Anyone ever have their 383 dyno'ed? Just trying to get a idea...

[Mark Barnes]

Just looking for a reasonable HP/TQ range for a non-stroked 383. Any other additional power adders are fair game, just 'splain what you got.

 

[beanhead]

We rebuilt my cousin's factory (at the time) '70 RR 383 about 17 years ago and he basically copied the baseline version of this motor:
https://www.motortrend.com/how-to/mopp-0209-383-engine-restore/

The difference was his had headers from the git-go, on the dyno it made a best of 352 hp. I don't remember torque or rpm but it was a real nice driving motor.

 

[Darter6]

Do you watch You Tube ?
If so Nicks Garage has a good video about a dyno pull of a 383 he built for a Dodge pickup.
He does lots of Dyno videos.

 

[BSB67]

Instead of other peoples dynos on 383 motors that will ultimately be different than yours, consider this as an alterative or in conjunction with your research.

Extrapolate hp/cuin from other builds (440s) to the 383. As an example, if a well documented 440 build makes 1.0 hp/cuin on a credible dyno, you can reasonably presume that if you use the same parts in a similar build on a 383, it will be at least 1.0 hp/cuin, probably a little bit more. This is not exact, but you should be able to find a lot of info on 440 builds that will get you in the ball park.

 

[PRHeads]

In the realm of street cars.........
Unless being built for competition use, building towards a specific power level doesn’t really make a whole lot of sense.
For anything that will see “real” street duty, the plans should revolve around how the car will be used, and the companion equipment(gears, converter, exhaust, etc).

Attempting to build a 550-600hp 383, and then installing it into a 70 Imperial with a stock 12” converter, 2.76’s, and single exhaust won’t result in motoring bliss.

Particularly when the build is going to be slanted towards the milder side, or near stock driveability, take a cue from the factories.
Build a bigger motor.

Use parts that are a good match for the intended use, and it will make what it makes.
As long as all the pieces are on the same page, it should make what would be “expected”.
If the projected number is below your expectations....... it’s usually better to just scale the whole thing up(more cubes).

 

[rikkitik]

Use parts that are a good match for the intended use, and it will make what it makes.
As long as all the pieces are on the same page, it should make what would be “expected”.

Well said ,as always, Mr Porter. Completely agree.
YEARS ago, my first real "build", was an iron headed 383. Dual plane Weiand, 750 DP, good old PSHB484 cam (adv 2 deg), headers. Of course, back in '78, I didn't have the "interwebs" to tell me what POS's the manifold and cam were.....
And, not knowing any better, I was pretty happy when that engine put my big 'ol '69 Charger through the traps at 104mph (3.23 gears, no posi). Same engine transplanted to a '71 Cuda went 112.
It was a fun, super reliable motor. I spun that thing 6000rpm (honestly though, I tried shift points of 5600, 5800, and 6000, et and trap hardly changed, but I liked how it sounded at 6k ). I put a bit over 36k miles on it before I sold it, never had a problem, the next owner didn't either.
So, as suggested above, think it through, pick well matched parts, and don't worry about "chasing a number". A solid build should put you easily in the +1hp cu.in. range.

 

[ir3333]

cam for lo end torque (short duration decent lift) if it'a a street motor.A big cam will perform poorly at lo rpm but make a better hp number at hi revs...where you won't be driving.

 

[PRHeads]

Depending on how serious your hot rodding efforts are, for the mild street to hot street/mild bracket race builds........ the typical range for a 383 not using any “exotic” parts will usually end up between 350-475hp.

383’s respond just like you’d expect to all the normal hop up parts/techniques.

 

[Mark Barnes]

Thank you all for your informative posts. I built this motor with the best components I felt I could afford, and in a certain time frame. ...this time around.
The only other thing I would have LIKED to do, (but my wallet disagreed with me), would be to put on Trick Flow 240 heads.
Is there a roundball figure for additional HP over a set of bowl blended, port matched, 2.14I, 1.81E valve 516 iron heads? Worth the money, or just drive what ya got?

 

[PRHeads]

Imo, you’d have to have a pretty serious type of build to warrant TF heads on a stock stroke 383.

Decent CR, big cam, big intake...... wanting to make some top end power.

I’ve only dyno tested a handful of 383’s.
I’d say the main reason for that is when the builds are in the planning stages, it’s usually a next to zero dollar upgrade to build a 440 instead....... and that’s what ends up being built.

