does anyone make high compression pistons for a 170
Same here, no war, just differing opinions! Being able to explain our different opinions without name calling and insulting one another is wonderful!
Bill, I applaud you and greatly appreciate the ability to have a debate without it turning into mudslinging immaturity! So many times do disagreements on forums become overblown and childish!
That being said, I intend on proving you wrong on this boosted 170 vs NA 225 thing in the hopefully not to distant future. Or at least giving it one hell of a try!
Well, in 75 (almost 76) years, I should have learned SOMETHING about how to treat my fellow man... If I act immaturely at 75, it makes one wonder just when I am going to learn something about the proper way to act; I don't have another 25 years to get it right... lol!
I am not sure where you think I am coming from on this 170/turbo issue, but just let me say this: I agreee that theoretically, the 170- motor is ideal for turbocharging; it has the best bore/stroke ratio of any of the three engines, has no excessive piston-speed issues that the 225 has, has a cylinder head that fits the displacement better than any of the other two, and will stress the block less because of its short stroke (less leverage,) which should make the crank and mains live longer. As a candidate for turbocharging, it is the best choice among the three OEM sizes, no argument.
MY CONTENTION, is that as a street performer in the competitive venue of real-world performers, even as well as it runs, it will never be a contender to the extent that a 225 is, because it is simply too small. The 33% size-advantage the 225 has going in, is just too much of an advantage to be overcome by the smaller motor. If you build a 500hp engine, like Ryan Peterson or Tom Wolfe did, you'd need a 170 that put out 2.94 horsepower per cubic inch, almost 3... and I don't think that is going to happen. If, indeed, it DID happen, it would probably require over 7,000 rpm to get it done, and the valve train necessary to achieve coherent opening and closing at that speed, under boost, would be a project all its own...
The considerations of practicality begin to encroach on such a project. The two 500 hp 225's I mentioned employ a 5,500 rpm red-line... an rpm limit that demands very little in the way of hardware upgrades in the valve-train. 340 springs that are shimmed a bit, stock lifters and rockers work fine at that rpm.
Raise the ante to 7,000 for the 170, and the scenario changes drastically. All of a sudden, lubrication may become an issue... and spark demands may increase, exponentially... two areas the 225 doesn't seem to have to deal with.
Getting 500 HP out of a 170 on gas may be possible, but it's going to require a lot of thought, hardware, and RPM.
Getting it out of a 225 is difficult enough... Why make it any harder than it has to be???:banghead: