I am finishing my 383 build but don't know what kind of numbers to expect. Here are the specs:
350 bored .030 over
Scat 5.7 rods
Eagle 3.75" stroke crank
Comp 4x4 cam .462" intake .480" exaust lift, 218 in. 226 ex. duration at .050"
Dart Iron Eagle 2.02" 1.60" heads
Edlebrock performer rpm intake
Edlebrock 600cfm or Holley 650 DP
MSD Ignition

What are some estimates on hp and tq numbers to expect? Thanks

my guess would be around 350 - 400 hp and great low end torque. go with the holley carb for performance

im doing a similar buildup my self.The fella at the shop where i had all my machine work done says mine should put out 470-475Hp,and since they have there own dyno and drag cars id say he probably knows what hes talking about,they also did the clearancing for the block and rods.
Im using the scat crank and rods
Flat top pistons
Comp roller xr288 cam
Trick flow 195cc heads
compression is right at 10.8
I also had them balance the assembley
so id say yours should be over 400 at the crank depending on which size head size you run :D

Should be between 185-200, I am trying to get all the flow I can without hurting mileage.

How MUCH $$ to build these>????

I am finishing my 383 build but don't know what kind of numbers to expect. Here are the specs:
350 bored .030 over
Scat 5.7 rods
Eagle 3.75" stroke crank
Comp 4x4 cam .462" intake .480" exaust lift, 218 in. 226 ex. duration at .050"
Dart Iron Eagle 2.02" 1.60" heads
Edlebrock performer rpm intake
Edlebrock 600cfm or Holley 650 DP
MSD Ignition

What are some estimates on hp and tq numbers to expect? Thanks


With a 408 sbc, 9.2:1 compression, vic jr intake, Dart Iron eagles (flow numbers for 200 cc iron eagles are virtually the same between your heads and mine with these smaller cams) a 230/230 @ .050 and .485/.485 isky cam, hooker headers, HEI with msd 6al, and a 750 silver claw carb I made 374 hp and 440 tq. I started at under 350 hp on the dyno and tuned it to the gnats ass. Thats a hydraulic flat tappet cam. A roller would make a considerable difference.


I'd look for numbers in the 350 hp range give or take but easily over 400 ft-lb or torque. At the time of the above dyno, the vic jr was a bad match to my combo and robbed a bunch of my low end torque. You have a stump puller right there.

I'm waiting on a summit order to start my 383 in my scout. Its a 10.0:1 motor with a .488/.509 214/222 @ .050 hyd roller, Dart S/R torquer 2.02/1.60's, TPI with holley 52mm TB and an "affordable-fuel-injection" harness and computer/chip. Im expecting 350-375 hp and a $hit ton of torque. 450-475 maybe. TPI's make HUGE torque.

I am finishing my 383 build but don't know what kind of numbers to expect. Here are the specs:
350 bored .030 over
Scat 5.7 rods
Eagle 3.75" stroke crank
Comp 4x4 cam .462" intake .480" exaust lift, 218 in. 226 ex. duration at .050"
Dart Iron Eagle 2.02" 1.60" heads
Edlebrock performer rpm intake
Edlebrock 600cfm or Holley 650 DP
MSD Ignition

What are some estimates on hp and tq numbers to expect? Thanks

What pistons? I just got my very similiar setup back from my machine shop about a month ago. Eagle Rotating assembly 10:1 pistons. Engine Dyno (not desktop) got me 468hp & 490ft/lbs, forgive me I'm at work and can't remember the exact RPM's.
I'm running the Dart Iron Eagle's but in 200 fashion, but they are way flowed out and port matched to a hogged out Victor JR. and a Edlebrock 750.

Machine shop and parts were a lil over $5000, plus a block, the bare heads, and the intake and carb.
Breakdown est.:
Eagle Balanced Rotating assembly $1700
Misc parts $1500 (gaskets,timing set, cam, lifters,springs, retainers,keepers, ARP studs, new exhaust valves, pushrods, roller rocker arms, oil pump, splayed caps, mainstuds)
$1900 labor & machine work (dressed & cleaned ports, splayed mains, clearance block, surface bore, cam bearings, race prep, assload of head & intake work.) Since I din't want to bang it up, I paid to have everything assembled. Yes I know I suck, but better suck than blown up again.

