[piscorpio]

Originally posted by Rice-Rocketeer
Nono, As I said in the first post, you can change anything you want about the engine. The only problem is you need to know what you're doing. If you don't, you need to get someone that does and having them fabricate stuff for you will cost you thousands. Now to change the R/S ratio you need to change both the rod length and the rod stroke length. To do this you need to get custom length rods (Not too hard) and you need to have your engine destroked. It's exactly like a stroker kit (And as expensive as well) you get a new crankshaft and various other bearings and things and this new crankshaft needs to be of a specific size. It's all math is what it is. If you can crunch the numbers and figure out what length rods with what crankshaft you need to get the magical 1.75 then you have no problem.

The problem is ppl goto college and spend years around race cars to learn this stuff. Think of this magic number as the point where everything is balanced. When you blueprint and balance an engine, you are relieving stress in a lot of areas because as unbalanced engine reciprocating components climb the rpm range, they get more and more unstable until they exceed the stress levels of the block and destroy themselves. Try to imagine an engine that's missing a piston rev to 10,000 rpm. Now imagine not climbing to 10,000 rpm but strapping a turbocharger onto this unstable engine. As the rpms climb, the extra force on the components will make things MUCH worse. It'll make the engine even more off balance than it was and it'll destroy itself with normal usage.

When you change the R/S ratio, you essentially have an engine that's fully balanced. And when you do that, the stress on other components that are not involved in the power making process is relieved. A fully balanced engine can rev higher and take more boost before engine components exceed thier maximum stress levels. Simply beefing up components on an imperfect engine is only a bandaid. It's not the solution to the problem.

But like I said before, if you're going to squeeze that much power out of your engine that R/S ratio is a concern, then you should be starting with a better base. You only need to worry about the stress the D16Y8's imperfect ratio will create if you plan to make some serious power OR want to keep the engine for 300,000 miles. For your average honda enthusiast, You shoudn't need to worry about such things. Like I argued in some other post, you could do an LS/VTEC swap, do the usual bolt ons and get forged rods and pistons. Rev limit it to 7500-8000 rpm and tune it accordingly, and you'll still have 200 wheel hp from a rather reliable engine. If you plan to make a 500hp dragster then start with a better base.

I am so sorry RR, you know I totally overlooked your first reply!! I understand completely what you are saying now. Thanks for writing this thread up man, its kind of opened up a new area of technical info for me, something new to learn about. (which Im always up for)