My DynoTune Went Horribly Wrong...
Drifting
Joined: Dec 2005
Posts: 1,720
Likes: 3
From: East Hampton CT
Compression: http://en.wikipedia.org/wiki/Compression_ratio
Around 200psi sounds about right....but some of the more senior engine builders on the forum can confirm.
Agreed on dissecting your oil filter to see what's going on in your motor before a complete teardown.
Lastly, what are your cam specs? Those will affect the DCR but should obviously be making way more than 350rwhp.
I recently lost a valve spring/rocker that caused one cylinder to lose compression and the engine ran horribly. Is it possible you have a dead cylinder (spark) causing the low hp values? Since you've checked compression, it is less likely that a spring or rocker failed.
Assuming all mechanicals check out (except the poor oil pressure...maybe lifter?) I'm wondering if you accidentally ended up with a stock LS1 (or near stock) cam ? If you went with something greater than a 224/224 you should have been putting down more than 400rwhp...not 350. I'm sure vendors mess up from time to time...and buying something used from the internet is even more suspect.
Around 200psi sounds about right....but some of the more senior engine builders on the forum can confirm.
Agreed on dissecting your oil filter to see what's going on in your motor before a complete teardown.
Lastly, what are your cam specs? Those will affect the DCR but should obviously be making way more than 350rwhp.
I recently lost a valve spring/rocker that caused one cylinder to lose compression and the engine ran horribly. Is it possible you have a dead cylinder (spark) causing the low hp values? Since you've checked compression, it is less likely that a spring or rocker failed.
Assuming all mechanicals check out (except the poor oil pressure...maybe lifter?) I'm wondering if you accidentally ended up with a stock LS1 (or near stock) cam ? If you went with something greater than a 224/224 you should have been putting down more than 400rwhp...not 350. I'm sure vendors mess up from time to time...and buying something used from the internet is even more suspect.
Thread Starter
Drifting
Joined: Apr 2007
Posts: 1,848
Likes: 1
From: Central Florida
Compression: http://en.wikipedia.org/wiki/Compression_ratio
Around 200psi sounds about right....but some of the more senior engine builders on the forum can confirm.
Agreed on dissecting your oil filter to see what's going on in your motor before a complete teardown.
Lastly, what are your cam specs? Those will affect the DCR but should obviously be making way more than 350rwhp.
I recently lost a valve spring/rocker that caused one cylinder to lose compression and the engine ran horribly. Is it possible you have a dead cylinder (spark) causing the low hp values? Since you've checked compression, it is less likely that a spring or rocker failed.
Assuming all mechanicals check out (except the poor oil pressure...maybe lifter?) I'm wondering if you accidentally ended up with a stock LS1 (or near stock) cam ? If you went with something greater than a 224/224 you should have been putting down more than 400rwhp...not 350. I'm sure vendors mess up from time to time...and buying something used from the internet is even more suspect.
Around 200psi sounds about right....but some of the more senior engine builders on the forum can confirm.
Agreed on dissecting your oil filter to see what's going on in your motor before a complete teardown.
Lastly, what are your cam specs? Those will affect the DCR but should obviously be making way more than 350rwhp.
I recently lost a valve spring/rocker that caused one cylinder to lose compression and the engine ran horribly. Is it possible you have a dead cylinder (spark) causing the low hp values? Since you've checked compression, it is less likely that a spring or rocker failed.
Assuming all mechanicals check out (except the poor oil pressure...maybe lifter?) I'm wondering if you accidentally ended up with a stock LS1 (or near stock) cam ? If you went with something greater than a 224/224 you should have been putting down more than 400rwhp...not 350. I'm sure vendors mess up from time to time...and buying something used from the internet is even more suspect.
Oil pump was removed and as I stated before, the valve was stuck on the closed position which I believe it would have raised the pressure instead of dropping it. I'm in the process of leak down and so far I've done 2 cylinders (5% and 4% leak results so far through the crankcase). If the leak down checks, then It has to be a bad cam..
Drifting
Joined: Dec 2005
Posts: 1,720
Likes: 3
From: East Hampton CT
The spring that failed on me was a PRC dual gold also. It had about 5k miles on it.
233/239 should be 425-450rwhp with your setup (do you have longtubes?)....not 350. Sounds like a bad (or wrong) cam.
233/239 should be 425-450rwhp with your setup (do you have longtubes?)....not 350. Sounds like a bad (or wrong) cam.
Thread Starter
Drifting
Joined: Apr 2007
Posts: 1,848
Likes: 1
From: Central Florida
Just sitting here trying to figure out whats the best way to get all the pistons at TDC (compression Stroke) one at a time.. 1 & 6 were easy because of the cam marks, but I still have 6 more to go.
