michics

Hello all,

I'm new to this site and looking to tap into the vast knowledge of LS motors on this site. So a little overview of what I'm considering. I have a former NASA American Iron Extreme winning 86 Mustang race car roller available that I'm considering purchasing to build back into a dedicated track car. Now I realize I can buy a dedicated track car for less $$$ than it will take to build out this one. But part of the deal is the challenge of building it and knowing what you have when completed. I've done several projects in the past so I know the work involved.
Ok, the Mustang has complete Maximum Motorsports suspension and has been light weighted considerably, cage, fire suppression, fuel cell, etc. So I'm thinking about the GMPP LS3 525hp crate engine ( All aluminum light weight, hp vs cost ) and a G Force built T5 (will handle 600hp, is light weight ) feeding to a 3:73 rear gear.

I have zero experience with the LS motors. Been a SBC carbureted guy my whole life. But thought it time to try something different. So looking for some feedback from the experienced road racers on things I need to be aware of with this combo. And I also have zero local contacts with LS experience to rely on. I'm already beginning to talk myself out of it !!

My questions:

-have read these motors have oiling issues on a road course. What oil pan should be used ?

-have also read that oil temps above 150 are harmful to the engine. This surprises me since sbc can run above 200 all day long and survive. What oil cooling system should I do?

-where to plumb oil cooling from the motor ?

-what power steering system works and how should it be plumbed ?

-Do these crate motors really startup as easy as people say ? Would use the GM stand alone wire harness.

-Would also probably use the GM front serpentine belt system with the high driver side alternator.

-Preferred flywheel, clutch setup ??

Thanks for your help.

Mike

mikedamageinc

iTrader: (49)

Most people run products from Improved Racing including oil pan baffle, crank scraper, and they make lots of cooler adapters that bolt to the side of the oil pan by the filter with or without built in thermostat. Serious racers also run an accusump, which you can also get from IR.

Pretty sure LS can handle more than 150, I think 200+ is where a cooler should be installed. Turn one power steering pump is what a lot of guys run, I have one and it's great but I only do autox and hpde. I've also heard good things about PSC. Either way a small cooler is standard.

I also run a LS7 clutch with billet flywheel that I'm happy with, but not making over 500 so can't help with that.

JimMueller

iTrader: (9)

Oil pressure loss: Long read from the Corvette forum, but you should sit down and read through it and find your comfort level.

https://www.corvetteforum.com/forums...the-track.html

Oil temps: I've read that road race LS's without an oil cooler can see temps above 290*F, so you should plan to run an oil cooler to keep it a little closer to 250*..

Oil cooling: I'd look at the Improved Racing items for the block mount, but you'll probably need to improvise on where you place the cooler, etc.

Clutch: If you want to save money, the LS7 clutch would be adequate with the stock crate engine. If you want it a little livelier then pickup a Fidanza 13lb flywheel for it, or go with a more expensive option ($800-$2500) which saves 20+lbs. Or you could go crazy and get something like a Quartermaster or Tilton 7-8" 3+disc setup. I think this is subjective to your goals.

gnx7

iTrader: (28)

The stock power steering pump will boil over in road race conditions. Get one from TurnOne or if you want to spend more $ the KRC ones are nice.

http://www.turnology.com/features/as...with-turn-one/

Improved Racing makes a nice billet oil cooler adapter with built in Tstat. I put them on lots of cars and they have good header clearance.

I ran a Quartermaster 5.25" triple disc setup that was only 13lbs for clutch/pp/flywheel; however it was on/off in 1st gear. Once you got going it truly was amazing with a GForce GSR 4spd dog box behind it and a 438ci LS7 in front (2470lbs RX-7 with 18x12's at all corners).

McLeod doesn't really advertise it; however they do make a small diameter clutch that would be a little easier to drive that is 23-24lbs for clutch/pp/Flywheel. Or a traditional twin disc with aluminum flywheel in the 36-38lbs range.

