Hot Rod Forum : Hotrodders Bulletin Board

Hot Rod Forum : Hotrodders Bulletin Board (
-   Engine (
-   -   New SBC 383 build question + parts list (

Filmjay 12-06-2008 07:50 PM

New SBC 383 build question + parts list
Hi guys.

I WAS going to use a 4.0L Northstar...but after spec'ing everything out for it, the dollar:performance ratio is just too much. $10K for a 400hp motor just isn't worth it imo. Especially the fact that I'd still need to invest another $2,000 JUST in the specialty tools and timesert kit needed. (N* blocks HAVE to be timeserted, no matter what.)

So I've decided to go with a motor that is your favorite, and mine...the SBC. They're relatively easy to work on, parts are EVERYWHERE, I know the opinions of some about the SBC around here. But, it's going in an early Z-car, so unless you can spec a Datsun 383, you can save those. But, it's 2600lbs of 600hp goodness...I hope. :sweat:

I've searched and researched as much as I can so that I can make a decently informed post...but I'd like the opinions of some of the more experienced guys around here, in case I'm missing something. I'm sick of all the crate motors I see, so I'm braving my first bare block be gentle. :D

This is what I've got so far. I'll add the links to the parts, and any questions I have afterwards....

World Motown 4.030 block - link to block

SCAT forged rotating assembly - Summit link

AFR Eliminator 210cc heads - link to Jegs Now, I HAD hoped to go with the 227cc heads here , but I can't find a compatible lifter kit. Yes, I know they come assembled. But with the cam and springs I'm planning on, they require a 1.6 int/1.5 exh rocker ratio. Does anyone know of a lifter kit for the 227cc's? I'd like to stick with Jesel, but don't know if they can customize a lifter kit.

Cam - Comp 259/264 @ .050

Lifters, Springs, and Retainers The taller springs also will need a .100 longer 8mm valve....which I can't find anywhere but on the AFR website. (Their site is down at the moment, so I can't link to it.)

Rocker Kit. This is just for reference as I'd need to contact Jesel and see if I can get a 1.6 int./1.5 exh. system made. Will probably add another $200. Oh well. Going fast ain't cheap.

I haven't chosen a pan yet, as I want to wait until I can mock the engine up in the car to see where the clearances are.

and a Dynatek downdraft EFI on top...Link ...will be used regardless of anything else. So any changes need to be based on this.

So...what else am I missing? Besides the little stuff I mean. OF course, all ARP fasteners, Clevite bearings, etc...
Suggestions on gaskets? I'd like to do a bit of porting and polishing, but the Dynatek site says NOT to port match as some Fel-Pro gaskets don't exactly match.
Also, the suitable would that cam be for EFI? The induction is basically a Weber replacement, but cam selection is an art I haven't yet fully grasped.

If all calculations are correct, this setup SHOULD be good for about 600-650 fwhp and 7,000 rpm...and a 150-200 shot of the funny gas, should I have the desire...but I don't have any of the desktop dyno programs to check.

What do the more experienced guys say?

Thanks in advance!

techinspector1 12-06-2008 08:38 PM

If I was lookin' for 600 hp in a Datsun Z, I certainly wouldn't be startin' with a small block....

Big-Block Chevy Engine Build - 707 HP (ON PUMP GAS) For $6,720-complete with part numbers and prices....

Filmjay 12-06-2008 08:58 PM


Originally Posted by techinspector1
If I was lookin' for 600 hp in a Datsun Z, I certainly wouldn't be startin' with a small block....

I guess I did neglect to mention that I'm doing a GTO conversion/replica...
So, a big obnoxious hood scoop is a bit out of the question.

It's not a race car. It's a replica of a classic that I am designing to run with, or better, than the modern models. Hence the desired powerband.

The dimensions are very important. It must all fit under the stock hood height. That's also why a IR EFI is being used regardless of anything else. The look of the original Ferrari Columbo motor. Modern performance, drivability, and reliability instead of the on/off switch that Weber's are notorious for.

But, that's why I'm not planning on using a BBC. With the style of intake I want to use, it would require pretty significant hood modifications.
Now, If I can come up with a 454 stroker, then that would be a nice option. But as it is, I'm not interested in wheel stands, drag slicks, forced induction, or solid axle rear ends for this project.

Thanks for your input though.