What pistons? I just got my very similiar setup back from my machine shop about a month ago. Eagle Rotating assembly 10:1 pistons. Engine Dyno (not desktop) got me 468hp & 490ft/lbs, forgive me I'm at work and can't remember the exact RPM's.
I'm running the Dart Iron Eagle's but in 200 fashion, but they are way flowed out and port matched to a hogged out Victor JR. and a Edlebrock 750.

Machine shop and parts were a lil over $5000, plus a block, the bare heads, and the intake and carb.
Breakdown est.:
Eagle Balanced Rotating assembly $1700
Misc parts $1500 (gaskets,timing set, cam, lifters,springs, retainers,keepers, ARP studs, new exhaust valves, pushrods, roller rocker arms, oil pump, splayed caps, mainstuds)
$1900 labor & machine work (dressed & cleaned ports, splayed mains, clearance block, surface bore, cam bearings, race prep, assload of head & intake work.) Since I din't want to bang it up, I paid to have everything assembled. Yes I know I suck, but better suck than blown up again.



Those are great numbers! What did your heads end up flowing when finished and what cam were you running?

Those are great numbers! What did your heads end up flowing when finished and what cam were you running?

I didn't have them flow test the heads for me, I thought about having it done, but didn't. I just had them hog them out the most they could, and clean out all the crap that restricted them, then had them port matched. As for the cam, I'll try and remember to grab the Cam Spec Card when I come into work tonight and get it on here. I did find the part # list in my briefcase here at work, but its no good cause I don't remember where it got bought from. 12-678-4 if anyone can id the vendor via the number sequence.

I didn't have them flow test the heads for me, I thought about having it done, but didn't. I just had them hog them out the most they could, and clean out all the crap that restricted them, then had them port matched. As for the cam, I'll try and remember to grab the Cam Spec Card when I come into work tonight and get it on here. I did find the part # list in my briefcase here at work, but its no good cause I don't remember where it got bought from. 12-678-4 if anyone can id the vendor via the number sequence.


Thats a comp sequence. went to the online catelog and found it

.520/.540 244/252 @ .050 solid flat tappet.

Its not roller but its still a lot more cam than what we're running above. Sounds like a good combo. your numbers sound like they're right on. Was this in some kind of race app I hope? Thats a lot of motor for anything short of a mud truck or a 1/4 mile car. Eitherway, thats a nice setup!

Thats a comp sequence. went to the online catelog and found it

.520/.540 244/252 @ .050 solid flat tappet.

Its not roller but its still a lot more cam than what we're running above. Sounds like a good combo. your numbers sound like they're right on. Was this in some kind of race app I hope? Thats a lot of motor for anything short of a mud truck or a 1/4 mile car. Eitherway, thats a nice setup!

Yep grabbed the card and thats all correct. Yeah its not roller, that shiz is even more high dollar, dang!

Anywho, yeah not in an offroad vehicle, 1958 Chevy truck built for wasting fuel and other general mayhem that could hold its own on the track.

im doing a similar buildup my self.The fella at the shop where i had all my machine work done says mine should put out 470-475Hp,and since they have there own dyno and drag cars id say he probably knows what hes talking about,they also did the clearancing for the block and rods.
Im using the scat crank and rods
Flat top pistons
Comp roller xr288 cam
Trick flow 195cc heads
compression is right at 10.8
I also had them balance the assembley
so id say yours should be over 400 at the crank depending on which size head size you run :D

10.8 comp with that small of a cam. Good luck running it on pump gas, and getting 475HP.

10.8 comp with that small of a cam. Good luck running it on pump gas, and getting 475HP.

Good point HeyBeerMan.
Small cams don't like a lot of compression with pump gas. Personally, I'd bump the cubic i's up too a 406, drop the compression too 9-5-1 to 10-1 and throw some 200cc heads on that puppy, for torque..And run premuim.

Try a 1970 LT-1 solid lifter cam. It should give you boatloads of torque with the 114 centerline and still have enough duration @ .050 too work decent with a little compression. Throw in some 1.6 rockers too bump the lift a little. [I could score you a copy-cat grind for about $60.00 bucks]
If you want a good program for seting up engine combos [This totally blows off the desktop dynos, BTW.], try the Performance Trends- Engine Anylizer (http://www.performancetrends.com/EA30.htm) , it rocks! [And worth the Hundred dollars they charge for it!]
I'll run your setup for you and see what kind of numbers I can come up with.
I've built three motors now using this program and two of them have been getting trophies.
*3 first places on the 540. [But a lot of broken drivetrain parts, hehe]
*3 second places on the 350. [A little easier on parts at 450 hp]
The third engine [496 Stroker Rat] is awaiting it's home in my 1965 Chevy, which I also plan too mudrace. [And win with.... :flipoff2: ]
-BW

