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Posted by: rush May 20 2015, 01:38 PM

Got my 3 bolt heads back and the shop put double springs....no charge...had them and thought I would like.
Drag race VW buddy says he used single as it made the engine work too hard
...any thoughts?

Posted by: SLITS May 20 2015, 01:47 PM

I was always taught that the second spring was more for harmonic control of the main spring than added seat pressure. I don't see the problem.

Posted by: rhodyguy May 20 2015, 02:45 PM

can i ask who did your head work?

Posted by: Jake Raby May 20 2015, 03:56 PM

If you don't have the RPM or lift to require them, all they'll do is raise oil temperatures.

Posted by: brant May 20 2015, 03:57 PM

we always ran them on race motors
never on street motors

Posted by: Dave_Darling May 20 2015, 09:56 PM

I don't know if it's still the case, but in years past a lot of cutting had to be done to fit the double springs. It made the already none-too-strong Type IV head even more prone to cracking.

And, yeah, if you don't need them they're not something you really want.

--DD

Posted by: sean_v8_914 May 21 2015, 03:25 AM

heavy springs take power to squeeze them.

Posted by: rush May 21 2015, 11:43 AM

Thanks I will lose a spring and go back to normal.
Rodyguy, always used Jerry at NW Con Rod but I sent some parts I had saved from 40yrs driving 20 different Pcars...and he knew I was putting together a red headed step child '912e' (mid 70's 911 w T4) and said he had some heads he would work up and mail...he doesn't do much machine, just restores...but the work he does "Uncle Ferry" would like

Posted by: stugray May 21 2015, 12:24 PM

Whoa there!
Once the heads have been machined for dual springs you cannot go back to single springs.
At least that is my understanding - maybe there is a collar or something you can insert to make it work, but I dont think so.

Posted by: rush May 22 2015, 12:01 AM

stugray...really? I am now stuck?
the "friendly favor' now looks like
not too great...