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The side relief design provides additional clearance for the crank’s reluctor wheel. Without this added clearance, No. 8 piston would hit the reluctor wheel.
Here’s an underside view that clearly illustrates the side relief/short pin design. Naturally, this also reduces reciprocating weight as a bonus.
As you can see, the compression height resulted in the oil ring groove intersecting the pin bore. A support rail (included) is installed first at the groove base, which will provide needed support for the oil ring package at the pin bore locations.
Valve pockets are precisely machined on CNC equipment. The domes were very nicely finished, by the way, with no need to remove sharp edges.
The oil feed hole and oil slot is clearly visible in this pin bore, which will provide needed lubrication for the full-floating pins.
The piston part number is laser etched on the pin boss area, which is a handy idea for any future service.
The ring grooves accommodate 1.5mm top and second rings and a 3mm oil ring package (including the support rail).
Our main bearings are MAHLE Clevite 77 Tri-Armour bearings, coated with a proprietary anti-friction/oil carrying coating.
The LS engine features the thrust bearing located at No. 3 main position. When installing the thrust bearings, the three-notch side of the thrust face must face towards the rear of the block.
Our rod bearings are also MAHLE Clevite Tri-Armour.
The bearing coating does not add a discernible thickness, so it isn’t an issue in terms of oil clearance.
The ARP main stud kit includes all studs for the 4-bolt main caps, the required 8mm side bolts and a set of nuts for the windage tray. The primary cap studs are 10mm, with a 2.0 pitch in the block and a 1.25 pitch for the nuts.
The cylinder head stud kit includes primary studs, the inboard 8mm studs, hardened washers and nuts. Both the main and head stud kits include a tube of ARP moly lube.
The primary studs actually feature 11mm x 2.0 threads for block engagement, but 7/16″ x 20 threads for the nuts. ARP did this for a reason-if you lose a nut, it would be easy to find another nut in 7/16″ x 20, but trying to find an 11mm x 1.25 would likely be difficult. Caution: While a thread pitch of 20 (inch thread) and a thread pitch of 1.25 (metric) is very similar, they will not interchange and will result in thread lock-up.
ARP did the same for the small inboard head studs, they used an 8mm x 1.25 thread for block engagement, but featured a 5/16″ x 24 top thread. It’s clear that the smarter-than-most folks at ARP put some thought into this.
We plan to use a complete array of ARP threaded fasteners for the entire build of this engine.
Each ARP stud features a handy hex drive for easy servicing.
The crank snout bolt for the LS engine is a long boy. Shank diameter is 16mm, thread pitch is 2.0 and shank length is 110mm.
Melling offers a high volume and a high pressure/high volume oil pump. We’ll use the high pressure/high volume version. The oil pump mounts to the front of the block and is crank driven.
Our timing set is from Scoggin-Dickey, featuring multi-key crank and cam gears and double roller chain.
Our ATI Super Damper kit features serpentine pulleys and a mandrel for mounting to the LS style crank.
Our bumpstick is a hydraulic steel roller from Crane.
The cam grind number is etched onto the nose for easy reference.
The Crane hydraulic roller lifters feature flat sides for register with the OE style lifter trays.
Note the angle-drilled oil bleed hole.
The Crane lifters feature heavy duty trunions and hardened roller bearings.
Our cam card.
Before checking our rod bearing clearance, I organized and measured each rod bolt for relaxed length, using our GearHead Tools stretch gauge. Here the gauge is zeroed for a bolt before the bolt is installed.
I installed and removed all of our rod bolts with the rods secured in this GearHead Tools rod vise. This vise features a non-metallic contact surface for each side of the big end to prevent nicks and gouges.
With bearings and cap installed, this rod bolt was carefully tightened to 0.005″ stretch, monitored by our stretch gauge.
Due to the extended stroke of our crank, we expected to do a bit of block clearancing, but it’s relatively minor. The bottom of each bore needs to be kiss-notched to clear the rod bolt heads. Here we see number 1 rod’s inboard bolt head contacting the forward bottom edge of cylinder No. 2.
This close-up clearly shows the area of concern. The bottom of each cylinder will require this clearancing (see the marker outline). Once all locations have been marked, the grinding will only take about 30 minutes max.
OUR PARTS LIST (to date)
BLOCK
Aluminum GM LS2 P/N 12568950
Block completion kit P/N SDLS2CK-1
CRANKSHAFT
Lunati forged P/N J0711ER
(4.000″ stroke, 2.100″ rod pins)
Call (800) 652-0406, ext. 13431
CONNECTING RODS
Lunati H-beam forged (6.125″) P/N 6125H3
Call (800) 652-0406, ext. 13431
PISTONS
JE forged P/N 243016
Call (800) 652-0406, ext. 13432
WRIST PINS
JE P/N 927-2250-15-51C (full float)
Call (800) 652-0406, ext. 13432
WRIST PIN LOCKS
JE P/N 927-073-MW
Call (800) 652-0406, ext. 13432
PISTON RINGS
JE P/N J60008-4000-5
(4.005″ bore; 1.5/1.5/3.0mm)
Call (800) 652-0406, ext. 13432
PISTON RING SUPPORT RAILS
JE P/N RA4000-183
Call (800) 652-0406, ext. 13432
TIMING SET
SDPC double-roller P/N SD7245
Call (800) 652-0406, ext. 13433
MAIN BEARINGS
MAHLE Clevite Tri-Armor P/N MS2199HK
Call (800) 652-0406, ext. 13434
ROD BEARINGS
MAHLE Clevite Tri-Armor P/N CB663HNK
Call (800) 652-0406, ext. 13434
GASKET SET
MAHLE Victor P/N CS5975
Call (800) 652-0406, ext. 13434
CYL. HEAD GASKETS
MAHLE Victor MLS P/N 54332
Call (800) 652-0406, ext. 13434
OIL PUMP
Melling P/N 10296 (hi-volume)
Call (800) 652-0406, ext. 13435
CAMSHAFT
Crane hydraulic roller P/N 144HR00162
Call (800) 652-0406, ext. 13436
LIFTERS
Crane hydraulic roller P/N 144536-16
Call (800) 652-0406, ext. 13436
HEAD STUD KIT
ARP P/N 234-4317
Call (800) 652-0406, ext. 13437
MAIN STUD KIT
ARP P/N 234-5608
Call (800) 652-0406, ext. 13437
CRANK DAMPER/PULLEYS
ATI 7.5″ Super Damper kit P/N 917286
(damper with primary serpentine pulley, A/C pulley and crankshaft mandrel)
Call (800) 652-0406, ext. 13438
MISC. ARP FASTENERS
(all stainless steel 12-point except crank damper bolt, cam bolts and flexplate bolts)
134-1002 cam retainer
134-1003 cam sprocket
434-8002 valley cover
430-2101 intake manifold
400-2401 carburetor studs
244-2901 flexplate
434-1502 timing cover
434-3202 water pump
434-1504 rear cover
434-3102 motor mount
234-2503 balancer bolt
434-1301 exh. header
434-6902 oil pan
Call (800) 652-0406, ext. 13437
Tags: ARP, ATI SUPER DAMPER, BEARINGS, BLOCK, CAMSHAFT, CAMSHAFT SPECIFICATIONS, CRANE, CYLINDER HEAD STUDS, J&E, LUNATI, MAHLE CLEVITE, MAIN STUDS, MELLING, OIL PUMP, PISTON RINGS, PISTONS, ROD BOLT STRETCH, ROLLER LIFTERS, TIMING GEARS
