LQ9 408 Stroker Budget Build - Finance-Friendly 408

With the rotating assembly OK'ed to go into our block, we turn to the piston rings. In the interest of time savings, we had SAM set our ring end gaps for us, but for reasons mentioned earlier it's always a good idea to at least check to ensure they're within spec. We find that they match the values listed on SAM's blueprint sheet: 0.018 inch for the top rings, 0.025 inch for the second rings. With the rings we're using, these are good specs for a N/A build such as ours.

With cylinder #1 at bottom dead center, note the skirt of the Wiseco piston sticking out the bottom of the bore. Wiseco is adamant about designing the proper skirt taper into all of its piston designs, a critical specification that is often under-appreciated by other manufacturers.

After a thorough block cleaning, first up in engine assembly is the use of Scoggin-Dickey's PN SDL SPK ($74) LS Engine Plug/Dowel/Side Bolt kit. It includes all the coolant and oil gallery plugs needed for an LS engine along with cylinder head and transmission locating dowels, but since the 10 side main bolts duplicate what we have from ARP, we'll set these aside for our next build.

We're about to begin final assembly ... but not before we introduce the tools and supplies we grabbed from Summit. While this author's shop is fairly well-equipped, there were a few odds and ends I needed for this particular buildup, and all can be had for an affordable price. Clockwise from top: PN WMR-W89409 Performance Tool Valve Spring Compressor ($39); PN PRO-66902 Proform Valve Spring Height Micrometer ($48); PN SME-904030 Summit Non-Adjustable Piston Ring Compressor, 4.030-inch ($24); PN TFS-9100 Trick Flow Cylinder Head Work Stands ($32); PN PRO-66793 Proform Valvetrain Checking Springs ($6); PN RPO-RP01335 Royal Purple Max-Tuff Assembly Lube ($16); PN CLE-2800B2 Clevite "Bearing Guard" Assembly Lubricant ($8); and PN SUM-900016-1 Summit Magnetic Base and Dial Indicator Kit ($26). You won't see them all used this issue, so keep a lookout for the rest in action next time.

With all coolant and oil plugs in place, the Clevite 77 main bearing upper shells go into the block and receive copious amounts of the Clevite Bearing Guard lubricant provided by Summit. Don't forget the thrust surfaces on #3! This main bearing set can be had from major retailers under PN MS-2199 H (part number varies slightly based on whether using standard or undersize bearings) for about $145.

The K1 Technologies crankshaft receives a thorough cleaning with brake parts cleaner, compressed air, mineral spirits, and lint-free towels. Mind the oil passages! Of note: a crank key is not supplied, so be sure to grab a stock LS unit in your travels.

The crank's main journals are spread with Clevite Bearing Guard, and it is lowered into place in the block. Note how we've yet to install our ARP main studs--unlike during preassembly, we are choosing not to take a walk on the wild side. (I must be getting old.)

ARP's LS main stud kit (PN 234-5608, about $187 at major retailers) is a great upgrade over the stock bolts, and is strongly recommended for any kind of stroker thanks to the vastly increased stresses the bottom end will experience. The 190,000-psi-rated studs go in just snug, then the main caps slide over them with lubricated bearings.

Word to the wise: even experienced engine builders can be forgetful. After seating the caps with a rubber mallet, I discovered that some of the outer ARP studs were protruding beyond their threaded upper portion, and some inner studs had too little thread showing. (Main cap #1 has one of the former, and main cap #2 one of the latter, in this photo). As it turns out, I had forgotten that the studs are in fact slightly different: the ones with more of the upper threads, and which are overall slightly shorter in length, go in the outboard positions. The moral of the story is that you can never be too careful, no matter your experience level!

After correcting my mistake, the ARP nuts are put on with ARP moly lube under their heads and on the threads of the studs. The inner bolts are torqued in sequence to 15 ft-lbs, and the crank is hit with a rubber mallet rearward, then forward, to align the thrust bearings. All main bolts are torqued in GM sequence to ARP's specs of 60 (inner) and 50 (outer) ft-lbs.

The ARP side main bolts get 19 ft-lbs with moly lube on their threads and a dab of RTV under their heads (to prevent oil leakage to the outside of the block). Crankshaft secured.

Time to assemble the pistons to the connecting rods. Each is thoroughly cleaned (as is the piston pin) before a Spiralox is installed into one side of the piston (shown; pull them out like a slinky to facilitate insertion). All friction surfaces are lubricated with oil, the pin is inserted through both piston and rod, and another Spiralox is placed at the other end. Care is taken not to assemble the rod onto the piston backward. Orientation rules in this case are as follows: the chamfer in the big end of the rod always faces the intake valve relief in the piston. Note also that thanks to their offset-pin design, there are specific pistons for odd- and even-numbered cylinders with appropriate "FWD" markings that must point to the front of the block.