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Old 11-15-2006, 10:03 PM
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Originally Posted by onovakind67
I think you're lying to Engine Analyzer. You need to put real data in for the cam, not just switch the selection from flat tappet to hydraulic. You'll never get the same area under the curve from a flat tappet cam that you can get from a roller.
I would agree with you - physically, the roller is better. I understand getting the valves open quicker should allow more air to flow compared to a flat tappet variety that opens the valves more slowly. I just thought it would be worth more power than that.

As far as inputting the right info - when the computer spits out the result it gives you a duration @ .200" lift as well - and when I change the cam type (mild hyd roller, agg roller, mild flat, aggr flat) you can see that the numbers change. That suggests to me that the program is in fact taking into account more and less aggresive lobe profiles.

What I'm suggesting here is that all the money spent on going roller (which I thought was going to be worth every penny) was perhaps not spent in the right spot for me.

I did input real data for the cams. Actually tried to get a "best" run from each type, (which of course meant choosing different adv. durations), but when it was all said and done - I could have chosen the right flat tappet cam and been within 10 or so HP throughout the powerband. When you change the type of cam in the program, it just simulates a more aggresive lobe - which allows a comparison of two cams with the same @ .050" durations.

If one is looking for a more radical valvetrain, the roller (hyd. or especially solid) would be the way to go - however, on a street vehicle with any manners, that sort of cam is not necessary so I'd say the flat tappet is just near as good at that point.

If my 406 was 12.0:1, I could run that 306/314 in there on pump gas - DCR would be close to 8:1 - and she would fly. However, there are -20cc reverse dome pistons in it that give me 9.9:1. The 306/314 is just tooooo big.

I would have been better off buying an LM-1 and tuning the engine properly - you can gain way more than 10 HP and probably several MPG too. Course I bought one anyway. I have learned SOOO much from mine. LOVE IT!
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