0w30 German Castrol, 95 LT1, 3,364 Miles. NOT GOOD

[Buffman]

Well it looks like the engine in my 1995 Buick Roadmaster Sedan Limited at 174K isn't doing good. You can see by the report I hadn't done a UOA in over 2 yrs. Over the past two years the car has spent a lot of time in and out of storage. Heck I didn't start driving it this year till July. Last year it was August, as it spent a couple months in the body shop for some work. Whether or not I racked any miles on the oil during those periods I usually always changed it out.

I figured I was going to do a UOA to see how the GC was holding up in the car. The previous 3 reports were from M1 0w40, and really wasn't impressed with it. SO when I changed my Oil pan gasket (last UOA) and pan (powdercoated too), I went to German Castrol. Have been running a Auto-rx Maintenance dose also. Most of all my driving is 45mph and above. I drive 30 minutes to work everyday (one way). and it's most all highway, but does require me to make a potential 7 stops.


I don't have a clue where the increased silicon came from, but I'm sure it was a leading cause in the increased wear numbers. The only thing I can think of is the powdercoated intake I installed prior to this OCI. Intake was media blasted and powdercoated (friend does coatings/finishes for living). I sprayed the intake out good with the air hose before I installed it, but perhaps I didn't get all of the blasting media out. The intake tract is in good shape and isn't leaking. Neither are the intake gaskets. Air filter is the same S&B that's been on since the last UOA and has a prefilter on it. It's in good shape, and I haven't driven in any dusty environments.

Had I sent this sample out earlier I wouldn't have taken a 1000 mile trip with the car. I have almost 2,000 miles on this OCI now. I plan on draining it this weekend and sending the sample in. Engine doesnt' sound any different, still makes great power, and even the worthless autometer oil pressure gauge reports good oil presure for the mileage.

I'm hoping the next sample shows different, otherwise might be rebuild time in the spring. BTW I've only ever used race gas once in the car and that was over 1.5yrs ago, and it was only ever 5 gallons. Blackstone must assume since I raced it I used leaded race gas. I can't complain, I've abused the car for 50K. 130+mph WOT blasts, 13.5 sec 1/4 Mile runs, and constant street abuse..

 

[addyguy]

I suspect your explanation is dead-on. Insoluable are very, very high for the mileage, so there is a lot of abrasive dirt in the system. That combined with the excess fuel is giving you high wear readings, especially at the bearings.

This is a perfect case where you ned to do several short 1-2k 'flush' runs with a cheap dino to get all the 'junk' out tof the engine. Only then can you see how the engine is REALLY wearing....

 

[Buffman]

Hopefully this next run will look better. If not might have to get some cheap dino in it in the spring. Funny thing was I changed the intake, then after driving it around, changed the oil the next day. Guess I should have kept the old oil in there a little longer. Forgot to mention filter used with AC DELCO PF52 Ultraguard Gold.

Again, not sure where that 1ppm Titanium came from, unless from my wedding ring...

 

[FZ1]

I'd stop the ARX and ,if it wouldn't hurt too much,drive it a little easier,then see how the uoa comes back.

 

[Buffman]

I guess I'll see in a week after I get this current oil drained out. Knowing my luck all the lead is gone and I'm riding on copper. The 650mile is trip was a lot of up hill/down hill driving. Pretty much 70-90mph...

 

[addyguy]

I don't think the engines a write-off. LT-1's just seem to have a 'dirtier' signature than other engines. Even with this being the case, they are tough engines. Once you got the 'work junk' flushed out of the engine, I'd just go with a 10W-30 HM oil for the winter, and maybe a 15W-40 HDEO in the summer, and change them at 4-5k miles.

 

[Buffman]

I don't drive the car in the winter anymore, and with the 0w30 GC being a thicker 30 weight, I should be okay with that choice. besides i have 35 quarts of it left to burn up. Still produces good old pressure (have to hook up the mechanical gauge for accurate readings)

I generally change the oil at 3K anyways since I am pretty hard on it

 

[OVERKILL]

Why is the Autometer gauge useless? I've had very good luck with their gauges......

 

[Buffman]

Originally Posted By: OVERK1LL
Why is the Autometer gauge useless? I've had very good luck with their gauges......


it's inaccurate. It's a electric sending unit gauge btw, not a mechanical one. Ever since I bought it, it's always read on the low side. Maybe it's a ground issue (I attached a ground strap to the outside of the sending unit and it didn't help), or maybe it's the gauge.

I haven't checked it in awhile, but last time I hooked my mechanical gauge (wiki with a 1.5% span accuracy) assembly, the autometer was off by about 8-9 psi at idle, and 12psi revving it.

So I guess I should use the word inaccurate rather than worthless since it still works

 

[OVERKILL]

OK, that makes sense. Mine is mechanical. Only electrical one I have is coolant temp.

