A base stock will not cure this issue. Base stock composition can affect things like the oxidation resistance and sludge prevention but not a design or assembly error.
Need an oil recommendation - lost an engine using VR1
- Thread starter 70GS455
- Start date
Here is the car which is not finished. And the engine from last go round.
Here is my YouTube with some videos of the pulls and initial start up:
Attachments
That's a whole different thing than journal bearings being at 0.003" instead of 0.002". He never said what the rod big end side clearance was.
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Side clearances were around
.020"
dnewton3
Staff member
I still say even 50 psi at 230 F should be more than adequate to lube the engine system.
First of all, 230F isn't "hot" to a decent motor oil. Heck, many SAE tests are run with the oil at 250F solely for the purpose to stress the test to simulate heavy loads in real life, for hours at a time. 230F is a very reasonable sump temp under load, especially for such short dyno runs.
What I believe is the case is there a LOCALIZED oil supply issue; at that crank journal (7, 8). It's not that the engine didn't have enough oil pressure. It's that the pressure or volume was possibly insufficient at that specific location. That, to me, sounds more like a machining issue, or perhap a cleaning issue? Perhaps a small chip or other debris is restricting the oil feed at those journals? Or maybe the bearings at those journals were improperly installed? Or maybe those bearings were not sized properly relative to the others? Etc ...
I suspect you have a mechanical problem, not a lube selection problem; I seriously doubt the oil brand/grade was at fault here. Therefore needing an "oil recommendation" isn't going to fix this issue, as the oil cannot fix what it did not cause.
That's the way I see it at least.
First of all, 230F isn't "hot" to a decent motor oil. Heck, many SAE tests are run with the oil at 250F solely for the purpose to stress the test to simulate heavy loads in real life, for hours at a time. 230F is a very reasonable sump temp under load, especially for such short dyno runs.
What I believe is the case is there a LOCALIZED oil supply issue; at that crank journal (7, 8). It's not that the engine didn't have enough oil pressure. It's that the pressure or volume was possibly insufficient at that specific location. That, to me, sounds more like a machining issue, or perhap a cleaning issue? Perhaps a small chip or other debris is restricting the oil feed at those journals? Or maybe the bearings at those journals were improperly installed? Or maybe those bearings were not sized properly relative to the others? Etc ...
I suspect you have a mechanical problem, not a lube selection problem; I seriously doubt the oil brand/grade was at fault here. Therefore needing an "oil recommendation" isn't going to fix this issue, as the oil cannot fix what it did not cause.
That's the way I see it at least.
A good oil is one that doesn't cook at your running temps and doesn't cause any PSI loss.
So, you pick any synthetic oil and monitor the PSI and temp gauges. Without data, EVERYONE IS JUST GUESSING.
Here are some great choices. The 10w30 is 3.5+ HTHS and a good start without going overly thick. If your oil temps get too high and you lose PSI, then mix in the 10w40 or 15w40, 1 quart at a time, as needed. If a full sump of 10w40 or 15w40 isn't enough, then you move to the 50 grade:
www.mobil.com
www.mobil.com
www.mobil.com
www.mobil.com
Obviously, you can pick any brand with equivalents to the above products....Amsoil, RoyalPurple, Castrol, Valvoline...
Hopefully the builder addressed known issues and upgraded/modded as needed:
www.musclecardiy.com
www.diyauto.com
Since the oil filter usually doesn't have a built in filter bypass, make sure your builder replaced or reused the original oil filter bypass(ball/spring/plunger/whatever). With no internal engine block filter bypass(a common foolish GM engine builder mod), a cheap filter can leak, balloon, or blow off. Regardless whether the OE bypass is working or not, my recommendation would be to use a filter with a bypass valve, and an ADBV, to hopefully keep the filter and oil passage above it full of oil. 2002 Duramax 6.6 filter, I believe, has a bypass and antidrainbackvalve and many brands offer an option.
So, you pick any synthetic oil and monitor the PSI and temp gauges. Without data, EVERYONE IS JUST GUESSING.
