Need an oil recommendation - lost an engine using VR1

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Jan 25, 2023
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Sensational headline I know but some of that was my fault. I have a 1970 BBB that I had finished and put it on an engine dyno for testing. Had 10W-30 conventional VR1 with a can of GM EOS added for break-in and remained in the crankcase for the duration of testing. Made a large number of pulls and ended up with a best of 595 hp/ 625 ft-lbs on 93 pump gas. Specs are 10.7 CR, ported aluminum heads, roller cam and rockers, dual plane intake, carburetor, headers, offset ground crank for increased stroke, 482 ci, stock oil pump with higher pressure spring. Upon initial startup and cold oil, oil pressure was really good at idle (like 56 psi).

The part that was my fault: The bearing clearances were big at .003 to .0033 on the rods and .0035 to .004 on the mains. I did not adjust to a thicker oil. Decided to wing it and hope for the best. We also let the oil get too hot during some pulls and oil pressure was low at just under 60 psi at 6000 rpm on a few occasions because of it. Ended up spinning rod bearings 7 and 8 (The last to get oiled on this engine).

The reason I blame VR1 in part was due to a later conversation with a Buick engine builder. He stated that he always saw a large drop in oil pressure with VR1 as the oil heated up compared to room temp oil. He switched to Driven break in oil and saw much less pressure drops with temperature during his dyno testing.

What we have corrected: after a rebuild rod clearances are now .0021 to .0022" and mains are .0023 to .0025", crank was replaced, extra qt oil pan, additional windage screen, new aftermarket timing cover with oil pump and improved oiling, added an external oil line which oils from the rear, larger Baldwin B9 filter, Driven BR30 break in oil, limits on oil temp during pulls.

Why a temperature stable oil is more critical in this engine vs others: the oil pump is external and is steel gears inside an aluminum housing, main bearings are not priority oiled - lifters and cam bearings are oiled first, then the mains, oil pump oils from the front first.

The mPAO oils intrigue me due to their VI and other marketing terms but wanted to get some expert opinions on which oil to use after break in.
 
That’s quite a story.

I guess the bottom line is Valvoline doesn’t know what they are doing but fortunately Driven does.

Next time perhaps you should not “wing” it.
To be fair, he could have meant to word it as that the Driven brand was probably a better quality and usage for what he was doing with it. I'm gonna give it a bit to see the follow up and hear what the OP has to say.
 
You put too thin of an oil with known excessive clearance and what else wrong but ran it anyway? Cold oil pressure is meaningless. I helped a friend restore a 67 GTO he bought in a box and we rebuilt the engine . Upon start up one of the guys that read AE Hass writings immediatly said you need thinner oil, the oil pressure is to high!
 
Those new clearances should work fine with even a 5-20 oil. I have a supercharged 5.4 that makes about the same power as you and has .0022 clearances. I either run RP HPS 5-30 or M1 Euro 0-40 in it but I have the HV oil pump too.
 
Sensational headline I know but some of that was my fault. I have a 1970 BBB that I had finished and put it on an engine dyno for testing. Had 10W-30 conventional VR1 with a can of GM EOS added for break-in and remained in the crankcase for the duration of testing. Made a large number of pulls and ended up with a best of 595 hp/ 625 ft-lbs on 93 pump gas. Specs are 10.7 CR, ported aluminum heads, roller cam and rockers, dual plane intake, carburetor, headers, offset ground crank for increased stroke, 482 ci, stock oil pump with higher pressure spring. Upon initial startup and cold oil, oil pressure was really good at idle (like 56 psi).

The part that was my fault: The bearing clearances were big at .003 to .0033 on the rods and .0035 to .004 on the mains. I did not adjust to a thicker oil. Decided to wing it and hope for the best. We also let the oil get too hot during some pulls and oil pressure was low at just under 60 psi at 6000 rpm on a few occasions because of it. Ended up spinning rod bearings 7 and 8 (The last to get oiled on this engine).

The reason I blame VR1 in part was due to a later conversation with a Buick engine builder. He stated that he always saw a large drop in oil pressure with VR1 as the oil heated up compared to room temp oil. He switched to Driven break in oil and saw much less pressure drops with temperature during his dyno testing.

What we have corrected: after a rebuild rod clearances are now .0021 to .0022" and mains are .0023 to .0025", crank was replaced, extra qt oil pan, additional windage screen, new aftermarket timing cover with oil pump and improved oiling, added an external oil line which oils from the rear, larger Baldwin B9 filter, Driven BR30 break in oil, limits on oil temp during pulls.

Why a temperature stable oil is more critical in this engine vs others: the oil pump is external and is steel gears inside an aluminum housing, main bearings are not priority oiled - lifters and cam bearings are oiled first, then the mains, oil pump oils from the front first.