Thread Starter
Drifting
Joined: Apr 2007
Posts: 1,848
Likes: 1
From: Central Florida
Leak Down Test Results
Ok, So using the following procedure, there results are as follows"
Cam gear and Crank Gear dot to dot checked 1&6.. Rotate 90* check 8&5.. Rotate 90* check 7&4.. Rotate 90* check 3&2 all locking the crank by placing the car in gear with rear tires on the ground and emergency brake on.. REGULATOR SET AT 100 PSI
#1 produced 5% leak into the crankcase
#2 produced 5% leak into the crankcase
#3 produced 3% leak into the crankcase
#4 produced 5% leak into the crankcase
#5 produced 4% leak into the crankcase
#6 produced 4% leak into the crankcase
#7 produced 4% leak into the crankcase
#8 produced 4% leak into the crankcase
So whats left to look at? THE CAM?
Cam gear and Crank Gear dot to dot checked 1&6.. Rotate 90* check 8&5.. Rotate 90* check 7&4.. Rotate 90* check 3&2 all locking the crank by placing the car in gear with rear tires on the ground and emergency brake on.. REGULATOR SET AT 100 PSI
#1 produced 5% leak into the crankcase
#2 produced 5% leak into the crankcase
#3 produced 3% leak into the crankcase
#4 produced 5% leak into the crankcase
#5 produced 4% leak into the crankcase
#6 produced 4% leak into the crankcase
#7 produced 4% leak into the crankcase
#8 produced 4% leak into the crankcase
So whats left to look at? THE CAM?
Thread Starter
Drifting
Joined: Apr 2007
Posts: 1,848
Likes: 1
From: Central Florida
Oil and filter have approximately 60 miles and looks amazingly clean. Looked for signs of metal in the oil pump but nothing was found, I will open up the oil filter next and look for gold colored metal in there. If I don't find anything in there, then the noise could have been valvetrain noise from low oil pressure. Next step is the cam... I need to find a degree wheel and make sure it's not off..
Burning Brakes
Joined: Nov 2004
Posts: 781
Likes: 0
What lifters are you using? New?
What length of pushrods? How did you decide length?
I wonder if you have a valvetrain issue and not getting full lift from your cam/valves.
I'm not familiar, yet, with the LS1's oiling passages/plugs/circuitry... could there be a plug missing, or something to this effect, causing improper oil flow or excessive bleed-off?
What length of pushrods? How did you decide length?
I wonder if you have a valvetrain issue and not getting full lift from your cam/valves.
I'm not familiar, yet, with the LS1's oiling passages/plugs/circuitry... could there be a plug missing, or something to this effect, causing improper oil flow or excessive bleed-off?
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Team Owner
Joined: Nov 1999
Posts: 26,679
Likes: 17
From: This vette goes to 11 Milford MA
St. Jude Donor '03-'05
Is your oil pump on with a spacer to clear a timing chain? If it is, you need to bolt up the pickup first, then the pump.You also MUST use a new O-ring,even if your original one looked fine. This stupid $5 part caused me a lot of headaches. If you do the opposite, the O-ring won't seat, sucks air, and drops the oil pressure.
Thread Starter
Drifting
Joined: Apr 2007
Posts: 1,848
Likes: 1
From: Central Florida
What lifters are you using? New?
What length of pushrods? How did you decide length?
I wonder if you have a valvetrain issue and not getting full lift from your cam/valves.
I'm not familiar, yet, with the LS1's oiling passages/plugs/circuitry... could there be a plug missing, or something to this effect, causing improper oil flow or excessive bleed-off?
What length of pushrods? How did you decide length?
I wonder if you have a valvetrain issue and not getting full lift from your cam/valves.
I'm not familiar, yet, with the LS1's oiling passages/plugs/circuitry... could there be a plug missing, or something to this effect, causing improper oil flow or excessive bleed-off?
No plugs are missing, I made sure of that during assembly. Everything that came off went back on. I did state that the oil pump valve was stuck on the closed position and had to be pried out, but no one has commented on it weather it can be part of the oil pressure issues or not.
Thread Starter
Drifting
Joined: Apr 2007
Posts: 1,848
Likes: 1
From: Central Florida
Is your oil pump on with a spacer to clear a timing chain? If it is, you need to bolt up the pickup first, then the pump.You also MUST use a new O-ring,even if your original one looked fine. This stupid $5 part caused me a lot of headaches. If you do the opposite, the O-ring won't seat, sucks air, and drops the oil pressure.
I removed the oil pump and o-ring looks new, no signs of ever being pinched.. I ordered a new pump and o-ring.
Tech Contributor
Joined: Jan 2007
Posts: 19,470
Likes: 1,171
From: Dyer, IN
No spacer was used. There are no clearance issues. The oring is brand new blue gm. It was installed with the engine out of the car and upside down on an engine stand. However, when Installed, I tighten the oil pump to the block first, then I placed the o-ring on the tube, lubed it and inserted it on the oil pump and then tighten the single 10mm bolt. Then placed the other end of the tube over the main stud and tighten.
