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2.7 Valve Springs
Ok, Got the heads, Got the 964 Cams...Now the question is do I put titainium springs in or not....
I understand that OEM springs are a good product, But with the really close clearance between the Piston head and the valves, would it be NECESSARY to put the added ridgity to prevent any type of floating at high RPM..... Now if so, what are some recommendations on brands?
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Signature Phrase " CATCH ME IF YOU CAN" 1988 Porsche 930 "Squerly" Built by "Porsche Doc" -------------------------- 1974 Porsche 911 (2003 - 2012) 2000 Boxster S (2006 - 2008) |
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12-20-2006, 04:11 AM
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I got to ask, how close is close ?? Pistons can be pocketed to give room for error..these going in your 2.7 ?? I assume you are using CIS pistons as there is no other reason to use those cams ( that i can think of ). Remember, you are closest near TDC not @ TDC. You might want to use clay or solder to check
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12-20-2006, 12:19 PM
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Clay
Yes we are going to use clay and see how close. the 8 to 1 compression ration will help, but still curious to how close.
It is a CIS system, So the question still stands, is it necessary for a tighter spring? Chris
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Signature Phrase " CATCH ME IF YOU CAN" 1988 Porsche 930 "Squerly" Built by "Porsche Doc" -------------------------- 1974 Porsche 911 (2003 - 2012) 2000 Boxster S (2006 - 2008) |
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12-20-2006, 01:56 PM
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IMO no- if you have proper clearance and shim to SC ht. If you do not have proper clearance, make it or risk it ?? Cis will not turn up far enough to spend $$ on TI springs.. Is a good sys but the will run out of air around 7g something
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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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12-20-2006, 02:26 PM
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Cool...
Got it. I will get new OEM springs and go from there.
Thanks for the advice. Have a Merry Christmas Chris
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Signature Phrase " CATCH ME IF YOU CAN" 1988 Porsche 930 "Squerly" Built by "Porsche Doc" -------------------------- 1974 Porsche 911 (2003 - 2012) 2000 Boxster S (2006 - 2008) |
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12-20-2006, 04:24 PM
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Just to add to what afterburn says,
If you stay with the stock RPM limits and shim to SC specs then you don't need the aftermarket springs or retainers. I would want to run with a rev limiter to make sure you don't exceed a safe speed. You should get no float at these RPMs. PS, I think new OEM springs are move expensive that John Doherty's (camgrinder) aftermarket springs. I'd consider them if you have to replace your old OEM springs. -Andy
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12-21-2006, 11:36 AM
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bought new springs
I took your advice and bought OEM springs. I do have a 7000 rpm rev limiter installed in my MSD box. I put the money in to other goodies for the car.
I will post the results when I am complete. Chris 
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Signature Phrase " CATCH ME IF YOU CAN" 1988 Porsche 930 "Squerly" Built by "Porsche Doc" -------------------------- 1974 Porsche 911 (2003 - 2012) 2000 Boxster S (2006 - 2008) |
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12-23-2006, 04:58 PM
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Be sure to check your valve to piston clearence!!!!!!!!!!!!!!! You should have .080" intake & .100" exhaust. Remember REV limiters DO NOT work on deacceleration!!!!! Clay and solder work,but..... are far too inaccurate and a pain in the a*s. Check it with valve screw method. One turn equals 1 mm or .040".this is the way we check every engine we build stock or otherwise.Let me know if you have any questions about doing this.I'd be glad to walk you through it.Tim
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12-23-2006, 07:11 PM
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Thanks, I will keep you in mind thru this process
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Signature Phrase " CATCH ME IF YOU CAN" 1988 Porsche 930 "Squerly" Built by "Porsche Doc" -------------------------- 1974 Porsche 911 (2003 - 2012) 2000 Boxster S (2006 - 2008) |
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12-23-2006, 07:40 PM
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Track Car
Squerly
