bits of 383 build info

grumpyvette · Sep 16, 2008

place a single rod/piston assembly with well oiled bearings and no rings installed on the first cylinders journal, and have the cam installed DOT TO DOT WITH THE TIMING SET INSTALLED, to check basic clearances ,now, rotate the crank thru a couple full rotations so the piston slides freely in the oiled bore, while you look closely at the rod too block clearance and rod too cam lobe clearance, if the cam lobes too close the edge of the rod bolt upper/edge of the bolt or rod itself needs to be filed/ground for clearance since you can,t grind the cam lobe, on the block the block gets clearanced ground, you want about a .060 minimum clearance. a large paper clip can be used as a crude feeler gauge,
a 1/2" dia carbide cutting burr in a die grinder can do it in seconds,once thats done you move that piston & rod to the next cylinder and repeat 7 more times, etc. don,t forget to clean up afterwards, and DON,T forget the rodand piston has the exhaust/intake valve and rod bearing radius fit correctly in only one dirrection on that cylinder

BEFORE

notice how the rod bolts come close to the cam bearings and cam lobes,as the pistons reach top dead canter in the bores, this clearance must be individually checked and should be no less than about .060 (generally you cam use a LARGE plastic tie-wrap
https://www.amazon.com/BuyCableTies...D=41U9CtmwOuL&preST=_SY300_QL70_&dpSrc=detail

placed between the cam lobe and connecting rod bolts or connecting rod shoulder areas to check clearances as the soft tie-wrap will not damage the cam lobe while you verify clearances)

why you need to verify the cam to rod bolt clearance

on some stroker applications SOME rods need to have the bolts ground for cam lobe clearance

AFTER

Small Chevy

Fastener Type Torque Spec

7/16 in. outer main cap bolt 65 ft.-lbs.
7/16 in. inner main cap bolt 70 ft.-lbs.
3/8 in. outer main cap bolt 40 ft.-lbs.
11/32 in. connecting rod bolt 38-44 ft.-lbs.
3/8 in. connecting rod bolt 40-45 ft.-lbs.
Cylinder head bolts 65 ft.-lbs.
Screw-in rocker arm studs 50 ft.-lbs.
Intake manifold bolts (cast iron heads) 30 ft.-lbs.
Oil pump bolt 60-70 ft.-lbs.
Cam sprocket bolts 18-20 ft.-lbs.
Harmonic damper bolt 60 ft.-lbs.
Flywheel/Flexplate bolts 65 ft.-lbs.
Pressure plate bolts 35 ft.-lbs.
Bell housing bolts 25 ft.-lbs.
Exhaust manifold bolts 25 ft.-lbs.

Big Chevy

Fastener Type Torque Specs

Main cap bolt, 396-427 2-bolt 95 ft.-lbs.
Main cap bolt, 396-454 4-bolt (inner/outer) 110 ft.-lbs.
3/8 in. connecting rod bolt 50 ft.-lbs.
7/16 in. connecting rod bolt 67-73 ft.-lbs.
Cylinder head bolts, long 75 ft.-lbs.
Cylinder head bolts, short 65-68 ft.-lbs.
Screw-in rocker arm studs 50 ft.-lbs.
Intake manifold bolts (cast iron head) 25 ft.-lbs.
Oil pump bolt 65 ft.-lbs.
Cam sprocket bolts 20 ft.-lbs.
Harmonic damper bolt 85 ft.-lbs.
Flywheel/Flexplate bolts 60 ft.-lbs.
Pressure plate bolts 35 ft.-lbs.
Bell housing bolts 25 ft.-lbs.
Exhaust manifold bolts 20 ft.-lbs.

http://www.fourwheeler.com/techarticles ... to_11.html
IF your going to use ARP main cap studs THE TORQUE SETTINGS ARE DIFFERANT than the orriginal BOLTS, the STUDS ARE STRONGER, BUT,you might also consider that main studs generally install after cleaning the threads in the block with a tap,blowing them dry with high pressure air, oiling the studs course threads with the thread sealant and fine threads end with the ARP thread lube, when you screw them into the block the full thread depth,by hand, then get backed out one turn, the main caps installed and the nuts torqued in stages to seat and hold the main caps, now LOOK at those STUDS the end in the block threads is SAE COURSE thread, the end your torqueing the nut on is SAE FINE THREAD with a much differant PITCH that requires less tq to give the same clamp loads

http://www.arp-bolts.com/catalog/Catalog.html

Why do they get backed out by one turn? I'm trying to think of the physics behind it, but I can't think of any good reason. What is the physics answer, Grumpy?

