so i was reading this, http://www.streetlegaltv.com/news/ne...ing-sbc-block/ and got really confused as to how you can put big block cylinder heads on a sbc. i know that thing is bored to hell and back but still arent the general dimensions of both blacks completely different?

 

THINK about "bore spacing" for a couple of seconds.

If you move the cylinders farther apart in the block, what happens to the crank? the cam? the heads?

A block like that belongs in the "if you have to ask, it's not for you" category. No matter how "cool" the advertisement makes it seem. Definitely for people with cubic $$$$ to spend on getting every last possible HP out of a SBC (think: WOO http://www.worldofoutlaws.com/sprint/ ) not something for the casual novice street engine buyer.

 

so dimensionally the blocks are the same except a bbc has more thickness and width to it, but since the heads are spaced like that of a bog block then a big blocks cylinder heads can be used

 

It's not about "thickness" or "bore" or even "boring to hell and back"; it's about bore SPACING.

Think!!!!

What is "bore spacing"? It's how far the bores - the CYLINDERS - are from each other, right? OK then:

If you move the bores farther apart, what happens to the pistons?

Then what happens to the rods?

Then what happens to the crank journals?

Then what happens to the crank?

Where are you going to find a crank like that? How many sources do you suppose there are for it?

Now, think about what happens to the combustion chambers of the heads. If you move them farther apart, what happens to the valves?

Then what happens to the push rods?

Then what happens to the lifters?

Then what happens to the cam?

They don't mention deck height either. That would determine what intake would fit down in between those BBC heads. What are the odds, do you suppose, that ANY off-the-shelf BBC intake from ANYWHERE would fit that?

Bottom line, EVERY SINGLE PIECE of that motor would be a one-off.

Nice looking stuff for sure. Maybe even a "good idea" in terms of making power LEGALLY in certain classes. But practical for the rest of us... maybe not so much. Certainly not something for the casual TV watcher to install in his daily driver, mimicking the hosts during a half-hour show.

 

i appreciate, all the help, i understand what youre talking abou but when i first read it and then the other couples times i reread it, it made no sense whatesoever to me, but this definitely clears things up a bit