What are the thoughts on valve springs? I experienced failures of two inner springs on my motor last season. As I result I bent two valves. Is there any reason we couldn't allow 944 Turbo valve springs? I understand that these springs are slightly stiffer than the standard 944 springs, but can be used with out modification. They are also significantly cheaper than standard 944 valve springs. The only performance advantage would be that it would allow the motor to rev higher before valve-piston interference occurred. Since we use stock software, this won't benefit anyone accept with reliability. Besides cost, the 944 Turbo springs provide a little bit of extra over-rev protection. That's a very good thing in my book. Thoughts?

-bj

WOW Bj ! I'm sorry to hear about this on your engine.

My first responce is I have never seen or had any problem like this before. So I would guess that it is not an issue with the valve springs but something else that damaged your engine. maybe the valve height was not shimed to the correct height and that caused the valves to get bent ? I also had a head come straight out of the machine shop installed it on a car and it had one valve get bent. i thought the height had been messed up ?

Does the turbo motor use the same lifters / followers ?

This is something we should look at and talk about for rules changes.

Ken when you get a chance please start a new section in the forums for rules changes . Thanks Ken

And Thanks BJ for bringing this up for review.

Guys, I hate to do this, but I would have to disagree with it. Reason being, once you start allowing mixed/matched components, you are opening up a new can of worms. There are DOZENS of parts that are cheaper than OEM replacements, many that would provide HUGE advantages in reliability or ease of acquisition with no additional performance improvement BUT, once you start going down that road, it isn't long before someone wants to consider doing something else and before you know it, the class has loss its original design. I have seen it before in the Stock Car racing world. The class votes to allow V6 springs in the front of a 4cyl car because they were cheaper to buy as a replacement. Then, the speeds increased because of increased corner entry speeds, then they wanted a better tire and then they started braking spindles, hubs and rotors so then they wanted aftermarket replacements. Before you know it, your $1,000 entry level race class is now up to $3,000 just to be competitive. Just my

I have to agree with the above. Look at "spec" miata - close to 6k for a new motor? since when do ford motors cost the same as a Porsche motor? As well as the continued stories of needing 30k to produce a front runner car? I haven't mentioned this before but I was a little disappointed in the rules to allow modified dashes and cutting the spare tire well. Hopefully the rule makers will keep in mind the original purpose of this class and to stay true to the word "Spec".

To add my 2 cents as well - it sounds like you have/did have an underlying issue to your valve troubles. Poor "lapping" of the valve maybe?

BJ, shop around. Paragon had better prices for the exhaust valve springs. The Turbo ones on Pelican are "OEM supplier", which may not be of the same quality. This is certainly true of the the lifters - many problems reported with the INA lifters that are an "OEM supplier" as the genuine Porsche ones.
Your reasoning is sound, but there may be other unintended consequences. More variables opens up more opportunities for problems. Good of you to ask rather than just do it b/c it would be hard to tell, in any case.

As I remember, the car was driven for a while before this was figured out - may be a part of the bent valves part, but who knows. We all know where to look 1st for a lack of high RPM power now.

I have heard of a number of valve spring fail over the years. I believe that only happens on 20 year old stock valves after an untold number of hours.