jcorenman

Here's a copy of Castrol's product data sheet (dated Sept '11 but current on their website).

http://www.castrol.com/liveassets/bp..._Sept_2011.pdf

The viscosity numbers look OK I think. The question is how much of the hi-temp viscosity is oil versus viscosity-improver's which don't lubricate very well. Zinc is not spec'ed. but what struck me as very odd is that the 5w-50, while meeting all of the API spec's, does not meet ANY of the manufacturer's specs. That is unique among all of the oils listed. Why would that be?

Dan, do the cams and lifters look OK? And have you opened the filter, to check for metal? I am thinking that the cylinder-wall damage could also be a failure elsewhere, which put a lot of metal into the oil.

LT Texan

Jim, the piston rings are scuffed mainly where the cylinder wall is scored. Haven't looked closely at the cams and lifters yet.

Alex, haven't pulled out the oil pump yet.

I have the filter and saved a quart of oil out of the crankcase. So I can send that away for analysis.

Here's what I saw leading up to the failure:

Oil pressure held steady at just below 5 on the gauge while cruising (around 70mph and 3k rpm).

Hot idle, I was still getting just under 3 on the pressure gauge.

Car ran great up to about 15-20 minutes before failure. At that point, she started barely surging - like a fuel delivery problem - but just barely surging enough that I could feel it. I don't think a passenger would have noticed. Figured I'd stop for gas and see what was up. But didn't find a good spot.

All during this time, I kept my eye on the gauges. Oil pressure was fine, just below 5. Coolant temp was just a tad above normal, normal being about 1/3 between the two white lines. She runs cool on the highway. Volts were just above 12, which worried me because that is low and I worried that the electric fan kick on, but she wasn't running cool enough to shut it off. Yes, the A/C was running and running real good. Fan on second setting.

Then she gave out. It was like I turned off the ignition. Which I think was the cylinder(s) not holding compression and not igniting the mixture. I am sure I looked at the gauges when she gave out and didn't see anything odd. What immediately went through my head was fuel pump relay. Then it was all about making it past the concrete barrier on the slow lane to the shoulder. There was a couple feet of shoulder on the fast lane, then a pretty steep drop to the median.

So the slight surging was my only real symptom leading up to the failure.

LT Texan

At this point, probably best to stat looking for a shortblock in good condition.

SeanR

You might have had a nice over fueling problem, it washed the oil away from the walls and that caused the issue. Get that oil sample sent out to Blackstone and please let us know what they say.

LT Texan

I think you're right about the oil analysis.

Air/fuel gauge always around 14.5:1 while cruising. I always
keep an eye on that. I was watching it close when it started surging.

Mechanic commented on the nice color of the plugs.

The one on the right came out of #1.

Leon Speed

Those plugs are really really clean!

docmirror

I wish we had leakdown results.

LT Texan

leakdown? I watched it pump up compression of 50-75psi on the left bank, and the right bank's numbers deteriorated the more the mechanic turned her over.

The plugs weren't that old, but I had the CIS tuned really well.

LT Texan

for the oil analysis, Blackstone lists a $25 standard analysis.

Is this what I want?

SeanR

Yes,

my thought on over fueling is just a guess, I've no idea unless you were traveling through a sad pit.

docmirror

Where was the compression air going? I can't tell from the pics, but based on the rings, it doesn't look like it was going past the rings.

You didn't have excess fueling as the plugs are very nice looking.

LT Texan

Another thing.

After it died, the starter could only just crank the engine.

Before, the starter would spin the crap out of it.

I figured the piston's coating gave way and it was the friction
of piston aluminum mush against the cylinder walls.

I was surprised to see the scoring of the cylinder walls.

But I guess, chrome moly rings always win.

Also, I ordered a kit for the oil sample from Blackstones, but they
said to expect 1 -2 weeks to get it.

Mrmerlin

put an oil sample into a sealed bottle if it did have extra fuel in it you wanna keep it from evaporating out of the oil,
put the sample into the refrigerator not the freezer

LT Texan

Got the results from Blackstone today. Basically, the report doesn't show any issues from what I understand.

I did get an opinion off-line from a member of this forum who said that the damage was caused by heat. That the engine got VERY hot. And that would cause the pistons to expand more that the cylinders, causing piston to wall damage.

That makes sense to me, except that the engine was running cool - as normal.

It was well below 1/2 on the gauge and that is normal.

Previously, it did get hot when I was adjusting the A/F ratio and the electric fan fuse had blown. But that was months ago.

Maybe that planted the seed and running it for 4 hours at 70 mph on a 90 degree day did it in?

I think best to move on, get a motor built and get her back on the road.

And don't let it get hot again?

soontobered84

Dan,
You probably don't really want a short block. You may come out better buying a long block 4.5L as my understanding (I could be wrong) is that some of the essentials to rebuilding a 4.5L are no longer available? I'm sure someone will correct me if I'm wrong. I would also think that you would probably want to keep an original type engine in your car?