Well according to the race shop i cant run anymore than 32 degree's timing.the heads are aluminum so they'll take the heat.And the cam was recommended buy comp cams using there cam card and is around 240@.050.Dam bradshaw those are some nice engines! :D
I do agree though those numbers seem a little high too me too :shaking: .Thatd be great if you could run some numbers for me the cam is the 12-433-8 by compcams,heads are trick flow 64cc chambers and 195intake ports.Intake is the edelbrock rpm airgap,headers are 1 5/8 with spintech mufflers.Let me know what other figures ya might need :D

Thank's RumpityZ!http://www.bigfootforums.com/html//emoticons/new_thumbsupsmileyanim.gif
A 240 @ .050 cam should handle a little compression just fine with those aluminum heads....

We're running 10-35-1 [540] and 10-68-1 [350] with aluminum heads [350cc and 200cc, guess wich one has the 350cc's?http://www.bigfootforums.com/html//emoticons/new_lmaosmiley.gif ], CNC'd chambers [I swear by these chambers!] with no problem whatsoever on pump gas.
-BW

PS, I'll go back through the thread, check the specs you have and see what the Anylizer come's up with.. :D

Rumpity, just a couple of questions.

Do you have .125 radius main and rod ["H"] Bearings? What type of rings and pistons? Stock type or short skirt racing pistons? Accessories, pwr steering, AC, alt.?
What are the primary tube lengths of your headers and what type and size Carb are you running?
That should get us pretty close.

You are getting around 412 hp @ 5575 rpms, 440 ft pounds of twist @ 4325 rpms.
*With a Holley 750 vac sec.
*Slightly better than stock pistons.
*2 1/2 inch dual exhaust with Dynomax Walker Evans mufflers..Good for 750cfm.
*Pwr steering, water pump, flex fan, alt.
*Low windage.

Only thing is I have you on 97 octane too get rid of the knocks.
Pretty potent setup IMHO, though...... :D

Damm CNC chambers sweeeet,and 350cc heads holy a family of fat racoons could live in there all winter :D .The crank is the scat 9000 no .125 on the radius and the bearings are clevitte H Series (matter?).The piston were normal skirt hyperutectic with the anti scuff coating.Umm lets see the headers are hooker shorties,and the accesories are as you described.Wow 412 with accesories thats pretty good :D So on a real dyno running big headers and no accesories that number might not be too far off of what the guy at the shop was guessing at.Its amazing what your actuall power comes out to hehe after adding on all the goodies.

Looks like a good combo eccept the 600 edelbrok is a bit to small. Go to a q jet for both more cfm and better off road performance. As far as power goes should be in the area of 400hp and 440tq. What kind of converter in the truck?? Or is it a stick?? Also stick to some 1 5/8" long tube headers for better low and midrange performance.

Rumpity
Earlier, I ran your motor with 1 5/8x30 primary headers and a 750 Holley vac secondary.

I totally agree with rockhog about the Q-jet. If you can find one of the early non-smog type replacements, that would be sweet. I think Jeg's has a few different replacement models for various applications.

FWIW
It say's 473hp @ 5575 and 486 ft lbs @ 4325 with 342 ft lbs @ 2450 rpms with your same setup, as before-But uncorked, 1 5/8x30 headers, 750 carb with no accessories.

With a 600cfm carb, shorty headers [1 5/8x14 inch pri?] with a 2 1/2 inch/750 cfm dual exhaust and accessories, it should be good for 399hp @ 5575rpms, 414 ft lbs of torque @ 4325.
[It's funny how accessories, the wrong headers/carb, etc can eat up HP.]

Hey bradshaw, mind doing me a favor?

427 Big block .030 over (4.28 bore x 3.76 stroke = 433 total)

*Ported oval port heads (330 intake/260 exh) with 2.19/1.88's
*12.0:1
*.650/.650 solid roller 272/272 @ .050 on a 110
*Vic Jr intake (oval port with port match)
*1050 dominator
*1.7 roller rockers
*2 1/8th (2.125) long tube fender dumps w/ 4" collector, Open exhaust
*no accessories
*all the normal hi-po elctronics you'd find in a drag car
*110 leaded race fuel

combo is th400, 4800 converter, dana 60 w/ 4.88's and a 33x17 slick (yah tire is too big i know.) 3400 lb 1964 nova with me in it, sitting at the light.

