Bronze dist gear and valve guides impacting used oil analysis numbers? Or bearings...

[stantaur]

I've been running a bronze dist gear with our 2004-vintage LT-1 with Erson 253/259 solid roller (with AFR 210s that have bronze guides), and am concerned by the copper and lead content shown in the used oil analysis. Inside the filter (cut open properly, not hacksawed), there's a shiny bronze sheen to the oil. Can't really feel it between the fingers. Oil from the pan is normal appearing & no sheen. Is this normal for bronze distributor gear?

Used oil analysis shows 27 units copper (vs all 350s they've tested being 10) and 31 units of lead (vs all 350s being 11).
There's 1 unit of tin vs. universal average 350s having 2 units of tin.
Very low iron, chrome, aluminum, no insolubles, no fuel dilution (wideband tuned since new, 14.7:1 cruise and 12.5:1 WFO).

Oil pressure is great (30ish idle, 55-60 at cruise), no bad noises, car burns 1 quart per 1000 miles, leakdown is 3 to 3.5% across all cyls.

The lead and copper concern me, making me wonder if it could be bearings. Want to do the right thing and drop the pan to change out bearings if this isn't normal bronze distributor gear self-sacrificing.

I'm changing over to composite dist gear.

Welcome your thoughts.
383BronzeDistribGearOilReprtAnon.pdf

[stantaur]

Pulled the dist gear and found it to be a non-bronze gear (so I'll be going back in with the Comp Cams composite... scratching my head why our builder didn't use bronze gear on a 2004 Erson solid roller back when we assembled it - 7000 miles of wear now).



So I called up Blackstone and they asked if we'd used any additives in the engine. Matter-of-fact we did, having tried Restore as we were chasing an oil consumption issue and running out of ideas. Thought maybe it'd help w/ring seal (despite the 3% leakdown of compression rings, cold, I figured maybe the oil rings could be borked & we'd be able to rule it out if so).

Blackstone said Restore is perhaps 95% distillates and the other 5% un-named CSL (many figure it's ~ 60% Copper, 39% Lead and 1% Silver (or some rough approximation). Mystery of the copper sheen to oil filter drainout is likely solved, as we'll be keeping an eye on the UOA after cycling through 3-4 oil changes with inexpensive oil to "wash" out the residual Restore.

FWIW, the Restore was reasonably well-reviewed at Bob Is the Oil Guy and Project Farm. In our case, it didn't help our oil use, and won't be going back into the mix. Oil consumption & plug fouling was traced to valve guide seals. I changed out the AFR black rubber valve seals with blue viton AFR valve seals (and using high-temp thread sealer on the intake studs that go into the runners). We're now using maybe 1 qt every 800 - 1000 miles, vs. 1 qt per 250 mi with black seals, so that's close enough for me unless we find good reason to swap short blocks out for a 427 or 454 Blueprint.

Thanks again for the ideas and guidance. Wishing you guys a wonderful Holiday Season & 2019.