Why is that?

 

because stiffer springs "push" lifter stronger agains camshaft, so it wears quicker. not something I´m worried about as I do 3k Miles a year.

 

LOL

it doesnt exactly work like that

 

your post have probably less value than my bad answer. Please explain

 

If the springs are too light, they will let the valves bounce and slam into the seats which causes a lot of wear and damage.
There is a great thread here somewhere about all the valvetrain issues..

 

Loose less power in the valvtrain, I'm not boosted and run under regulations, so it's better to do it right.
The soft ST duals could most probably been enough in my case, but as mentioned, don't copy part of a design.

When you have (good enough in your judgement) control of your valve movement, extra springs is just waste.

 

So.. getting back to this before I order my things for my relatively low-rpm (~7800max) BP6D w 264 cams build, should I just avoid the ST light doubles and just buy the VS855s?

 

I completely forgot about this thread and had already ordered supertech heavy doubles for my spare head. *ponder ponder*

 

fwiw I went with the ST singles for 7,800 rpm on my Tomeis.

 

I'm running the super double heavys. I am also using the OEM 99+ retainers for some reason that forgot about.

So many 8200rpm + moments. Less than 20psi levels though.

 

Any modification needed to use the stock retainers with the supertech duals? Quite a few failures reported with the ST Ti retainers in other applications. Don't feel like checking whatever I install every 5-10k to see if it's holding up.

 

ST retainer has a wider center extrusion that tightly holds the inner spring. So snug the spring clips and holds on to it. The stock retainer is smaller and doesnt hold the inner spring and also the flat seat only covers 2/3rds of the spring. It's loose enough that the spring can move sideways around 2mm.

They would bolt up, but I'm not sure if things would get damaged with the inner spring not held in place fully. It might rub or chatter against the outer spring.

ST retainer


Oem BP05 retainer


Side by side

 

Made custom steel retainers for my ST duals, but the cost was about 3x the Ti retainers.
Machine time is not cheap here.

 

How do the Ti retainers fail. Do they deflect upwards, crack or just wear?

They are a good amount lighter than steel so they are attractive for anyone chasing revs like myself.

 

The failure I've seen was due to wear, all the way through (only inner spring holding the valve), possibly due to not tight enough so the spring rotates against the retainer wearing the soft Ti.

 

I've been running the VS855 for several thousand miles without issue. 18psi, 7800rpm.
Over reved once to 8000+, wasn't logging but wasn't that bad of a miss. No issues from that so far. Factory valves, keepers, etc.

 

If that's the case, maybe a thin washer between the TI and retainer to stop any wear. I was actually thinking of shimming them up a bit tighter, maybe it's not a bad idea to stop them rotating.

 

Time for a necro-post. Lots of speculation above, but very little experience with the VS-855. Can I get an update from the people using the cheap Volvo springs? I'll buy the ST doubles if I have to, but I'd rather put that money towards a BE oil pump, tires, prostitutes or cocaine. Thanks

 

I put some in about 4 weeks ago.
its a tired B6
port matched & polished general clean up of ports
Genie headers
272/264 220/215@0.05" cams 10/9 lift
CR10.5:1
MS2
max RPM 7500
running HLA's
spring pressure recommended by manufacturer 66lbs

initial reaction after running cams in again....smoother at low RPM. More vibrations at the top. But it seems to have smoothed out a little over a few weeks and a few high rpm runs.
will not get a chance to dyno it as the engine now needs replacing. But unlikely because of the springs.

that's as much as i can tell you.