Here are some great choices. The 10w30 is 3.5+ HTHS and a good start without going overly thick. If your oil temps get too high and you lose PSI, then mix in the 10w40 or 15w40, 1 quart at a time, as needed. If a full sump of 10w40 or 15w40 isn't enough, then you move to the 50 grade:
Mobil Delvac™ Extreme 10W-30 | Mobil Delvac™ Engine Oils
Learn how Mobil Delvac™ Extreme 10W-30 synthetic diesel oil can help prolong engine life and reduce oil changes.
www.mobil.com
Mobil 1 Racing™ 4T 10W-40 motorcycle oil | Mobil™
Mobil 1 Racing™ 4T 10W-40 synthetic motorcycle oil offers high-performance advantages beyond conventional motorcycle oils or similar viscosities.
www.mobil.com
Mobil 1™ V-Twin 20W-50 motorcycle oil | Mobil™ Motor Oils
Mobil 1™ V-Twin 20W-50 motorcycle oil is formulated to offer outstanding protection in four-cycle, V-Twin type engines –particularly those that are air-cooled.
www.mobil.com
Mobil 1™ 15W-50 | Mobil™ Motor Oils
Mobil 1™ 15W-50 is designed to help keep your engine running like new by providing exceptional wear protection, cleaning power and overall performance.
www.mobil.com
Obviously, you can pick any brand with equivalents to the above products....Amsoil, RoyalPurple, Castrol, Valvoline...
Hopefully the builder addressed known issues and upgraded/modded as needed:
How to Upgrade the Oiling System in Buick Engines • Muscle Car DIY
The single biggest weakness of any Buick engine is the oiling system. The original design of the oiling system has more than a few issues, including small oil feed holes, misaligned bearings, and poor cam and lifter oiling. All of these issues are easily fixed if you take the time to learn the...
www.musclecardiy.com
400/430/455 Block ID, Prep and Oiling mods by Jim Weise | buick | diys | DIY
400/430/455 Block ID, Prep and Oiling mods Compliments of Jim Weise @ www.v8buick.com 10-8-2010 For a while now, folks have been asking me to finish the page I did on this topic, on my website, but I figured a thread here would be
www.diyauto.com
Since the oil filter usually doesn't have a built in filter bypass, make sure your builder replaced or reused the original oil filter bypass(ball/spring/plunger/whatever). With no internal engine block filter bypass(a common foolish GM engine builder mod), a cheap filter can leak, balloon, or blow off. Regardless whether the OE bypass is working or not, my recommendation would be to use a filter with a bypass valve, and an ADBV, to hopefully keep the filter and oil passage above it full of oil. 2002 Duramax 6.6 filter, I believe, has a bypass and antidrainbackvalve and many brands offer an option.
Since it has a roller cam and rockers (per post #1), you don't have to worry about flat tappet lubrication needs. In an engine with that much HP I wouldn't be comfortable running a 5W-30 unless the oil temps stayed below ~225F. And if you do decide on a 5W-30 go with a Euro formula to get the 3.5+ HTHS viscosity. Or look for a stout xW-40. No need to mess around with mixing viscosities.
Off topic but Ford and Chevy engines are the best engines to hot rod , they hold up and competent machine shops know how to do them up right. Back in my hot rod days my group of car and boat friends would build big blocks Chevy for cars and boats and they would run and run, Olds, Buicks and Pontiacs no so good.
Cool engine, but I don't think your oil is the issue. First calculate the centrifugal force of engine oil at 6500 rpm (small safety factor) on a 3.25" main journal - 59 psig at the main bearing. Then calculate the oil flow with those loose tolerances. Finally measure the oil gallery diameter, including the center where the drilled holes don't line up and calculate the oil pressure drop (the formulas on the internet and since it's faster than 1.5 feet per second it's considered turbulent flow) and add a safety factor. I think you'll find that you can't get there from here with those bearing clearances.
If you don't like this much math, replace the two damaged connecting rods and crankshaft, then run the new engine up to 5000, 5500 and 6000 rpm. When it spins a rod divide the rpm that you want it to run by the rpm it failed at, square the result and multiple it with your 60 psig oil pressure. The result is the required engine oil pressure. With the extra oil being thrown around and aerated by the crankshaft I don't see a means of de-aerating the oil enough to make pressure.