I can’t recall ever testing a very mild 383.
Interestingly, the one that made the most power had the least flowing heads....... but had the biggest cam.
I point that out to illustrate that it’s always about the overall combination, not just one item in the combo that gets you to a certain power level.

 

[RemCharger]

Yep, ease er up to about 5500.. then STAND ON IT ! (Hang on to the wheel and shift quick)

 

[Mark Barnes]

Imo, you’d have to have a pretty serious type of build to warrant TF heads on a stock stroke 383.

Decent CR, big cam, big intake...... wanting to make some top end power.

I’ve only dyno tested a handful of 383’s.
I’d say the main reason for that is when the builds are in the planning stages, it’s usually a next to zero dollar upgrade to build a 440 instead....... and that’s what ends up being built.

I can’t recall ever testing a very mild 383.

Interestingly, the one that made the most power had the least flowing heads.
....... but had the biggest cam.

I agree, it IS interesting that the one 383 that made the most power had the least flowing heads.
Would you care to expand on why that may have happened, and what the "big" cam was?
I know that there is no replacement for displacement. I would have built a bigger motor if I'd had my druthers, but I had a 383 sitting in the garage and my son asked me to build a car with him. Done deal.

 

[67charger383]

Copying an old build from a some book I forget which

600+ hp N/A 383

TRW 12.5-1 Dome Pistons

Weiand tunnel ram

2x 660 center squirters

600+ lift 300+ duration solid roller cam

Milodon pan and external oiling

Race ported 915s

Worked and polished stock rods

ARP rod bolts

Girdle

1-7/8 headers

To be run on E85 but the build I'm replicating was a alcohol motor.

 

[Mark Barnes]

Copying an old build from a some book I forget which

600+ hp N/A 383

TRW 12.5-1 Dome Pistons

Weiand tunnel ram

2x 660 center squirters

600+ lift 300+ duration solid roller cam

Milodon pan and external oiling

Race ported 915s

Worked and polished stock rods

ARP rod bolts

Girdle

1-7/8 headers

To be run on E85 but the build I'm replicating was a alcohol motor.

Wow! That is a stout cam for a 383. 12.5-1 compression? A little high for crappy gas/my purposes, but mine came out at 10.2-1 and I'm happy with that. Gonna see how it runs, hopefully this weekend. Still looks like this right now.

 

[PRHeads]

Would you care to expand on why that may have happened, and what the "big" cam was?

Three of the 383’s I tested all made pretty similar power....... like in the 480’s.
Two were hot street builds, one was a bracket race engine.
The two street builds got solid cams with duration @.050 in the 240’s on a 110lsa, the bracket build was 256 on a 106.
One street build got prepped RPM heads, the other got ported big valve 346’s.
The bracket build got unported 906’s with stock sized valves.
All were tested with 1-7/8 headers and RPM intakes.

The street motors were run on pump 93, the race motor got a pump gas/race gas mix.

All made mid-480’s for HP.
Until I did a little “cheating” with the bracket build.
On that one I had done some testing with an electric water pump, oxygenated fuel, and a carb spacer.
With those items in place, the power got bumped up to 504hp.
In that configuration it was also running the largest carb.

The others would likely have made similar power if tested with the same items.

 

[RemCharger]

Friend of mine ran the same style edelbrock build and showed 490 if iirc..with an edelbrock carb against protest..
Put the holley on at the track and picked up, ran in the 12.30 area / survivor 70 challenger/good gears conv etc
Ran 11.60/70 on a 75 shot

 

[PRHeads]

My bracket build went a best of 11.26@119 in my 3670lb race weight 68 Satellite.
Flat good, battery up front, electric w/p, mechanical fuel pump with the Oe 5/16” fuel line.
8” converter, 4.56’s, 9 x 30 radial slicks, cal tracs, open headers.
Typical ET’s around that time were low 11.40’s. 60’ times in the low/mid-1.50’s(best of 1.51).

Heads flowed in the low 230’s.

 

[ir3333]

My bracket build went a best of 11.26@119
8” converter, 4.56’s, 9 x 30 radial slicks, cal tracs, open headers.
Typical ET’s around that time were low 11.40’s. 60’ times in the low/mid-1.50’s(best of 1.51).

383's love to rev and make the best power when they do.

 

[SlinktRR]

I used to run a 1971 383, all stock except for a .484 purple cam. It dyno'd at 324hp on an engine dyno, stock factory rating was 300hp. It was a fun motor with the cam I would shift at 6200rpm.

 

[PRHeads]

Here’s one of the 3 I mentioned previously........ but which one?