383 how would you build it
Thread Starter
Instructor
Joined: Aug 2007
Posts: 131
Likes: 0
From: Madison NJ
383 how would you build it
I want to build a 383 for my 70 vette and I want to for now leave my stock 4sd and 3.08 rear. I like to go as big as practical. How would you build it.
Compression
Cam
Heads
Intake
Carb
and what HP/TQ would you expect.
Compression
Cam
Heads
Intake
Carb
and what HP/TQ would you expect.
Burning Brakes
Joined: Dec 2003
Posts: 1,004
Likes: 7
From: Adelaide South Australia
If you're going to keep the 3.08 diff, then you need to steer towards a high torque output setup.
Plenty of options... check out the specs of the Year One Extreme-torque 383 as a guide.
http://www.yearone.com/serverfiles/f...EX8116&Style=2
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
383's are old school. Why not 396 or 408 ci out of the same 350 block?
Melting Slicks
Joined: Jul 2005
Posts: 2,060
Likes: 46
From: winter haven florida
St. Jude Donor '12
Racer
Joined: Dec 2003
Posts: 487
Likes: 160
From: Two Lane Black Top
Well part of that depends on what you want to do with the car...
383 go as big as you can go...small block 396, 408, 427 or 434 etc if the $$$ allows...
I'd probably go with something as follows...for a 383 an add a little more cam with the bigger engines
Compression 11 to 1
Cam - 236/242 XE lobes comp cams LSA or 232/236 XE lobes if the heads flow excellent mid-lift. LSA ~110 or 112 for a nicer idle.
Heads - AFR or maybe Dart's newest
Intake - Performer RPM
Carb - Q-Jet
and what HP/TQ would you expect.
I'd shoot for around 450hp & 500tq flywheel
Note for best results specific are best left to experts for max results. Find a good engine builder with a proven record or a nice crate engine thats match to what you want.
383 go as big as you can go...small block 396, 408, 427 or 434 etc if the $$$ allows...
I'd probably go with something as follows...for a 383 an add a little more cam with the bigger engines
Compression 11 to 1
Cam - 236/242 XE lobes comp cams LSA or 232/236 XE lobes if the heads flow excellent mid-lift. LSA ~110 or 112 for a nicer idle.
Heads - AFR or maybe Dart's newest
Intake - Performer RPM
Carb - Q-Jet
and what HP/TQ would you expect.
I'd shoot for around 450hp & 500tq flywheel
Note for best results specific are best left to experts for max results. Find a good engine builder with a proven record or a nice crate engine thats match to what you want.
Melting Slicks
Joined: Jul 2005
Posts: 2,060
Likes: 46
From: winter haven florida
St. Jude Donor '12
Well part of that depends on what you want to do with the car...
383 go as big as you can go...small block 396, 408, 427 or 434 etc if the $$$ allows...
I'd probably go with something as follows...for a 383 an add a little more cam with the bigger engines
Compression 11 to 1
Cam - 236/242 XE lobes comp cams LSA or 232/236 XE lobes if the heads flow excellent mid-lift. LSA ~110 or 112 for a nicer idle.
Heads - AFR or maybe Dart's newest
Intake - Performer RPM
Carb - Q-Jet
and what HP/TQ would you expect.
I'd shoot for around 450hp & 500tq flywheel
Note for best results specific are best left to experts for max results. Find a good engine builder with a proven record or a nice crate engine thats match to what you want.
383 go as big as you can go...small block 396, 408, 427 or 434 etc if the $$$ allows...
I'd probably go with something as follows...for a 383 an add a little more cam with the bigger engines
Compression 11 to 1
Cam - 236/242 XE lobes comp cams LSA or 232/236 XE lobes if the heads flow excellent mid-lift. LSA ~110 or 112 for a nicer idle.
Heads - AFR or maybe Dart's newest
Intake - Performer RPM
Carb - Q-Jet
and what HP/TQ would you expect.
I'd shoot for around 450hp & 500tq flywheel
Note for best results specific are best left to experts for max results. Find a good engine builder with a proven record or a nice crate engine thats match to what you want.
Description
Part Number:12-433-8 [10] Grind Number: XR288HR
Lifter Type: Hydraulic Roller Lifter Engine Family: Chevrolet 262-400 c.i. 8 cyl. 1955-1998
Description: Hydraulic Roller-Street / Strip applications, 9:1 CR, intake, headers, 2800 stall, gears.
