jayyyw

So, I had lined up a buyer for my complete long block because I wanted to build something a little stronger and to make a little more power. Before he committed to the purchase, he asked me to send off an oil sample to Blackstone. Curious myself, I agreed.

I got the results back and saw lead and Ti were at elevated levels. Needless to say, the deal did not go through. I would not have felt right selling the motor like that.

Now, I have to figure out what the next step is. I have one last raced lined up for this coming Friday. After that, I am going to pull out the motor and look over the bottom end.

There's a few options I'm playing around with. I'm most concerned about the Ti levels and the condition of the rods. If they don't show any wear, I will likely reuse them and refresh the bottom end.

I will post the report in a few.

AzDave47

Would that be your first oil sample, Jayyw? I will look at the results, compare them to mine and give you feedback.

I am glad I had the bottom end redone on my engine. The BL report trend clued me in, but the real push was that coupled with some low oil pressure excursions. The rods and main bearings showed some problems but really were not that bad, pictures in my thread at post #77-79

https://www.corvetteforum.com/forums...tom-end-4.html

I have looked at the oil pump, saw nothing but had the Blue Katech pump with better scavenging installed, which will work for my road course play better than the OEM and eliminated one other potential problem area. The WCCH reworked heads with valves/guides/springs/retainers all had 12K miles on them, the period when Ti showed up for the first time and lead levels doubled. WCCH checked out the heads while the bottom end was getting forged and the measurements are in the thread above, but were all .0011 to .0016, which was great.

Patriot Six

AzDave47

Just do BL oil analysis and get a report trend going. One report is tough to evaluate unless the numbers really suck. I had 8 or 9 BL analyses to compare before I had CPR rebuild the bottom end. Only the last two had Ti in them and those were after all the HCI work. There was none in the OEM engine samples at 46K miles.

Patriot Six

jayyyw

Yes, unfortunately it's my first sample. I do not have anything to compare against, except for other people's reports, such as yours. I would appreciate your feedback!

My oil pressure is great; 70psi cold and low 30s @ 200 degrees. I've been running Mobil 1 15w-50 ever since I deleted the oil cooler. I change the oil within 2000mi and sometimes way sooner. I'm always tinkering with the car and I run it hard every chance I get.

My heads were redone back in June by LME. They told me the guides were worn from the previous work by LPE. OEM intake valves and new stainless exhaust valves were used. I have, maybe, 1500mi on the new heads. 43,XXX on the shortblock. Bone stock until 32,000mi on the dot.

I do rev my motor much higher than most would feel comfortable. Oil pressure drops very slightly at 7500rpms due to cavitation in the pump. That and multiple nitrous hits could explain the elevated numbers.

jayyyw

43,XXX on the stock shortblock. It was bone stock till 32,000mi.

It's definitely something that will always be on the back of my mind, if I decide to stick with the OEM Ti rods.

jayyyw

Unreal

Sucks. Best of luck with whatever you do.

35 Ti does seem awfully high.

double06

You are 35 and the averages are only 2 I would say that is out of spec. Not sure what normal is someone with more know ledge can chime in.

jayyyw

Do you see it now? Maybe try a refresh.

Thanks. Staying optimistic that the rods are okay.

Definitely something going on there. Have not noticed any metal in the oil or abnormal oil pressures.

I will sample the oil one more time before I pull the motor out and get an analysis.

ssbowtie1

Even if the rods are ok, with all the failures out there is it worth the risk of reusing them? How much longer until they become an issue?

Are the aftermarket rod options crap compared to stock? It seems like everyone is trying to reuse stock rods.

AzDave47

My Ti was only 8 and my lead was 16 before the rebuild, so you are way above my readings. Have you had any low oil pressure lights or have you seen the idle oil pressure drop significantly after idling for 45 seconds or a minute? The 35 for Ti is the highest reading I have seen posted.As a minimum and first step, check the valve spring retainers and see if they show wear or some gouging.

Unreal

The lightweight rods are one of the reason the ls7 makes great power and a big advantage to NA builds. Aftermarket rods are not crap, in fact they are awesome, but heavy.

jayyyw

Hard to say. I'd like to keep them for the weight savings they offer. There's a lot of talk of forged rotating assemblies robbing horsepower. Dave's build showed that that's not always the case. His forged bottom end build made almost exactly the same power as his SBE setup. Same cam, top end, compression, fuel, etc...

When I was talking to a builder about going to a 440ci setup with a 4.185" bore, I was advised against it. He told me i'd be sacrificing +/- 40whp. In a max effort setup, I'm not even willing to sacrifice 5whp.

I've raced a lot of different setups. The SBE cars always seem to run a little harder.

Definitely concerning. I have not had any low oil pressure warnings or even lower than normal readings at idle or at cruise. Did have one weird thing happen but I think there may have been water in the plug. Had a few good rain storms and left my car, uncovered, outside. When I grabbed the sample, I just drained a little oil and then topped it off with fresh oil. I drove down the tollway after and the oil pressure gauge was pegged at 100+ psi, then would drop to 50psi, then peg itself again, then drop down and show XXX, and repeat. It's been normal ever since, though.

Mordeth

35 is high but multiple readings are needed to rule out an anomaly. Start by inspecting the valve spring retainers if they are titanium. They can wear on the underside (the lower surface), especially if springs are fatigued. Seen it many, many times. Next is the intake valves and finally (obviously) the rods. I have inspected dozens and dozens of LS7s, removed and rebuilt my own LS7, and unfortunately once the titanium shows up it typically doesn't go away. It will start to work it's way into the bearings, which will then lose lubrication and eventually you get a spun bearing.

Also, there is nothing inherently wrong with using a titanium rod. In fact, titanium rods offer the best strength-to-mass ratio of all the materials.

jayyyw

I'm going to get another sample in the ~1000mi interval they recommended. Either way, I'm pulling the motor to inspect it thoroughly.

Jayfabs

double06

The rod difference is about 150 grams per rod I think (630 grams vs 480 grams). So almost 3 pounds (1,200 grams) of rotating weigh however I think the Callies crank is like 6 pounds (2,500 grams) lighter (I remember Josh weighed his). Though the rod is moving around more so I could see it having more effect. Could there be some loss in power with heavier rod, yes, but I think a 20 pound (9,100 grams) lighter flywheel would have more of an impact and those usually add like 10 hp.

SivaSuryaKshatriya

Don't the crank and rod act as one assembly since they're attached? Thus the net effect would be -3 lbs to the rotating assembly, granting you an increase over stock, yeah? If that's the case then one would probably be better off with a heavier but non-titanium rod as long as they get a lighter crankshaft to compensate (if titanium wearing into the motor is what we're worried about).