LS2 block, LS7 oil pump possible?
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
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.
Last edited by Pyro6000; Aug 13, 2012 at 10:16 AM. Reason: Correction
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.
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.
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
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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
The Best V8 Stories One Small Block at Time
Let me know if you need some info I have data logs I can show you
Tim
Let me know if you need some info I have data logs I can show you
Tim
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
Last edited by 96 Comp T/A; Aug 14, 2012 at 03:21 AM.
The landing should not be a big deal if there is oil in the pan.
Tim
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
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.)
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
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.)
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
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.








