Greetings,

I would like to know what is the right part number for the Volvo springs everyone is using on the BP cylinder heads and if they are compatible with the VVT heads. Thanks for sharing this information.

 

Information is already posted in a very clear and informative thread. It was also discussed again in several other threads.

Is there any reason you felt the need to create a new one? I'm just wondering.

I'm feeling nice today, so here you go:
https://www.miataturbo.net/engine-pe...ng-info-70450/

Lurn2Search

 

Dude I aready read that thread and somewhere it talks about VVT springs may not be compatible with the volvo springs. I would like clarification if they are compatible in order to purchase a set. Thanks for sharing the link though.

 

what makes the vvt springs not compatible? they are the same dimensionally as the bp4w just a tad bit softer

 

I am reading this thread. In post # 25 the OP refers to the VVT valve springs and the fact valvetrain springs are longer and not identical or some like that. That's all I know at the moment, I am learning and reading about this stuff.

https://www.miataturbo.net/engine-pe...ll-hype-47919/

 

Interesting. Although that thread is from 2010 and he admits to "guessing" on some of the specs.

 

Did you see this?
https://www.miataturbo.net/diy-turbo...4/#post1232942

looks like they work on a bp6d just fine

 

Springs are just springs...
Using Internet "knowledge" blindly for suspension springs doesn't hurt much, but valvetrain is something else.

If you know enough to set the preload/seat pressure, check rate and bind margin you will have no problem with using whatever springs you can find. If you don't know what I'm referring to, stay away and find someone trustworthy to do to upgrade for you.

More than one have unintentionally installed ST duals without the stock spacers (hence a different seat pressure).
Valvetrains are never easy.