darts new shp block
AT $1456 there not CHEAP but they a certainly a BARGIN compared to putting $1000 in machine work into a 35 plus year old chevy block thats noware near as stong and very likely to be rusted internally and one that might have cracks
and at $1000 less than thier full race block its a deal for a street/strip engine combo
whats the differance?
its got a bit less machine work, its not quite as thick and its got less nickle in the casting, and theres less options
" IF YOU CAN,T SMOKE THE TIRES FROM A 60 MPH ROLLING START YOUR ENGINE NEEDS MORE WORK!!"
IF theres any way your going to invest in a decent aftermarket block as a base for a SBC you sure want a relieable/durrable rotaing assembly, ID strongly advise a 5140 0r a 4340 FORGED CRANK and 7/16" ARP rod bolt rods and a bit of thought as to the compression ratio, forged pistons and a decent valve train to avoid damage to the block
with a 4340 FORGED crank theres not much in the way of significant mechanical strength lost going to the more comon 350 main bearing size journals and you reduce the bearing surface rotational speed just a bit so rotational frictions reduced slightly and most SBC cranks are designed for that bearing dia.
CHEVY SMALLBLOCK V-8 Crankshaft Casting Numbers
SBC TWO PIECE REAR MAIN OIL SEALS
1130.......327.......forged..medium journal...3.25" stroke
1178.......302.......forged..medium journal...3.00" stroke
1181.......305,350...cast....medium journal...3.48" stroke
1182.......350.......forged..medium journal...3.48" stroke
2680.......327.......forged..small journal....3.25" stroke
2690.......350.......forged..medium journal...3.48" stroke
3279.......302.......forged..medium journal...3.00" stroke
3474.......283.......forged..small journal....3.00" stroke, military tank use
4577.......327.......forged..small journal....3.25" stroke
4672.......327.......forged..medium journal...3.25" stroke
310514.....350.......cast....medium journal...3.48" stroke
330550.....350.......cast....medium journal...3.48" stroke
354431.....262.......cast....medium journal...3.10" stroke
3727449....283.......forged..small journal....3.00" stroke
3729449....265.......forged..small journal....3.00" stroke
3734627....327.......forged..small journal....3.25" stroke
3735236....265,283...forged..small journal....3.00" stroke
3735263....283.......forged..small journal....3.00" stroke
3782680....327.......forged..small journal....3.25" stroke
3814671....327.......forged..small journal....3.25" stroke
3815822..265,283,302.forged..small journal....3.00" stroke
3835236....283.......forged..small journal....3.00" stroke
3836266....283.......forged..small journal....3.00" stroke
3848847....283.forged or cast..sm. journal....3.00" stroke
3849847....283.......forged..small journal....3.00" stroke
3876764....283.forged or cast..sm. journal....3.00" stroke
3876768....283.......forged..small journal....3.00" stroke
3884577....327.......forged..small journal....3.25" stroke
3892690....350.......forged..medium journal...3.48" stroke
3911001....307,327...cast....medium journal...3.25" stroke
3911011....307,327...cast....medium journal...3.25" stroke
3914672....327.......forged..medium journal...3.25" stroke
3923279....302.......forged..medium journal...3.00" stroke
3932442..267,305,350..cast...medium journal...3.48" stroke
3941174....307,327...cast....medium journal...3.25" stroke
3941178....302.......forged..medium journal...3.00" stroke
3941182....350.......forged..medium journal...3.48" stroke
3941188....350.......forged..medium journal...3.48" stroke
3949847....283..forged or cast..sm. journal...3.00" stroke
3951130....327.......forged..medium journal...3.25" stroke
3951529....400.......cast....large journal....3.75" stroke
SBC ONE PIECE REAR MAIN OIL SEAL
10168568...265.......cast....medium journal...3.00" stroke
12552215...364.......cast....medium journal...3.62" stroke, Gen. III, 6.0L
12552216...325,350,364.......cast....medium journal...3.62" stroke, Gen. III 5.7L LS1, 5.3L, 6.0L
12553312...293.......cast....medium journal, 3.27" stroke, Gen. III, 4.8L
12553482...293.......cast....medium journal, 3.27" stroke, Gen. III, 4.8L
14088526...305,350...cast....medium journal...3.48" stroke
14088532...350.......forged..medium journal...3.48" stroke
14088535...305,350...cast....medium journal...3.48" stroke
14088552...350.......forged..medium journal...3.48" stroke
and if your going to drop $1500 on a BARE BLOCK your probably going to want to try to insure it doesn,t get cracked when a cheap cast crank fails so an ALL FORGED AND BALLANCED ROTATING ASSEMBLY is a good idea.
People wonder why it's cheaper & easier to buy a "crate" engine rather than a buying a bare block and building with your own components. After all, if you assemble it, you save the cost of labour, right? Wrong!!
Originally Posted by grumpyvette
It's the economy of scale. If you buy one block, one forged crank, 8 forged pistons, etc..., you get charged top dollar for every piece and it adds up quickly. If a company builds 1000 (or 10,000), they get lower unit costs on all components, even the blocks themselves. This is especially true for OEMs since they're likely taking most of the parts off the shelf rather than buying from suppliers.
That being said, a "crate" engine likely isn't hand-assembled or perfectly matched to your specific application. There's a good reason why guys like grumpvette never lack for jobs.
bits of 383 build info
place a single rod/piston assembly with well oiled bearings and no rings installed on the first cylinders journal, and have the cam installed to check 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
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.
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.
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 stud 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
grumpyvette, do you recommend using loctite for the SAE coarse threaded end of arp studs?