The mPAO oils intrigue me due to their VI and other marketing terms but wanted to get some expert opinions on which oil to use after break in.


If you are going 2 run an engine to 6000 rpms you will need an Oil Accumulator, its a small tank that holds 1 to 3 quarts of oil, What cylinder heads are you running, 4 a 482ci Motor the dyno numbers you posted, is this Chassis Dyno or Rear Wheel dyno numbers?
 
If you are going 2 run an engine to 6000 rpms you will need an Oil Accumulator, its a small tank that holds 1 to 3 quarts of oil, What cylinder heads are you running, 4 a 482ci Motor the dyno numbers you posted, is this Chassis Dyno or Rear Wheel dyno numbers?
I'm trying to keep it as stock looking as possible. With an accumulator I would have to run an external pump and all the hoses. I don't think I can hide that.

The heads are TA Performance Stage 1 Street heads. They flow 325 cfm.

The numbers are from an engine dyno and are at the flywheel numbers
 
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I'm trying to keep it as stock looking as possible. With an accumulator I would have to run an external pump and all the hoses. I don't think I can hide that.

The heads are TA Performance Stage 1 Street heads. They flow 325 cfm.

The numbers from an engine dyno and are at the flywheel numbers
What are the specs on your camshaft at 0.500ths lift?
 
The part that was my fault: The bearing clearances were big at .003 to .0033 on the rods and .0035 to .004 on the mains. I did not adjust to a thicker oil. Decided to wing it and hope for the best. We also let the oil get too hot during some pulls and oil pressure was low at just under 60 psi at 6000 rpm on a few occasions because of it. Ended up spinning rod bearings 7 and 8 (The last to get oiled on this engine).
Sounds more like an oiling supply issue than the oil used and the bearing clearances. What was the maximum seen oil temperature? The "low" oil pressure was also caused by the larger journal bearing clearance along with possibly too hot of 10W-30. But oil pressure doesn't mean lack of lubrication (which is what you seemed to have) as long as the PD oil pump is moving the same oil volume - which it should have been doing. If the oiling paths to rods 7 & 8 is causing an issue in supplied volume, then it could have done the same thing on a thicker or different oil.

What we have corrected: after a rebuild rod clearances are now .0021 to .0022" and mains are .0023 to .0025", crank was replaced, extra qt oil pan, additional windage screen, new aftermarket timing cover with oil pump and improved oiling, added an external oil line which oils from the rear, larger Baldwin B9 filter, Driven BR30 break in oil, limits on oil temp during pulls.
Since you improved the oiling system supply to rods 7 & 8, you will not know for sure if the oil volume supplied to the spun bearings was the root cause - I think it was. But nobody wants to smoke another engine again to prove that.
 
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I have a feeling the pump was starving and what it could pump was going to the front most bearings. As someone noted an oil accumulator is a good idea. But even having an extra quart in there at all times would help a bit.
 
Generally the old addage of "10psi for every 1k rpm" would indicate that your approximate 60psi at 6000 rpm should have been reasonably sufficient.

Not sure why you said oil pressure was '"low"; I don't think that's the issue.
That's just the oil pressure at the oil pressure sensor before the total oil volume leaving the pump goes into the oiling system circuit. It tells you nothing of the branched oil flow volume going to each individual engine component that is force fed oil by the pump. As in this case, it sounds like rods 7 & 8 have an oiling branch that is questionable in terms of the oil volume reaching them.
 
Generally the old addage of "10psi for every 1k rpm" would indicate that your approximate 60psi at 6000 rpm should have been reasonably sufficient.

Not sure why you said oil pressure was '"low"; I don't think that's the issue.
There were a few pulls where pressure was below 60, and that was when the oil was hot. There were quite a few where it was 70
 
Sounds like a clearance problem , more than an oil problem. Even a slightly thin oil would not make bearings spin that soon.
Too tight of bearing clearance is way more dangerous then too much clearance. Too tight of bearings get the oil super hot inside the bearing, as has been shown many times. And as also shown, regardless of the bearing clearance, more viscosity always gives more MOFT, and higher RPM also gives more MOFT. This sounds like rods 7 & 8 were essentially partically starved of oil ... so an oiling supply issue, not a bearing clearance or oil viscosity issue - although I'd probably run a xW-40 in that caliber of engine vs a xW-30.
 
Too tight of bearing clearance is way more dangerous then too much clearance. Too tight of bearings get the oil super hot inside the bearing, as has been shown many times. And as also shown, regardless of the bearing clearance, more viscosity always gives more MOFT, and higher RPM also gives more MOFT. This sounds like rods 7 & 8 were essentially partically starved of oil ... so an oiling supply issue, not a bearing clearance or oil viscosity issue - although I'd probably run a xW-40 in that caliber of engine vs a xW-30.
I wonder if he prelubed it. Spin the oil pump with a drill.
 
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