LLLosingit

iTrader: (4)

They really are plug and play and very simple to connect, Most likely has fuel pump/ Fan/ Grounds/Constant 12v/ Switched 12v.
Supply the correct fuel pressure and it should run great right out of the box providing that you haven't changed cam or injectors.

.boB

iTrader: (1)

"Dedicated track car" - what does that mean, exactly? A few NASA HPDE events a year? Or a full schedule endurance racer? Makes a big difference. I'll assume you'll be doing a full NASA schedule.

All engines have oiling issues on the road course. You'll need a 7-9qt fully baffled pan, and a 2-3qt accusump. A dry sump system would be nice, but...

Whoever told you oil temps above 150* are harmful is kinda clueless. Tests in the arctic show that oil temps below about 160*F causes excessive cylinder wall wear. Minimum oil temp should be about 180*, and some people say 200*. Max oil temp depends on duration and type of oil.

Oil coolers usually get plumbed from the side of the oil pan, just above the oil filter. But some aftermarket pans don't have that provision, so you have to be more imaginative.

No reason not to use the factory power steering system on a stock engine. Works well, and it's already there. Be sure to use a good cooler, though; don't let it overheat.

Use the GM harness if you're going to use the stock engine and don't require any tuning. Tuning requires you to buy additional parts, software, and licensing. This can get expensive. Then it becomes a toss up to using an aftermarket system. I used a Megasquirt ECU and a custom built harness because it was cheaper and easier for me.

The GM serpentine system works well, and usually fits well. Again, no reason not to use it.

As for the clutch, there are dozens of choices available to you. Pick the one that matches your use and budget.

pdxmotorhead

Just thoughts on the install,,
On the road course cars I've worked on, we installed a cooler loop to the oil cooler, using a adapter to move the filter off the engine, so the filter, cooler, and the accusump are all remote. You'll need a 1 way check valve between the accusump tee and the engine in the cooler loop, Otherwise the sump will blow part of the oil out the relief valve on the oil pump..

If you add an accusump, there are two valve types, manual ball valve and electric.
If I use an electric it gets wired to a pressure switch that opens the valve on demand, if you just power it with a toggle switch the accusump solenoid valves don't last long. There solenoid valves are one way when not turned on, the sump will fill but won't let oil run back.

(This is the way I do it, read the instructions for Accusump as well... !!)
When you are ready for first start, I always fill the sump out of the car, remove the air pressure fitting and the oil valve, and blow 5 lbs of air in to the oil side of the sump to push the piston back, fill with oil and reinstall the valve. then install the sump in the car. replace the air fitting and with the accusump oil valve shut put in about 20 lbs more pressure than your engine runs hot. (All engines work just a little different on pressure so its a gradual adjustment process... )

When your shutting the car down, run the engine about 2500 for a few seconds(Long enough to ramp the oil pressure up) then close the Accusump valve so the sump is full so you get the cold start oiling benefit if you want, and don't forget that you need to manage the total oil fill for max level without hitting the crank since you'll have the sump + oil pan worth of oil. We installed longer dip sticks that we marked for base fill and base fill + Accusump.. (We were using the large Accusumps so like 3.5 quarts of extra oil... )

I try and keep oil temps between 175 and 215, somewhere above 220 oil can start to breakdown increases as the temp climbs, I've had engines filled with redline hit 300 and live but I don't recommend it.. (Engine had a cooling issue)

Good luck..

steering_experts1

We can help with upgrading your power steering system. We offer rebuilding/upgrading services and new products for most LS accessory drives. Our power steering pumps are designed to reduce horsepower consumption, reduce fluid temperature, and are designed for high performance use. Feel to contact us by one of the methods below, or check out our products on your website.

Thanks,
Junior

79_T/A

iTrader: (1)

What are your goals for the car? Will you be doing track days, time trial, whee to wheel racing?

What’s your experience level on the road course?

I ask because an AIX prepped car is going to be pretty damn fast, and will make lots of grip. I ask these questions because the LS3 has the worst oil control of any LS motor. If you are serious about this car, and plan to drive it hard, an entry level dry sump might be a good option for you. It will make the car dead-nuts reliable on track.

