- Location: Milton, Ontario, CANADA
345 power possibitlities
So what kind of power could I expect from a stock 345ci hemi with a 500 cfm 2 barrel carb, headers and a good ignition system? I just cannot afford the $450 for a 4 barrel intake. Never mind the trouble of finding them. Someday, but for now, what does anyone think?
The trouble with trouble is that it usually starts out as fun!
Re: 345 power possibitlities
The Holley 2 bbls are rated for flow
at a higher test vacuum than their 4
bbl. carbs - so the 500 cfm two barrel
rating is actually closer to about 350
to 400 cfm for an equivalent Holley
4 bbl.
Still the a 500 cfm Holley is a good
choice (the only sensible one,
actually, if you're limited to the
stock 2 bbl intake) and has at least
as much and probably slightly more
airflow the stock Carter WCFB
4bbl. By the way...are you sure
your engine is a 345 and not the
more common 330 or 341 version?
The 341 4bbl. engines were factory
rated at 295 *gross* horsepower,
with a single - and less than 400
cfm - WCFB Carter 4bbl. The much
more common 330 and 341 base
engines came with 2bbl. carbs
- but I thought the hi-po 345 engines
were only used in the Adventurer
and all of them with two WCFB
Carter carbs. I've never seen or
heard of a 345 that came with a
even a single-four, let alone a two
bbl intake. At any rate, regardless
of whether the engine is a 341 or a
345, assuming the engine is in good
shape internally, a set of headers
and good free flowing exhaust
combined with a decent ignition,
a hotter (but mild enough to
still be streetable) cam and a 500
cfm Holley two barrel should really
wake the sleeping beast up.
Depending on the cam, you should
be able to achieve somewhere in
the low 300 *net* horsepower
range, even with the restrictive
two barrel intake.
By the way- for a better ignition,
I'd suggest something like a
Pertronix or other conversion to
get rid of the points and triggering
an MSD 6 box and coil for a good
street and mild race ignition set-up)
By the way too, a "hotter"
ignition won't do much good
unless you also open up the plug
gap to take advantage of the
increased spark potential. Any
ignition- whether a bone stock
'57 Mopar points and coil set-up,
or a high-dollar, super, trick of
the week, aftermarket ignition
set-up, advertised as being
capable "of a kazillion volts at
15,000 rpm" and guarenteed to
"stop everything and increase
everything else" <grin>,
will only put out *exactly*
enough voltage to jump the spark
gap. If the stock ignition can fire
the existing stock plug gap at a
given rpm and load without
misfiring, a "hotter" ignition
won't show any appreciable gains.
Be sure to use a good quality cap
and rotor - preferably one with
copper contacts and good low
resistance plug wires too to finish
off your ignition system, too.
mart
===========================
at a higher test vacuum than their 4
bbl. carbs - so the 500 cfm two barrel
rating is actually closer to about 350
to 400 cfm for an equivalent Holley
4 bbl.
Still the a 500 cfm Holley is a good
choice (the only sensible one,
actually, if you're limited to the
stock 2 bbl intake) and has at least
as much and probably slightly more
airflow the stock Carter WCFB
4bbl. By the way...are you sure
your engine is a 345 and not the
more common 330 or 341 version?
The 341 4bbl. engines were factory
rated at 295 *gross* horsepower,
with a single - and less than 400
cfm - WCFB Carter 4bbl. The much
more common 330 and 341 base
engines came with 2bbl. carbs
- but I thought the hi-po 345 engines
were only used in the Adventurer
and all of them with two WCFB
Carter carbs. I've never seen or
heard of a 345 that came with a
even a single-four, let alone a two
bbl intake. At any rate, regardless
of whether the engine is a 341 or a
345, assuming the engine is in good
shape internally, a set of headers
and good free flowing exhaust
combined with a decent ignition,
a hotter (but mild enough to
still be streetable) cam and a 500
cfm Holley two barrel should really
wake the sleeping beast up.
Depending on the cam, you should
be able to achieve somewhere in
the low 300 *net* horsepower
range, even with the restrictive
two barrel intake.
By the way- for a better ignition,
I'd suggest something like a
Pertronix or other conversion to
get rid of the points and triggering
an MSD 6 box and coil for a good
street and mild race ignition set-up)
By the way too, a "hotter"
ignition won't do much good
unless you also open up the plug
gap to take advantage of the
increased spark potential. Any
ignition- whether a bone stock
'57 Mopar points and coil set-up,
or a high-dollar, super, trick of
the week, aftermarket ignition
set-up, advertised as being
capable "of a kazillion volts at
15,000 rpm" and guarenteed to
"stop everything and increase
everything else" <grin>,
will only put out *exactly*
enough voltage to jump the spark
gap. If the stock ignition can fire
the existing stock plug gap at a
given rpm and load without
misfiring, a "hotter" ignition
won't show any appreciable gains.
Be sure to use a good quality cap
and rotor - preferably one with
copper contacts and good low
resistance plug wires too to finish
off your ignition system, too.
mart
===========================