Desk top dyno

[bigal389]

4.6 with Late cam with 1.7 Rockers, 1 ft. lb. of torque rises at higher RPMS

4.6 late cam 1.7.PNG

[Cheromaniac]

Higher ratio roller rockers or a performance cam won't add much if the engine's still choked off by the stock head, stock throttle body, and stock airbox.

[jeepxj3]

Yay, right side up.

Also the 1.7:1 roller rockers add 2-3* more duration to In and Ex.

Could re-calculate with 1.7 and +2* duration and +3*duration.

[bigal389]

Mopar 229 with 1.7 rockers plus 3* of duration the 228 effectively became a 229 when 3* was added

Capture.PNG

[jeepxj3]

Thanks.

That shows that the 1.7:1 roller rockers will add +1HP at 3500, +5HP at 4000, +12HP at 4500 and +15HP at 5000 on a Mopar 28 cam when compared to 1.6:1 rockers. And that is exactly how the 1.7 roller rockers make a stock cam feel. They add more power and extend the rpm range instead of falling off at 4000rpm.