L46 cam

[Gene M.]

Re: L46 cam

This thread is going all over the place. William started asking about the difference L46 to L79. Then Joshua asks about 30-30 a total different animal solid lifter cam. Following this is talk about LT1 cam. More on a 327 LT1 hodgepodge. Then Joshua, the question of the hydraulic lifters by sealed power. Then finally seal power lifters for 962/151 are good for 6500 rpm. That must be shift point cause a production vintage hydraulic lifter engine won’t stay together very long at that rpm. GM red line them (L46 & L79) at I think 6K, then they start laying over.

[Duke W.]

Re: L46 cam

As reported in the Tale of Two Camshafts article, one Special 300 HP engine kept pulling to 6800 before it laid down due to lifter pump-up. The other owners didn't want to rev beyond 6000, but since the other 327s also have Crower Sportsman rods and well massaged heads, they are capable of the same revs without ill effect although I recommend a normal redline of 6500 for this engine configuration. It's best to stay short of lifter pump-up because it will take the engine several seconds to recover from the event.

Setting up OE valve spring installed height to achieve .090-.100" short of coil bind at full lift (lobe lift X 1.44) will make for a valve train limiting speed of 6500+ with hydraulic lifter cams. The L-79, L-46/82, and McCagh Special will make useable power to this engine speed with massaged heads, and aftermarket rods in lieu of the weak OE rods make for a bulletproof bottom end. The same configuration with the LT-1 cam will make useable power to 7200, which is the start of incipient valve float, and I recommend a normal redline of 7000.

Duke