CBR RR throttle bodies

[jtopiso_imp]

I had a cyl head ported on one of my modern cars- spent a couple thousand all said and done on the project (spare head, shipping, porting, gaskets, etc to install)

The head showed great improvement on the flow bench. Made zero gains on the dyno.

Again- not everything that worked on engines from 30-40 years ago still applies.

Stuff like cams, muffler, fueling- sure because we are removing intentional limitations Honda had with sound, emissions- but stuff like TB and valve sizes, cyl head port shape and casting flash flaws, well I'd really be surprised to see any big gain. But lets see if we can dig up the valve sizes for S&G.

1140cc is a good amount of displacement- agreed.

I agree. The CB is limited due to emissions, consumption, noise, durability... but I am sure it is also as efficient as it can be, so the "volumetric efficiency" must be pretty much optimized from stock: there won't be any signifficant bottleneck on its breathing.

A different thing is that valve timing can be changed to get more power on the high end (at the cost on losing some on the low end, or worsening emissions, or some other regulations the CB must adhere to from stock)