383 needs more power

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If it drives good and has nice power, run it...

Don't get all caught up in numbers...
 
Finally, someone knows how to talk gears. Numbers go down it's LOW they go Up it's geared HI.
I've always said 4.11's is lower geared than 3.23's.
Kind of like "low gear" on a tractor is geared for more power. Or 4-low on a 4x4. Or granny low on a 4 speed truck. Or 1st gear on a 727 could be called "low" gear.
 
Oh , I'm sorry I switched digits . Yes , @ 230hp something is WAY off . But I still say tune, tune ,tune and work from there . There's more in it if you have a healthy engine .
 
Here is a little different approach for you for some more "Seat of the Pants" performance.

What type of wheels are you running, are they steel ? There is a comparison between the weight of the Steel Wheels and the much lighter Aluminum Wheels. The people running the 7" wide Steel Cop Car Wheels, man those are really really heavy . . . just even picking them up.

Here goes: so on average the steel wheels weigh 20 lbs more per wheel as compared to the lighter aftermarket aluminum wheels. Times 4 that is 80 lbs of rotating mass that you have to spin up every time you take off and then for braking you have to slow it back down again.

So this is like having an 80 lb flywheel that you have to spin up and slow down every time you start and stop with the steel wheels. Swapped to the aluminum wheels on one of my cars, noticeable improvement. Making better use of the power you are already making, kind of like fully releasing the emergency brakes that are slightly dragging. Lighten up the load, and it goes to beat heck, better gas mileage too.

Have Fun with your 383 A Body . . .
 
looking at you cam peak power at 4400 ish that is a two barrel range cam are you sure the carb is opening up all the way or the cam was installed way advanced?
 
I would use the Hughes Whiplash cam if I was retaining the factory heads and short block.
I would use a 3.55 gear if I was replacing a 4.10.
These recommendations come at my conservative old trial by error been there done that age. lol
 
PS. 383's love zero deck with ported closed chamber heads
 
IMHO,

If after you change your gears, you are not satisfied with your tire spinning ability. Change out your torque converter for one that is closer to your max power / torque rpm. Don't recall which. @AJ/FormS I think laid it all out for me once.
 
He's talking about this camshaft.

11-651-47 - XTREME Energy™ Hydraulic Flat Tappet Camshafts with 18736542 Firing Order 4 & 7 swap firing order.

Hardly low lift for a hydraulic flat camshaft. That's a stout camshaft for a stock stroke 383. Which is what we're talkin about here, not a stroker. Apples to oranges and does the OP no good. Lets keep the discussion down to what he HAS so we can better help him. Ok?

To the OP, first off, how does the car RUN? I mean omitting anything you have learned dyno wise? Are you happy with it? Will it smoke tires? Does it accelerate briskly? It may well be fine, because it's possible to lose 100 HP through the drive train.

That said, here's where "I" recommend starting. First, run a compression test and post up the numbers. This will give us a good idea about the static and dynamic compression ratios of the engine. My guess is, it will be 120 or less. We can better advise you with compression test numbers so get crackin and let us know.

You have lots of options. You can taylor the camshaft timing to better match the initial cylinder pressure readings. If they are low, you can advance the camshaft timing. If that engine has stock compression pistons in it, I would put that cam somewhere around 100-102 ICL. But that's getting ahead of ourselves. Lets get those compression test numbers first and we can go from there, ok?


Put the kids to bed last night and went straight to the garage to get some compression numbers. Compression ranged from 135-145psi.
 
did he see the 4 & 7 swap in the firing order?

I believe I posted the incorrect camshaft. The camshaft dano posted in post #13 is the correct one, I believe. Although that's not been verified.
 
Put the kids to bed last night and went straight to the garage to get some compression numbers. Compression ranged from 135-145psi.

That's consistent and that's a good indicator that the engine is in decent shape. A little low. Do you know if the camshaft was degreed or was it installed dot to dot? If dot to dot, it might be worth your time to degree it. If you don't want to go to the trouble, then we can move onto getting the ignition timing optimized. I would recommend looking at the camshaft timing though, because getting camshaft and ignition timing both where they need to be can add a lot. Up to you though.
 
That's consistent and that's a good indicator that the engine is in decent shape. A little low. Do you know if the camshaft was degreed or was it installed dot to dot? If dot to dot, it might be worth your time to degree it. If you don't want to go to the trouble, then we can move onto getting the ignition timing optimized. I would recommend looking at the camshaft timing though, because getting camshaft and ignition timing both where they need to be can add a lot. Up to you though.

I couldn’t say how the cam shaft was installed dot to dot or degreed. If I was to degree it, how much so?
 
That would depend on what the degree wheel says. It is a minor PITA to do, but a PITA it is. It’s mostly setup time and getting the mic set up well for a good and consistent reading over and over again.
 
Yes , @ 230hp something is WAY off .
Well, probably not so much. There is the thing with how horsepower was measured back in the day... almost as confusing it seems
as the endless dyno discussion.
335HP back then was measured GROSS, so the engine was measured on a factory dyno sans accessories... naked so to speak.
The same engine was rated something like 280HP as per SAE NET standards installed with accessories, comparable how they rate engines today.
We are speaking flywheel horsepower!

Now take your 230HP measurement from the chassis dyno, add the drivetrain losses, and you are at about 280HP at the flywheel again.
So not much seems to be wrong with your engine.

When you want more power, get better heads and bump the compression (which better heads will automatically do in most cases).
 
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I know this may be silly, but are your ignition components in good shape? You'd be surprised what you can do with stock replacement plugs, cap and rotor if they're bad.

Also, what kind of headers are you running? Are they appropriately sized? Better heads and a different cam will net you more power, but headers are part of the power equation too.
 
back to post # 6 you said max hp was at 4400 rpm that's way off with that cam in a 383 should be closer to 6000rpm so is your carb getting open all the way? someone could of installed the cam on the advance dots that are on some timing sets and didn't dial it in. are the secondary's opening up the spring could be too heavy or no vacuum to it ,with your engine you should be near 320 hp at the rear tires
 
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Here is a little different approach for you for some more "Seat of the Pants" performance.

What type of wheels are you running, are they steel ? There is a comparison between the weight of the Steel Wheels and the much lighter Aluminum Wheels. The people running the 7" wide Steel Cop Car Wheels, man those are really really heavy . . . just even picking them up.

Here goes: so on average the steel wheels weigh 20 lbs more per wheel as compared to the lighter aftermarket aluminum wheels. Times 4 that is 80 lbs of rotating mass that you have to spin up every time you take off and then for braking you have to slow it back down again.

So this is like having an 80 lb flywheel that you have to spin up and slow down every time you start and stop with the steel wheels. Swapped to the aluminum wheels on one of my cars, noticeable improvement. Making better use of the power you are already making, kind of like fully releasing the emergency brakes that are slightly dragging. Lighten up the load, and it goes to beat heck, better gas mileage too.

Have Fun with your 383 A Body . . .

Here we go with the light aluminum wheels, know what it did for waking up this 318, 4 bbl, can imagine what it will do for that 383.

Oh Yeah . . .

20190910_192253.jpg
 
I would be happy with 320 at the wheels too. But it’s only 230 at the wheels.
You have 230 at the wheels ? you know it might be more. There are cars right here on Fabo that claim 400/500 at the wheels and only run 115 in the 1/4. lol
Don't buy in to dyno numbers, if it feels good to your butt, that's all that counts.
The secret is in the heads.
 
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