No need to worry about oil temps over 200. Whoever told you 150 is quite foolish. You need to get up over 200 to burn off moisture that collects in the oil. I have experience with maintaining LS engines used in Grand Am, World Challenge, SCCA Trans Am, and the NASCAR K&N Pro Series. They are all dry sump engines, and the oil gets pre-heated to 200 degrees before we even start the engines. If you use good oil like Driven or Redline, you can run them all day long at 250 degrees.

michics

Thanks to everyone for they're replies. Very good information. For clarification, my intent is to run about half dozen lapping type track events a year. No wheel to wheel or timed run type stuff. I have not made a decision on building back the AIX car. And yes this car is already light weighted and with a aluminum LS motor would likely be quite fast. I have done about 6 track events so my experience level is not that high. But I've been a lifetime Chevy V8 performance guy I will have nothing less. I currently have a 70 Camaro Pro Tour car with a 500+ 406 sbc that I've run on the road course so I know what to expect in regards to the power level. As always one needs to keep the brain engaged as they do this stuff.
I have read numerous reports about oiling failures of the LS3 and that's why I'm asking for your opinions. The cost to power to weight ration of this engine makes it pretty appealing and should be trouble free except for oiling issue. So of the LS engine family is there another series that is better suited to road course duty ??

Thanks

gnx7

iTrader: (28)

It isn't really the generation or year LS engine that has oiling problems... it's the combination of sticky tires, downforce, and G Forces that the stock oiling system can't keep up with. So on the low end you run a baffled wet sump pan and Accusump combo. The best way as noted is to go real dry sump.... it's cheaper to run a dry sump from the beginning.... then putting a hole thru the block due to a rod failure.

I owned this car at one point and the new owner wanted to get used to it (stepping up from a Miata full race car) so upon selling it to him I offered him the choice of a 438ci or an LS2 with basic upgrades (still had the ARE dry sump on it). He chose the LS2 and it consisted of a 100% stock LS2 bottom end aside from rod bolts, stock LS3 heads with dual springs/LS3 intake, baby road race cam, long tubes and it made 460rwhp. He raced it for 2-3 full seasons in SCCA and NASA TTU and it never once gave him issues. Shift points were 6600rpm I believe. What made it last was the dry sump system.

79_T/A

iTrader: (1)

The LS3 has the worst oiling issues by far. The cylinder heads pool more oil than any other LS head. It’s so bad in fact, that we had to add external drains from the cylinder heads when we campaigned Corvettes in World Challenge. We didn’t have to do that with the cathedral port heads we ran in Grand Am. Granted these are all out race applications with downforce and pro drivers, but the evidence is out there that the LS3 has the most issues. Both engines had Daily Engineering dry sump systems.

260DET

Yeh I looked at a LS3 head but could see no way to fit an effective external drain, my other thought was to ventilate the sump directly rather than though the heads.

NSFW

Are there internal drains that could be hogged out to get the oil back to the pan more quickly?

DietCoke

iTrader: (18)

The short answer is no. Link bar lifters and a polished lifter valley help some.

NSFW

Thanks.

JimMueller

iTrader: (9)

So it sounds like the only way to make the LS3 safer under road course high lateral G's (without a dry sump) would be to go back to cathedral heads & intake? Where the heck can you mount the correct size oil tank in a dry sump system outside of the cabin without relocating the battery?

joelster

Not to knock on the T-5 transmission but getting a wrecked 2010-2015 SS manual, will yield you an LS3 and a Tremec 6 speed, which can handle significantly more power. Better yet try to find a wrecked 1LE and it will have a close-ratio Tremec.

DietCoke

iTrader: (18)

Accusump is a 9/10ths solution. It keeps my exocet alive, and i turn more Gs then most purpose built race cars. Also have all the supporting mods - restricted pushrods, crank scraper, baffled trap door pan, etc.