4 barrels and intakes are over rated on a street car

[66Satellite47]

Where did you get that fact from ?
I've seen it stated in many different ways
even today jusT checking it out on a Bing Search

I think
'don't quote me'
I remember reading/hearing it somewhere,
I don't remember where
(it may be just a wives tale, that stuck)
but;
that "allegedly" newer Net HP ratings
was actually at the output shaft of the transmission
not at the flywheel like before
taking into account, that total/inclusive parasitic loss,
usually 15%-25% less/loss
if all things were equal, from old rating to new

it's not At the Wheel HP, like today's drum dynos
IIRC that part is correct
I've seen it stated both ways too

take what ever way you like...
I'll go with the ol' school terminology

Bud, I agree, the "Net HP" & "RWHP"(rear wheel HP) are not the same. my understanding is the switch to "net" was a calculated number including parasitic losses, maybe at driveshaft(averaging manual vs auto?).

 

[chargervert]

I was driving my 68 Charger 383 2 barrel car,and I came upon a 73 Dart sport 318 4 barrel car racing a 70 Javelin 360 car. You should have seen the looks on their faces when my Charger blew by them in between the two cars while they were supposedly racing each other! My friend in the passenger's seat was laughing his *** off,and the girl in the backseat was screaming at me calling me crazy for beating both of them! I told the guy in the Dart sport that he came in third! Lol Those were good times!

 

[66Satellite47]

Some of the unusual good performance of some engines may come from factory "mismatched" parts. I had friends in the mid '70s that had junk yard 340's only 2-3 years old, low miles. One from a '71 Duster had 7-340 connecting rods & 1-318 rod all factory. The other had a 340 & 4spd out of a '70 Duster with a 340 TA block, the only TA block I've ever personally seen. Stuff happened on the assembly line!

 

[BB BELLA]

OP must have stumbled onto the rare and elusive 318 HEMI 2 barrel.

"Semi-Hemi"

 

[Ron H]

Yeah, but they're all pretty worthless, so don't let it bother you.

And I took about 20 java mugs to Goodwill...

 

[Ron H]

"Semi-Hemi"

A relatively fresher handle given to the poly motor...

 

[Slap Stick]

A relatively fresher handle given to the poly motor...

Just like today's "hemi".

 

[Slap Stick]

Sorry, Wrong again.
The NET rating was not wheel HP, it was still flywheel HP. They just factored in the parasitic losses of the alternator, water pump and fan, P/S pump, exhaust system, A/C, etc.

And transmission, differential. Its rated as in the car.

And I don't understand the point you're trying to make. The OP stated his 318 is pepper than his 360.
I can understand that. The 360 has a bigger cam and carb but still has the same gears and converter. It doesn't make as much torque at low rpm.

 

[Kern Dog]

And transmission, differential. Its rated as in the car.

And I don't understand the point you're trying to make.

The point I am making, not trying to make is that the net ratings are not measured at the wheel.

This magazine spells it out.

Gross versus net ratings:

The text of the article:

Now the money shot up close:

In the late 60s, there were chassis dynos but they were not that accurate. Here is one of their charts:

 

[66Satellite47]

Thank you Kern, that pretty well sums it up. That SAE number MAY have included a calculated average trans and axle loss too. Not sure about that.

 

[BeatersRus]

Some of the unusual good performance of some engines may come from factory "mismatched" parts. I had friends in the mid '70s that had junk yard 340's only 2-3 years old, low miles. One from a '71 Duster had 7-340 connecting rods & 1-318 rod all factory. The other had a 340 & 4spd out of a '70 Duster with a 340 TA block, the only TA block I've ever personally seen. Stuff happened on the assembly line!

this is very true.
ive personally seen that before.
then again,all small block rods were the same except for the pins,even with diff part numbers you can still swap rods all over the place.
( disclaimer,there was a period of bushed versus floating pins)

OP must have stumbled onto the rare and elusive 318 HEMI 2 barrel.

whats with the rudeness?
guy was happy about his car and you cant seem to deride him enough for his happiness?
why did it take you 4 pages to finally make a legit point that most of us knew already?
if you hate 318-s so much,then why bother even replying on the thread?

 

[toolmanmike]

Gross vs Net horsepower. A good article even though they talk about Chevy engines. https://ateupwithmotor.com/terms-te...uch as the,, exhaust systems, and accessories.

 

[Kern Dog]

Part of that article:


"SOME COMMON MISCONCEPTIONS
Let’s clear up a couple of common misconceptions about gross and net horsepower ratings:

1. Contrary to some assumptions, net horsepower ratings do NOT measure horsepower at the drive wheels. Both gross and net ratings are at the flywheel and do not reflect power losses in the drivetrain."

 

[Photon440]

Way back in '78 when my road runner still had the factory 383 (now long gone), a friend showed up, driven by someone I'd never met in a 1970 383 Coronet. Being kids, we ended up tooling around town for awhile then ended up doing burnouts in a mall parking lot. His burnouts were much more impressive, he could light them up with ease. Back home later, he remarked that his was a 2bbl. I didn't believe it, he had to open the hood to show me.

 

[coloradodave]

Way back in '78 when my road runner still had the factory 383 (now long gone), a friend showed up, driven by someone I'd never met in a 1970 383 Coronet. Being kids, we ended up tooling around town for awhile then ended up doing burnouts in a mall parking lot. His burnouts were much more impressive, he could light them up with ease. Back home later, he remarked that his was a 2bbl. I didn't believe it, he had to open the hood to show me.

60 psi in the rear tires...

 

[coloradodave]

Who knows, some 318s may have had some 340 cams.
A barber I used to go to years ago bought a new Monte Carlo. Ran like stink but got terrible mileage.
They found out what was wrong. It had 4.88 gears.
I'd bet substitutions were made when parts bins were empty to keep the line going.

I'd be amazed if Chevrolet had boxes of 4.88 gears on the assembly line...what car were they meant for? Also, although my memory is foggy, I believe the 10 and 12 bolt rearends required a different carrier for lower gears.

 

[BeatersRus]

speaking of misconceptions.
heres uncle tony explaining why the small block head design is better than a hemi or a big block.
theres a bunch of hemi head and bb head design discussed as well.
cheers !

 

[pearljam724]

Way back in '78 when my road runner still had the factory 383 (now long gone), a friend showed up, driven by someone I'd never met in a 1970 383 Coronet. Being kids, we ended up tooling around town for awhile then ended up doing burnouts in a mall parking lot. His burnouts were much more impressive, he could light them up with ease. Back home later, he remarked that his was a 2bbl. I didn't believe it, he had to open the hood to show me.

I’m tellin ya. Over rated on a street car.
A 2 barrel will get the job done, just as well. The key, is having a good running motor. Period

 

[BDF6]

ficticious.

 

[BDF6]

https://www.forabodiesonly.com/mopa...-rated-on-street-cars.472829/#post-1973127712

Different reaction on FABO. Lots of teens over there.

That thread was really entertaining, thanks for the link!