BE 100% SURE that the oil pump bolt or STUD doesn,t protrude past the inner main cap surface , because if it bears on the rear main bearing shell it will almost always result in a quickly failed rear bearing
the threads must bear evenly and align correctly with the studs centerline, for the stud to apply max loads over the total threaded surface ,the threaded section must be under tension alone and engage the total threaded surface in the block, if the stud is torqued into place, youve preloaded the threads bearing the load and they are partly under compressive loads ,your basically jacking the bottom of the threaded hole away from the threaded section, and appling THOUDANDS of lbs of extra stress to the blocks web area if you torque the threads to the same 100 ft lbs the original bolts were tightened to, the threads in the block will now have added stress once the full tension loads on the studs and main caps is applied by torqing the nuts on the studs ,theres added stress on the block, if the studs have bottomed out and are pushing on the bottom of the threaded hole making the block web area more likely to crack or the crank saddles to distort.
keep in mind FACTORY BOLTS are made slightly shorter to PREVENT the bolt tip bottoming out in the hole, but bolts cause wear on the threads because they are tightened while the bolts still advancing deeper into the threaded block, studs cause far less wear because they fully engage the threads bearing the loads before the tensive load is applied

heres what ARP says
"STUDS vs. BOLTS

ARP recommends the use of main studs over bolts whenever possible for several key reasons. First is the ability to obtain more accurate torque readings because studs donâ€™t â€œtwistâ€ into the block. All clamping forces are on one axis. By the same token, there is less force exerted on the block threads, which contributes to improved block life (very critical on aluminum blocks). Finally, there are factors of easier engine assembly and proper alignment of caps every time"

ARP's instructions (for head studs)state that you should thread the studs into the block until they're hand-tight, but with the head on the block, this is difficult. Fortunately, ARP was thoughtful enough to incorporate a fitting for an Allen wrench into the head of each stud. So, using an Allen wrench, I threaded the studs into the head until I could no longer turn the wrench with two fingers. This method seems to have worked nicely

1. Clean and chase appropriate threads in
block to ensure proper thread engagement
and accurate torque readings.
2. All hardware (and caps) should be
cleaned and inspected prior to installation,
looking for any shipping damage or defects.
3. Screw studs into block, finger tight
ONLY. For permanent installation, apply
Loc-tite (or similar adhesive) sparingly
to threads. Be sure and install the caps
promptly before the cement sets to prevent
misalignment of studs in block.
1. Clean and chase appropriate threads in
block to ensure proper thread engagement
and accurate torque readings.
2. All hardware (and caps) should be
cleaned and inspected prior to installation,
looking for any shipping damage or defects.
There are a number of important considerations
when installing ARP main studs.
3. Screw studs into block, finger tight
ONLY. For permanent installation, apply
Loc-tite (or similar adhesive) sparingly
to threads. Be sure and install the caps
promptly before the cement sets to prevent
misalignment of studs in block.

First and foremost is making sure the
block and studs are as clean as possible.
Foreign matter and debris can easily affect
the quality of thread engagement and
cause erroneous torque readings. Do not
re-cut threads in the block â€“ use the special
â€œchaserâ€ taps as listed on page 87 of this catalog.
This will preserve the integrity of the
threads and provide better engagement.
Calibrate your torque wrench â€“ even new
wrenches have been known to be off by as
much as 10 foot pounds! Use consistent
tightening techniques.
4. Install main caps, checking for binding
and misalignment. Lubricate threads, nuts
and washers with oil or ARP moly assembly
lubricant before installation. Note that torque
specs will vary by lubricant. Moly lube is
most consistent. Have block align honed.
5. Using the instructions provided with
the studs, tighten the nuts to proper
torque values three times. NOTE: If using
Loc-Tite or similar cement, proper preload
must be achieved prior to it setting up.

