LQ9 408 Stroker Budget Build - Finance-Friendly 408

Next, the rings are put onto the piston. This particular piston kit uses a 1/16, 1/16, 3mm set with nitrided steel top rings and Napier second rings that Brian Nutter says offer "excellent oil control and phenomenal sealing. Many dyno facilities with blow-by meters (including Wiseco's own in-house dyno) confirm these hi-tech rings often have the lowest amount of blow-by they've ever measured. The key to this is superior ring machining for the flattest, roundest, and finest surface possible. Although this technology seems like overkill for a street engine, Wiseco feels these racing technologies are more important in street-driven engines due to the life expectancy required." Again, the updated `X' piston kit includes rings said to be even better! At the suggestion of Judson Massingill, Wiseco also sent us a different set of oil ring expanders (from a 4.020-in. ring set) to use in order reduce oil ring tension and free up even more power. According to Massingill, piston and ring friction accounts for around half of frictional losses in an engine, with the oil rings representing up to 60 percent of ring-related friction, so gains here can be substantial--the ring set can amount to 15 percent of BHP, he says! While the tradeoff will be a bit of additional oil consumption, this is not much of a concern on an engine that isn't destined for daily driver duty (after all, we're by no means shooting for fuel economy on this build).

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!

The cylinder walls are scrubbed with ATF, then given a coating of engine oil. The piston skirts and the outer edges of the rings are also lubricated. Then the Summit ring compressor is oiled up, set atop the block, and the piston is inserted. Check out the detail of the face of the Wiseco piston, which has valve pockets designed to accommodate the valve sizes and locations of both cathedral- and rectangular-port LS heads.

Though Wiseco's LS multifit pockets create a large amount of negative volume from overlapping valve pockets, "we remedy this with our novel `Wiseco flow-dome' that can't physically interfere with any combustion chamber, and promotes flow around the valves and better cylinder evacuation. It also allows a machine shop to tune the volume from, for example, -3 cc to a -7 cc flat top pretty easily," says Brian Nutter. All this, in addition to the piston's strength. Brian mentioned the company's 2618 alloy LS forgings are commonly used in 2,000 horsepower 7-second turbo cars!

With all pistons in, our 7/16 ARP 2000 rod bolts are tightened. K1 Technologies gives a spec for torque plus angle (30 ft-lb. + 60 degrees), but recommends the rod bolt stretch method. So do we: a stretch gauge is zeroed with the bolt just snug, then removed and the bolt tightened with a breaker bar. Experienced builders will have a feel of when the bolt is nearing proper preload; beginners will require a bit of experimentation.

The rod bolt stretch gauge is put back on, and we verify that we now have 0.0060 - 0.0064 in. of stretch; slight tightening or loosening may be required to get within this range. (Ideally, the stretch gauge is left in place as the bolt is being tightened, but the deep skirt design of LS blocks usually prevents this for most bolts).

The process is repeated for all rod bolts and short-block assembly is complete! In our next issue, we'll finish off the engine assembly and put our 408 on the engine dyno to see what kind of numbers we come up with. Though we haven't filled you in on specifics like our cam and cylinder head selection, we've got high hopes for a horsepower figure; care to place a wager now? (Let's just say my money's on the Number of the Beast!)