Cam options


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By Litshoot - 4 days ago
Hi again, here to beat a dead horse. Im looking to get a rowdy sounding cam, but its been difficult to really hear whats out there. Building a 292, possibly a stroker in future, going in 3k ranchercho with 5 speed.

Im curious about the organ 977-280 290 on a 108
1313- 272 282 on 108
Both have higher dcr(ivc closes earlier) and more overlap at .050, advertised is similar or less. Is this line of thinking flawed, or worth moving forward to ask oregon
Seth
By KULTULZ - 4 days ago
... whew ...
I would talk directly withe OREGON CAM and/or ISKY TECH as to what you want and how to go about it.

CAM TECH has changed a lot since 1957.

Most responses here are HP.

And don't forget the valve-train.

And if/when you get a recommendation(s), share it here.
By Ted - 2 days ago
The factory supercharger cam has a reasonably rumpy idle.  The basic specs for that particular camshaft are 290° advertised, 234° @ 0.050”, ground on 110° lobe centers, and has a lobe lift of 0.290”.  I’ve always considered this camshaft to be worth about 15HP over the factory 1957 camshafts when installed in basically stock engines.  Isky can reproduce this camshaft on new blanks.

As a general rule, reducing the lobe centerline increases the engine rumpiness or lope at idle at the expense of reduced manifold vacuum at idle.  That reduction in manifold vacuum reduces the signal to the carburetor which will require some extra carb tuning in which to compensate.

For normally aspirated engines, using 110°/108° or even smaller lobe centers will give that lopey idle versus using a camshaft that has a wider lobe centerline.  For any kind of boosted application, it’s always best to use a wider lobe centerline to prevent the boost from escaping into the exhaust during the valve overlap cycle.

There is a balance between the static and dynamic compression ratios that must be maintained in order to have decent driving characteristics.  Not having sufficient static compression ratio when using a camshaft with increased duration will have the dynamic compression ratio too low to make adequate torque and be a good driver.

Here’s the link to an earlier post about camshaft selection.
http://forums.y-blocksforever.com/FindPost170419.aspx