Sohc Vs. Dohc

[plkmonster2]

So what is so much better about the DOHC? I have a scenario for you all. Ok, so you have 2 identical bikes, and one has a head with a SOHC, and the other has DOHC's. Lets leave all other variables alone. Now, both engines have the same duration, lift, and overlap on the cams. Now, in this situation, what makes the DOHC better than the SOHC? Like comparing the 400 to the Z400. Soemone told me that the secret is in the higher compression, which I know is better, and the 2 seperate cams. How can 1 extra cam give more power with the same variables? Don't they add rotating weight? Or is it that you can alter the exhaust timing to suit bottom end, or top end, liek people with the YFZ's do? Thanks! And Wilkin250r, please respond!

[chazekxt]

the dohc will rev a lot faster

[plkmonster2]

Ok, nevermind. I decided to use the search, lol. In a previous thread, wilkin posted that they don't have to use rockers, and are more precise. I see now.

[bradley300]

but a SOHC designed like a 450r's unicam, which is better? it seems the unicam has the same benefits as the DOHC, but with less rotating mass

[bwamos]

The benefit of the DOHC over a SOHC is that it allows a different angle/pitch of the valves a the top of the engine.. allowing a more precise entrance/exit of the gasses into the cylinder.

The SOHC on the 450r simulates a DOHC w/ less rotating mass.. so in "theory" it's actually the better setup.

[wilkin250r]

Sorry to take so long to reply. I generally don't get on much during the weekends.

I don't think the added rotational mass is really that significant. Compared to the crank, flywheel, and counterbalance, the added camshaft is a fart in the wind. Its like adding washers to your lugnuts on your tires. Yes, in theory you're adding rotational mass, but is it really significant compared to the rotational mass of your tire?

[Juggalo]

wilkin, old friend, sometimes i dont know what this site would do without you. haha

[plkmonster2]

Lol for Wilkin... haha. He always has the best metaphors...

[wilkin250r]

Originally posted by Juggalo
wilkin, old friend, sometimes i dont know what this site would do without you. haha

Everybody would still think that high-octane will make you go faster...:blah:

[sickmojave]

Originally posted by wilkin250r
Everybody would still think that high-octane will make you go faster...:blah:

you mean to tell me it don't.. :eek:

LOL J/k

[UglyMotha™]

Originally posted by wilkin250r
Everybody would still think that high-octane will make you go faster...:blah:


according to last post i read they still do :confused: