What is everyone's engine design preference?

[DavidBoren]

Thanks for the replies. And keep them coming.

I hear you about the long stroke increasing piston speed overall, and I figured that it will still be at a higher speed at TDC, than that of the 5.3 piston. But it's no more than that of the other LS engines with a 4" throw, and people spin them plenty fast without detonation issues. So I think I will be ok there. And, I'm looking for torque, with absolutely not a single care of what the peak horsepower ends up being.

Horsepower sells cars, torque wins races.
-Carroll Shelby.

My focus on torque is what led me to the 359 stroker. I'm not all caught up on big cubes or high horsepower. I want a streetable, fun, torquey motor that meets some simple theory criteria I have put together, namely being undersquare.

I want to stay with the 3.78" bore, instead of the 3.9" bore, because the blocks use the same sleeves, so the 4.8/5.3 sleeves have more "meat" than that of the 5.7 sleeves. So the thicker sleeves will handle the extra side load on the pistons from the increased stroke. And the thicker sleeves will handle boost better (if I can ever afford a W180AX for it).

Or at least that's my thoughts on using the 3.78" bore. Wiseco makes forged slugs for the 5.3 with the correct pin height for use with a 4" crank and 6.125" rods, and all the other parts will be stock LS parts.

[Flash68]

Interesting thread. At least it doesn't talk about Camaros... yet.

I really became interested in the Nascar stuff after seeing the teams give away their stuff on the used market after their "life cycle" was used up.

But I also wanted/needed something that didn't have to be rebuilt every 500 miles (1 race).

As much as I would love to play with a 9000 rpm motor, I wanted to gain the needed low and mid range torque and bring the powerband down for durability and less maintenance. So a 4" stroke was used instead of the 3.25" that the Cup cars use.

4.170 x 4.0 = 437"

Of course with the small chamber size of the SB2.2 heads (mine are 51cc, many are in the 40 something range) this made piston design pretty much impossible to achieve 11:1 to 12:1 in order to get to pump gas range. So, to minimize the dish in the piston and keep it "acceptable" according to my engine builder we ended up around 13:1 compression. So, the other pump gas came into the picture... E85. Several stations not too far from me. I am good with that.

Even though a .800-.900 lift cam would be right at home with the heads, we decided to use a milder cam (.660ish net lift) with a lower rocker arm ratio (1.7 instead of 1.9 or 2.0). Again, all to keep things lower maintenance.

I really wanted a toned down Nascar motor with all the cool parts and look but not the rebuild cycle. Time will tell but I think we achieved that without giving up the BIG power. In fact the trade off to gain the torque is what I am really excited about.

640 ft #s out of a pump gas SBC. I'll take it.

[DavidBoren]

Thank you, Flash. That is exactly the sort of answer I was looking for. I have heard that it is better for the longevity of the valvetrain to let the cam do the work, instead of compensating with higher ratio rockers. That sounds like a nice engine you have put together. 600+ pounds of torque is no joke.

I was also thinking that using the 4" crank, would slide my power band to the left. I might even use a truck cam in it for the initial build. I'm looking for a relatively tame, yet torquey, motor that I don't need to rev the piss out of.