Inside the 1000 hp LS, Dai Yoshihara’s Formula Drift Powerplant

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We used a Brian Crower mechanical roller cam for our engine. Due to drifting’s extended amount of time on the rev limiter and violent changes in engine RPM, we have found that hydraulic rollers like the factory cam, even the low lash performance style ones tend to lose motion control which can result in valvetrain failure.

The cam is custom ground for the RHS blocks 55mm journal size and to our secret specifications which are optimized for valvetrain stability and higher backpressure created by the turbo.

To increase our engines durability, we used Brian Crower shaft rockers.  Since drifting has such violent engine RPM fluctuation, we found that BC’s stainless steel rockers are the best for long-term use.

We have seen drift engines beat up high end, heavy duty alluminum bodied shaft rockers before but have never had a single problem with these parts. The rockers pivot on shafts riding on needle bearings instead of a stamped steel surface sliding on a trunnion with the rocker tip being a roller rather than a sliding steel surface.  Less friction, stronger and impossible to slip sideways and fall off.

We used Crowers extreme heavy duty XP roller lifters. In the past, we had experienced pitting to the roller on the exhaust lifter due to the higher loads it sees pushing open against boost pressure.

We had run Crowers regular roller lifters for better oil control to the top end but this time we opted for the XP parts as they provide a lot more oil feed to the roller to keep them lubricated better.

We used Crowers recommended dual valve springs to keep valve motion under control at high RPM.

Lightweight but strong Crower titanium retainers are also used. The retainers use 14-degree keepers for better valve retention at high RPM.

Because our engines trick canted valve angle All Pro cylinder heads have a somewhat odd stem diameter and overall length, we had to get some semi-custom valves built for us by Rev Racing Engine Valves.

The intake valves are stainless with a huge 2.250″ diameter with a heat-resistant Inconel exhaust valve that is 1.625″ in diameter. The valves are swirl polished for better flow with the intake valves having a flat contour and the exhaust valves being tuliped for good flow as well.

Stay tuned, in the next article we will cover the engines assembly and talk about how it came out in actual competition use!

Sources

JE Pistons

King Bearings

RHS

Brian Crower

Callies Performance Products

Lunati 

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