Filmjay 12-06-2008 09:06 PM

Oh, and I DO like that 496 write-up. If could make it work under the stock hood and between the stock frame rails w/ a down draft induction...I'll jump all over that sucker.

techinspector1 12-06-2008 09:17 PM

Wait, let me see where I went wrong. Let's's not a race car, but it will require a 600-700 hp motor that's not classified as a race motor. Hmmm, nope, still doesn't make any sense. Let me try again. Cam is 259/264 @ 0.050". Hmmm, yeah, now I get it, just your average grocery getter street cam. Oh, and here's the kicker in your words "drivability, and reliability".

Are you on drugs?

Filmjay 12-06-2008 10:06 PM

No sir. I'm shooting for 600 fwhp. Which would equate to about 500 rwhp...give or take.

I also stated that cam selection was definitely not my forte, and that I still had a lot to learn in that department. That's why I posted my proposed setup. For advice and possible revision....not flaming.

Now, I didn't mean it was a grocery getter. That's not to say it wouldn't make the occasional 1/4 pass though.
But, I don't want to be fabbing up tubular subframes or pushing the firewall back and DO want it to fit under the stock hood height.
..and drivability and reliability was ONLY mentioned for the reason why I'm using an IR EFI instead of a Weber carb induction. I do know that there's nothing practical about a 2600lb/5-600hp car. But, what I mean by it's not a race car is that I'm not building it to win trophies or accolades. I'm just doing it to do it. Nothing else.

Now, if you're done being indignant about your suggestions, I'd love to hear more. I've said that I've still got a lot to learn, and would love to do so.
And I DO thank you for the links you posted. I do like that Car Craft 496 buildup. But again, I've never really dealt with stuffing a big block in a little bitty car...and I do have specific requirements in size, weight, and dimensions that I'd like to stick to. Only BBC's I've ever dealt with were crate motors and stuffed in older generation American iron with square miles of engine compartment space.

Anyway...thanks again for the BBC info. I've found a Caddy 472 in a Z under the stock hood, so I'll take that into serious consideration.
But the dizzy is up front on the Caddy motors, so that makes it an easier fit. Most V8/Z swaps usually are pretty close to the firewall. But, I didn't know it was possible. That's why I didn't consider it.

...and yes, I am on drugs. I had a hood from a 67 C10 fall while I was under it a while back. :P

Filmjay 12-06-2008 10:23 PM

Based on that 496 buildup, what would you start with for a short block?

I don't have swap meets of anything of the like nearby that I can just go pick up an old hot rod motor. :rolleyes:

35hotrod 12-06-2008 10:27 PM

Sbc 383
Hello Filmjay
Pretty interesting (and ambitious) project you've got there. From the parts you've listed it sounds like you have some money to spend. For 600-700 hp you definitely want more than 383 cubes. Dart sells a nice block with splayed main caps and comes with a 4.125 bore with capability of 4.165 while maintaining .230 cylinder wall. If you want normally aspirated power, there just ain't no replacement for displacement. You can easily obtain obtain 434ci in a small block package. Personally, I wouldn't strive for a 7500 rpm small block for street use just for the sake of longevity. At that level you will be building a race car engine. Also, your cam selection uses a 106 degree lobe separation angle. On a carbureted engine this can boost torque creating better cylinder scavenging due to the intake and exhaust overlap. This also creates a phenomenon called reversion at lower rpm. Fuel injection does not like reversion. Carbs are not as sensitive to this as FI. If you check cam specs for high performance FI factory engines such as the LS7 Corvette and others you will find LSA's in the 110-114 degree range. Learn more about cams and valve timing, too much duration and/or overlap can make an engine no fun todrive on the street.

techinspector1 12-06-2008 10:32 PM

Yeah, well maybe I was a little gruff, but look at the moniker under my screen name. I've lived on this rock long enough to be a curmudgeon when I deem it necessary. If it walks like a duck and quacks like a duck, then it must be a duck.

Now, back to your project. I posted the first link just to prove that a BBC can and has been shoehorned into a 240Z. The hideous scoop probably wouldn't be necessary if a guy lowered the motor properly between the frame rails and used the type of induction you're thinking of.

Using a SBC to arrive at the type of power you're contemplating just doesn't make any sense. The bores stock bores are 4.000" compared to any BB with 4.250" stock bores. Larger bores will allow larger valves which will pass more air which will make more hp. Any motor you use is simply an air pump. The more air you pump through it, the more power you make.