Cam Family: XTREME Energy™ Retro-Fit Hydraulic Roller Camshafts
you will not want to go this route as far a cam and comp. your gears will not support this cam as a street friendly car. i would keep your comp down to around 10.5 or less depending on the cam to avoid detonation. a big cam will need rpms to be in its power range and heads with big intake runners will kill low speed tq and hurt throttle response. bigger will not be better with a 3.08 gear. i did this on my last 383 and learned my lesson. if you are going with a big cam you will want to change gears so the motor can get into its power band quicker. i would look at afr 195 heads for a 383 or even a 396 for your application. afr 210's for anything bigger.
the real question is how will the car be driven and would you be willing to change the rear gears to get more performance? the above cam with a 383 at 10.5 comp would be a great choice if you decide to change gears to 3.55 or more.
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Or what about OD transmissions that drop you to 2.50 gearing?
Instead of spending money on rear gear changes you should spend your money on power. I don't evn bother down shifting to pass somebody!
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Le Mans Master
Joined: Apr 2005
Posts: 6,359
Likes: 428
From: Seattle Area WA
I'm with George, I wouldn't bother with gears at this point.
I ran a 383 with 3.08s and a TH350 for years and I never had a problem with not enough torque nor hitting low 12s at the long gone Orange County International Raceway, or the track in Vegas, of course the nitrous didn't hurt either
Build a 10.25:1 motor with a decent street friendly cam, good flowing heads like the AFR 195s or the Brodix Iks and a LT1, Z28 clone intake, and a holley 750 dp annular discharge.
I ran a 383 with 3.08s and a TH350 for years and I never had a problem with not enough torque nor hitting low 12s at the long gone Orange County International Raceway, or the track in Vegas, of course the nitrous didn't hurt either
Build a 10.25:1 motor with a decent street friendly cam, good flowing heads like the AFR 195s or the Brodix Iks and a LT1, Z28 clone intake, and a holley 750 dp annular discharge.
Last edited by Scott Marzahl; Feb 10, 2009 at 04:12 PM.
Instructor
Joined: Aug 2008
Posts: 235
Likes: 0
From: Orlando Florida
I made my own 383 from my orig. 78 block...converted to 4 bolt mains, all forged rotating assy, 9.5:1 compression (pump gas), aluminum heads, full roller motor, MSD hot ignition, costs about 5 grand and dyno'd at the wheels 355hp/325lbs torque= 450 hp at crank...runs 12.50's quarter mile et connected to a 5 spd Tremec...you could pump out more hp/torque with better compression, but I wanted to add a procharger to it later...good luck...DDBS
Racer
Joined: Dec 2003
Posts: 487
Likes: 160
From: Two Lane Black Top
That is not a valid point! I have a 2.73 rear and a 4 speed in one of my cars. It is not a big deal if you have motors of 500+ foot pounds.
Or what about OD transmissions that drop you to 2.50 gearing?
Instead of spending money on rear gear changes you should spend your money on power. I don't evn bother down shifting to pass somebody!
Or what about OD transmissions that drop you to 2.50 gearing?
Instead of spending money on rear gear changes you should spend your money on power. I don't evn bother down shifting to pass somebody!
Race Director
Joined: May 2005
Posts: 10,674
Likes: 122
From: Millington Illinois
St. Jude Donor '08-'09
this came from comps web site.
Description
Part Number:12-433-8 [10] Grind Number: XR288HR
Lifter Type: Hydraulic Roller Lifter Engine Family: Chevrolet 262-400 c.i. 8 cyl. 1955-1998
Description: Hydraulic Roller-Street / Strip applications, 9:1 CR, intake, headers, 2800 stall, gears.
Cam Family: XTREME Energy™ Retro-Fit Hydraulic Roller Camshafts
you will not want to go this route as far a cam and comp. your gears will not support this cam as a street friendly car. i would keep your comp down to around 10.5 or less depending on the cam to avoid detonation. a big cam will need rpms to be in its power range and heads with big intake runners will kill low speed tq and hurt throttle response. bigger will not be better with a 3.08 gear. i did this on my last 383 and learned my lesson. if you are going with a big cam you will want to change gears so the motor can get into its power band quicker. i would look at afr 195 heads for a 383 or even a 396 for your application. afr 210's for anything bigger.
the real question is how will the car be driven and would you be willing to change the rear gears to get more performance? the above cam with a 383 at 10.5 comp would be a great choice if you decide to change gears to 3.55 or more.
