340 dyno chart thoughts
Yawn... and you build your engines,your way... Just ,my opine.... He has plenty of mechanical compression,to pull a .484 Purple shaft...(have you run one,properly tuned?), good cylinder heads(Edelbrocks,are.. enhhh,o.t.b....) need real cam timing,to run....There are several ways,to get there.... I would use a cam,instead of expensive head porting....
I agree it could be run, I Never said he didn't have enough compression, did I?
What I DID say is there's no way those two cams are going to have the same idle vacuum.
Either cam could be run, but whatever you gain at the top you're gonna lose something similar at the bottom.
Saying you can run 10 degrees more duration on both lobes while narrowing the lobe separation by 4 degrees won't have a negative effect on idle quality and low speed drivability is patently false and misleading. There will be a sacrifice and it will be both measurable and noticeable.
Whether that is a worth while sacrifice is a matter of personal taste.
OP wants a cam with a strong vacuum signal for his power brakes and that's that's what he has got. It's also pretty healthy in it's own right for a mild 340 build. I see nothing wrong with it and the hp gains from changing it out are going to be marginal anyhow.
You mentioned that "good heads" need "real cam timing". Are you referring to high flowing cylinder heads and long duration cams?
If anything it is low flowing cylinder heads which "need" more cam as they are starving the engine for air.
High flowing heads need a cam with high lift to be used to their full potential, but ultimately are comparatively less dependant on high duration specs to make power.
This is why modern engines with roller cams and high flowing heads make 400+hp with ultra smooth idle and perfect street manners. Great heads, Lots of lift and little duration cut on wide lobe separation.