http://www.arp-bolts.com/FAQ/FAQ.html

I usually use this sealant (sparingly)on the course ends of main cap studs that screw in hand tight, and ESPECIALLY on head studs that enter water jackets

calculate horse power from intake port flow rates
http://www.wallaceracing.com/calcafhp.php

http://www.wallaceracing.com/calchpaf.php

http://www.wallaceracing.com/ca-calc.php

http://www.wallaceracing.com/max-rpm.php

http://www.wallaceracing.com/lpv.php

http://www.wallaceracing.com/chokepoint.php

http://www.wallaceracing.com/chokepoint-rpm.php

http://www.wallaceracing.com/area-under-curve.php

http://www.wallaceracing.com/piston-speed-velocity.php

http://www.wallaceracing.com/header_length.php

this thread and its related links and its contained sub links contain a huge amount of related useful info you can use

TBucket Engine Project (Dart SHP)

It's time to get this party started! Last night I picked up some of my parts, the only thing left to come in, is the Mahle piston and rings. This is just the first order, mostly the things I need right now to get started. It's been over ten years since I've driven this car and I am SOOO ready to...

garage.grumpysperformance.com

grumpyvette · Sep 16, 2008

I got asked recently what hydrolic roller cam ID suggest for a street/strip 383 combo?(obviously theres a wide sellection that may work,)

ONE GENTELMAN pointed out ,after shopping around one of the least expensive deals seems to be the EDELBROCK CAM BELOW

http://www.jegs.com/i/Edelbrock/350/22015/10002/-1#

WATCH VIDEO

SB-Chevy 283-400 Hydraulic Roller Camshaft Kit

Duration Advertised 296Â° Intake/300Â° Exhaust
Duration @ .050'' 234Â° Intake/238Â° Exhaust
Lift @ Valve .539'' Intake/.548'' Exhaust
Lift @ Cam .359'' Intake/.365'' Exhaust
Lobe Separation Angle 112Â°
Intake Centerline 107Â°
Intake Timing @ .050" Open 10Â° BTDC
Close 44Â° ABDC
Exhaust Timing @ .050" Open 56Â° BBDC
Close 2Â° ATDC

IVE used similar cam designs (durration/lift/)in the past with excellent results and $709 for the cam, roller lifters and pushrods is a good value, naturally the REST of the components and the cars drive train and the cars intended use will effect the choice
the only thing that makes me hesitate is the quality of edelbrocks cam cores.AS most IVE SEEN are not billet but cast cores which are less durable and on a 383, PLUS you want a small base circle cam......for rotating assembly clearance issues ,one reason I usually suggest this cam in similar combos

http://www.cranecams.com/index.php?show=browseParts&action=partSpec&partNumber=119661&lvl=2&prt=5

http://www.jegs.com/i/Crane/270/119661/10002/-1#

http://www.jegs.com/webapp/wcs/stores/servlet/KeywordSearchCmd?storeId=10001&catalogId=10002&langId=-1&N=0&Ntt=11532-16&Ntk=all&Nty=1&D=11532-16&Ntx=mode+matchallany&Dx=mode+matchallany&searchTerm=11532-16

Grind Number: HR-230/359-2S-12.90 IG
Operating Range: 3000-6500 RPM
Duration Advertised: 292Â° Intake / 300Â° Exhaust
Duration @ .050'' Lift: 230Â° Intake / 238Â° Exhaust
Valve Lift w/1.5 Rockers: .539'' Intake / .558'' Exhaust
Lobe Separation Angle: 112Â°
Max Lift Angle: 107Â° ATDC Intake / 117Â° BTDC Exhaust
Open/Close @.050'' Cam Lift: Intake - 8Â° BTDC (opens) / 42Â° ABDC (closes)
Exhaust - 56Â° BBDC (opens) / 2Â° ATDC (closes)

with either cam youll want a 3000rpm stall converter , about 10.5:1 cpr and a 3.73-4.11:1 rear gear to maximize the preformance and a low restriction exhaust, headers and a high flow intake

