 2 springs or one per valve |
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| rush |
 May 20 2015, 01:38 PM
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#1
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Newbie  Group: Members Posts: 25 Joined: 15-May 15 From: orcas island, wa Member No.: 18,731 Region Association: None  |
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? |
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| SLITS |
May 20 2015, 01:47 PM
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#2
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"This Utah shit is HARSH!" Group: Benefactors Posts: 13,602 Joined: 22-February 04 From: SoCal Mountains ... Member No.: 1,696 Region Association: None  |
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.
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| rhodyguy |
May 20 2015, 02:45 PM
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#3
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Chimp Sanctuary NW. Check it out. Group: Members Posts: 22,060 Joined: 2-March 03 From: Orion's Bell. The BELL! Member No.: 378 Region Association: Galt's Gulch |
can i ask who did your head work?
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| Jake Raby |
May 20 2015, 03:56 PM
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#4
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Engine Surgeon Group: Members Posts: 9,394 Joined: 31-August 03 From: Lost Member No.: 1,095 Region Association: South East States |
If you don't have the RPM or lift to require them, all they'll do is raise oil temperatures.
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| brant |
May 20 2015, 03:57 PM
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#5
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914 Wizard Group: Members Posts: 11,613 Joined: 30-December 02 From: Colorado Member No.: 47 Region Association: Rocky Mountains 
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we always ran them on race motors
never on street motors |
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| Dave_Darling |
May 20 2015, 09:56 PM
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#6
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914 Idiot Group: Members Posts: 14,981 Joined: 9-January 03 From: Silicon Valley / Kailua-Kona Member No.: 121 Region Association: Northern California
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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 |
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| sean_v8_914 |
May 21 2015, 03:25 AM
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#7
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Chingon 601 Group: Members Posts: 4,011 Joined: 1-February 05 From: San Diego Member No.: 3,541 |
heavy springs take power to squeeze them.
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| rush |
May 21 2015, 11:43 AM
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#8
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Newbie Group: Members Posts: 25 Joined: 15-May 15 From: orcas island, wa Member No.: 18,731 Region Association: None |
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 |
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| stugray |
May 21 2015, 12:24 PM
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#9
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Advanced Member Group: Members Posts: 3,824 Joined: 17-September 09 From: Longmont, CO Member No.: 10,819 Region Association: None |
QUOTE Thanks I will lose a spring and go back to normal. 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. |
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| rush |
May 22 2015, 12:01 AM
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#10
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Newbie Group: Members Posts: 25 Joined: 15-May 15 From: orcas island, wa Member No.: 18,731 Region Association: None |
stugray...really? I am now stuck?
the "friendly favor' now looks like not too great... |
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