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Registered
Join Date: Jun 2003
Location: St Petersburg, FL
Posts: 3,814
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3.2 / 3.3 Rev Limit ?
With upgraded rod bolts and a tweaked valve train whats considered the safe upper limit on the 74.4 stroke motors?
It looks like I will be going with some super cup cams so the valvetrain will have to deal with some additional lift. |
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02-15-2005, 04:21 PM
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Registered
Join Date: Jul 2001
Location: Portland Oregon
Posts: 7,007
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I surely would not exceed 7200 RPM using better rod bolts, valve springs & retainers.
With aftermarket rods and some lower end oiling mods, you can safely go to 7800+.
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Steve Weiner Rennsport Systems Portland Oregon (503) 244-0990 porsche@rennsportsystems.com www.rennsportsystems.com |
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02-16-2005, 05:30 PM
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Registered
Join Date: Jun 2003
Location: St Petersburg, FL
Posts: 3,814
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Thanks for the info Steve. I guess I will set the rev limiter to 6800 for a little extra safety margin.
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02-16-2005, 06:01 PM
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Registered
Join Date: Mar 2004
Location: City of Seattle, WA
Posts: 3,374
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Steve, what would you say to the same question on an SC based build? TIA.
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Andy |
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02-16-2005, 06:44 PM
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Join Date: Jul 2001
Location: Portland Oregon
Posts: 7,007
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Quote:
 Andy: A stock SC's bottom end is safe to 7200 however the OEM SC cast pistons are not. If you are using CIS pistons, keep the revs to 6500. The forged Mahles are good well beyond 7800,.....
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Steve Weiner Rennsport Systems Portland Oregon (503) 244-0990 porsche@rennsportsystems.com www.rennsportsystems.com |
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02-16-2005, 09:32 PM
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Registered
Join Date: Jun 2001
Location: Sweden
Posts: 5,911
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There is no point revving turbo motors past 6500 RPM...they usually make max power around 5500 (as long as there are no hot cams involved), reving past that is good only for "matching revs" for next gear.
Most of time, it just ads more noise and streches rod bolts :-)
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Thank you for your time, Last edited by beepbeep; 02-17-2005 at 08:16 AM.. |
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02-17-2005, 02:24 AM
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Still Doin Time
Join Date: Nov 2004
Location: Nokesville, Va.
Posts: 8,225
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Excellent point. Unless the engine has been 'leaned-on' with good upgades, max Hp and Tq have already been reached BEFORE the redline.
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'15 Dodge - 'Dango R/T Hauls groceries and Kinda Hauls *ss '07 Jeep SRT-8 - Hauls groceries and Hauls *ss Sold '85 Guards Red Targa - Almost finished after 17 years '95 Road King w/117ci - No time to ride, see above '77 Sportster Pro-Street Drag Bike w/93ci - Sold |
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02-17-2005, 06:28 AM
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