First Generation Firebird-L Mailing List ......................................................................... The normal rule of thumb is 10 psi per 1000 rpm. But that is like a BARE minimum. Understand that oil is less about lubrication and more about cooling.
The melling M54 is a high pressure pump. The high volume thing is a chevy carry over. Pontiacs need higher oil pressure because the main bearings are so large. The oil pressure is what keeps the crank from grinding on the bearings... I would be concerned at both the temp AND the pressure. At this point your bearings are probably shot...that's my guess. Running around at high temps with lees that ideal pressure is a recipe for trouble. 12 to 15 is too low in my opinion and 220 230 is too high. One may be causing the other. But by now it's a mute point. I would double check with a different gauge. If it is the same result....break out the check book. What is the condition of the oil ? does it smell burnt ? Dose it look like burnt coffee ? maybe send a sample off for analysis. It will tell you if there is metal in it. -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Bo Svenson Sent: Saturday, September 19, 2009 5:57 PM To: First Generation Firebird-L Subject: Re: [FGF] engine problems need advise First Generation Firebird-L Mailing List ........................................................................ . I recently hade my 400 stroked to 467 by a reputable builder. It put out 410 horses on the dyno. The compression is 8.5:1. The builder installed a high-pressure oil pump. The engine runs at 220-230 degrees with a reconditioned 4-core brass radiator. At start-up my oil temperature is 80. At 220-230 my oil pressure is 12-15. Cause for alarm? The valve train is fairly quiet. Thanks! Bo > From: Pete D <[email protected]> > Reply-To: First Generation Firebird-L <[email protected]> > Date: Sat, 19 Sep 2009 13:52:26 -0700 (PDT) > To: First Generation Firebird-L <[email protected]> > Subject: RE: [FGF] engine problems need advise > > First Generation Firebird-L Mailing List > ........................................................................ . > What are the bearing clearances set to? Some builders will set the clearance > to the high side to get a little more power. This is not advisable for a > street engine because of the issue with oil pressure. Low pressure = a noisy > valvetrain, ask me how I know. > > re: oil pump; if you're not running a standard pump then a high-volume pump is > a better choice vs. a high-pressure. If I recall a hi-press pump can have an > adverse affect on the bearings. > > Another possibility for low pressure is a faulty lifter(s). One or 2 bad > lifters can drop pressure as much as 10psi, [again ask me how I know]. > > PeteJD > [69 400] > > > > ------------------------------------------------------------------------ > Submissions to Firebird-L: <[email protected]> > Unsubscribe from Firebird-L: <[email protected]> > Help: <http://FirstGenFirebird.org/firebird/Firebird-L.html> > > Classifieds: <http://FirstGenFirebird.org/ubb/> > Owner Pictures: <http://FirstGenFirebird.org/show/> > > ------------------------------------------------------------------------ Submissions to Firebird-L: <[email protected]> Unsubscribe from Firebird-L: <[email protected]> Help: <http://FirstGenFirebird.org/firebird/Firebird-L.html> Classifieds: <http://FirstGenFirebird.org/ubb/> Owner Pictures: <http://FirstGenFirebird.org/show/> No virus found in this incoming message. Checked by AVG - www.avg.com Version: 8.5.409 / Virus Database: 270.13.105/2380 - Release Date: 09/19/09 17:50:00 ------------------------------------------------------------------------ Submissions to Firebird-L: <[email protected]> Unsubscribe from Firebird-L: <[email protected]> Help: <http://FirstGenFirebird.org/firebird/Firebird-L.html> Classifieds: <http://FirstGenFirebird.org/ubb/> Owner Pictures: <http://FirstGenFirebird.org/show/>
