derzvette

Hi all,

I am cross posting from Corvetteforums at the advice from another member there - seems like you guys are more DIY with engine building and such. Would appreciate if you have any insight to these issues I have.

http://www.corvetteforum.com/forums/...-diverter.html

Background: 2000 C5 Corvette with 427 LS3 swap. Used 30w Break-in Amsoil.
Brand new engine - build specs attached.
I have a dewitts radiator w/ EOC - I am running 7~7.5qt oil at the moment. I do NOT have the 7psi bypass oil lines as such on the C6.
Currently has 10w-30 Synthetic Amsoil w/ zddp.
Oil Pump is GM 12612289


Had the car at the tuners shop - ran into oil pressure drop. As the car reaches 4k rpm + it starts to drop pressure (from 36psi, down to ~30psi) and takes a bit for the pressure to recover. It does seem like the pan is being drained, as when I pulled over and pulled the dipstick, I didn't see any oil on it (or I missed it.) Waited, pulled the stick again and saw oil on it. Note : When I first pulled the dipstick a small puff of white smoke came out, so I am burning oil (oil not reaching bearings?)

I don't see how the pan would be drained at a low pressure (36psi isn't a lot) or I have something missing in the block reducing resistance. (missing galley plug?)

This is what I've decided so far.

Before removing engine – pull oil diverter block off and cap with provided plate - start car / see if there is a difference in pressures at warm idle. If possible, remove oil filter and inspect to see if rear oil galley plug is installed properly.

If no change – pull engine. (If I can check these without pulling engine, please advise)

1)verify rear galley oil plug is installed properly
2)remove oil pan – verify if oil pick up tube and oring are installed properly
3)pull front cover off / remove oil pump – verify pump oring was installed properly.
4)install new oil pump (back to LS6 ported pump)
5)check what reluctor cam wheel is installed (if x4 replace with x1) (Separate issue- if I pull the block I'll try and knock two birds out with one stone.)
6)check if front oil galley plug is installed properly
7)Inspect all parts for premature damage
8)decide if we need to pull block apart or re-install engine

Also, will:
-Install aftermarket windage tray
"MAST Motorsports LS Stroker Windage Tray, Full Length"
-Install aftermarket rear galley plug
"Precision LS Billet Barbell" - SCC


This project has been a complete nightmare. Honestly I'm out of funds and can't afford if the block goes sideways. I've also installed a T6060 / 3.5 DSS / C6 Z06 Diff all with built internals. (nothing to do with oil pressure though.)
Let me know if you need any more information.

Old Geezer

iTrader: (3)

OEM dash gauge? If so, put a real gauge on it.
The "puff" may have been some condensation. Check the PVC system.
I'd vote for item 2-3. Easier to verify the real psi, B4 doing that, tho.

dw456post

Did the valley cover have the rubber seals for the towers?
Maybe they built it with increased bearing clearances and you need to run 40 weight?
I had a major engine builder on here tell me that 25# at wot was ok. I didn't think so.

derzvette

Will do - we hooked up a computer to the car (forgot the port name) and it showed similar PSI. could be an issue with the sensor, doubtful, but will rule out.


Does anyone know the correct hose setup for DeWitts radiator oil cooler lines? Model: 1139097E (EOC on the left) Does the oil come in the top from the engine and go out the bottom into the engine? that would make the most sense to me...

**Edit**
>http://www.corvetteforum.com/forums/...e-routing.html
Looks like hot oil in to the bottom of the rad - cold oil out top to the engine. Anyone want to confirm?

derzvette

Uhhh - Not exactly sure. on the rubber seals. for the knock sensors? (they are now on the side of the block)

With the break in oil I saw similar PSI. I can try heavier weight though.


--Does anyone know if its possible to see the rear galley oil barbell from the oil filter location? (looking up?) I might try a borescope.
**Edit** I'll look in the pre-filter port to the filter to see if the curved end of the barbell is there.

Greg_E

iTrader: (4)

I think he is talking about the o rings on the underside of the valley cover that block off the DOD oil passages on LS engines that don't have DOD. Very different than the valley cover on the LS1 you are replacing.

