Valve Springs

[dswiders]

Guys,

What sort of springs should be used when changing over and at what cost ?

Would it be advisable to change them for the Stage I or II ?

Daniel.

[Pretzel]

Thanks for the explanation Peter, I shall be putting better Valve springs into the required upgrade list !

a car would have to ping very hard and for a long time to destroy a donk wouldnt u think?

In my experience, for an engine to be destroyed, detonation does not have to be hard or long. I have had an engine fail after getting what we believed to be a bad batch of fuel (I didn't bother to test any though)

The vehicle had been on a Dyno, and was tuned fine, ran probably 30 laps around Phillip Island. (Same fuel it was tuned with). Put in more fuel, and did not manage to get another half a dozen laps, before having it stop !

I did not notice any Pinging, but it had obviously been there once the motor was pulled down!

This was a normally aspirated engine, I imagine things are a whole lot more critical in a Turbo Charged engine !

Edited 13/01/04 12:55 AM by Pretzel

[aps]

PRETZEL I trust my explanation on the valve spring issue was helpful,in addition to better valve springs a low restriction exhaust is the real key to consitant performance and reliable engine operation.When the power level approaches 300 Kw with the stock exhaust the back pressure gets very ugly,and the increased exhaust gas temp is really hard on both the valves and valve springs,I would not suggest going past 300Kw before having a good think about the exhaust and its performance.Food for thought.

[Pretzel]

Peter,

Yes, your explanation was very helpful.

At this stage I'm planning to go for either Phase II or Phase III so either way the exhaust would be sorted out in the process.

Just making sure I have all the facts (And in this case it was a suggestion on your web-site for the Phase III, so I wanted to understand why) Before I go and spend the dollars ! I'd rather get it right the first time !

Your availability to answer questions is much appreciated. Thanks again !

[xrdreaming]

Hi all,

I Spoke to one of the head engine builders at FPV today to ask if the BOSS 290 valve springs would fit the T.

The short answer is yes they will but DON'T DO IT!!!

I am not sure of what pressure rating they use on valve springs (Peter might be able to help here) but he tells me that the BOSS 290 springs are rated at 180 and that it would be easy for the springs to unseat the valves of a T under some circumstances.

I would have thought if you were putting 300kw through your T then they would be the perfect choice but I am no expert and the expert said no so just a warining for you all.

[hypnodoc]

Hi all,

I Spoke to one of the head engine builders at FPV today to ask if the BOSS 290 valve springs would fit the T.

The short answer is yes they will but DON'T DO IT!!!

I am not sure of what pressure rating they use on valve springs (Peter might be able to help here) but he tells me that the BOSS 290 springs are rated at 180 and that it would be easy for the springs to unseat the valves of a T under some circumstances.

I would have thought if you were putting 300kw through your T then they would be the perfect choice but I am no expert and the expert said no so just a warining for you all.

Just like auto mods, the valve spring seems to remain an unanswerable mystery at the present moment

[aps]

Just like auto mods, the valve spring seems to remain an unanswerable mystery at the present moment

The valve spring issue has been confusing for many xr6t owners and tuners alike. APS will release a range of upgraded springs at an affordable price in the near future. We have been testing valve springs over the past 9 months and the results are promising.

Peter

APS