IM currently running the crane 119661 cam in MY 383 and Ive tested over a dozen cams in that engine, so if its a street/strip combo ID suggest going that route, SMALL BASE CIRCLE AND BILLET CORE.....yeah! YOU GET WHAT YOU PAY,FOR and DURABILITY FOR PARTS TENDS TO COST MOREGOSFAST posted this great photo to illustrate the differance between rod designs
yes the cam lobes can very easily contact the connecting rods when the cam index is out of its proper timing, on almost any chevy engine the cam lobe center lines will be spaced at between 103 and 116 degrees, with the piston at TDC theres SUPPOSED to be about .060 MINIMUM clearance between the connecting rod bolts and cam lobes, this is a mandatory clearance check point and a plastic cable tie can be used to gauge clearance, its best done on each individual connecting rod to cam lobe clearance point AFTER the cams been degreed into the block as each connecting rods being installed but Ive generally done it during the several trial assembly points where I check other clearances like block to connecting rod clearance.

thats why on some stroker crank engines a SMALL BASE CIRCLE cam is used to MAXIMIZE CLEARANCE,between the two moving parts.
a cams lobe lift is the difference the lifter moves off the cams base circle between its base circle and its max lobe lift, thus a cam with a 1.1" diam base circle and a .400 lobe lift would have a , .400 lobe lift and if you had 1.5:1 ratio rockers a .600 valve lift, but if you wanted more clearance you could use a smaller base circle at .900, and a 400 lobe lift this would allow the connecting rod, to sweep by with an additional amount of cam lobe to connecting rod bolt clearance, the change in diameter generally requires a swap to a stronger cam billet core . vs cheaper cast core,to maintain cam strength

removing the rod caps during clearance checks while building your 383 ,does seem to allow you to see the clearance issues a bit easier

the cam rotates while indexed by the timing chain at 1/2 crank shaft speed , there are connecting rods designed to provide additional clearance.

http://www.scatcrankshafts.com/index.htm
don,t forget to verify the cam to connecting rod clearances
a cams VALVE LIFT is determined by the DISTANCE the lifter moves as the cam rotates under the lifter base as it moves from the cam lobe base circle
(the closest the lifter comes to the cams center line)
up to the cam lobes ramp to the lobes peak,
(the furthest the lifter up off or from the cams center line)

your cams lift, is the result of the lifter movement, or distance it travels from the cams base circle, where the valves seated, to the point in the cams rotation where the lifters moved along the ramp surface fully up on the nose of the cam lobe where the valves at full lift.
example
lets say in this case we compare two imaginary cams
a standard cams base circle is 1.125" and
your cams running on a .900 base circle
both cams have a .560 valve lift and run with 1.5:1 rockers
so both cams will need to move the lifter .374"
that means the standard cam lobe will be 1.125"+.374" or 1.499" from the cams base to the cam lobe nose
that means the small base cam lobe will be .900"+.374" or 1.274" from the cams base to the cam lobe nose
which is significantly smaller,
small base circle cams are generally only used when connecting rod clearance necessitates there use

the BASE CIRCLE IS NEVER A CLEARANCE ISSUE, its the cam LOBES that can potentially contact the edge of the connecting rods or bolts, this is why the rods or rod bolts are machined for additional clearance for the cam lobes as you rather obviously CAN,T machine the cam lobes themselves without destroying their function.
now think about it for a few seconds
the cams lobe lift and the cams LSA or LOBE SEPARATION ANGLE
both have an effect on the cam lobes potential interference with the connecting rods

notice how the rod bolts come close to the cam bearings as the pistons reach top dead canter in the bores