Assuming 100% volumetric efficiency, the 496 moves 918 CFM at its hp peak of 701 @6400 rpm's. In order to make that same power with a 383, you'd have to wind it to 8,300 rpm's to pass the same amount of air. That doesn't sound "driveable and reliable" to me. On the other hand, twisting a BB to 6400 sounds quite reasonable to me.

Up to and including 500 hp, a SB is probably the best all-around choice for ease of installation, cost of parts, reliability and power in a small light package. But over 500 starts to get into BB territory in my opinion. It's sort of like asking a boy to do a man's job.

HalfOunce 12-06-2008 10:39 PM

If you are going with a small block and using an aftermarket block why not stroke it farther than 3.75? and why not go with a bigger bore small block to start. I bet the target numbers would be easier to obtain...

techinspector1 12-07-2008 12:00 AM


Originally Posted by Filmjay
Based on that 496 buildup, what would you start with for a short block?

I don't have swap meets of anything of the like nearby that I can just go pick up an old hot rod motor. :rolleyes:

To follow the Car Craft build, you'd start with a Mark IV block with 4-bolt mains. Most of the 70-90 454 Mark IV's could be found with either 2-bolt or 4-bolt mains. Here are some casting numbers.
3999289 71-79 454 (the block used in the article)
361959 73-90 454
3963512 70-76 454
10051107 454 Bowtie block. Siamezed bores, can be safely bored to 4.500". With a stock stroke 454 crank in this 4.500 block, displacement is 509 cu. in.

There seems to be a problem with using Mark IV heads such as the AFR's or any other Mark IV head on a later Gen V block. Here's a blurb from Chevrolet....
"Important Technical Note:
Use of the adjustable valvetrain Mark IV cylinder head is not recommended with the new “Gen V engine,” except with Bow Tie racing blocks and all Gen VI with six-bolt composite front covers.
Changes in the configuration of the “Gen V’s” coolant transfer passages allows coolant to seep into the lifter valley when the Mark IV head is used. Mark IV camshafts, water pumps, intake manifold, distributor and clutch housings can be used with the new “Gen V” engines. “Gen VI” 454 crate engines and bare block P/N 12550307 are the only “Gen VI” blocks that have machined fuel pump boss."

Filmjay 12-07-2008 01:55 AM

Alriiiiiight! Now we're back on track. :thumbup:

I would totally agree on the BBC opinions here. But I wasn't so sure about stuffing one in such a tight space. But, since I've seen that it can be done without having to totally refab the front end, I'm definitely game.
Besides, nothing sounds like a big block. :D

Now...I DO have quite a budget planned. But, I've timed the project for 2-3 years total to give myself room to acquire the parts a little at a time. But, I've budgeted about $10-$12K for the engine. The SBC I put together in my first post comes in a little over the mark though. I don't mind going up to $15K, but I don't want it any more than that. The Dynatek EFI is already gonna be $5-$6K.
Of course, cheaper is ALWAYS better, but I don't want to sacrifice quality. Forged components are a MUST, as I will probably end up putting it to a little of the funny gas.

Guess I've got some reading up to do on big blocks, in addition to cam selection. :smash: :D

Koolaid 12-07-2008 09:34 AM

Like others have said - don't limit yourself to 383 cubic inch on a small block. If it's all aftermarket stuff just go straight to a 434 and you're up in the big block displacement without the big block weight.

RippinRon 12-07-2008 09:43 AM

Have you conisdered a LS series engine? 402 inch stroked ls2's and ls3's are getting over 500 rwhp with mild cams and headers. Plus LS stuff is way cheaper than sbc stuff now. And whats with fwhp are you converting it to front wheel drive.

SSedan64 12-07-2008 12:35 PM


Originally Posted by RippinRon
Have you conisdered a LS series engine? 402 inch stroked ls2's and ls3's are getting over 500 rwhp with mild cams and headers. Plus LS stuff is way cheaper than sbc stuff now. And whats with fwhp are you converting it to front wheel drive.

FWHP= Fly Wheel Horse Power
LS parts cheaper than Gen I ??

All times are GMT -6. The time now is 03:04 PM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright 1999 - 2012. All Rights Reserved.