6th Gen Heads on 5th Gen motor?

Do they fit? I've been told the 6th Gen is a better head, although I don't know if you can disable the VTEC or mod it to work on the 5th Gen as it does on the 6th Gen?

[image: View Post]chuwachi, on 24 July 2010 - 06:30 AM, said:

Do they fit? I've been told the 6th Gen is a better head, although I don't know if you can disable the VTEC or mod it to work on the 5th Gen as it does on the 6th Gen?

No and no and no :biggrin:

I've never seen any evidence or even heard suggestions that 6th gen heads are better than the 5th.
There is no way (short of divine intervention) to either remove vtec or to install GDC from/to the 6th gen heads.
Why in the world would you even want to do something like this?
GDC is where it's at.
Just enjoy the hek out of your 5th gen. Those heads will last forever and if they ever explode, you can buy a new set on eBay for next to nothing.

[image: View Post]chuwachi, on 24 July 2010 - 06:30 AM, said:

Do they fit? I've been told the 6th Gen is a better head, although I don't know if you can disable the VTEC or mod it to work on the 5th Gen as it does on the 6th Gen?


They won't work. The 5th. gen. uses gear driven cams and the 6th gen. uses cam chains.

The subject of disabling VTEC is something that gets discussed here often and the consensus is to leave it alone. I've only read of one instance in which someone was able to get all 16 valves operational at all times. I also read it ran horribly. Maybe the guy was still working on fueling issues, I don't know. As for the 6th. gen having superior heads, that's debatable. While the 6th gen. does put a couple more horses than the 5th gen., who can say for sure these two horses are attributable to head design.

I once read of an Englishman on the European VFR forum that installed an entire 5th gen. motor into his 6th. gen. VFR. It ran quite well, too. On the other hand, I don't think I've ever heard of somebody installing a 6th gen. motor into a 5th gen. VFR.

If you really want more power out of your 5th gen., your best bet is to install a supercharger. RWHP (rear wheel horsepower) will increase by over 50%. If you just want slightly more horsepower, then just do what everybody else does and get an aftermarket exhaust canister, PC (power commander), and a better air filter. If your bike doesn't already have them, you can also get catless headers (only the '98-'99 had them.) Another option is to play around with the bike's gearing (i.e. the sprockets) for better acceleration. While this wouldn't give you additional horsepower, it'll give you a mechanical advantage.