Thread: Cam for 400

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With the big problem of lack of zinc in oil these days, whatever grind you choose I'd suggest getting it as a hydraulic roller. The flat tappet cams just don't seem to live anymore. Friend of mine has to replace his Lunati, less then 4,000 miles on it and losing a couple lobes already......

Remember those cams are probably designed for a 350 so a 400 will tame the cam some. Something with a slight lope in a 350 will idle dead smooth in a 400. 400s need a larger cam to breath through 350 heads. Half a bottle of GM EOS at each oil change is way cheaper than a roller cam conversion. Keep the valvesprings reasonable, break it in right and flat tappets can last.

I had a 400 bored .030 with dished piston, 58cc heads with 2.02"s/194's, my cam was the 58239th cam that UltraDyne ground. cam was a 276/286 at .0045", 221/230 at .050", .454"/.454" valve lift, and 110 LSA. It should be in the engine on a 104° to 106° ATDC ICL--ie, 4 to 6 degrees advanced. It should work with anything between 9:1 to 10.5:1. Power in a 406 should be from just off idle to 6000, with peak around 5200. Idle should be around 750, and there was enough vacuum to work power brakes. I used stardard felpro blue gasket, Q-jet with drilled idle mixture jets and I run 87 octane, with th350 tranny. I ran 87 octane with 36-38 degs timming and had no ping. My cam was a flat tappet and if you use the correct oil (study your oils on which "TO" use, ("Most" diesel oils or farm use oil) and a bottle of GM EOS during break in you'll have no problem!

Mine had a healthy lope to it , with factory torque converter, and a shift kit.

Pat