 

[steve20]

the LT1 is a workhorse, and dirty signature defines it best.
Can you advise of the modifications you've made to get this behemoth to do 13.5 in the quarter? My 95 Corvette (weighing 3150 lbs) with a 6 speed and 3.42 gearing, can only manage a 13.2 @ 108 in the quarter. The mods may be contributingto the wear numbers.
Steve

FWIW LT1 motor is my favorite of all time

 

[Buffman]

Originally Posted By: steve20
the LT1 is a workhorse, and dirty signature defines it best.
Can you advise of the modifications you've made to get this behemoth to do 13.5 in the quarter? My 95 Corvette (weighing 3150 lbs) with a 6 speed and 3.42 gearing, can only manage a 13.2 @ 108 in the quarter. The mods may be contributingto the wear numbers.
Steve

FWIW LT1 motor is my favorite of all time





I don't really think any of the mods would contribute to wear except maybe the air intake assembly. Even then silicon numbers with the prefilter on the air filter have always been around 10-15ppm. Internal wise the only mods are new valve springs and Comp Cams Pro Mag 1.6 Roller Rockers (installed 4yrs ago). I Know Ring Flutter can be an issue on LT1s above 5800rpm, so most all shifts are completed by 5800-6000rpm. It doesn't burn a drop of oil, or leak it.

Otherwise it has 3.73s, Try-y headers, Delete Pipes, Xpipe, and Prostreet Mufflers. 4" Driveshaft, SS suspension. Aftermarket rear LCAs. Competition Engineering 3way adjustable shocks (used to have QA1s up front, then they leaked). RAISS intake, Custom Tuning done by myself. Best Mod is the 9.5" 3400rpm stall torque converter. 2.45 STR ratio. It goes 13.52s at 99.55mph. At the time I ran that the AFR at WOT was way too lean (mail order tune) for my tastes, so I've gotten it down to around 12.9-13.2, and made some suspension improvements (new shocks up front).

I'm confident if I ever got to race in better air (DA where I race is always 99% of the time 400 ft+) I could get close to 12s. Friend with the exact same car (well a caprice) with lesser mods has gone 12.7s in good air. I was running Drag Radials for awhile, then had the opportunity to buy a set of Drag Wheels from a friend. They had ET Drags on the rears. They hooked good everytime, but personally thought they were too much for the car, i.e too much rolling resistance. If I ever go racing again (lost the bug to go) I want to see what I can do on street tires, or just go back to using Drag Radials. I think that and the lean AFR what was not making it gain anything at the track. I've dropped a bit of weight from the car (still weighs just around 40xx lbs) and when I went to the 4" AL DS, didn't gain anything. Put the 33lb (each) skinnies up front (stock wheel and tire weigh 62lbs each) and didn't gain a thing. That and after a recent opti replacement I found rust all over the optical disc on a 2yr old vented opti. So it's running it's best ever, just I've never had the time to want to go back to the track (I'll only go at the beginning and end of the season when the air is cold and dry) and best that 2yr old time.

 

[OVERKILL]

fantastic times! My Townie runs 16's with the stock converter and 4,200RPM shift point. Stock shortblock with E7 Mustang heads, FMS cam, Crane 1.7 RR's, Vic 19lb/hr injectors, Mustang ECM and Explorer intake with 65mm TB.

I have a 2,500RPM stall for it in the basement, and a Baumann shift-kit that is going in a low-mileage Vic tranny that I picked up for a case of beer. Also have a 4" Aluminum PI driveshaft and 3.73's. Hoping for low 14's with it. MPH is currently only 89 with the 4,200RPM shift point, which is killing the ET, since it pulls the engine out of it's power band.

Impressive times for a boat! I bet it's turned a few heads and raised a few eyebrows

 

[Buffman]

Some people may not like it, but it indeed turns heads. Especially if I'm feeling in the mood to open the cutouts. You know your car is loud when a guy on a Harley makes a turn and looks back at your car wondering ***>..

People at car shows always ask me about "THE SWAP". I'm like those are just fuel rail covers. That's a stock engine

 

[Patman]

Originally Posted By: Buffman



I'm confident if I ever got to race in better air (DA where I race is always 99% of the time 400 ft+) I could get close to 12s.


You should've been here last weekend, I went to the dragstrip on Sunday and the DA was hovering around -800 ft all day long! I ran a best of 12.99 on that day. A couple of years ago I was lucky enough to be at the same track with the DA at -1350ft! I ran 12.81 at 109.4 that day! The lowest DA I've ever heard at this track was -2000ft, unfortunately I wasn't there that day!

 

[Buffman]

yeah the only DA you find like that around here is A Cecil and those east coast tracks. On occasion you might see a -500-600ft but it's late at night during MIDNIGHT Madness when they let the track go to [censored].

 

[steve20]

I LOVE BIG FAST cars-this is a great example-nice shine on the paint as well. Thanks for the pics.
I agree, I believe one of the best mods was the addition of the stall.
Not sure you can hear it well, but does your LT1 can sound like a sewing machine at times-?
Steve

 

[Buffman]

Nope I have a freak set of Comp Cams Pro Magnum Roller rockers (1.6s Self-Aligning) Even with them currently set at 1/4 Turn preload they are whisper quiet.

 

[Buffman]

Got the new analysis back today. Everything has come back down. The silicon is still high at 51ppm, but iron, lead, and copper, and tin are down. I'll probably keep the oil changes at 1000 miles or so for a little while maybe with conventional oil to wash any of that silicon out.

Will post full report tonight.