Raised cam

Good morning all,
I'm new to this board but not to engines in general. Had several BBF's over the years but nothing more than 500 HP.
Curious about when the build requires a raised cam block? Is it HP dependent or RPM based?
It would make sense for shorter pushrods and improved stability but i don't know where that "line" is....

thanks for any response to this.

Have a good day.

When you run out of crank to cam clearance.

djfry460 wrote:Good morning all,
I'm new to this board but not to engines in general. Had several BBF's over the years but nothing more than 500 HP.
Curious about when the build requires a raised cam block? Is it HP dependent or RPM based?
It would make sense for shorter pushrods and improved stability but i don't know where that "line" is....

thanks for any response to this.

Have a good day.

That’s a Chevy problem with their measly 9.8” deck heights

Sorry all, i meant at what performance level is it required and / or best practice?
i understand the physical limitations

djfry460 wrote:Sorry all, i meant at what performance level is it required and / or best practice?
i understand the physical limitations

"Physical Limitations" is the only reason it would be REQUIRED.

ok thank you

You can’t swing a big stick in a small yard

djfry460 wrote:Good morning all,
I'm new to this board but not to engines in general. Had several BBF's over the years but nothing more than 500 HP.
Curious about when the build requires a raised cam block? Is it HP dependent or RPM based?
It would make sense for shorter pushrods and improved stability but i don't know where that "line" is....

thanks for any response to this.

Have a good day.

This is a BBC problem.  Next to the BBC, the 385 Series is already "rasied cam" block as a matter of speaking.  There are no camshaft clearance issues with any of the common BBF stroker kits, not even with alumnum rods.

wickettoby1 wrote:

djfry460 wrote:
Curious about when the build requires a raised cam block?

That’s a Chevy problem with their measly 9.8” deck heights

Deck height has nothing to do with it. In fact, aftermarket 385 Series blocks were once available in a shorter 9.75" (and even 9.30") deck height.

It's specifically the cam-to-crank centerline dimension of the BBC that is sometimes the issue.  The Ford 385 cam-to-crank centerline is 6.078" while the original BBC cam-to-crank centerline is just 5.152" (5.552" on the raised cam BBC cylinder blocks).

Thank you all for the information.