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Std Valve springs or High performance?
I am building a 3.4 Race mild race engine JE 10.5, GE60 cams, 46MM PMOs
revving to 7000 rpm. Should i fit aftermarket valve springs? Titanium valve keepers? Bruce Anderson s book states "none of the aftermarket valve springs are as good as the original" |
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03-29-2014, 03:55 AM
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Join Date: Dec 2001
Posts: 9,569
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7000 I would use stock springs that you have tested
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'66 911 #304065 Irischgruen ‘96 993 Carrera 2 Polarsilber '81 R65 Ex-'71 911 PCA C-Stock Club Racer #806 (Sold 5/15/13) Ex-'88 Carrera (Sold 3/29/02) Ex-'91 Carrera 2 Cabriolet (Sold 8/20/04) Ex-'89 944 Turbo S (Sold 8/21/20) |
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03-29-2014, 03:58 AM
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What about lighter keepers?
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03-29-2014, 04:05 AM
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Have you had experience knife edging cranks? Pros and Cons
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03-29-2014, 04:06 AM
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Doesn't seem to be a drawback to lighter valve train except the price.
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'66 911 #304065 Irischgruen ‘96 993 Carrera 2 Polarsilber '81 R65 Ex-'71 911 PCA C-Stock Club Racer #806 (Sold 5/15/13) Ex-'88 Carrera (Sold 3/29/02) Ex-'91 Carrera 2 Cabriolet (Sold 8/20/04) Ex-'89 944 Turbo S (Sold 8/21/20) |
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03-29-2014, 06:35 AM
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Location: Portland Oregon
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JMHO,......
New stock springs are not as good as they used to be and older ones have usually lost some seat pressure due to long-term fatigue. Race engines NEED all the over-rev protection they can get to help prevent piston-to-valve contact and this means GOOD aftermarket springs (there is some junk out there). Further, the 3.0 and later retainers are sintered metal which fractures when valves contact pistons, even lightly. We always use Ti retainers in any race engine that will see 7K or more. Good springs & Ti retainers are simply insurance, just like rods & rod bolts. 
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Steve Weiner Rennsport Systems Portland Oregon (503) 244-0990 porsche@rennsportsystems.com www.rennsportsystems.com |
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03-29-2014, 11:21 AM
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Hi steve,thanks for your input.
What brand springs and Ti retainers do you recommend ? I am wanting to run this motor as a one plug (programable MSD) using JE 10.5 :1 pistons and the GE 60 cams 1.5/8 headers straight out the back.46 pmo ,i can run any fuel I like , What octane & and advance would u recommend ? Should I balance this engine? What port work ? The car is used for many type of events from street racing,hill climbs, track days etc. Not road registered . 5 gears 930 LSD 1070 kg wet inc driver. Many thanks for your help. John |
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03-29-2014, 03:37 PM
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Quote:
Contact me directly (off forum).
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Steve Weiner Rennsport Systems Portland Oregon (503) 244-0990 porsche@rennsportsystems.com www.rennsportsystems.com |
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03-29-2014, 06:11 PM
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Join Date: May 2008
Location: Stuttgart & Miami
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Shrick springs...top notch.
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03-29-2014, 06:48 PM
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