Titanium Valves

[Sandy 191]

Rolling road figures are open to alot more error than engine dyno, knowing or un-knowing. I dyno alot of 2 litre engines, from some of the best builders in the country and it's extremely rare to see any genuinely keep making power beyond 8500rpm, but in rolling roads, they often seem to carry on, because of the climb of the "transmission loss" correction. I know from my own use of rolling roads, that quirk can be made favourable as desired. I'm not an armchair critic or an envious competitor; first and foremost I try to present the facts as I see them. Worth noting that at 4500rpm, that "300+bhp" engine graph, showed less torque than one of my full race 1400s, make of that what you will!

 

As I've said before on this subject, any engine that can be reliably revved beyond 9k rpm fairly regularly, without spewing its guts, is clearly well assembled and I don't doubt the engines in question will bear good comparison with their peers. However, personally I prioritise the broader power curve, driveability, durability and reliability over headline power figures, which taken alone don't tell you much about the overall standard of the engine and since most of the people on this forum will not have a bottomless pit of money for jewellery components and potentially regular problems and rebuilds, this is relevant I think.

 

Putting another engine to compare in the rollers etc, with or without the arrogant bravado of a childish wager; is not going to tell which engine is better, even if the top line figures are the important issue, the operator can deliberately or unwittingly create errors in the readings. An engine dyno is the only place that truly scientific figures can be recorded (but still requires suitable climatic correction and a disciplined operator). Rolling roads are not truly scientific and everyone should understand that.

[kyepan 291]

the David vizard video i posted covers titanium valves and valve springs.

[Matts205gti-6 3]

I understand all your points and don't want to fall out with anyb

[Matts205gti-6 3]

Anybody and sandy I know what you are saying its just a lot of time money has gone into the build and I'm discussing about the 300bhp titanium engine when I have the steel version which is just as good for less money the point I'm making is my engine is a claimed 283 bhp on the rollers and I've done a 12.4 @ 114 mph is that not impressive for an engine like this? That's all im saying ? Everybody has a point of view but slating another company or engine or car is out of order I have not written any negative comments about anybody else's builds. Cheers

[Sandy 191]

I can't really relate 1/4 mile times I'm afraid, I've not really got any experience of them; but I would imagine the car/tyres/driver are major factors as with any discipline. Dave P's hillclimb 1600 106 rallye did a 12.7s @110mph at Crail in the damp, with ~195bhp, that's about the only yardstick I have.

 

As I said, I don't doubt the engines being discussed are good; but how they are being compared to others, isn't really precise or representative of overall performance/quality.

[Matts205gti-6 3]

Ok good let's move on I would rather discuss things, rather than have negative comments written on here, on another note have you had any experience or rate a dog box set up for gti-6 I'm thinking of going down that route but not sure how reliable it is with a high revving engine?

[dcc 855]

Im sure phil (pip470) had 220bhp and ran an 11.8?

[Matts205gti-6 3]

13.8 I know him 11.8 would be a world record for front wheel drive n/a

[dcc 855]

Ah!

 

We were both wrong...

 

He ran a 12.808

[Matts205gti-6 3]

Lol I was gonna day 11.8 would have been very impressive

[pip470 61]

Hellooo. 12.8 is my best. 11.2 seems to be the best in the uk with alvins old civic in the fwd n/a class. That car will probably the first in the tens. 12.4 is a great time. Threads like these are really counter productive. What I like most about 205's is how versitile they are. A few of us like drag racing, more like track driving, some like the occasional sunday blast. The thread cybernik posted too about yhe guy who likes to sew hiz 205. There all great things we are doing with 205's and thats what makes us a good community. Lets not start comparing each other to find out who is the best.

 

I think titanium valves are only needed in extreamly high reving engines. They are expensive and reasuringly shiney which I think is important. Im using standard valves for my build and we will see how it does.

[Matts205gti-6 3]

Great comment mate I'm going Santa pod tomorrow if your about ???

[pip470 61]

Id love to but the shift work im on always seems to clash so im on the next two nights. Ill be there for flame and thunder though to get one last fix to keep me going over Christmas. Good luck tomorrow, I hope you get the weather as its like Russian roulette at this time of the year. Let us know if you beat your time.

[Matts205gti-6 3]

Thanks mate will do keep you updated might go to flame and thunder hope weather is ok forecast looks good !!

[pip470 61]

A cool video of where the uk is at.

http://vimeo.com/30638519

[TT205 42]

F*cking gearbox

[Tom Fenton 1,542]

Ha ha, been there done that, it is unbelievably frustrating when you know that elusive time is in the car, but you can't quite get it all just right.

 

Anyone know what 60ft times the top boys are pulling? I've done a 1.67 which felt bloody awesome.

[Matts205gti-6 3]

1.8 the best I've managed 60ft

[DanteICE 72]

On the topic of titanium valves, I'd say that pure titanium would be off the cards due to the poor frictional qualities of titanium. That is, unless you know the secret that the formula 1 boys use to have almost pure titanium gears for the gearbox. I don't know what titanium alloy you'd need to use though tbh.

 

Geoff

[MiniGibbo 142]

One none of us could afford..?

[DanteICE 72]

Well I can't say much because I really shouldn't know about it but in reality it's amazingly simple. I'd guess with a bit research you could find out how they do it.

[DanteICE 72]

F**k it.

 

http://www.patentgenius.com/patent/6210807.html

 

For anyone who cares. It basically is a method of adding oxygen to titanium which "shown that the coefficient of friction of commercially pure titanium markedly decreases when it is heated in air at 350.degree. C. for 17 hours"

 

Boom! Simple...ish.

[MiniGibbo 142]

Interesting stuff.

[calvinhorse 870]

 

The main issue with Titanium is that it wears out machine tools very quickly, and that it is not that stiff compared to most steels, though it is far lighter.

 

 

It doesn't wear tools out quicker than steal especially stainless and certainly not inconel

[SurGie 54]

Its the refining side of things with titanium, men in white coats and the use of magnesium sp is where the costs come from. It has to be heated to a very high temp then compressed or tempered type of process to make it what it is.