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
keep in mind the course thread section is not being screwed in or the threads moved as the nut on the fine thread upper end is torqued to spec. and that thread requires the ARP thread lubricant to get the correct stretch and that stud needs to be cycled up to full torqure then released and retorqued,a minimum of three times to get the stretch/tq correct
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
SB-Chevy 283-400 Hydraulic Roller Camshaft Kit
Duration Advertised 296° Intake/300° Exhaust
Duration @ .050'' 234° Intake/238° Exhaust
Lift @ Valve .539'' Intake/.548'' Exhaust
Lift @ Cam .359'' Intake/.365'' Exhaust
Lobe Separation Angle 112°
Intake Centerline 107°
Intake Timing @ .050" Open 10° BTDC
Close 44° ABDC
Exhaust Timing @ .050" Open 56° BBDC
Close 2° 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
Grind Number: HR-230/359-2S-12.90 IG
Operating Range: 3000-6500 RPM
Duration Advertised: 292° Intake / 300° Exhaust
Duration @ .050'' Lift: 230° Intake / 238° Exhaust
Valve Lift w/1.5 Rockers: .539'' Intake / .558'' Exhaust
Lobe Separation Angle: 112°
Max Lift Angle: 107° ATDC Intake / 117° BTDC Exhaust
Open/Close @.050'' Cam Lift: Intake - 8° BTDC (opens) / 42° ABDC (closes)
Exhaust - 56° BBDC (opens) / 2° 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 MORE
BIGGER is NOT always BETTER, and since both the header primairy dia. and length and the collectors , which have a huge effect on the resulting scavaging can,t be changed as we change engine rpms, we need to maximize the cylinder scavaging charicteristics so as to maximize the cylinder filling and extend the rpm band of the torque curve but once your have the collectors and headers primairy designed to maximixe the scavaging in your chosen and intended rpm range and run the collectors to a (X) to induce both increased scavaging and lower restriction to flow theres not much that a larger exhaust past that point can do badly but increase the noise levels while it should be rather obvious that a smaller than ideal exhaust will hurt the upper rpm band as it tends to be a restriction
yes if you have a smaller exhaust dia. it tends to act like an extended collector and increase low rpm torque at the cost OF being A restriction ONCE THE RPMS BUILD PAST A CERTAIN POINT.having both collectors empty into an (X) pipe EFFECTIVELY instantly doubles the cross sectional area of the exhaust pulse and significantly reduces the return reflected pressure wave, almost making the collectors act as if its running without any restiction compared to a true dual exhaust IF the exhaust pipes are large enough to provide a very low restriction at that point
as I POINTED OUT ABOVE...
theres plenty of fluid dynamics math and research out there to show that the distances the exhaust travels between exhaust pulses and the diam. and length are easily calculated, and past that length the second previous pulse has little effect compared to the current and previous pulse energy and reflective wave
and lets not forget the cam timing displacement and intake port all effect the cylinder scavaging the headers can effectively provide also
LETS ASSUME I WANT MY 383 TO MAKE MAX POWER IN THE 5000RPM-6300RPM BAND (mostly so I can run street gears and pump high test gas and a low maintinance hydrolic roller cam, and IM willing to sacrifice a good deal of street driveability to maximize my corvettes track potential)example , my 383 vette has a cam with exhaust cam timing that opens at 83degs bbdc, thats 97 degs atdc, http://www.cranecams.com/?show=brows...61&lvl=2&prt=5
Bore: (Inches) 4.03"<BR>Exhaust Valve Opening Point: (Degrees ATDC) 97 degs
Peak Power RPM: 5500rpm Calculated information appears below
Header Pipe Diameter: (Inches) 1.84"<
Header Pipe Length: (Inches) 37.65
Collector Diameter: (Inches) 3.5
Collector Length: (Inches) 18.82
useing the above calculators we quickly find I should have about a 3 sq inch intake port cross sectional area, the exhaust should be about 39" long in the primairy 1.825 dia,and about 18" -20" long in the collector, about 3"-3.5" dia.
a matching compression of about 10.5:1-11:1 and a cam in the 230-235 durration range at .050 lift, heads that have the same 3 sq inch port and flow about 280cfm this will tend to maximize the power at THAT rpm band, and ideally a 3.90:1-4.11:1 rear gear ratio and a 3000rpm-3500rpm stall converter
but that above will NOT work nearly as well as a smaller and less radical combo in the 1500rpm-4500rpm most cars spend 90% of thier time in
its all a compromise and most people don,t realize how miserable that combo will make the daily driven car that rarely get above 4500rpm, where a smaller and longer exhaust would scavage more effectively but give up some of the potential for max power when the cars raced
your 100% correct if you were looking to cruise at 2500rpm , the cams above will be a P.I.T.A. on a car designed mostly for mid rpm cruiseing, you could get good performance from them but the street manors in traffic will be less than ideal....certainly manageable but not exactly smooth
youll be far better off with something similar to these, if street manors and low to mid rpm cruising are a higher priorty, but have a LONG talk with the manufacturer of your choice about your combo and expectations before sellecting your cam and matching your combo gearing and compression, head lift restrictions and flow charicteristics
Intake Exhaust This is an emission legal cam which makes
Advertised Duration 282/ 287 over 400HP with our CNC"D LT heads and
Duration at .050 212 /226 F-car headers. Great with an auto or six
Gross Lift .483/.520 speed.
Lobe Separation 112
GOSFAST posted this great photo to illustrate the differance between rod designs
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
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
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