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1981 911SC Targa
Join Date: Aug 2007
Location: Missouri
Posts: 171
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valve springs with 964 grind
I am rebuilding and had my cams reground to 964 specs. Are the oem springs off of my 1981 SC that had 96k on it alright to use or should I replace them.
Is so, what brand is the best for the money with this grind? Thanks
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Frank 1981 911SC Targa 1967 Buick GS-400 |
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12-08-2008, 07:23 AM
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3 restos WIP = psycho
Join Date: Feb 2005
Location: North of Exit 17
Posts: 7,665
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I like EBS springs; they are a bit stiffer than stock without being too stiff, yet won't break like the stock ones seem to do lately. Money well spent and cheaper than the high end (8K RPM) springs you will find with other vendors.
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- 1965 911 - 1969 911S - 1980 911SC Targa - 1979 930 |
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12-08-2008, 08:57 AM
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Registered
Join Date: Jul 2000
Location: So. Calif.
Posts: 19,910
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"I like EBS springs; they are a bit stiffer than stock without being too stiff, yet won't break like the stock ones seem to do lately........"
Really? Is this anecdotal or real, the part about them breaking? Not that this forum is the center of the Porsche repair universe, but I haven't observed any frequency of broken valve spring reports. Sherwood |
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12-09-2008, 11:01 PM
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3 restos WIP = psycho
Join Date: Feb 2005
Location: North of Exit 17
Posts: 7,665
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When it happened to me, two separate, highly respected mechanics both mentioned that stock springs have had a higher propensity for failure in the last decade or so than in the past. Both now go with aftermarket springs in even stock applications. Another local guy had the same thing happen to his 3.2 that happened to my 2.0S. Different motors, same problem. I'd say "real".
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- 1965 911 - 1969 911S - 1980 911SC Targa - 1979 930 |
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12-10-2008, 05:34 AM
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Air Medal or two
Join Date: Jul 2003
Location: cross roads
Posts: 14,123
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I have herd of floating them.....(bad ).....but not failure.....we need more info
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D troop 3/5 Air Cav,( Bastard CAV) and 162 Assult Helicopter Co- (Vultures) South of Saigon, U Minh Forest, Delta, and all parts in between |
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12-10-2008, 05:46 PM
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I'd upgrade just for the higher redline (I have EBS).
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2014 Cayman S (track rat w/GT4 suspension) 1979 930 (475 rwhp at 0.95 bar) |
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12-16-2008, 10:35 AM
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Registered
Join Date: Jul 2000
Location: So. Calif.
Posts: 19,910
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Quote:
Sherwood |
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12-16-2008, 10:58 AM
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Certified Pre-Owned
Join Date: Aug 2002
Location: Nanny State
Posts: 3,132
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The other good thing about the stiffer spring would be a bit of over-rev protection I would think...if you can add 1500 rpm with stiffer springs and stronger retainers it may not save you...but it might...
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'84 Carrera Coupe |
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12-17-2008, 07:30 AM
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Air Medal or two
Join Date: Jul 2003
Location: cross roads
Posts: 14,123
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seems like a rev limiter would be a better solution
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D troop 3/5 Air Cav,( Bastard CAV) and 162 Assult Helicopter Co- (Vultures) South of Saigon, U Minh Forest, Delta, and all parts in between |
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12-17-2008, 07:59 AM
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Registered
Join Date: Oct 2003
Location: Central Fla
Posts: 1,864
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Springs
Rev limiters don't help if you stick it in the wrong gear, Over the years I have seen alot of stock springs break using them in stock apps., Those cams do not require much over stock pressures so if EBS has a proven set I would go with those over new OEM springs.
Mike Bruns JBRacing.com
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The two most useless things to a driver are the braking distance behind you and nine-tenths of a second ago. |
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12-17-2008, 08:19 AM
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1979 Porsche 930 3.4
