It is with much regret that I have to share this with you all: When building my Group A motor 2 years ago we used VAC "hi perf" Valve springs (made by eibach) and titanium retainers. Their website claimed "Our Spring Kits feature a custom dual spring capable of turning 12,000 RPM for that added piece of mind (Over-rev/Mis-shift).............These springs are capable of handling much higher lift for even the most aggressive of cams like the Schrick 320°. " and their tech guy assured me that their springs would be suitable. My engine uses a 320 Schrick inlet, and revs are limited to 8700. The installation was correct, with no bind issues etc. After 5 events, total 600km, one inlet valve spring has broken in 2 places, and the titanium retainers are seriously worn. Thankfully no other engine damage occurred. The response from VAC has been unsatisfactory - no investigation, no explanation, no interest. Regardless of whether this is a race engine, in my view, any product sold commercially should be suitable for it's intended use. My advise is as follows: 1) do not use VAC S14 valve springs in race applications, and certainly do not use the titanium retainers 2) do not expect much customer service from VAC I admit I was advised against using their products at the time, but the cost of the SRD7 springs was prohibitive, especially given the total cost of rebuilding the car. Hindsight is a wonderful thing - the engine could have been destroyed if a valve had dropped, or worse..
There was some surprise on another forum at the amount af wear sustained on some Ti retainers. Glad you were lucky. Disappointing response from VAC. Perhaps you should post up on another forum, where VAC has more customers and where Steve@VAC posts.
For those reading this that might be quick to draw false conclusions, just 2 points: 1) Just because this particular brand of TI valve spring retainer has shown a quick rate of wear (600 km), it does not follow in general that TI is unsuitable as a material for retainers. Many people have run TI retainers for years without any issues. 2) the failure of the valve spring is an independent issue. They did not fail due to some wear on the valve spring retainer. Bill, I dont know of any past problems with the SRD7s and I have run my set for a very long time (10s of thousands of km on the track) without any issues. Although the acquisition cost is high, they amortize themselves over just a few seasons and in particular if they prevent just 1 valve train related engine failure, costing not only your engine but also your race weekend, not to mention the time & money spent getting to the track event but missing out on some of the races. There is more to valve spring design than just seat pressure, open pressure and spring rate. John
Just my 2c to add. Raw Ti is very prone to galling, and anywhere you have a situation where another metal surface is in contact with Ti you have the risk of this happening. Bill I am guessing your retainers were probably just raw Ti. It looks from the photo that all of the retainers were being eaten by the springs, not just the worst few you have arrowed? Conrad
And my 2c worth. I have used Schrick Ti retainers on the advice from John and I was always concerned about the way they fitted in with the SRD7 springs. I have recently had the head apart and there is absolutely no noticable wear on the retainers, so again it is down to quality. Disappointing response from VAC but that seems to be the way of it.
In Bills pictures above, we may also observe that the STEEL retainers are also worn after just 600 km. John
You're right, the race I missed was the main feature event at the biggest Historic meeting we have here in Australia, and given that I had already had a 2nd and two 3rd places, another podium was likely... The thing that disappoints me the most is when manufacturers or parts suppliers make "over enthusiastic" claims about their products. We thought we had done sufficient research, but I have learnt my lesson !! Started the engine yesterday - with rebuilt head including SRD7 springs - what a beautiful sound !! cant wait to drive it again Thanks to all for your advice and collective wisdom Bill
I too have experienced similar wear on the retainer and spring seat. Mine were Ti retainers made by Ferrea with no coatings. I believe my wear was due to a resonant frequency / harmonic. The valve guides where also wearing prematurely. I’m trying Schrick retainers, with appear to have a coating. I made the seats from A2 and hardened them to Rc52. I haven’t pulled the head down since installation so I can’t comment as to how these are holding up. Drew
Sorry to hear about your troubles. This is a major problem here in the US with companies claiming whatever they think makes them sales and then they are not backing up there claims. It is sad that you had to find out the hard way. It is good that you have come forward so other don't make the same mistake. I am planning on tearing down my 2.5l soon. I have Schrick valves, valve springs and Ti retainers installed in my engine. I will update all of you of my findings. Maybe I shouldn't say that but I doubt I will find any horrible surprises. Thomas
In order not to hi-jack Bills feedback thread, it is probably better to split the more general discussion about valve springs and create a new thread in the general discussion area. That thread is located here: http://board.s14power.com/showthread.php?t=6209 John