No problem Buckshot.
Good info.
Question though. The head figures 330/260-Is that CFM or ccs? The primary tube length, and are they equall?
I can run a generalized run but the more accurate the info, the more accuarate the results.
I'm going too try an email myself a graph and if it does work-I may be able to email you an actual graph, with hp/tq numbers at ten different PRM levels. All kinds of info I'm too lazy too type.
It can even tell you what the volumetric efficiency, fuel consumption, spark advance, friction hp, piston speed, piston G's, the A/F mix quality it has at any given rpm level. Mind boggling..
Here's a generalized run:
It say's 739 hp @ 7000 rpms, 736 @ 7500 [only 3 hp loss after peak HP, that's called "hangin' in there"!], 615 ft lbs @ 5500rpms. At four grand you have 494 ft lbs of tq and 377 horsepower...Not a bad launch at all.... :grinpimp: [Although with a 4500 stall, it would have 553 ft lbs-tq and 474-hp off the line..]
This is with 330/260 cfm ported oval port heads at 57.3%/61.2% int/ex efficiency, 2 1/8 X 30 primaries/10 inch collector headers and four degrees advance...No accessories.. :D

Sorry, miss-read your stall rating, and thought it was 4000 rpms,, a 4800 rpm stall would rock even harder yet!!! :smokin:

Sorry, miss-read your stall rating, and thought it was 4000 rpms,, a 4800 rpm stall would rock even harder yet!!! :smokin:


sweet! thanks man. The headers are not equal but close. the longest is probably over 30", I havent measured them. The head #'s are flow numbers. The heads were stock a 702 casting number whish is a stock 257 cc intake runner and 99 cc chamber. stock they flow about 265 cfm so they're got some pretty good port work done.

With 257 cc heads you lost 2 horsepower but gained boatloads of torque!
583 ft lbs of tq @ 4500rpm, 500 hp @ 7000rpms.

621/592 [tq/hp] @ 5000rpms.

618lbs and 709hp @ 6000rpms.

Peak tq/hp is 623lbs tq @ 5500rpm and 737hp @ 7000.

725 hp @ 7500rpm

689hp @ 8000rpms.

Nice motor, Buckshot... :grinpimp:

Check out Air Flow Researches web site.Theres a couple different combinations of 383`s. some have six inch rods,some 5.70.The combo I copied was 6.0" eagle rod and crank,Je piston. 195 street heads,comp extreme roller retrofit 12-433-8 .520in .540ex prfrm rpm.4779 dp for fun,quadrajet for wheeling.I have around 9.7 compr.It`s supposed to make around 500 horse,513trque,there combo shows 457trque at 2500.I know I lost power because my headers are only 15/8" and theres uses 13/4".Defently makes big power.American speed and acouple others use the same cam heads ,intake, carb,with eny were between 9.5 to 9.8 and get the same horse and torque numbers within 5 or 10 of each other.Runs good on reg gas,Mild ping hot days full throtle with 36 degrees timing.the only problems I`ve had are with fraging acouple valve springs,My fault I got used to leting the rev limiter keep it to gether.I did one of those watch this on a muddy job site .The chip falied on my msd.I let off after the poping and it shut off by it self.The holley is awsome around town,but wheels like crap .I never can seem to dial the quadrajet in all the way,but it starts idles and wheels good.It`s smog time again ,thought this would be the last year for my 76.So in goes the old 180,000 mile 350 again. eny way check out air flow research ,american speed,Super chevy mag 383 articules. JB

not too bad at all! I did good with that cam choice. the car should be going through the traps at ~127-130 mph or so at 7000-7500 with my gears. She should run tits if I can keep it off the rear bumper :)
I'll find out dec 4th.

