Counting Cars 383 rebuiild and horse power

[Inspector71]

In a past episode of Counting Cars, the crew restored a 64 Fury with a 383. They rebuilt the motor and I believe upgraded the cam. If I remember correctly, the 383 4 bbl with stock heads and intake, dyoned at 350 hp. What I was wondering, if one added aluminum heads and intake, a different cam, and headers, nothing too radical, what type of hp might they expect? I realize this is always a guesstimate but I was hoping to get a ballpark figure. Thanks.

 

[Bruzilla]

There's really no telling since there are so many different intakes, cams, headers, etc., and each yields it's own unique performance gain. It could be a 100 HP gain, or a loss, depending on what combination you use.

 

[RustyRatRod]

I think with smart parts choices the 383 could see 425 or so HP. More if you're willing to raise compression and run race gas. They can make basically the same power as a 440, but they do it at higher RPM.

 

[Cranky]

Yup to what Rusty said....these days, it's really easy to produce 1 hp per cubic inch and with some thought and choosing the right combo of parts, going over 400 isn't that hard either.

 

[Meep-Meep]

X2 Rusty; Cranky. I think of a 383 as a big two stroke (if you want to make serious power). For a hot street car build, but drivable, it is what it is so get used to not 440 performance. The 383's have always treated me well.

It would be fun to take some modern light weight pistons and rods, cut down the counterweights to offset the weight so you don't make it into Swiss cheese while balancing it, slap in a big nasty cam and let it rip! Teach those SBC guys a leeson

 

[Inspector71]

Thanks for the replies. I'm still thinking of going with a stroker 383 for the fun of it and, yeah, I want it streetable. My guess is, in a 68 Charger with a Dana60 373 sure grip, with aluminum heads, intake, radiator making it lighter (plus the thin metal left after I've sanded all Missouri rust away), 375 to 400 hp shold be plenty for fun (and taking down my radical 1967 Pontiac GTO with a stroked 400. I guess I've got a motive here but if you knew this guy and had to put up with him....oh brother). Anyway, I've been on this forum a little while and I have never come across a better informed bunch who really know their stuff. You have no idea how many times you all have stopped me from making a mistake with your answers to the many questions from those of us who are just getting into this again. I salute you all.

 

[dvw]

If your going to the trouble to stroke it start with a 400/440. 383 pistons are less common and more expensive. Stock stroke 383 with .500 cam, Eddys, headers, Performer RPM or street Dominator will get 400-450 depending on build technique and compression. How much maching do you want to spend $ on?
Price the hold build firtst. Then look for used heads and intake, plenty out there.
Doug

 

[Inspector71]

dvw: Thanks. lots to think about before I rush into this. I've decided to slow down and start pricing out the various ways to go. It may be a while but your advice is a big help.

 

[dla4567]

I believe Muscle Motors makes a stroker kit for the 383, that being said, they also recommend going with the 400 block instead of the 383. You could also make a small investment into a dyno program for your computer. With that you can swap parts all day and they are suprisingly accurate.

 

[Inspector71]

Thanks, I'm on my way to check it out now.

 

[super-bee_ski]

I think with smart parts choices the 383 could see 425 or so HP. More if you're willing to raise compression and run race gas. They can make basically the same power as a 440, but they do it at higher RPM.

By adding aluminumn heads there is NO GAIN unless the Heads "FLOW" more than the original.
Like Rusty implied, more work needs to be done.

My original 383 in the Superbee was rated at 335HP
My original STOCK 426 Hemi dynoed at 457HP W/ aluminumn Stage V heads.
(They are not as Heavy)

 

[Inspector71]

Super-bee_Ski, Thanks. My thoughts on the heads are to bring the weight down as much as possible. I've only been in one race in 20 years and it was because a guy in an Escalade was trying to cut my little car off and drive me into the weeds. I can't say at my age I'd ever be in a race again, but, I can see my Pontiac GTO neighbor fanatic "toying" with me. He sure doesn't like Mopars. I'd like to think I could hold my own if the time ever came....

 

[RustyRatRod]

Pontiacs never had any street creed at all. Slow heavy POS.

 

[theman440]

Another thing you have to keep in mind - all things being equal when you switch to aluminum heads you need to go up 1 point in CR to make the same power.

 

[67 coronet]

for making good street hp the key is matching all your parts to build power in the same rpm range.biggest mistake made is putting too big a cam with crap heads and a single plane intake.all you make with that is an expensive pig.

 

[IQ52]

Another thing you have to keep in mind - all things being equal when you switch to aluminum heads you need to go up 1 point in CR to make the same power.

Not true. Show me your evidence. I can show you dyno tests to the opposite.

 

[RustyRatRod]

...and I can pull all kinda mag articles that state the same thing. That's an old myth I wish would go away. The type of metal a head is made out of has NO effect on compression. Compression is a ratio. A comparison of volume of the cylinder from BDC to TDC. The head could be made outta wood and as long as the chamber is the same size as iron or aluminum, the compression doesn't change.

 

[67 coronet]

...and I can pull all kinda mag articles that state the same thing. That's an old myth I wish would go away. The type of metal a head is made out of has NO effect on compression. Compression is a ratio. A comparison of volume of the cylinder from BDC to TDC. The head could be made outta wood and as long as the chamber is the same size as iron or aluminum, the compression doesn't change.

well,wood might expand a bit,but you are correct rusty.

 

[IQ52]

Generally, it is not in reference to the compression ratio changing, but to the thermal conductivity of the two metals. Aluminum conducts heat faster. So the thought is the aluminum head will conduct heat away from the combustion chamber quicker, causing a loss of horsepower. So they figure you have to add compression to make up for the heat loss.

However, the combustion process happens so quickly, that the loss, if any, is so small you'll not be able to measure it. Reality really bites here because the temperature of the head is controlled by the water in the cooling system. Will the water will accept the heat quicker from the aluminum head or the iron? If the water won't receive the heat any faster from the aluminum or iron, the aluminum head is stuck with the heat anyway.

In fact, in the tests I have seen, between heads that flowed the same, with the same combustion chamber shape and size (so therefore the SAME COMPRESSION RATIO), in each case the ALUMINUM HEAD MADE MORE POWER than the iron head.

In Moparville it doesn't matter anyway. Everytime you replace a stock factory iron head with an aluminum head, your getting an improved combustion chamber shape and better flowing ports. BINGO........more horsepower!

 

[theman440]

I'll stop pretending to be an engine expert now...