cam

[tealcherokee]

That's the perfect cam for a supercharged application. Even if you keep the engine naturally-aspirated, it should provide good low rev torque and a smooth idle.



I don't know what you were researching but you're mistaken. A dual pattern cam with a longer exhaust duration is exactly what you need in a 4.0 or stroker 'cause the cylinder head port flow on the exhaust side is less than 70% of the intake port flow.
I can tell you that my Crane cam works beautifully with strong torque from idle to redline. What more could you want?

well the guys at clifford sent me some stuff, and i found it pretty intersting, give them a call, they love to talk about stright 6's

 

[brent]

I ran the hesco rvob for about 2 weeks after the stroker, hated the thing, wouldn't idle worth a crap, it had diffrent lift / duration for exhaust/intake, I changed the rockers to rollers, still didn't like the cam, then changed the valve springs and went with the clifford 264/264, idle is smooth as stock with the same mid and top end and better bottom, than the rvob. so I sold the rvob on ebay for $10

 

[tealcherokee]

single duration is better for the straight 6, hands down. high lift also is a plus.

 

[Dr. Dyno]

I ran the hesco rvob for about 2 weeks after the stroker, hated the thing, wouldn't idle worth a crap, it had diffrent lift / duration for exhaust/intake, I changed the rockers to rollers, still didn't like the cam, then changed the valve springs and went with the clifford 264/264, idle is smooth as stock with the same mid and top end and better bottom, than the rvob. so I sold the rvob on ebay for $10

The Hesco RVOB is a single pattern cam with a duration of 214* @ 0.050" intake and exhaust, valve lift 0.470" intake and exhaust, and a LSA of 110*. The reason for the lopey idle is the narrower LSA which produces a greater amount of valve overlap, and the intake duration is comparatively long.
My Crane 753905 is a dual pattern cam with a 112* LSA and the idle quality is the same as stock in a stroker. Bottom end and top end are strong, midrange is sensational.

 

[j99xj]

The Hesco RVOB is a single pattern cam with a duration of 214* @ 0.050" intake and exhaust, valve lift 0.470" intake and exhaust, and a LSA of 110*. The reason for the lopey idle is the narrower LSA which produces a greater amount of valve overlap, and the intake duration is comparatively long.
My Crane 753905 is a dual pattern cam with a 112* LSA and the idle quality is the same as stock in a stroker. Bottom end and top end are strong, midrange is sensational.

Interesting. But how did Jeep engineers manage to make the 96+ engines idle smooth with an LSA of 107.5 degrees?

It would seem that a 107.5 degree LSA would be far too tight to run on a vehicle that needs a smooth idle with lots of intake vacuum.

Perhaps they had supercomputers run a fluid dynamics model with many differential equations to get the numbers they wanted.

Well whatever they did, they did good on the 96+ engines. It's almost a miracle that they could lower the torque peak by 1000 rpm without affecting the top end horsepower number of 190 with only tweaking the cam settings.

 

[Dr. Dyno]

I agree that the '96+ OEM cam is a pretty good unit and the main reason for the smooth idle is the short duration (188* intake/192* exhaust @ 0.050") and the short valve overlap despite the 107* LSA. As you can see, it's a dual pattern cam with a longer exhaust duration. Its only downside is the modest valve lift (0.408" intake/0.414" exhaust), but that's nothing a set of 1.7 ratio roller rockers couldn't fix.