Pyro6000

Hello,
This is my first post here, so I apologize already if this has already been covered. (I did a quick search)

Anyways, my father has a 685hp @ 6500rpm LS2 in his dune buggy. Today he lost oil pressure and developed a rod knock. He shut it down quickly, but heard it knock. The engine is coming out this week.

He's never been happy with the oil pump options that he's seen. IIRC he tested a stock one, katech, and one other name brand aftermarket. He chose the one that showed the highest pressure in his test. Without going to a completely external system like a Barnes, what is the best oil pump upgrade out there for the LS2 crank? Will the LS7 one work? (Does it need the matching timing cover to work?)


More info on the motor:
Callies 4.000" crank, Oliver billet rods, CP pistons, mechanical roller lifters, .700" lift Comp Cam, All Pro LSW heads, T&D rocker arms, custom Engler 8-hole fuel injection with FAST XFI/XIM computer system, MSD coil packs, and headers running into a single Gibson dual-in-dual-out muffler.
Picture: http://i5.photobucket.com/albums/y16...p/DSCN1193.jpg

96 Comp T/A

iTrader: (8)

The LS7 pump will bolt to the LS2 block or any other LS series engine, however you have to have the long snout crankshaft (LS7 or aftermarket) in the engine to drive it. If your dad has gone through three oil pumps trying to find the one with acceptable pressure, he might have a rod/main clearance issue. Using the oil pump that pumps the most amount of oil may not be the best option, if you are simply pumping the pan dry. You might want to consider something like an accusump to increase the engine's reserve of oil.

Reckless

iTrader: (9)

96 Comp is correct, but you will also have to have the LS7 oil pan and use a dry sump tank and lines.

Pyro6000

He has a Callies 4.000" LS2 crank, I am unsure of the snout length. It does have loose bearings, IIRC 2.5-3 thousandths clearance, but he's running Joe Gibbs HR-4 full synthetic 20w50.

The three oil pumps were not installed in the engine and tested, he made up a testing jig with a pressure gauge and ran them with an electric drill in mineral spirits.

Correction: Bearing clearance is 1.5-2 thousandths.

Another thing I should mention is that this is not a new engine. Since it's last rebuild, it's been run for about 3 years. This is the first time it's lost pressure like that, so it is not a common issue.

Quick Carl

The way you guys drive those dune buggy/ sand rails you may be better off adding an accusump for those times you're upside down and still standing on it, LOL.
Check with Clay (LSMonster) on here as he does a ton of LS Sand rails.
LS7 set-up requires pan,front cover, long snout crank, extended oil pump drive on lower timing gear, tank, lines and it still don't work upside down.

427 zeo6

You need a crank with the longer front snout, the oil pump, the timing cover and LS dry sump pan. You can get a oil tank from Speedway for around $300-400. I don't think an Accusump is a good solution for a sand buggy, go with the dry sump.
For bearing clearances, remember your dealing with an aluminum block go for 0.002-0.0025 on the mains and same for rod bearings. If your spinning the motor up for extended periods of time, look at the oil passages in the block and oil pan and rework them for better flow.

Pyro6000

He just got off the phone with Schumann and they claim that their oil pump will run 110lbs cold pressure, 85-90 warm, 50 at idle. I think he's going to try that route instead of converting to LS7 dry sump.

There is no worry about pumping the pan dry, as the overhead is restricted and there is plenty of drainback. Upside down isn't an issue either, for two reasons. First reason is a momentary kill switch on the throttle pedal to quickly and easily shut the motor off during "OH S***" moments. Second reason... It's already been upside down twice without issue. (I actually have videos on YouTube for both rolls, lol.)

I agree about the accusump... Don't want to go that route.

As for the bearing clearance... It was that loose the first time it was built, and I'll tell you why it isn't anymore. With the block in the parts washer with 180 degree soap water, the mains grew a lot more than a normal aluminum race block. I don't remember how much exactly, but it was enough to tighten up the clearance without issue.

Here is a very short video of the car: (It stays upright in this one)
http://youtu.be/BhI5QWXqQZM

Gray86hatch

iTrader: (83)

I have a Schumans set up and have for a year. It works great. Do all the pickup tube mods and install the pump like Vern tells you it should work great.

Mine makes 75 cold idle. will max out a 150 gauge by 2000 cold. 1500 rpm 190 oil temp is 65-70. wot 7500 makes 105-90.

I have the lightest spring in the bypass and 5-30 ls30 oil in it.

Tim

Gray86hatch

iTrader: (83)

I agee on the mains. Mine are .002. First time the machine shop set them at .0028 He assured me this is how he runs alum blocks. Made the main bore dimension on the big end and once it was hot lost some cruch on the bearing. Made a mess of the whole thing took a year to recover from that mess. Found a new machine shop that was more experienced.

Let me know if you need some info I have data logs I can show you

Tim

96 Comp T/A

iTrader: (8)

X2,
If you do a little research in the road race section where these engines are subjected to sustained high RPM, and high oil temperature operation, this has been an issue that has been dealt with before. Some folks set static main clearance as low as .001"!


Here's a good thread with a lot of smart people offering suggestions on clearance.
https://ls1tech.com/forums/generatio...ggestions.html

Quick Carl

If you are doing the back bumper wheelies and nose dives like most of these sand rails, you momentarily don't have any oil at the pick-up so it doesn't matter whose pump your running. That's why I would like the accusump for insurance. I've seen some going up crazy hill climbs just standing on the throttle all the way to the top and if drag cars have problems for just a short wheel stand....

Gray86hatch

iTrader: (83)

If the pan pickup and pump are correct you should not have issues with the wheelstands. I don't seen any pressure variations with my car and 1.28 60'

The landing should not be a big deal if there is oil in the pan.

Tim

Pyro6000

Thanks so much for this post. This is almost exactly what I was looking for!

Carl,
Oiling this car has never been an issue with wheelies and nose dives. He has an oil light that you can see from Mars, and it doesn't flicker under those conditions. (Not that it nose dives much, you're thinking of rear-engine cars as opposed to this mid-engine car.)

427

iTrader: (3)

The oil light sender will have a PSI number, it does not come on if the PSI stays above that even if it's air/oil/foam. If the sender has a buffer (really small hole in the fitting) it could go 0-60-0-60-0-60PSI in 1/10 second intervals and the light will stay off on a 50PSI sender.
The sand rail application will have oil pressure issues for sure, but they may not last long enough to cause failure at your power level.

Kurt

Gray86hatch

iTrader: (83)

Kurt

What Vern and Tim have told me is alot of the issues are commming from the pickup tube. The screen is to tight and the entrance to the pump is a little tight even when ported.

Vern includes a new screen and takes the o-ring out and uses a 2 bolt flange with gasket.

Also they add a o-ring to the pump at the outlet.

Tim

Pyro6000

Update:
Weighing all the options, he's strongly considering the LS7 setup. Found an entire kit (new/take-off) in a deal that may be too good to pass up.

Also, turns out that Callies LS2 cranks were made with both snouts. Not sure which one he has, but Callies apparently will lengthen them if need be.

Gray86hatch

iTrader: (83)

You would need a new crank the snout is longer for a ls7 drysump

Tim

Che70velle

iTrader: (6)

The dry sump ls3 engine in the grand sport Vette, has a longer snout crank also, in case you guys go crank shopping.

Pyro6000

I heard that Callies will weld an extension on the snout if it needs it.
I think the motor will come out tonight. Measure up the snout then and see where to go from there.