RHS LS1 Engine Build - Trial By Fire

Yes, you can get the lifters out while the heads are still on. It takes some finesse, but it is possible! These large windows also allow plenty of room to access the sixth head bolt. You will also notice provisions for factory knock sensors, which is definitely a plus.

Assembling the tall deck requires a couple of special parts. Since the cam is raised, you will need the RHS-specific cam retainer plate along with a block-specific front and rear cover. RHS also sells a really nice main cap removal tool, which greatly reduces the chance of damaging the caps when prying them up. With everything in place, it was time to put everything together.

The first step is to install the bearings, applying a liberal amount of assembly lube before lowering the huge Lunati 4.600-inch stroker crankshaft. You can't see them here, but the RHS block allows you to run GM oil squirters to cool the pistons, which is a welcome addition for nitrous or blower guys.

RHS clearly spent a lot of time focusing on the main cap area, as they have made some substantial improvements in this area. Starting with thick mating surfaces, RHS then doweled each cap for strength and had them made in billet. All of this adds up to a super-strong foundation, especially with the billet caps.

Half-inch ARP studs bring everything to a close, making sure to lock the caps, bearings, and crankshaft in place. This design virtually eliminates the use of a girdle, as the block has been built to withstand huge power, from the ground up.

With the crankshaft in place, we moved our attention to assembling the rest of the rotating assembly. Diamond Pistons sent us a set of huge 4.165-inch pistons, which sit atop a Lunati forged H-beam rod.

Remember those long 6.38-inch sleeves? With everything installed you can get a good look at how much clearance you still have, even on the largest 4.600-inch stroke.

Our first camshaft was pretty mild for an engine of this size. With 247/257 degrees of duration, 0.675 inches of lift on the intake and exhaust and a 112 lobe separation angle, we weren't expecting huge top end power, but we could count on a ton of down-low torque.

With the camshaft in place, we bolted the RHS specific cam retainer in place and double-checked the rest of our short-block. We didn't use the option, but it is nice to know you can run the larger 60mm roller bearing cam, if you needed to.

Since the cam is raised 0.388 inch, it requires an extended timing chain. You could order one with 2 additional links, or just purchase the correct one from Comp Cams when you order the block (part numbers weren't available at the time of publication, but should be by the time you read this).

With the timing chain installed and the short-block finished, we laid on a set of the new RHS/Comp head gaskets and bolted down a pair of stock LS7 heads. These gaskets are rated up to 3,000 hp and, according to Comp, virtually eliminate the need for O-ringing.

Our valvetrain was a fairly simple setup. A set of Comp's short-travel race lifters ride atop the camshaft, moving a set of 5/16-inch diameter, 7.950-inch long pushrods. We didn't try it out, but RHS tells us the 1.060-inch bushings will fit in here, for those running larger keyed lifters.