Bore vs stroke increase effect on X cam?

Probably too broad of a question, and I know testing is the best answer. Or maybe a thread has alredy covered this? Also understand each will require an different cam to optimize power.

But is there general input? Example is 4.420 x 4.300 528" engine. Have a given cam. Now increase the bore to 4.560 and leave all other parts equal, 562"

Versus: Increase stroke to 4.600 or X amount to create similar cubic in outcome, and leave bore @ 4.420. I assume torque will gain a good bit vs the bore increase.

How far away is the original cam getting away from being optimal for its intent using differnt methods of inch increase

Having seen this topic before, I remember a discussion about it several years ago on some other forum.
The prevailing opinion was that the increase (or decrease) of stroke has the greater affect on the combo. Because of the increase in piston speed and the greater signal it will pull through the intake tract.

Piston speed sets the demand the airpump creates. Changing stroke is a much greater change on demand then changing bore. Changing bore to increase it can help camshaft allowing the head to flow more air in.

[quote="J.Toney"]Probably too broad of a question, and I know testing is the best answer.  Or maybe a thread has alredy  covered this? Also understand each will require an different cam to optimize power.

But is there general input? Example is 4.420 x 4.300 528" engine. Have a given cam. Now increase the bore to 4.560 and leave all other parts equal, 562"

Versus: Increase stroke to 4.600 or X amount to create similar cubic in outcome, and leave bore @ 4.420. I assume torque will gain a good bit vs the bore increase.

How far away is the original cam getting away from being optimal for its intent using differnt methods of inch increase














What cly head is being used,and intake?

TFS A460's, later TFS intake