With all said and done, we end up with a super-strong block and all-forged rotating assembly for under $2,800--talk about a tough act to follow, especially considering all of these parts are brand new! While we've yet to add in the cost of other necessaries like main and rod bearings, things are still shaping up nicely for our short-block.
Machine Work And Short-Block AssemblyOf course, our parts weren't quite ready for their day in the sun--they still needed to be machined before we could make them a part of our budget LS. While the vast majority of the work to be done involved the block, the rotating assembly would need to be balanced as well. The School of Automotive Machinists (Houston, TX), one of the most respected names in motorsports education, was happy to help out. Started in 1985 to impart students with the "art of engine building," SAM offers courses ranging from engine block and cylinder head machining to use of CNC equipment. Not to mention, SAM fields a pair of winning LS-powered Camaros at races around the country--and founder Judson Massingill is one of the most knowledgeable individuals in the United States when it comes to V-8 race engine building.
Check out the photo captions for a rundown of the machine work done by SAM (where GMHTP contributor Stephen Kim lent a hand at photography), followed by assembly of our short-block back at this author's New Jersey shop. Then, grab our September issue for the remainder of the engine assembly, a full dollar rundown of how much (er, little) this 408 set us back, and of course, dyno results!
 Our 4340 steel K1 Technologies...  Our 4340 steel K1 Technologies crankshaft, which Brian Nutter says "is capable to taking the highest levels of power and does so without breaking the bank." Some features in addition to those we've already mentioned include straight journal oiling, ensuring constant flow (rather than having oil flow stall at intersections as with cross-drilled cranks) as well as excellent journal finish with tolerances held to 0.0002 in. in all respects. While ours is a 4-incher, strokes ranging from 3.622 inches all the way to 4.250 are available for LS engines. |  After determining the connecting...  After determining the connecting rods' rotating and reciprocating masses, as well as the masses of the rod bearings, piston rings, and piston pins and Spiralox, SAM spins our crank on its balancer and removes weight where necessary to achieve a perfect match for all rotating assembly components. |  A proper balance not only...  A proper balance not only ensures engine longevity, it also frees up horsepower! |
 With everything in hand back...  With everything in hand back at this author's NJ shop, the first order of business is removing the main caps from the block. Check out this handy LS Main Cap Removal Tool I got a hold of a while back from Thomson Automotive. It's sold by a few online retailers for around $225--not recommended if you're only building one engine, but it's a welcome addition to the tool arsenal of a frequent LS builder as it avoids the need to fiddle with socket extensions under the "wings" of the caps. |  S.A.M. set our bearing clearances...  S.A.M. set our bearing clearances for us, but since your machine shop may not have quite the same reputation, it's good practice to at least double-check them (if they had been checked at all). Allow us to demonstrate: the upper main bearing shells are cleaned and put in place in the block, then the crank is placed atop them. In the interest of not scratching the crank journals, don't do this with the main studs installed (I, on the other hand, get an adrenaline rush and other excitement from such brushes with danger). |  The lower main bearing shells...  The lower main bearing shells are cleaned and go into the appropriate main caps (SAM numbered each shell for us). The caps are then placed onto the main journals with a piece of Plastigauge in between. Opinions vary on the accuracy of this method, but that argument notwithstanding, Plastigauge also allows us to evaluate specs like crankshaft runout (not that we're expecting any from K1, but this is good practice in any engine build). |
 Our ARP main studs are torqued...  Our ARP main studs are torqued in sequence, then immediately loosened and the caps removed. We see a consistent 0.002-in. clearance or just under for each main bearing, which is a bit less than what is shown in SAM's blueprint record; their measurements were done with super-precise micrometers, so are probably more accurate. Also, there's no sign of any journal taper (inconsistent strip width along its length) or crankshaft runout (which would show up as varying clearances between mains), so that's good. |  The Plastigauge is cleaned...  The Plastigauge is cleaned off of the journals and bearings with mineral spirits, then the crank is removed and reinstalled with oil-lubricated journals and bearings. After snugging the main studs, the crank thrust bearings are aligned with a rubber mallet, then the crank spins freely as shown! |  While this would be the opportune...  While this would be the opportune time to check them, we take SAM's word for it on the rod bearing clearances (0.0025-in. on the blueprint sheet); this is not recommended for just any old machine shop though! To check rotating assembly clearances (critical with a larger-than-stock crankshaft stroke), a piston is temporarily assembled to a rod via a lubricated wristpin. Notice the doweled nature of the K1 rod caps, another high-strength feature. The piston/rod assembly is then treated to a lubed rod bearing and inserted at the #1 position. |
 The crank is rotated to check...  The crank is rotated to check clearance all around. Just at the bottom of the opposite bore is where one often encounters clearance problems between the block and rod bolt, but as you can see, there's no such issue here. I check one other cylinder on the opposite bank just to be sure--this is important since the bolt heads of even-numbered cylinders can also come close to the main oil gallery on the driver side of the engine, but it checks out fine on #8. Brian Nutter explained that K1 takes great care in designing rod bolt lengths and rod dimensions to maximize clearance in LS blocks, and we're happy to keep the Dremel tool in its box! |  With cylinder #1 at bottom...  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. |  Wiseco provided this diagram...  Wiseco provided this diagram to illustrate, and those who attended the 2008 AETC conference also received some excellent information on this topic from Judson Massingill (this very diagram was even included in his presentation). The gist of it is that incorrectly designed piston skirt taper can result in the so-called break point passing below the bottom of the cylinder--and as you might imagine, it's called the "break point" for a reason! This is especially important in the case at hand since the 6.0L iron LQ9 block has a bit shorter cylinder length than other LS blocks common to stroker builds. |