RODS WELL AWAY FROM CAM LOBES

RODS CLOSE TO CAM LOBES

WITH THE CORRECT SOFT WARE BOTH THE PISTON TO VALVE CLEARANCE AND CAM TO ROD CLEARANCE CAN BE CALCULATED
BUT ANY COMPETENT ENGINE BUILDER WILL PHYSICALLY VERIFY CLEARANCE

http://garage.grumpysperformance.com/index.php?threads/virtual-dyno-software.2301/#post-53646

http://www.auto-ware.com/software/eap/eap.htm

rods designed like the 3 SERIES generally won,t work with stroker cranks while the 2 series usually will

the connecting rods you sellect make a huge differance in the rod to cam lobe clearance, even a small base cam won,t clear some designs, it should be obvious that the connecting rod with the thru bolt has a great deal less cam lobe clearance potentially than the cap screw design next to it., and the cap screw rod probably clears the blocks oil pan rail area easier also

grumpyvette · Sep 16, 2008

Im running that crane 119661 cam retarded 4 degrees BTW but detonation has not been a problem, remember that the coolant temp, air temps the engine sees, QUENCH distance, type of head gasket and its construction ,ignition advance,plug heat range,piston to bore clearance, exhaust valve seat width, and oil temp and pollishing your combustion chamber and piston domes, and your AIR/FUEL RATIO , and the effective DYNAMIC compression ratio, have a noticable effect on detonation

and if you do see detonation, theres octane boosters like TOULUENE

http://www.gnttype.org/techarea/misc/octanebooster.html

http://www.team.net/sol/tech/octane_b.html

http://www.elektro.com/~audi/audi/toluene.html

a great deal of the info you may want can be calculated after carefully measuring the intake port and runner length and cross sectional areas.(remember its not the intake port gasket cross sectional opening, cross sectional area, its the smallest part of the port cross sectional area and valve throat areas that limit port flow rates)
if as an example we selected a port with about a 2 sq inch cross sectional area, you'll find max torque on a 350 will fall near 4000-rpm and port stall near 6000-rpm thus it makes sense to match the cam timing and lift/duration and the drive train gearing to match the rpm range,power curve and port flow.
or put a bit differently, theres no sense in selecting a cam designed to operate well at 7600 rpm if you port stalls at 6300 rpm

http://users.erols.com/srweiss/calccsa.htm

http://users.erols.com/srweiss/calcplv.htm

http://users.erols.com/srweiss/calchpaf.htm

http://www.wallaceracing.com/chokepoint.php

http://www.rbracing-rsr.com/runnertorquecalc.html

http://www.walmart.com/ip/Texas-Instruments-TI-30X-IIS-Scientific-Calculator/1535939
http://www.summitracing.com/parts/cca-5605/overview/
related info, that you might need
http://garage.grumpysperformance.co...heads-for-small-block-chevys.3293/#post-26213

http://garage.grumpysperformance.com/index.php?threads/what-are-these-heads.4702/#post-12742

http://garage.grumpysperformance.co...-by-step-guide-with-pictures.5378/#post-71848

http://garage.grumpysperformance.co...ther-efi-intake-manifold-info.431/#post-26322

http://garage.grumpysperformance.com/index.php?threads/porting-can-help.462/page-3#post-59145

http://garage.grumpysperformance.co...ads-tuned-intake-turbulence.12998/#post-67611

Volume (CCs) of Head Gasket
CCs of Head Gasket = Bore x Bore x 12.87 x Thickness of Head Gasket
COMMON SBC INTAKE PORTS
felpro # 1204=Port Size: 1.23" x 1.99"=2.448 sq inches

felpro # 1205=Port Size: 1.28" x 2.09"=2.67 sq inches

felpro # 1206=Port Size: 1.34" x 2.21"=2.96 sq inches

felpro # 1207=Port Size: 1.38" x 2.28"=3.146 sq inches

felpro # 1209=Port Size: 1.38" x 2.38"=3.28 sq inches

felpro # 1255 VORTEC=Port Size: 1.08" x 2.16"-2.33 sq inches

felpro # 1263=Port Size: 1.31" x 2.02"=2.65 sq inches

felpro # 1266=Port Size: 1.34" x 2.21"=2.96 sq inches

felpro # 1284 LT1=Port Size: 1.25 x 2.04''=2.55 sq inches

felpro # 1289 FASTBURN=Port Size: 1.30" x 2.31" 3.00 sq inches
http://users.erols.com/srweiss/calccsa.htm

Your RPM computed from your Cross Sectional Area of 1.95
(the smaller AFR HEADS)
and Bore of 4.03 and Stroke of 3.75 is 5,569.12 .

