[IntegraBad18c]

I was (yes, I did, believe it or not) flipping through a Super Street mag at work today. I noticed that Toda made a stroker kit for the b16. It made the b16 have 1.8 liters of displacement. Would this be the same rod length/stroke length (same rod ratio) as our one of our b18's? Considering the port volume size of the b16 head, this engine package would then be similar to that of the LS/VTEC, no?

 

[IntegraBad18c]

BTW, I'm a lazy SOB. I've been through your articles a couple times around. And, yes, I'm still working on a chart for that rod angle/crank angle trigonometry crap I was doing....I didn't want ya to think that I'm asking new things before I finish what I started.

Anyhow, what the hell is a rocker arm ratio?

 

[MichaelDelaney]

the Toda kit is basically a CTR rod at 134mm length on a stock 87.2 mm stroke B18C crank and their forged domed pistons with the correct compression height so that everything tucks in nice and neat inside the b16a deck height. Everything is of course blueprinted. Can you do this yourself for les than what Toda charges? absolutely. The rod ratio is 1.54.

A rocker arm ratio is the multiplication factor that the arc of the rocker arm imparts to the max.lift provided by the cam. So the actual total max. valve lift is a mathematical product of multiplying the cam lift by the rocker arm ratio.

The rocker arm ratios are only fixed at max lift on any of the Hondas.

However, the length of the wiper pads makes the ratios variable. You can't just multiply a "fixed" ratio number times incremental cam lifts to see what's to happen at the valve at all cam degrees.

This is why an actual Honda head must be used to measure actual valve timing, if you're actually concerned about the "important" part of cam timing (namely the overlap).

The rocker arm ratio for B series at max. lift is 1.58.
cheers