High rpm type 4 Options

[r_towle]

What is a street able motor (valve train) set of materials that could sustain 7k rpms ?

So, what valve material, spring materials, push rods, lifters etc.

No ceramic lifters unless they are out on the market again.

Rich

[Jake Raby]

The engine I built for the Mighty Spyder in 2005 coupled a 69mm stroke with a 105.7mm bore and twin plug LE 230 heads and a RAT roller camshaft and lifters. It made power to 8,500 RPM and is very street able. Peak power was 265HP.

12:1 CR and twin plugs (runs fine on pump gas) were the key at making this engine well behaved enough for street service, while making a ton of gross power at the top end of the RPM range. The roller cam builds a ton of torque through better chamber filling at low valve lift values.

EFI also helped a ton with direct ignition as it gave better resolution for tuning the flat spots out at low and mid-range throttle positions and MAP levels. Carburetors would have been very difficult to tune for street service with this combination.

The owner is now in his 70s and drives the car on the street all the time, he also competes in hill climbs and all other sorts of track activities, too.