What a quad Mr. Wteceraserman, please tell me how your eraser 520 compared to your DS650, I would be willing to read as much as you wanted to post about your "Eraser".

 

Who's Kaiser Sosei?

 

1986atc250r
sorry if I did'nt read the rest of the posts but I got to this one point and had to reply
"steel valves one word reliability"
you do understand that titanium is stronger than steel in both tensile stregnth and mallability (sp?)
don't you know titanium is also lighter that steel
so if you have two identical items one made of steel and the other made of titanuim you are going to say the steel is more reliable?
I beg to differ
titanium is stronger in every aspect over steel it will resist wear 50 times better than steel
titanium also disipates heat better than steel
titanium is also lighter and when you are speaking about valves the lighter the better due to the fact the weight of the valve train determines what rpm valve float occurs meaning the lighter the components the higher you can rev the engine with out causing damage to it and the higher you rev the engine the more air you displace in a given amount of time thus = more horse power
so that basically tell's you Honda put steel valves in this engine just to save money they can pay (there cost) 30.00 per steel valve vs poss 70.00-80.00 per titanium valve thus they saved money by giving you an inferior product period and this can not be debatable in no way shape or form (other than cost) is steel superior than titanuim if it was more reliable then what would any one use titanium for other than weight savings.
Thanks Doc.

 

Thanks for setting the record straight Doc.

 

First of all if you read all the other posts you might understand why titanium is not as reliable as stainless. It is actually a softer metal in some ways than steel and so more prone to galling (losing some of it's metal to other metal surfaces in friction contact) and also prone to elongation under heat. It is a common misconception that because Titanium resists tortional bending better than steel, that is is stronger in every aspect. It is not"harder" which is why coatings are used to prevent galling. The reason some one uses Titanium is precisely due to the reduced weight as you mention in your post, so (A) you can run a lighter spring on the same valve and save friction loss(read horsepower gain) from compressing the lighter springs - (a decent gain on a 4 or 5 valve head) at the same rpm's. or (B) using the same springs as before, increase the return speed of the valve with less "valve bounce" due to lower valve mass, and thus increase your rpm limits on the engine.

The titanium racing valves used in Nascar, and other high performance engines are typically changed after every race - similarily with those used in motorcycle racing......and they do not use the least expensive stuff but the specialy coated titanium valves to resist galling. These valves do increase performance there is no doubt, but they are not there for reliability. Most of the true"high performance" valves are well over the $60.00 to $70.00 mark per valve. Like most performance enhancements to an engine, reliability is not the issue - making it through the next race is considered reliable. In longer races where prolonged high rpm's are an issue(read heat) - like desert racing as mentioned earlier- then titanium valves may give up the ghost before the race is completed. Not to say that all titanium valves would, but the stock ones may not be the most exotic ones.

 

Thanks for saving me the trouble MDE3 [img]i/expressions/face-icon-small-smile.gif[/img]

Gary - [img]i/expressions/face-icon-small-tongue.gif[/img]

 

Sorry 86atc250r........

lol didn't mean to steal your thunder, you are obviously more than capable of defending yourself........[img]i/expressions/face-icon-small-wink.gif[/img][img]i/expressions/face-icon-small-blush.gif[/img]

 

One could easily pose the question as too whether on a high revving engine, is the heavier steel valves REALLY more reliable? Less weight, less drivetrain shock, friction, and disipating heat help keep NASCAR engines running and high rpm's helps keep an engine alive. Nascar is an extreme for engines....500 miles on a NASCAR engine is equal too 250,000 on a regular engine.

 

Anyone want to know about the performance about the TRX 250r let me know. A "guy i know" SHH!!! got one at the dealer show in cali.

 

i ment the 450r , just so use to saying 250.