Your RPM computed from your Cross Sectional Area of 2.05
(the Larger AFR HEADS)
and Bore of 4.03 and Stroke of 3.75 is 5,854.72 .
you,ll barely notice the about 300 rpm shift in the power band on the lower part of rpm range but appreciate it much more on the upper edge of that power curve

heres a chart FROM THE BOOK,HOW TO BUILD BIG-INCH CHEVY SMALL BLOCKS with some common cross sectional port sizes
(measured at the smallest part of the ports)
...........................sq inches........port cc
edelbrock performer rpm ....1.43.............170
vortec......................1.66.............170
tfs195......................1.93.............195
afr 180.....................1.93.............180
afr 195.....................1.98.............195
afr 210.....................2.05.............210
dart pro 200................2.06.............200
dart pro 215................2.14.............215
brodix track 1 .............2.30.............221
dart pro 1 230..............2.40.............230
edelbrock 23 high port .....2.53.............238
edelbrock 18 deg............2.71.............266
tfs 18 deg..................2.80.............250

USE THE CALCULATORS
http://www.rbracing-rsr.com/runnertorquecalc.html
http://www.wallaceracing.com/chokepoint.php
http://www.wallaceracing.com/header_length.php
http://www.superchevy.com/how-to/en...-0902-chevy-engine-port-variations-measuring/
http://www.hotrod.com/articles/choosing-the-right-camshaft/
http://garage.grumpysperformance.com/index.php?threads/bits-of-383-info.38/
read these
viewtopic.php?f=52&t=2203

http://www.wallaceracing.com/runnertorquecalc.php

http://www.airflowresearch.com/index.php?cPath=75

viewtopic.php?f=52&t=333

http://www.carcraft.com/techarticles/11 ... index.html

http://www.circletrack.com/techarticles ... index.html

http://www.circletrack.com/techarticles ... index.html

http://www.circletrack.com/techarticles ... index.html

http://www.vetteweb.com/tech/vemp_0204_ ... index.html

http://www.pontiacstreetperformance.com ... rArms.html

viewtopic.php?f=52&t=181&p=215&hilit=+girdle#p215

http://www.enginebuildermag.com/Article ... itch_.aspx

if your thinking the parts you select don,t effect your results, heres two 383 sbc engines that were dynoed, on the first it makes good torque due to the mild cam and decent vortec heads but notice torque peaks at about 4200rpm and power above about 4800rpm is restricted due to head flow and cam timing and compression limitations
viewtopic.php?f=52&t=126&p=1193&hilit=louis#p1193
this is a 383 with vortec 170cc heads a decent intake and milder hydraulic roller cam

Camshaft Type: HYD. Roller
Camshaft Lift: .495 IN X .500 EX
Camshaft Duration @.50: 220 IN X 224 EX
Cylinder Head Type: Iron Vortec
Chamber Size: 64 cc
Valve Size: 1.94 IN X 1.50 EX
Compression Ratio: 9.5:1
Rocker Arm Type: Stamped Steel
Rocker Arm Ratio: 1.5:1

on the second 383 engine it makes good torque due to the more aggressive cam and aftermarket heads but notice torque peaks at about 4800rpm and power pulls too above about 6000rpm due too increases in head flow rates and increased cam timing , and larger valves and increased compression increases, that the increased cam timing allow
this is a 383 with aluminum performance 195cc heads a decent intake and roller cam

Camshaft Type: HYD. Roller (custom specs)
Chamber Size: 64cc
Valve Size: 2.02 IN X 1.60 EX
Intake Runner Volume: 195cc
Compression Ratio: 10:1
Rocker Arm Type: Full Roller
Rocker Arm Ratio: 1.6:1
even this power curve could be increased with better heads , a different intake, changes,made with a different cam and more compression
calculate horse power from intake port flow rates
http://www.wallaceracing.com/calcafhp.php

http://www.wallaceracing.com/calchpaf.php

http://www.wallaceracing.com/ca-calc.php

http://www.wallaceracing.com/max-rpm.php

http://www.wallaceracing.com/lpv.php

http://www.wallaceracing.com/chokepoint.php

http://www.wallaceracing.com/chokepoint-rpm.php

http://www.wallaceracing.com/area-under-curve.php

http://www.wallaceracing.com/piston-speed-velocity.php

http://www.wallaceracing.com/header_length.php
http://garage.grumpysperformance.com/index.php?threads/can-you-get-there-with-tpi.10494/#post-44284

http://garage.grumpysperformance.com/index.php?threads/c4-larger-intake-runners-l98-tpi.13785/

http://garage.grumpysperformance.co...m-dyno-results-and-other-info.433/#post-37683

http://garage.grumpysperformance.com/index.php?threads/hey-grumpy-do-i-need-bigger-injectors.5583/

http://garage.grumpysperformance.com/index.php?threads/port-speeds-and-area.333/

http://garage.grumpysperformance.com/index.php?threads/ideal-tpi-build.12203/

http://garage.grumpysperformance.co...sure-hurting-your-combo.495/page-2#post-35063

http://garage.grumpysperformance.com/index.php?threads/a-caveat-about-profiler-cylinder-heads.10065/

http://garage.grumpysperformance.com/index.php?threads/a-well-designed-c4-exhaust.786/#post-57392

http://garage.grumpysperformance.co...ther-efi-intake-manifold-info.431/#post-32491

http://garage.grumpysperformance.com/index.php?threads/tpi-throttle-body-size-48mm-52mm-58mm.546/

http://garage.grumpysperformance.com/index.php?threads/sources-for-tpi-parts-and-info.590/

http://garage.grumpysperformance.com/index.php?threads/bits-of-383-build-info.18/

http://garage.grumpysperformance.com/index.php?threads/my-current-corvettes-383-combo.430/

grumpyvette · Sep 6, 2011

383 Stroker FAQ from http://www.chevymania.com/tech/383.htm
The 383 chevy is one of the most powerful engines you can build. It is also the source of many questions and a lot of confusion. This is a basic 383 information page. The info is specifically about the properties and special conditions they may require in there buildups.

What is a 383 and what do I need to build one?
A 383 is a 350 production block with a 400 production crank. The crank has some special machine work done, namely the main journals of the 400 are 2.65" and the 350's are 2.45" so they must be turned down by .200" to make the STD. 350 main bearing size. Since the 400 is externally balanced you will need a balancer and flywheel/flexplate for a 400 CID chevy motor.

Do I need special pistons?
Yes and no. The added stroke of the engine would push the piston out of the bore by .125" if you used stock 350 pistons and rods. If you run stock 350 pistons and 400 style rods you can get away without special pistons but The skirts may also hit the counterweights since the 400 crank has larger weights and is longer from the centerline outward. If you go this route you need to pay close attention to crank to piston skirt clearance.

What's with this rod thing?
The 400 uses a 5.56" long connecting rod. All other small block chevy's use a 5.7" rod. The reason for the shorter rod is GM decided not to raise the piston pin higher so they shorted the rod the appropriate length to prevent the piston from popping out. 383's can have many different rod lengths but the first ones used stock 400 rods and stock 350 pistons with relieved skirts before custom pistons were available.

Which rod is better and why?
The longer rods are better than shorter ones. For a full explanation see the rod FAQ

Will longer rods cost more or require special work?
Yes and Yes!! The longer rods themselves don't cost more but the pistons you need will raise in price. The pistons will have higher piston pin heights and will have rings higher up on the piston. In cases where a non stock rod of 6.00" or longer the pin will actually intersect with the oil ring. These will require support rails for the ring. The longer rods will also make cam to rod clearance an issue. Special grinding or clearancing of the rod bolt shoulder will be required and/or a reduced base circle camshaft will be required.

What will the block require?
The block will need to be notched in the oil pan area. The longer stroke crank will need deeper notches to clear the counter weights and rod throws.

Should I balance the motor?
Yes!!!!! Any time you change geometry from stock a balance job is neccessary. That is if you want it to live! The pistons and rods are lighter than stock 400 versions and there is too much counterweight. This will make for a lot of vibrations and that is bad for a motor.

