I did not realize it until just now reviewing the data, but the worst case oil temp was 230 deg F and oil pressure just made it to 50 psi.
Need an oil recommendation - lost an engine using VR1
- Thread starter 70GS455
- Start date
Yes, pre lubed with a drill motor and it read about 45 psi, kept it going for about 30 to 40 seconds. When it first fired up, pressure came right up
twouvakind
Site Donor 2023
I wouldn't think that oil temperature and pressure would not cause any issues if rods 7 & 8 were supplied with adequate oil flow. No oil is going to fix an oil supply issue.
How long of dyno pulls were you doing at WOT, and how much time between them? I can't see a dyno pull lasting very long unless you were doing something wild.
Pulls were from 3500 to 6000 at 400 rpm per second. So looks like about 6 secs plus a few seconds at the start to stabilize.
We would usually wait about 15 to 25 minutes between pulls to look at the data and make changes. But on the ones with super hot oil, there were only a couple minutes between. I finally mentioned about oil temps and we started using a big fan on the oil pan to cool the oil off but I think by that point the damage had been done.
I don't think you can blame the oil with clearances that large.
Your oil pressure isn't low at 60 psi at 6000 rpm. My track car has just ~35 psi at 6500-6800 rpm and the bearings are fine. The issue is insufficient film thickness for the bearings. Also, VR1 is not a break-in oil and EOS doesn't make it a break-in oil.
Those clearances need a 50 grade oil, but the engine didn't need those clearances. At that power, the standard .0022-.0028" with a 30 grade oil is good.
Valvoline VR1 vs Driven BR30
Ca.....1200.....625
Mg....700.......0
Mo....80.........0
P........1300.....2600
Zn.....1500......2800
KV100.....10.6.....11.8
TBN.........7.5.......2.1
Those clearances need a 50 grade oil, but the engine didn't need those clearances. At that power, the standard .0022-.0028" with a 30 grade oil is good.
Valvoline VR1 vs Driven BR30
Ca.....1200.....625
Mg....700.......0
Mo....80.........0
P........1300.....2600
Zn.....1500......2800
KV100.....10.6.....11.8
TBN.........7.5.......2.1
Did you have the cam bearing feed holes at 3 and 7 o'oclock? Buick 455s as you know are finicky with the oiling. I assume per your post that you modified the oil passage from 1/2 inch to 5/8(assuming you have a 70 block as Buick changed to 5/8 passage in late 70, early 71) and added a 5/8 pickup tube. If that mod wasn't done you are almost guaranteed to wipe out nbr 7 and 8 bearings. I used VR1 for over 20 yrs in my GS and never had an oiling problem except for the usual rear main leak and valve covers at times. Used Gibbs break in oil and VR! after that. Wasn't pushing as much HP as yours as mine was 434 at the rear wheels. TA perf also recommended clocking their bearings for their dual groove cam bearings. That should be done whether you used their bearings or any manufacturer. Agreed with others that your bearing clearances were off.
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230 degrees F is “super hot oil”????? I have run cars and motorcycles at 285+ all day long.
Yes, back-grooved cam bearings are in per TA instructions. The block is a 76 and all oil mods were done (I wrote the article on George N's website about oil mods to the timing cover and filter adapter).
I realized clearances were too much but decided to proceed as I didn't want any more delays.
What weight oil?
We have the issue with these motors that hot oil is a two-fold problem. First, not only does the oil thin and viscosity go way down, but secondly the aluminum oil pump housing expands and increases the pump internal clearances. These engines will never survive at those oil temps. We have to take all precautions in order to get these to live.
M1 0W-40
Sounds like quite the ordeal, stinks that it happened. But I think you’ve answered your own question, and it wasn’t the oil’s fault, at least not directly. Your last sentence should always cause a hard stop in any project, especially when dealing with a fine piece of machinery like you’ve assembled so far.
An old saying (which is as much a reminder to myself as anything): If you can afford to fix it, you could have afforded to do it right the first time. Looks like you got a handle on things; remember that moving forward til everything is “right” and you’ll be much happier.
Got any pics of the engine/car? 😃
I don't think it was necessarily the bearing clearance. If it was, all the rod and crank journal bearings would most likely show signs of damage. Still think the main/root cause was inefficient oil flow to rods 7 & 8 that smoked out. Maybe @70GS455 can chime in about the shape of all the other bearings.
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Do you believe the issue was with the base stock composition? And this brand is the solution?
Then that is a poor design all around. You seem to want to blame the problem on the oil and view a different brand as a solution but that is not the root cause. I would not want an engine that is life-dependent on a brand of oil.
Not necessarily. If the block wasn't properly align-honed and/or the rod side clearance on the loose side, it could create the outlier that's on the extreme of the tolerances, becoming a focal point for torsional vibrations, and put undue stress on that bearing that the low viscosity (for the clearance) couldn't withstand. It could be a sloppy machining practice thing that wouldn't be an issue otherwise, or rather wouldn't show up, except in the case of insufficient MOFT.
All other bearings looked fine.
I don't know for sure that base stock was at issue.
But I do want to have the best chance for a positive outcome. So I am open to suggestions on the best path forward wrt oil