Calorific? Is that like splendiforous Tigger?:p Just teasin'...I didn't see an occupation listed in your profile, slimdave, but if you're a student like seemingly 90% of the people in this Forum, that would make a nice treatise. "That" being the combustion characteristics of the rotary "window" combustion chamber. To all the studentins out there--any takers?
ps..it's "caloric" as in caloric bomb, isn't it? I've been outta school a lllooonngg time but I do remember the bomb bit from Physics...

 

No, not a student, but I have qualifications in Marine engineering, and a Masters degree in aeronautical engineering (so let me tell you that those big aerofoils on the back of riced-up civics - or anything really - are a piece of ****).

"Calorific" is what I've always been told. "Caloric" sounds like Jules Verne to me, but who cares. You say potato, Dan Quale says potatoe.

That "delayed combustion" thing is a bit elementary really. It's equivalent to the loss in volumetric efficiency that you get a very high revs, and applies to rotaries and bonigers alike . Big industrial diesel engines like those made by B&W or Sulzer get incredible efficiencies through running at below 100 rpm. Same thing. If the higher octane takes longer to burn, then that's what happens.

 

My bad...it's bomb calorimeter, used to measure the BTUs of a given substance..ie. its energy content.

 

Hey you Ohio people, I was inDayton two weeks ago and this guy on Hoover street has a gsl-se, cream color just sitting in his driveway rotting away...You can tell it has been sitting for years..It had 99,000 miles on the odometer ( I guess I was trespassing cause no one was home..ooopps)..Wish that guy would do something with it cause it had potential...cjf

 

Well, it ain't me. Mines rotting away in the garage. I may have a little cruise past there, see what the scenario is with the owner. Is a GSL-SE a good thing?

 

Most ppl agree it's the best of the 1st gens.

 

Either one is correct for this application of the derivation of calorie, I checked the big Random House Dictionary. I've always used caloric, but calorific is apparently OK too.

I agree on the big airfoils on Civics. Even better than that is ANY spoiler on a Hyundai Excel. Rice! At least my wife's Regal doesn't have one.

Simply put, on a boinger there is a better crank angle several 10-15 degrees after TDC, so peak combustion pressure MUST come somewhat after TDC. If preignition causes peak combustion pressure to occur before at or near TDC (detonation), broken parts definitely are a possibility. I would think it a little less important on a rotary. Then again the apex seals ARE a bit fragile and if it occurs before TDC, then the combustive force would be trying to move the rotor backwards (detonation) at the same time as the eccentric shaft is trying to move it forward. Oops, broken apex seals at the very least, maybe cracked housings or blown gaskets too.

On octane, on NA use 87, on turbos use higher octane. The higher the octane the slower the combustion. Detonation is not always caused by preignition, sometimes it is caused by too much spark advance at given conditions, i.e. ambient temperature hot, lower octane gasoline (burns up too fast) etc. The reason ignition is advanced at higher RPM is because the speed of combustion or flame front is not changed by engine speed and there is less time in the combustion cycle to create the needed peak pressures at the right time to make the most power. Thus centrifugal advance starts the process earlier.

Hell, I lost myself there. Derailed my own train of thought.

 

The definitive answer. It's obvious you could lay out a thesis on the subject, thanks for contributing!