The gears in the Melling pump are thicker and deeper for more capacity. We WPC treated them for fatigue strength and longer life.
For a crank, we chose an Eagle with a 4″ stroke. When building an engine for durability, piston speed is always an issue as that is what largely determines ring wear. When stroking an engine, angularity, and piston side load also increases as well as stress on the connecting rods. 4″ is the same as the OEM LS7 stroke so it has been OEM validated to be ok for the LS7 that actually revs higher stock than our intended use.
With LS engines another consideration is that the bottom of the bore is short on these blocks and the piston skirts hang below the cylinders at bottom dead center, unsupported. This can cause rocking and rapid wear on the bottom of the bores and excess piston wear. For this reason, it is not advisable to go to a longer than 4″ stroke on most OEM LS engines. The LS7, LSX, and aftermarket racing LS variants have deeper cylinders and this is not an issue.
We used Eagle’s strongest crank made of high nickel and molybdenum 4340 steel. The Eagle crank is machined from a non-twist forging. This is considered to be the best way to forge a crank because it offers the best grain alignment of the metal. This crank is rated for 1500 hp and is possibly overkill but drifting is brutal on parts and this engine has to hold up for a long time. Eagle also offers a lower cost crank made of 4130 Chromoly that is rated for 1000 hp. We got the crank with a newer spec 58 tooth reluctor wheel.
We also got the crank with Eagles optional ESP Armor treatment. ESP Armor is what gives the crank the look that it has been chrome plated. It is not a plating but a secret process that gives the crank journals a superfinished surface that is 8 times smoother than typical micro polishing. This greatly reduces friction, improves bearing life, increases power (as much as 4%) and increases the cranks fatigue strength. Eagle is so confident in the process that they will warranty the crank from breaking for one year!
For connecting rods, we used a set of Eagle’s top of the line CRS rods. These rods are made of Eagle’s proprietary alloy that exceeds the strength of 4340. They have a few different machining details that the standard rods don’t have for more strength.
The CRS rods are an H beam type in construction. One of the design features that give more strength is the rib going down the center of the H channel. Another is the two small holes to oil the wrist pin bushing in the sides of the rod instead of having one big hole that weakens the highest stressed point of the small end.
7 comments
Do you think using thermal paste (ala CPUs) would help increase heat transfer on the main bearings?
Might aid in bearing spinning. Usually, engine builders advocate a tight fit on the main saddle for best heat transfer.
it won’t one bit: It will just desolve in oil. Let alone the chunks that get stuck at the oil pickup or the bearings. It just will not work if you really want to remove heat: Graphite paper. Bit that will nog keep the bearing in place. A graphite-silicon based sealer will most likely transfer heat a little less, but will be more resillient to spinning bearings.
Then again: Bearings normally won’t spin that much, unless there are either opposing forces ( flat 4’s for instance) or when the stroke gets to large compaired to the connecting rod. It isn’t so much extra power as it is the rod stroke length.
Mike – any thoughts on using a stock 4.8 crank to reduce the stroke and increase the rod length?
For a road racing or circle track car sure. A drift car needs grunt so I don’t think I would ever destroke one. Mange rod ratio, yes but not destroke. For Dai Yoshihara’s engines, I run a big 4.250 stroke for grunt but also run a super long 6.350 rod with a tall deck block. This gives a stroke to rod length ratio of 1.494:1 which is within the realm of OEM production engines yet still packs a bunch of displacement into a small package. One of our older blocks with a big bore gives us 477 cubic inches!
Mike – What is the best roller rocker / shaft roller rocker option for a stock ls3 head?
For drifting with lower rpm, probably Crower.