In the last issue we began this engine journey by crafting together the short-block for our 461ci LS engine. For those who might have missed part one you can catch it on our website (www.camaroperformers.com
). In short, we combined an RHS LS aluminum block, 4.250-inch Lunati rotating assembly, Wiseco slugs, and a ton of meticulous machine work to end up with a very stout short-block. And while a rock-solid bottom end is critical, the parts bolted on top are equally important if the goal is big, reliable power.
Engines are nothing more than big air pumps. As such, power is a factor of how much air can be efficiently moved through it. So, the top end of any engine can make or break it in terms of power output, no matter how nice the bottom end is. For this reason, we sourced a pair of Mast Motorsports Black Label heads topped with a voluminous 102mm FAST intake. This combination proved quite capable of feeding atmosphere to the cylinders, and in a non-boosted application, this is even more critical.
As for the dyno results, Tom Nelson remarked, “I was impressed with the power output and the extended power range. It had a very broad and long torque curve for such a short hydraulic-cammed motor. The heads flowed great, and I feel with a solid roller and individual-runner set up, this same motor would very easily make 825 hp without sacrificing torque. Which when you think about it, is pretty amazing. In the end, 720 hp and 662 lb-ft from a naturally aspirated pump-gas hydraulic-roller motor that can be putted around town is pretty awesome. These are 540ci big-block power numbers out of a 461ci LS platform.” On the road, the engine has all the manners one would expect an LS engine to have. And while gas mileage may have taken a hit, the performance gain was well worth it. On the track, the engine pulls hard all the way to its rev limiter of 6,900 rpm and, the low-end torque really helps pull the car out of the corner even if you’re in one gear higher than you should be. Even though we stuck with the wet-sump oil system, we have zero pressure fluctuation even in 1.2g-plus turns. Overall, it’s a lightweight engine that shows you can fit a lot of displacement in a relatively diminutive package.
1. If you want to make good...
1. If you want to make good power, you’ll need a killer set of heads. These rectangular-port LS3 12-degree heads have 270cc intake ports and are compatible with the six-bolt design of our RHS block. The design is somewhat unique since it utilizes Gen IV LS7 rockers but accepts LS3/L76 intake manifolds.
2. These fully CNC-machined...
2. These fully CNC-machined heads (PN 510-304, $1,599 ea.) use a 2.200-inch intake and 1.600-inch stainless hollow stem valves and feature thick .750-inch decks. They are also set up to work with big-bore (4.125-inch or larger) applications like ours.
3. Most manufacturers of high-end...
3. Most manufacturers of high-end heads provide flow numbers, but it’s always nice to check it yourself if you can. Tom Nelson, owner of Nelson Racing Engines in Chatsworth, California, has a sweet Superflow flow bench, so we decided to see if there were any gains to be had by fussing with the heads.