I'll go back and read SOME of the links a bit later. I don't give a crap what Summit and HR magazine publish.
I'd actually rather read an SAE paper on it, but I don't know where to find a good one specifically on the topic. I may make a few phone calls and see if I can scrounge a few SAE papers to read.
That said, I'll say this again. Real world testing, to the point it became ignorant proved there isn't jack squat to be had.
I was working my own program whole also working on a circle track 9.5:1 engine program. Low CR engines are a giant pain in the *** for several reasons. Exhaust heat being one of them. This was about the time all the Pistons became available that had reverse domes, and trench cut valve reliefs and all that other trick of the minute crap.
At the time we were using a full round dish piston and every whiz bang in gym shorts was telling us we left power on the table. I can't hear that an pad not try to fix it. So the sponsor boned up for brand new, reversed domed Pistons for us.
Bad news. That came with the pin .015 low so instead of the .045 piston to head we had, we now we're at .060, the so called "death rattle" distance.
I'd already spent way too much volunteer time and WAY TOO MUCH of my money on this wild goose chase to stop and deck the block or mill the heads again (a thing I hate to do anyway) so we made the decision to run them and prepare to reduce the timing to control the detonation we were promised which would destroy the whole engine in a matter of a couple of pulls on the dyno.
Dyno day gets there and the three of us prepare for a significant power loss just from the reduced timing, let alone.
And guess what?? The exact same CR with the new piston and the extra quench and you lay one dyno pull over the other. How could that be? Every single engine wizard in the country said quench mattered. Lash loops and timing changes showed us the exact same everything as the so called junk dished Pistons.
The sponsor watched all this and was mighty pissed. We were told we would now rotate the earth with his new slugs. It didn't happen. We even changed the ICL twice to see if the Newcombe wanted something else. Didn't matter. So the sponsor called the piston guy and he said they'd make the piston with the pin .015 higher and a deeper reverse dome, but the Pistons would be heavier. And we were told this would gain us what everyone promised So we paid half cost on those.
All the work, all the time and absolutely zero. Nothing. We ended up with 3 more designs that we paid for and not a single one made any difference.
One piston dude said the reverse dome needed to be very shallow. Another said it needed to be deep and mirror the chamber. Another said a round dish was the best.
Due to the limits of the compression ratio, the various changes to the different Pistons required a different compression distance.
I used to remember how many pulls we made, but we wasted a whole offseason chasing that infamous quench distance down. And it didn't make a pinch of crapola difference.
We thought we were just stupid so we just ran the car and ran very well. I was still working on my drag engine and I stopped worrying quench.
Almost 15 years later, I was working with another local engine builder, sharing flow data from our two different flow benches and discussing things we found using various valve jobs and such and we eventually came around to quench. He says he went through a time where all they did was chase quench. He found zero, just like we did.
In the end, he said I only do quench to get the CR I want. If I don't need the CR I don't do quench, unless the customer is brainwashed into the quench fantasy.
Across the years, I've run across several engine builders who found the same thing. And the answer was always the same. You can't out educate the interwebs and the comic books. So they never try and convince anyone that quench isn't what they are told it is.
I can recount other trips to the dyno to find the same results.
Quench doesn't matter in the grand scheme of things. It may help with a crap plug location. It will help with emissions.
That's about it. If you need the CR, by all means close it up.
BTW, in subsequent testing (we were hard headed and stupid and just couldn't believe all the hero's were wrong) we started playing with quench verses compression ratio.
Every. Single. Time. The power went up, it was CR related. Never once did power go up based on quench alone.
I can't say any more. Other than quench won't fix your issues. If you have too much CR for your fuel, closing the quench (which raises the CR BTW) will do zero for the detonation issues.
Before I forget, we tried locked out timing, slow curves, fast curves...much anything you can imagine. In the end, they all ran the best with with virtually identical timing curves. None liked to be locked out.
