I like the know the pro and con on bored out versus stroked 383 LS1/LS6 engines, if I am getting the whole engine (and the installation) from one of your excellent sponsor tuners.

I am looking for an engine that gives me good low end and mid range torque for streets and occasional spirited road track uses. My vehicle is a Camaro SS. I drive around 15,000 miles a year, so reliability is also a factor. My intention is this is the last engine mod that I am going to do to my SS for a while.

Yes, I am also prepare to get clutches, drive shaft and a 12 bolt 3.73 rear end plus a bunch of chassis, brakes, and suspension mods to balance the car. (Yes my SS is a 6 speed)

Thanks in advance for the advices

leungken <img border="0" alt="[Camaro]" title="" src="graemlins/camaro.gif" />

 

well this wont be a complete list but ill add what i know.

the advantages to all bore motors are better head flow because you can go with bigger valves and not get valve shrouding. also boring instead of stroking keeps the engine able to rev high, most stroker motors dont really rev high or fast.

stroker motors tend to rev less but they dont have to rev as much because they make lots of torque down low, one advantage of a stroker motor.

cant think of any disadvantages of an all bore motor but im sure there are some.

a stroker motor would run into the aforementioned valve shrouding with bigger valves, a bad thing when trying to feed 40+ cubes over stock. there are heads that do flow quite well on stock valves but a little extra bore never hurt anyone. most would rather have more bore than stroke though. im sure theres lots to add to my list but those are the basics of what i know.

 

I'd rather have the all bore motor. the only "disadvantage" to an all bore motor is you must have a shop that knows how to fit the bore liners CORRECTLY.

 

So what you said is, if I am looking for low and mid range torque increase, a stroke motor better fit my applcation then, correct?

 

Let me take a shot at this.

"the advantages to all bore motors are better head flow because you can go with bigger valves and not get valve shrouding. also boring instead of stroking keeps the engine able to rev high, most stroker motors dont really rev high or fast."

This is very good, all of these points are correct. In fact a head on a larger bore without larger valves will give you better head flow numbers. The reason you don't rev a stroker high is because the long stroke limits the engine rpm because the piston is moving faster, putting more stress on the internal parts.

"stroker motors tend to rev less but they dont have to rev as much because they make lots of torque down low, one advantage of a stroker motor."

If you have two engines that are equal in cubic inches, rod length and only change the bore and stroke the engines will have the same torque curve down low. The mysterious torque gain from a stroker is not because of the mechanical "lever arm" advantage of the longer stroke, it's the fact that you just increased the cubes!

"cant think of any disadvantages of an all bore motor but im sure there are some."

Weaker cylinder walls is one, but if done right you should have no problems.

"a stroker motor would run into the aforementioned valve shrouding with bigger valves, a bad thing when trying to feed 40+ cubes over stock. there are heads that do flow quite well on stock valves but a little extra bore never hurt anyone. most would rather have more bore than stroke though. im sure theres lots to add to my list but those are the basics of what i know."

I agree, with a larger bore and shorter stroke you can rev the engine higher, have less stress on internal parts, the engine can breathe better and you can even add larger valves and larger head ports due to the increased cubic inches.

One more plus to the all bore motor is that you don't need a new crankshaft, pistons and rods, just new pistons (& a re-sleeved block) Right now with the price of the Lunati crank, I would rather spend the money on the re-sleeved block.

Strokers were the cheap way to get more cubes, not on this engine.

Bret

 

The only negative issue with the all-bores is the potential for a dropped liner.
Cheers,
Chris