Then there's always the original small block Chevy main bearing trick. Use a plain bearing on the bearing caps or maybe a brass holding screw to block the oil flow as it goes around the bearing groove. This creates a local high pressure point that pushes oil into the crankshaft over to the rod journals. Years ago, Hot Rod Magazine found that they could run those engines at 6000 rpm on a 20 psig oil pump relieve spring.
If you don't like this much math, replace the two damaged connecting rods and crankshaft, then run the new engine up to 5000, 5500 and 6000 rpm. When it spins a rod divide the rpm that you want it to run by the rpm it failed at, square the result and multiple it with your 60 psig oil pressure. The result is the required engine oil pressure. With the extra oil being thrown around and aerated by the crankshaft I don't see a means of de-aerating the oil enough to make pressure.
Then there's always the original small block Chevy main bearing trick. Use a plain bearing on the bearing caps or maybe a brass holding screw to block the oil flow as it goes around the bearing groove. This creates a local high pressure point that pushes oil into the crankshaft over to the rod journals. Years ago, Hot Rod Magazine found that they could run those engines at 6000 rpm on a 20 psig oil pump relieve spring.
Off subject but when you find a fast buick, it. Is. Fast. Point blank period.
15w40 with about [email protected] as a minimum, HTHS >4.2
If it was mine, I'd use Delo 400 SAE 40, weather permitting. (above 40F)
Great "Muscle Car DIY" article originally attached by "Greasymechtech".
This excerpt from the article probably describes the reason for the failure of the original poster's Buick engine:
"One of the most important steps in building any Buick engine is measuring bearing tolerances. Be careful when taking your Buick engine to a builder that specializes in Chevy engines. Chevy engines are built to run loose, running bearing tolerances .0035-inch and more. This is perfectly acceptable for a Chevy. If you run a Buick engine that loose, it will likely blow up before you can even shut the hood. Most Buick builders recommend a tolerance of .0020 inch for the number-1, -2, -3, and -4 main bearings for high-performance street or street/strip applications. For serious drag cars, a tolerance of 0.0025 inch is sufficient.
Based on this, I doubt the type of oil used was the problem and no type of oil would have prevented the failure.
This excerpt from the article probably describes the reason for the failure of the original poster's Buick engine:
"One of the most important steps in building any Buick engine is measuring bearing tolerances. Be careful when taking your Buick engine to a builder that specializes in Chevy engines. Chevy engines are built to run loose, running bearing tolerances .0035-inch and more. This is perfectly acceptable for a Chevy. If you run a Buick engine that loose, it will likely blow up before you can even shut the hood. Most Buick builders recommend a tolerance of .0020 inch for the number-1, -2, -3, and -4 main bearings for high-performance street or street/strip applications. For serious drag cars, a tolerance of 0.0025 inch is sufficient.
Based on this, I doubt the type of oil used was the problem and no type of oil would have prevented the failure.
OVERKILL
$100 Site Donor 2021
That's a concerning quote in that it's incorrectly using tolerances in place of clearances. They are not the same thing.
That is when a 'writer' or 'editor' for a magazine is regurgitating what he thinks he heard from the machinists. I find it funny. But, clearance/tolerance is commonly misunderstood and really wished no one corrected it as often as we do. Its an easy way to learn who has hands on experience and who is talking from the armchair. There are many similar terms in all trades that can help identify an armchair bandit vs a tradesman.
OVERKILL
$100 Site Donor 2021
We differ on it being bothersome.
I liken it to the incorrect use of MW in place of MWh or GW in place of GWh when speaking on the subject of power generation. It's a very quick and easy way to discover who actually understands the subject matter and who is regurgitating something they've heard and doesn't understand the underlying concepts, hence not knowing the correct terminology.
If you word search that articles, they use the correct term of clearance in parts of the article, but incorrectly use the term tolerance in other parts of the article. For instance, the correct terminology.
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that isn't that big. lots of big block Chevys were over .004 from the factory. my 355 has 3.8 on the mains and over .004 on the rear main thrust bearing runs good with 50wt.