What kind of heads do I need?
Any kind you want. A 383 takes the same cylinder heads as a 350. The 383 does like larger heads and big valves but it is not mandatory to have 2.02/1.60 valves and huge intake runners.

Do I need steam holes in these heads?
No! A 383 uses a 350 block and it has no provisions for steam holes. It also cools like a 350 so only minor cooling system upgrades are neccessary.

What is the cost of this kind of buildup?
This is a tricky question and probably the most asked one! A 383 can be very pricey. The crank will cost a pretty penny to find a used one. There are several aftermarket companies selling '383' cranks that don't require any work so said. A crank can cost anywhere from 250 to over 1800$ depending on the kind and quality of the crank you buy. Pistons also fall into this wildly ranging category. You can spend 150 on cheap cast pistons or over 500 on light forged units. The balance job can cost from 120 to 240 depending on the shop, kind of balance job and the area you live in. Block work is not too bad. The only extra is the notching and that can be from 100-175 for the work. The rods are also another area of wide variety. You can get stock reworked 400 rods with ARP bolts for 100$ and you can order the 700$ sportsman rods and so on. If you order aftermarket rods that are profiled for stroker motors you will save yourself the grinding of the rods and/or the reduced base circle cam. If you get stock rods or non profiled rods you will either have to grind them yourself or pay your shop 50-100$ for this. You will also need to do this before the motor is balanced!!! I have built them for around 1600 and as much as 10,000 so far so do some leg work and pricing!

How much power will the stock 400 crank handle?
I have used a prepped 400 crank to 700+HP I have used basically stock cranks to over 550 HP so a stock nodular iron crank is fine for most buildups. The crank is strong because of the beefier construction of the crank.

What is the red line on these motors?
The red line varies from motor to motor depending on the parts installed and work done etc... A basic short rod 383 will live to 5500 and a 5.7" rod motor will go to 6500. Motors with forged internals and special work done can of course go higher. As a basic rule of thumb you can go 1000 RPM per 10PSI of oil pressure. If you have 70 PSI you can make 6000 with a 10 PSI safety margin. This rule will affect every kind of motor. It's kinda of an either/or here. You can go as high as your oil pressure permits or the internal parts permit whichever is lower!

What size cam will I need?
Probably the second most asked question is cam sizing. This is another tricky thing to pick. Since every single aspect of the engine and vehicle it's installed in will affect this I will just give another rule of thumb. 99% of rated ranges on products are based on the 350. If you have built a 383 you can add 10 degrees of duration to the motor and get very similar characteristics. For example; A 350 would probably have a moderate to rough idle with a 224 duration cam, measured @ .050 lift. The 383 will take a 234 duration cam to make almost the same idle and vacuum as the 350. These motors also like to breath so longer duration larger lift cams work well in them. Don't overcam! Just because you have a bigger engine don't go stuff the largest cam you can find into it. Most street engines use less than 234 degrees of duration @ .050! The motor is bigger so it will make more power with less cam so a 383 with a 214 cam will make more power than a 220 duration cam 350 if all else was the same.

What intake and manifold should I use?
Intake should be a high rise aluminum and a moderate carb. The 383 likes to breath so a bigger intake manifold like the RPM or Stealth would be a better choice but the performer and action + manifolds will work. Carb also depends on application but on the street under 6000 RPM you could get away with a 650! A 750 would make more power but is the largest you should go unless you are all out racing!

Are there any special things I need to pay attention to when assembling the motor?
Yes you must check cam to rod clearance and block to rod clearance. Both should be .050" minimum! All other specs will be the same as a 350 or whatever the manufacture specifies.

Should I run a high volume oil pump?
Only if you have a deep extra capacity oil pan. I personally do not like or condone high volume oil pumps on any engine. A stock oil pan will be sucked dry by a high volume pump @ 4500 RPM under hard acceleration. I have rebuilt more than a few motors that burnt up this way.

bits of 383 build info

grumpyvette

Administrator

TBucket Engine Project (Dart SHP)

grumpyvette

Administrator

grumpyvette

Administrator

grumpyvette

Administrator