Description
Part Number:12-433-8 [10] Grind Number: XR288HR
Lifter Type: Hydraulic Roller Lifter Engine Family: Chevrolet 262-400 c.i. 8 cyl. 1955-1998
Description: Hydraulic Roller-Street / Strip applications, 9:1 CR, intake, headers, 2800 stall, gears.
Cam Family: XTREME Energy™ Retro-Fit Hydraulic Roller Camshafts
you will not want to go this route as far a cam and comp. your gears will not support this cam as a street friendly car. i would keep your comp down to around 10.5 or less depending on the cam to avoid detonation. a big cam will need rpms to be in its power range and heads with big intake runners will kill low speed tq and hurt throttle response. bigger will not be better with a 3.08 gear. i did this on my last 383 and learned my lesson. if you are going with a big cam you will want to change gears so the motor can get into its power band quicker. i would look at afr 195 heads for a 383 or even a 396 for your application. afr 210's for anything bigger.
the real question is how will the car be driven and would you be willing to change the rear gears to get more performance? the above cam with a 383 at 10.5 comp would be a great choice if you decide to change gears to 3.55 or more.
This cam really needs gears. The 4 spd, 3.08 rear will not like this combo as well as 3.70 or better gears. You can drive anything on the street and everything is a compromise but the combo is not well matched. Overcammed for use. Don't agree with comp on running that cam with 9 to 1 compression though. Needs 10 to 1 or better. That is the cam I have in my 383. w/ 114 lsa. 10.4 to 1, 4.11 gears, T56.
Racer
Joined: Sep 2008
Posts: 387
Likes: 2
I was going to build mine according to Combo #11 of http://www.ryanscarpage.50megs.com/combos2.html.
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
I've had detonation problems of different motors over the years until I learned to just increase the duration
Racer
Joined: Dec 2005
Posts: 377
Likes: 14
From: Auburn Hills Michigan
I am building a 388 (.060 over stroked 350). I have Dart Pro 1 215 aluminum heads ported and polished. Custom Crane cam 590/590 lift with 1.6 roller rockers 246/254 duration at .050 lift hydraulic roller. 11:1 compression victor jr intake and 750 mighty demon carb. I used 918 beehive springs and titanium retainers. This setup should run on pump gas (93 only) and put 530HP to the crank with well over 500 lb/ft of torque through most of the rpm range. I can give you more specs if you are interested. This is going into a 1981 4 speed (m-21) with 3.73 rear. I have a feeling we will be doing the rear very shortly after the engine install.
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
I am building a 388 (.060 over stroked 350). I have Dart Pro 1 215 aluminum heads ported and polished. Custom Crane cam 590/590 lift with 1.6 roller rockers 246/254 duration at .050 lift hydraulic roller. 11:1 compression victor jr intake and 750 mighty demon carb. I used 918 beehive springs and titanium retainers. This setup should run on pump gas (93 only) and put 530HP to the crank with well over 500 lb/ft of torque through most of the rpm range. I can give you more specs if you are interested. This is going into a 1981 4 speed (m-21) with 3.73 rear. I have a feeling we will be doing the rear very shortly after the engine install.
IMO - it is not wise to run .590 lift on springs rated for only 1/100 of an inch more at .600. The springs don't last as long and the possibility of valve float can happen easier.
Last edited by gkull; Feb 13, 2009 at 10:09 AM.
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
That was my experience with my first 383 and Dart 215 pro1 heads with 2.08/1.625 valves. I installed a 240/248 S/R cam and the motor would power into the 7500 rev limiter, but it really didn't have much get up and go below 3500
I installed a slightly smaller cam and it made lots of fun with my 5 speed.
Race Director
Joined: May 2005
Posts: 10,674
Likes: 122
From: Millington Illinois
St. Jude Donor '08-'09
The problem with this build is too much duration for an RPM limited h-roller.
That was my experience with my first 383 and Dart 215 pro1 heads with 2.08/1.625 valves. I installed a 240/248 S/R cam and the motor would power into the 7500 rev limiter, but it really didn't have much get up and go below 3500
I installed a slightly smaller cam and it made lots of fun with my 5 speed.
That was my experience with my first 383 and Dart 215 pro1 heads with 2.08/1.625 valves. I installed a 240/248 S/R cam and the motor would power into the 7500 rev limiter, but it really didn't have much get up and go below 3500
I installed a slightly smaller cam and it made lots of fun with my 5 speed.