See picture in this link.
https://ls1tech.com/forums/generatio...ley-cover.html

dw456post

Yeah, what GregE said. I don't know what the bottom of the LS1 valley cover looks like as I don't have one ,but you have to seal up the 8 oil holes in the towers.

derzvette

I don't know what valley cover I have in there.. Pretty sure it was on when the builder sent it to us. Is it as simple as pulling the intake manifold and checking?
None of my invoices have "valley cover" - Perhaps my shop installed it / I'll find their invoice and look at what they used.


http://www.briantooleyracing.com/ls2...-12599296.html
>Is this the cover I would want to use?

Also - I am pretty sure all the galley plugs are there - I found another invoice from the builder. > See attached

derzvette

Before Valley Cover


I don't have a pic of just valley installed.. I'm pretty sure I have the typical LS3 no AFM valley cover. (DOD Covers don't have the PVC vent) Do some of these LS3 covers come without the rubber seals? I have to pull the valley cover to see if there are on top of the 8 towers, correct?

My cover with vent


>DOD Cover https://goo.gl/mYHmYT

derzvette

Found the PN for my valley cover - 12599296 looks to be the LS3 valley cover.. do they all come with the rubber seals? all the ones online I see do.

derzvette

I have confirmed my oil psi sending unit is accurate with a mechanical gauge.

into the engine we go!

derzvette

Per my builder, they are set at .0021 on mains and 0.0015-0.0025 on the aftermarket rods.

dw456post

Before tearing into the engine, drain the oil, get a new filter and put in 10w 40. Way easier than pulling stuff. Does that block have piston squirters?

derzvette

I'm not sure on the piston squirters... How would I tell? Heh... Never really encounter this question.

I have 10w-40 ready, but this would only assist keeping pressure higher, not avoid the drop in psi at high Rpm no? Unless the 30w is too thin and needs more existence past the bearings? Unsure.

Will do as much as we can before testing into the block that is for sure.

Launch

I found my ls1 oil filters would block way too soon and cause pressure drop. It was the second time I realized the filter is the issue, and nothing else. I babied the car home one day with 10psi and near 0psi at idle. Swapped the oil filter, had an instant 40+psi.

More research into why this would happen,, i found out that most of the LS1 oil filters don't run an internal bypass valve in them for when they get too clogged up, so you just lose oil flow/pressure entirely through the engine when the oil filter clogs, as the filter cannot flow oil through it properly.

I now have swapped the oil filter thread in my oil pan to use the later LS3 style oil filters which all run an internal bypass valve in them.

Better to have your oil bypassing the filter element and having proper oil flow and pressure through your engine, than having little to no oil flow which is catastrophe waiting to happen. And that is why the manufacturers put internal bypass in the oil filters. For some reason, most of the filters to suit early LS1's do not have a bypass in them.

derzvette

I haven't found it to be my oil filter - im using Mobil1 - M107. Have gone through multiple, and they do allow higher pressure (when oil is cold I see ~50+ @ 2k rpm) -

My oil sits around 230-240 while driving in traffic / hot. (have dewitts eoc which seems to keep it toasty but stable)

Gonna try the 10w-40, then maybe 20w-50 if that doesn't work well.
Will also pull the manifold+valley to see if any of the o rings split or moved.
If neither of those work, we will pull the pump and swap back to a non high volume pump (LS6 ported) and verify the o rings are in place for pump and pick up tube.

derzvette

1)went to 10w-40 - increased pressure (expected) issue persists
2) removed EOC - Pressure increased (3psi~ / expected) issue persists
3) mechanical gauge shows same pressure as oil sender sensor
4)pulled valley cover, all orings are intact and issue isn't there.

Gonna pull the meiling pump off and go to a non HV pump. (LS6 ported texas speed)
If that doesn't fix it... gonna work with builder to send the block back

hillshooter

I am a way noob here but I feel your pain. Just one curious thing to me. I have a Camaro but my LS3 holds 8 quarts of oil. you said you only use 7? Whats the difference?

derzvette

I actually use ~8qt as I have an EOC (external oil cooler)

I have an LS1 pan, you probably have an LS3 pan, there could be a difference. I do not know.

hillshooter

I would be shocked if the oil pump doesn't fix the issue.