Why is there not more concern about the fact that these springs lose seat pressure after some hours?

 

I've heard that about the Supertech springs, but I haven't heard anyone mention that issue with the Vulvo springs.

 

What springs are you referring to?

 

I've seen one post regarding the ST valve springs losing seat pressure but none over the VS855. Due to my limited exposure, I may have missed the discussion over the VS855's though.

 

Never mind, ignore me. I recall reading that somewhere but can't find any citation for it now. The only citation for ST springs losing pressure is Leafy, and he's hardly a reliable source for anything.

 

Ok I got an email from jegs saying my springs wouldn't ship until mid April some time so I just cancelled the order.

Does anyone have any Volvo springs I could buy off them? I'm really trying to get this engine together.

 

I lol'd.

 

If you value cheap over "soon," then wait.

If you value "soon" over "cheap," then get STs. It's either important that your motor be together prior to mid april or it's not.

 

If you wait until mid-april, expect to get pushed back yet again. I would not believe JEG's back-order date for this product. If you dont mind waiting possilby months (maybe forever), then feel free to wait. I said screw it and ordered ST.

 

I have heavy doubles right now too and am rebuilding a 'spare' VVT head that I'm looking to use VS855 for. I figure if carpassion can use them in a 400whp+ build, then they're good enough for me. The supertech doubles might be excessively strong and leave hp on the table in the name of safety. Just my 2c. Though with this wait, I am very close to calling it quits on waiting and going for ST singles.

 

The issue of VS855 being good enough or not shouldn't be an issue at this point. The problem is where to VS855 springs from.

 

I have read casually before to check into 4g63 springs.

anyone have any measurements or heard of that as well?

https://www.miataturbo.net/engine-pe...springs-87604/
https://forum.miata.net/vb/showthread.php?t=227920

 

Just put an order for these through JEGS. I am not in a hurry- I have parts to wash, inspect, etc before assembly begins. But hopefully I will get them by May!

 

Good luck, I placed my order 2 months ago, no dice. I decided to run ST valve springs.

 

https://www.ebay.com/p/Engine-Valve-...S-855/76678461

 

Only 2 available, gotta hunt for 14 more.

 

I've been going back and forth with BC on a suitable spring replacement that works with the OEM retainer on an 01-05 head.

Here is where we are so far / please cross check my numbers to see if I seem off anywhere.

I provided the VS855 spec sheet for reference so they knew what I was looking for roughly.

Took my VVT head, made some measurements.

-----------------------------------------
valve spring

od 26.23mm/1.033in

id 18.44mm/0.726in

retainer

od full 25.80mm/1.015in

provision to keep spring centered 18.25mm/0.718in------------------------------------------

After some research on their side they found a spring they think would be a good fit. I needed to measure the install height so some math could be done:

I installed a valve without spring, measured from area where the bottom of the valve spring sits in it's seat to the top of the valve. I did this with a digital caliper, nothing super technical. I then removed with math the height of the top of the valve down to the area of the retainer where the top of the spring will sit and also removed the shim as well.
This seemed logical as to how to get the measurement properly.1.8120" - 0.2815" - 0.0215 = 1.509" on a factory 2001-2005 Head

Once I provided that data the answer I was given was the spring suggested would have approx 65lb on the seat, and if the spring is shimmed to 1.450 “ it would yield 73 LBS or a 1.400” for 85 lbs

Now I'm on the hunt to see what shims are possible to make that happen, but theres nothing "exact" to the miata OEM shim I'm using as my measurement which is OD: 1.025in/25.45mm and ID: .7360in/18.70mm and when measuring how thick it is for shim comparison, .0215"/.54mm THICK.

Seems like the shim stuff is pretty common on the V8's but trying to find a reliable vendor for a shim, oh, and not a 100 pack of them either LOL

Was looking at the 6025 model.
https://www.dura-bondbearing.com/wp-...ITE-_Links.pdf

And this as a possible shim solution too.
https://www.supertechperformance.com...ng-shim-0-76mm

Here's something I couldn't find, or bypassed along the way accidentally. What is the spring pressure applied on the VS-855 with our BP heads?

 

Poscat for pursuing this. I would love to measure the stock spring seat pressure on VVT engines. AFAIK the intake springs are heavier compared to a BP4W due to the more abrupt ramps of the VVT intake cam, but I have no data whatsoever.

 

Important measurement will also be if there is bind at full lift with highest lift cams commonly used.

 

You are correct. I did measure the wire diameter on Intake vs Exhaust and there was a slight difference. I thought I recorded the data but must have just been an observation I made along the way. I can get the data on both the Intake and Exhaust springs since they're all out and I just lapped my stock valves in preparation for washing the head again/painting/final assembly. Valve springs are the only missing piece to putting this motor together.

Supertech is an option yes, but at a significantly higher cost due to the dual spring/ti retainer package. I run Supertech valvetrain in another engine of mine however the difference is that it's a more developed platform than the BP so I can mix and match retainers with different brands/metals etc. For example, I run Crower Chromoly retainers on top of Supertech dual springs in that build so I can have a strong retainer that's lighter than OEM but avoid the wear properties that come with Ti vs Chromoly.

Once I have the wire diameter what's the best calculation to vet out the math behind this? The cost from BC I was quoted seemed VERY fair so that's the route I am planning on going so long as I can shim them properly to add some additional lb'age.