528 Stroker Hydraulic Roller Cam choice....another one.....

[Moparict]

I am building a 528 stroker with 10.5:1 compression. TF 270 heads and a Hogans racing forward facing fuel injection intake manifold (Think Holley Low-Ram kinda thing). In my 440, I had a hydraulic flat tappet cam with 230 degrees of duration at 0.050 and it was a great street engine with stock heads and carburetor. How do I choose a hydraulic roller that peaks around 6K for the stroker? My gut says 250 degrees of intake duration at 0.050 would do it due to engine size delta and the increased flow of the TF 270's over stock heads (larger valves).


Am I too far off?

 

[radical rob]

Sounds close. My 494 runs 245/246

 

[PRHeads]

In many engines that use some sort of hydraulic lifter, often the ceiling of the power band is limited by the lifters ability to not get into a “collapse” situation during higher rpm operation.

Assuming you’re able to avoid that pitfall, a 250*@.050 HR lobe would support a peak in the 6000 range, provided the other components involved(heads, intake, headers, throttle body sizing) are also on that same page.

We had a 505 on the dyno here a couple years ago.
EZ-295 heads, Indy dual plane, QFT 1050/4150, 2-2 1/8” headers, 245/251-110 HR cam.
Peaked at around 6k, although it was more of a plateau than a “peak”.

 

[Paul_B]

I’m running a 245/256 duration hydraulic roller cam in my 528 hemi. It’s pretty much done making power around 6000 rpm and idles around 850 rpm. It has an almost stock sound of a muscle car but with just a touch of lope. I’d describe it as a muscle car with the cam turned up one notch.

The bigger inch engines do tame bigger cams.

 

[496 polara]

Be prepared for it to peak early. Mine did. 505 with 240 heads and a 247/253 hyd roller peaked at 5400rpm. Granted it still had over 600hp at 5800.