I removed the oil pump and o-ring looks new, no signs of ever being pinched.. I ordered a new pump and o-ring.
I removed the oil pump and o-ring looks new, no signs of ever being pinched.. I ordered a new pump and o-ring.
Le Mans Master
Joined: Dec 2003
Posts: 5,561
Likes: 448
From: Atlanta metro Ga.
Absolutely a stuck relief valve will cause low / no oil pressure. In fact that's really what happens when folks claim "my oil pump died".
So I assume you haven't run it since cleaning up the oil pump? My guess is you'll find your lost oil pressure..
As to the low dyno numbers.. ??
So I assume you haven't run it since cleaning up the oil pump? My guess is you'll find your lost oil pressure..
As to the low dyno numbers.. ??
Tech Contributor
Joined: Jan 2007
Posts: 19,470
Likes: 1,171
From: Dyer, IN
Absolutely a stuck relief valve will cause low / no oil pressure. In fact that's really what happens when folks claim "my oil pump died".
So I assume you haven't run it since cleaning up the oil pump? My guess is you'll find your lost oil pressure..
As to the low dyno numbers.. ??
So I assume you haven't run it since cleaning up the oil pump? My guess is you'll find your lost oil pressure..
As to the low dyno numbers.. ??
Thread Starter
Drifting
Joined: Apr 2007
Posts: 1,848
Likes: 1
From: Central Florida
Thread Starter
Drifting
Joined: Apr 2007
Posts: 1,848
Likes: 1
From: Central Florida
Absolutely a stuck relief valve will cause low / no oil pressure. In fact that's really what happens when folks claim "my oil pump died".
So I assume you haven't run it since cleaning up the oil pump? My guess is you'll find your lost oil pressure..
As to the low dyno numbers.. ??
So I assume you haven't run it since cleaning up the oil pump? My guess is you'll find your lost oil pressure..
As to the low dyno numbers.. ??
Melting Slicks
Joined: Dec 2004
Posts: 2,654
Likes: 1
From: Palo Alto CA
It does if the low oil pressure was keeping the lifters from pumping up.
A friend and I went through similar headaches with a fresh forged LS6 build for his '63 Pickup (it's gone 12.3 so far on the motor... and we've since picked up another 20rwhp w/ tuning). In his case it turned out to be the "barbell" plug that goes into one of the oil galleries in the back of the block, under the rear cover. Though, you never would have seen 50psi IMHO if the barbell was out. You should give your builder a call though and ask if they remember removing it and/or installing it. Most builders will take it out if the block got any machine work.
Good luck.
-TJ
A friend and I went through similar headaches with a fresh forged LS6 build for his '63 Pickup (it's gone 12.3 so far on the motor... and we've since picked up another 20rwhp w/ tuning). In his case it turned out to be the "barbell" plug that goes into one of the oil galleries in the back of the block, under the rear cover. Though, you never would have seen 50psi IMHO if the barbell was out. You should give your builder a call though and ask if they remember removing it and/or installing it. Most builders will take it out if the block got any machine work.
Good luck.
-TJ
Le Mans Master
Joined: Mar 2002
Posts: 8,466
Likes: 51
St. Jude Donor '17
New rods, pistons, rings, and bearings is more than a cylinder hone. As Doug suggested do a leakdown. I would also do a compression test. 15psi oil pressure could mean a pinched pickup to oil pump o-ring, or excessive main bearing clearance. Did you verify your clearances when installing the new bearings? What about rotating assembly balance? Di you check your rings for proper end gap?
---
I know I may be asking the obvious questions, but what you are describing sounds like some of these things were overlooked or not done to proper tolerances.
---
I know I may be asking the obvious questions, but what you are describing sounds like some of these things were overlooked or not done to proper tolerances.
Hey can you come work on my car man?
Melting Slicks
Joined: Jul 2006
Posts: 3,356
Likes: 1
From: Chesapeake Va
If the bearing clearance really is .003, that could cause a knock and low oil pressure. Clearance should be .0025 MAX, and should actually be tighter than that.
Did you have the crank miked? I have seen out of round journals be passed right over by a machine shop. On a crank that they polished no less. An OOR journal will cause an engine knock after only a few hundred miles. It wont spin a bearing but it will egg one out.
At this point I would be looking at a complete tear down.
BTW, I would also increase the top ring gap .003-.005. Better too loose than too tight when it comes to top ring end gaps. ESP with hypereutectics.
Did you have the crank miked? I have seen out of round journals be passed right over by a machine shop. On a crank that they polished no less. An OOR journal will cause an engine knock after only a few hundred miles. It wont spin a bearing but it will egg one out.
At this point I would be looking at a complete tear down.
BTW, I would also increase the top ring gap .003-.005. Better too loose than too tight when it comes to top ring end gaps. ESP with hypereutectics.