Valve spring drought
02-22-2019, 09:01 AM
#24
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.
There's a non vocal (for fear of backlash from forum sponsors and mods) group of people whom have a major disdain for the supertech valve springs because they take a set and after some use seem to have significantly reduced seat pressure. I never noticed that problem with them in my motor, though I'm not sure I ran them long enough and I also havent measure the seat pressure currently.
Reply
0
0
02-22-2019, 11:34 AM
#25
Former Vendor
iTrader: (31)
Join Date: Nov 2006
Location: Sunnyvale, CA
Posts: 15,442
Total Cats: 2,099
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.
Reply
4
4
03-21-2019, 03:41 PM
#30
Junior Member
Join Date: Aug 2016
Posts: 343
Total Cats: 2
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.
Reply
0
0
03-21-2019, 03:50 PM
#32
Junior Member
Join Date: Sep 2010
Posts: 108
Total Cats: 29
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
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
Reply
0
0
04-03-2019, 10:35 PM
#37
Newb
Join Date: Dec 2017
Posts: 31
Total Cats: 3
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?
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?
Last edited by _integrity; 04-03-2019 at 11:43 PM. Reason: format
Reply
2
2
04-04-2019, 05:32 AM
#38
Senior Member
Join Date: Jul 2015
Posts: 1,014
Total Cats: 140
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.
Reply
0
0
04-04-2019, 10:24 AM
#40
Newb
Join Date: Dec 2017
Posts: 31
Total Cats: 3
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.
Reply
1
1
