D-mailman
Well-Known Member
What he said...
70" 340 vs 72" 340 specs please
- Thread starter mopar410
- Start date
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What he said...
dodge freak
Well-Known Member
Instead I used the 273 dual quad aftermarket intake and slap two 500 Carters with no secondary air doors. Idles so sweet yet has the punch of a 750 DP Holley
the Victor intake with a Holley 850 DP would be better yet
340's are made to rev, if your not turning them to 7,000 or higher, you are leaving power off the table. A solid cam swap is next for my 340 and then its hello 7,000
As for compression, I recall back in the early 80's the replacement pistons many were using for street / strip cars was 11.5 to 1. I got old PAW ads with prices for rebuilt 340's short blocks with 11.5 forged pistons for under $1,000 out the door (I get sad looking at the ads, lol)
Stock pistons went out the door for serious racers and besides by 1980 the motors were 10 - 12 years old and getting rebuilt...most of those rides were ran hard and trash years ago, the cars that are still around today were likely baby all their lives
the Victor intake with a Holley 850 DP would be better yet
340's are made to rev, if your not turning them to 7,000 or higher, you are leaving power off the table. A solid cam swap is next for my 340 and then its hello 7,000
As for compression, I recall back in the early 80's the replacement pistons many were using for street / strip cars was 11.5 to 1. I got old PAW ads with prices for rebuilt 340's short blocks with 11.5 forged pistons for under $1,000 out the door (I get sad looking at the ads, lol)
Stock pistons went out the door for serious racers and besides by 1980 the motors were 10 - 12 years old and getting rebuilt...most of those rides were ran hard and trash years ago, the cars that are still around today were likely baby all their lives
dodge freak
Well-Known Member
The higher you go, the less you gain
From 8 to 9 to 1, the gain is more then going from 9 to 10, same with going from 10 to 11
The later year cars got 3.23 gears vs 3.55 - 3.91 even 4.10 gears, that alone makes a big difference..you could get 3.55 gears from the factory in 1973 but not many cars did..as SS used to say, 3.55's are **** gears, same performance as 3.23 and same MPG as 3.91's
The 340 really needs 4.10 - 4.30 gears to run strong IMO, its built to rev, let it and it will surprise you
D-mailman
Well-Known Member
The 340, THE best small block ever built, bar none. Large bore , valves located on bore centerline, floating pins, long rods, cam located high in block,...BEST flowing (intake) stock as cast heads, Excellent rod ratio @ 1.85, over built lower end, ..Best small block ever. So much better than all the 'other guys' . Best kept secret ever,..NEVER receive ANY ink from Chevy craft and the other mags, you would think it was Top Secret .
OldmanRick
Well-Known Member
Here, here :cheers:. I couldn't have said it any better.
Funny how every goob out there thinks mopar is limited by it aftermarket choices.When in fact the LA and the big blocks were as close to a racing motor that you could get back in the day,stock.And the "real" reason chevy has so many aftermarket choices is because they were not up to par(Mopar that is)stock:yawinkle:
All those hp examples have giving me alot of ammo aginst my dad,who owns a 69 mustang mach 1 with a 390.I think hes nervous,Since I put my 6 pack on my dart he has gotten him a 6 pack from the early 60's to pit on his mustang
All those hp examples have giving me alot of ammo aginst my dad,who owns a 69 mustang mach 1 with a 390.I think hes nervous,Since I put my 6 pack on my dart he has gotten him a 6 pack from the early 60's to pit on his mustang
D-mailman
Well-Known Member
Mopar 410, You have him covered,..NO problem .
swinger340
Well-Known Member
I love the big bore and short stroke of the 340. Quick revving and fun as heck to do drive. Have some 360s I could build but I keep falling back to the little 340s.
dodge freak
Well-Known Member
Well if Chevy would had stop building the 350 back in 1974 like Chrysler did, Chevy would not be as strong today as it is.
Mopar drop the ball by keeping the 318 and ditching the 340, IMO
It could have went like Ford did and used smaller port heads for 2 bbl carbs and larger ports for 4 bbls, instead they design a great motor and ditched it after 5 short years, yeah the 318 - 360 shared many parts but the 360 was not built to rev and the 318 lack CI and the smaller bore shroud the intake valves
If the 340 would have been made till 1978 like the BBM were, there be many more blocks out there and more interest from the after market part companies. Mopar is to blame, they called it quits in the early 70's and the after market catered to Fords and Chevy's.
Mopar drop the ball by keeping the 318 and ditching the 340, IMO
It could have went like Ford did and used smaller port heads for 2 bbl carbs and larger ports for 4 bbls, instead they design a great motor and ditched it after 5 short years, yeah the 318 - 360 shared many parts but the 360 was not built to rev and the 318 lack CI and the smaller bore shroud the intake valves
If the 340 would have been made till 1978 like the BBM were, there be many more blocks out there and more interest from the after market part companies. Mopar is to blame, they called it quits in the early 70's and the after market catered to Fords and Chevy's.
dgc333
Well-Known Member
When the manufacturers were measuring "gross" HP there was no standard test method. The SAE net measurement defined how the test would be done. Net requires all the accessories (water pump, alternator, power steering pump, AC compressor), stock air cleaner, stock fan and stock exhaust.
Prior to SAE net they didn't have any of those on the engine and were sometimes known to use headers to get the number.
The difference between gross and net was more often much more than 40hp. Just putting an undersized crank pulley on that Charger of yours can gain you 10-15 HP at the wheels. Don't under estimate the amount of power required to turn the accessories, especially the water pump and fan.
I've had some strong 318 and some dog 340 , a good strong (stock) 318 will keep up with a dog 72-73 340 , it happens . I've also had 2 70 318 Darts with 318 and 1 was 2 seconds faster in the 1/4 mile straight from the factory . Machining was really hit or miss back then , had a new 440 tnt seize up on me after 1 week of driving !
Yeah , strokers might make more power , but nothing like buzzing a 340 at 7,000 .
dodge freak
Well-Known Member
If the stroker makes more power, its due to more CI. Increasing the stroke to make more power is the wrong way about it. Increasing the stroke just adds friction and piston speed. Why the 273 became the 318 - 340 by increasing the bore and not touching the stroke.
Yeah then came the 360 but at first it was just used in heavy non performance cars Wasn't till the 340 was dead and gone before the 360 was thought as a performance engine
If you could punch out a 318/340 bore to get 410 CI, it outperform the 4 inch strokers.
Oh the extra torque, that is what rearend gears are for. You increase torque by using a high gear - 4.10, 4.30 gears for street tires, 4.88 and higher for taller slicks tires
Yeah then came the 360 but at first it was just used in heavy non performance cars Wasn't till the 340 was dead and gone before the 360 was thought as a performance engine
If you could punch out a 318/340 bore to get 410 CI, it outperform the 4 inch strokers.
Oh the extra torque, that is what rearend gears are for. You increase torque by using a high gear - 4.10, 4.30 gears for street tires, 4.88 and higher for taller slicks tires
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