My 496 mudrace motor [The money pit!]:
*454 Gen IV block four bolt with billit steel maincaps and studs.
*CAT 5140 forged steel 4.250 stroke crank with .125 radius.
*Scat 6.385, 4340 forged I beam connecting rods with 7/16ths capscrew *ARP rodbolts.
*JE floating pin 10.25.1 racing pistons.
*Childs & Albert Plasma Molly file-fit ring set.
*LS6 grind solid lifter camshaft. Flat tappet, 242/242 @ .050, 520/520 lift 1.7 [.554 with 1.8], 114 centerline.
*Direct Lube solid lifters...Real nice.
*Cam Correct variable timing, timing chain tensioner. [4 degrees of variable cam timing, good for 50 extra ft lbs tq @ 3000rpms bumping output too 611 ft lbs tq @ 3000rpms-from 561ft lbs tq.]
*Dynagear part num. #78710 quick djust timeshain set.
*Cam Correct billit 4 piece timing cover.
*Melling high vol/high pres. racing oil pump.
*Canfield 310cc [gasket matched and ported too 320cc, with CNC'd conbustion chambers] retangular port aluminum heads. 119cc chambers. 347/266 cfm @ .550/,550 lift. 2.25/1.94 valves. VTO seals.
*Isky 8005-A valve springs, Apollo Trick titanium retainers, 10 deg locks, Mellonited Severe duty undercut racing valves.
*All ARP 12 points bolts...Everything..
*Edelbrock Airgap RPM Dual Plane. Gasket matched and welded up, center port-top bolt holes. [May swap out for World Product Dual plenum]
*Holley HP 950cfm vac secondary race carb. [$$$]
*MSD Pro Billet Distrbutor, all mechanical.
*Moroso 6 qt pan with Windage Tray and Scraper.
*2x30x10 inch collector headers. [uncorked for now]
* Etc, etc, etc.

Good for 658 hp @ 6200rpms and 647 ft lbs tq @ 4325rpms.

561ft lbs tq @ 3075rpms.

And still making 635hp @ 6600rpms

350ft lbs tq @ 2200rpms. [370ft lbs tq with Cam Correct]
And 500 ft lbs tq from 2650rpm too 6600rpms.

I was planning on a bigger carb eventually. The 600 is just what I have right now. It will have full length Thorley headers with water pump, PS, and an alternator. The ignition is an msd 6 AL. I also have a built 700-R4 so it has the lockup converter. The numbers sound good so far. Thanks guys.

that 496 sounds like a monster. I love those torque nubmers. I went with the 427 because I had the standard steel crank. Next bore I'll throw a 4.25 stroker in it and maybe move up an ET class.

You're going too have a nice setup there Scott'sSpecial! :smokin:
That 600 should do fine for everything but the highest rpms....And will probably hang in there for any R's below six grand. 5500 too 5800rpms seems to be the line for those carbs in my experiences. I really dig the 4sp autos, they just don't like 600+ hp, or I'd run one myself, like your's. It's kinda like beating your head against a wall.....As in once you get the power you want, then you have too get the rest of everything too hold up too it....LOL!
Your setup should be fine though....



Buckshot.
If you ever need,
I can score you 4340 non-twist, forged crank, Std/Std, 3.76 stroke crank for your 427 and they run right at $250.00+ shipping from Competition Products, Oshkosh, WI. Not a bad deal...
920-233-2023
If you ever call-Ask for Roger Hurst and tell him BW [Monte and Gary] sent you, it might get you a deal. He's a great guy [He designs, produces racing parts and is a proffessional Sprint Car racer, he's the man!] and has saved me boatloads of money on Hot Rod motors in the past. [Plus he's a good friend...] I've saved so much money through these guys, I hardly ever buy anything from JEGs, Summit or PAW anymore. "CP is the place for goody parts..."

Through CP, I scored a CAT 5140 forged 4.250 stroke crank for $375.00. It was a "second" and the only thing wrong with it was that one of the counter weights was discolored from sitting in a box too long! It was perfect other than that and usually goes for $475.00! Their "Melonited" valves, cranks, rock and are better than "Nitriding." Slicker and tougher.

How MUCH $$ to build these>????


Unless you are planning on a race motor IMO you are better off getting a GM performance HT383 for under 4K. http://www.gmpartsdepot.com/store/p...&Product_ID=459

Unless you are planning on a race motor IMO you are better off getting a GM performance HT383 for under 4K. http://www.gmpartsdepot.com/store/p...&Product_ID=459
I was an inch away from swipeing the card on one of those. Those things are good deals IMO, plus they come with a warrenty. How can you go wrong. ZZ383/425 has425 horsepower at 5400 RPM, and 460 ft.lbs of torque at 4500 RPM all for $4800, not too bad at all.

Unless you are planning on a race motor IMO you are better off getting a GM performance HT383 for under 4K. http://www.gmpartsdepot.com/store/p...&Product_ID=459


Ive got less than 3k in my 383 TPI motor that would run door to door with that one. That includes computer wiring harness, all the injection and everything it took to get it in the truck and started.