Bad day on the dyno!

eric1h · 08-27-2009, 06:46 PM

So after a long wait, i brought the car to the dyno to get it tuned.

First run the car seemed to run fine, pretty rich, but hit a brick wall at 5500rpms.

Swapped down 4 jet sizes front and rear, and lowered the timing on the MSD, repulled, same thing, except it ran leaner, same brick wall at 5500rpm's

changed to new plugs made a few tweaks and went to repull, the car started making a mad knocking/tapping noise, after some investigation and cutting open the oil filter(brand new as of today) we found some metal shavings in there

So it appears we spun a bearing or something.

WTF!!???

Motor only ha 17k miles on it

David Eastman · 08-27-2009, 07:30 PM

Sorry to hear the bad news Eric. You put in alot of effort into this engine swap to be rewarded like this.

David

Gatorac · 08-27-2009, 07:50 PM

That sucks.

Cobra4B · 08-27-2009, 11:00 PM

WTF is right... not normal for a LSX at all. What kind of oil pressures were you seeing? What weight oil were you running?

NZGTRA17 · 08-28-2009, 01:19 AM

Not good news Eric. Always hard to know when you buy 2nd hand engines what they have been pulled for. E.g. could have been in a car that rolled and starved of oil momentarily etc.

Hope that the crank and rods come out of this OK.

Squerly · 08-28-2009, 07:30 AM

My worst nightmare... put the car on a dyno and watch it break. Sorry Eric, that really sucks. It's bad enough when these things happen but it's really rough after putting so much time into the project.

Cobrafang · 08-28-2009, 07:51 AM

Man I am sorry to hear that Eric. SUCKS like a brand new Kirby!

eric1h · 08-28-2009, 08:30 AM

Quote:

Originally Posted by Cobra4B

WTF is right... not normal for a LSX at all. What kind of oil pressures were you seeing? What weight oil were you running?

Oil pressure was 70psi at idle and 85-90psi in the upper RPM range

Oil was just some 10-40 valvoline

eric1h · 08-28-2009, 08:32 AM

Thanks guys, I'll get it sorted out, hoping its fairly easy fix. the knock is brand new and hasnt been run more than a few minutes so hoping the damage is minimal.

panozracing · 08-28-2009, 09:45 AM

I am really sorry too....after blowing about 5 myself (with 2 cars) is the exact reason we built engines that are capable of twice the hp that we actually run them at. Bullet proof is the name of the game...expense is secondary because of the time and effort and expense when they break....I have learned my lesson the HARD way!

Good luck...if its gonna happen it happened at the right place...ruining a weekend is costly and hurts MUCH worse.

NZGTRA17 · 08-28-2009, 01:48 PM

Quote:

Originally Posted by eric1h

Oil pressure was 70psi at idle and 85-90psi in the upper RPM range

I am not experienced with LS engines Eric, but that oil pressure sounds to high (particularly the idle figure).

Only time I have had oil pressure like that with a V8 is with a dry sump system with a way big pressure section fited to the pump (big block 1.25") on a small block. That was only 30psi at idle but would crank up over 100psi with cold oil at 4000+ rpm

Unless normal for an LS (which I though were normally oil low pressure) could have been a sign of a restriction in the oil path.

Cobra4B · 08-28-2009, 07:59 PM

That is very high oil pressure.. what the car up to temp and still showing 70 psi? I have a high volume LS4 oil pump in my car and get 40 PSI at idle w/ a M1 filter and 49 w/ a K&N w/ 5w40 amsoil when hot. The K&N bumps idle pressure as it's less restrictive than the M1 media.

In 2001 all LSXs got the LS6 oil pump. A stock car w/ 5w30 hot will make 29-30 psi at idle. A pre 2001 LS1 makes 25-27 psi at hot idle.

Did you touch the oil pump? My car makes mid 80s WOT when hot, but w/ a stock oil pump it should be mid 60's WOT hot and 50ish WOT super hot (270ish oil temp) on track.

Good luck.

eric1h · 08-28-2009, 08:12 PM

Quote:

Originally Posted by Cobra4B

That is very high oil pressure.. what the car up to temp and still showing 70 psi? I have a high volume LS4 oil pump in my car and get 40 PSI at idle w/ a M1 filter and 49 w/ a K&N w/ 5w40 amsoil when hot. The K&N bumps idle pressure as it's less restrictive than the M1 media.

In 2001 all LSXs got the LS6 oil pump. A stock car w/ 5w30 hot will make 29-30 psi at idle. A pre 2001 LS1 makes 25-27 psi at hot idle.

Did you touch the oil pump? My car makes mid 80s WOT when hot, but w/ a stock oil pump it should be mid 60's WOT hot and 50ish WOT super hot (270ish oil temp) on track.

Good luck.

The oil pump is a LPE HIgh Volume High Pressure Oil pump, that's what it's "supposed" to be at.

eric1h · 08-28-2009, 08:17 PM

and FYI, that's about the same pressure that my old 4.6L motor ran as well. it started out at 85-95 PSI at idle, devins car was/is the same.

Cobra4B · 08-28-2009, 08:23 PM

It all depends on how hot they are... oil pressure varys drastically w/ temp. You sure it's a high volume pump? LPE generally sells a ported LS6 pump which still has the stock gerotor. The LS4 pump has a different gerotor which flows more oil with each revolution.

70 psi at idle hot is too high... trust me. Hot being abotu 210 oil temp.

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