340/418 Stroker questions

moper said
I've run that same Crane cam. Crane is one of my favorites. That one's a great piece but it's still peaky and it's hydraulic which means more spring needed and less rpms because of the plunger. Depending on the piston and quench you might want to go a little bigger. I'd run a flat tappet in the 250-255 @ .050 and around .580 after lash. Simple, effective, almost bullet proof, and cheap. If you want more steam I'd bush the lifter bores and run a solid street roller with a little less duration at .050 and a little less lift. Something that will be easy on the springs.

I really like the Crane retro hydraulic roller lifters, and have had my engine up to 7000rpm with 1.5 rockers using the above cam. With 1.65 rockers and plenty of spring (.585"/.605" lift), the engine still revs 6500+rpm all day and makes gobs of torque right off the line. Peak power is at only 5500rpm. It would likely make more and peak a bit higher with a decent set of headers, as I'm only running 1 5/8" shorties until I get some custom pipes made.

Current spring pressures are 170lb on the seat and 375lb over the nose. Springs are Manley LS ovate beehives with 353lb rate. Crane says it's safe to run over 360lb of pressure on their hydraulic rollers, and 200lb/400lb is not uncommon - but they'll go even higher.

Here's an article on an 8500rpm engine running Crane retro hydraulic rollers. Admittedly it's a Chev :sad10: but with 570lb over the nose, it gives solid rollers a run for their money: http://www.carcraft.com/techarticles/1402_crane_hydraulic_roller_lifters/viewall.html

Here's my latest dyno. Red line is without the air filter, green line is with. The flat torque curve makes for a nice street engine. And my car runs easy 11s with a stick shift.

http://s1198.photobucket.com/user/Valiantdude/media/Dyno.jpg.html