ideal stroke for a turbo? shorter or longer?
 

More random engine thoughts....

I know that the shorter stroke engines rev higher, have better rod angularity characteristics, and are very durable. The shorter the stroke, the more bulletproof the motor. Does this idea only apply to NA motors, or do turbocharged engines see a benefit from a shorter stroke.

I don’t see a lot of short stroke 2.5, 2.6, or 2.8 turbo motors. I probably don’t see them because it’s just flat out easier to start with a 3.0 or 3.3 turbo engine. Okay, fine. I'll accept that. That doesn’t explain why I don’t see a lot of short stroke 3.2 (98mmx70.4mm) turbos. It’s also not uncommon for people to use the early 3.0 turbos as cores for short stroke NA rebuilds.

Does a turbo see any benefit from the higher revs that a shorter stroke engine is capable of, or is it better for a turbo to have a longer stroke like on the 74mm 3.3's, and 76mm 3.6's.

The 3.3 and 3.6 turbos are obviously capable of insane power, but at much lower RPM than a short stroke NA motor. What would a short stroke turbo be like? Is it counter productive t shorten the stroke of a turbocharged engine?

Let’s say it’s a 66mmx98mm on an early 3.0 case with custom JE's and EFI for the sake of discussion.

TIA

Read max. Boost by Corky Bell for some insight (well worth the $$) long stroke to take advantage of the low end torq.....never see a short stroke diesel....thats what I think I know and it changes from time to time

From what I understand, most guys prefer to have a little more stroke to give the the bottom end of the powerband a little more umph until the turbo can spool up. You can make up for the reduced ability to rev by changing the rod ratio and lightening up all the components. This is the same thing we do with the 914 when we get up into the 2.6+ litre range (4 cylinder of course).

Charles Navarro
LN Engineering
http://www.LNengineering.com
Aircooled Precision Performance

totally depends on your desired powerband, same as NA. most turbo engines don't tend to rev super high but that's a property of the tuning, not the fact that they use a turbo.