Spun rod bearing..

[KPSI]

I spun a bearing as well. Procharged with oil pump gears. Stock balancer. Not even 3k miles since being boosted. Tore everything apart. Motor was perfect except the bearing and crank. No idea why the motor killed itself.

Sponsored

 

[GT Pony]

Here is a quote from the oil test about oil viscosity, pressure and its effects.

" Oil “flow” is lubrication, and using thicker oil will simply reduce critical oil flow for no good reason. Plain bearings, such as rod and main bearings, are components that are not designed to be lubricated just by an oil film, they are designed to be lubricated by a flow of liquid oil. Keep in mind that oil pressure is NOT what keeps these parts separated. Oil pressure is a measurement of resistance to flow, and the pressure only serves to supply/move the oil to the clearance between the bearings and the crankshaft journals, and of course to move oil throughout the entire engine. The crankshaft journals and its bearing shells are kept separated by an incompressible hydrodynamic liquid oil wedge that is formed as the liquid oil is pulled in between the spinning parts. All liquids are incompressible (that’s how hydraulics work, including brakes with their watery thin brake fluid), so it does NOT matter what the viscosity of any liquid is. Thick oil or thin oil will create the same incompressible liquid oil wedge "

What's not true in the statement above is that the bearing's minimum oil film thickness due to hydrodynamic lubrication IS certainly determined by the oil viscosity. And the true viscosity in the bearing itself is a factor of the oil's temperature. The temperature of the oil film increases as the oil gets squeezed down in the bearing's wedge during rotation, which thins it out even a bit more.

That is why journal bearings fail when the oil gets very hot and thin, even if there was plenty of lubrication flowing. That is also why Ford and other manufacturers recommend a thicker oil for track use, because they know the oil will be running much hotter and thinning down with extended track use which makes the bearing minimum oil film thickness even less, and more risk in failing a bearing when metal-to-metal contact occurs. Get 5W-50 hot enough and you could make it so thin that a bearing could still fail ... so yes, the actual viscosity going through the bearing has a big effect on the actual small oil film that keeps the metal-to-metal contact from happening.

 

[GT Pony]

Another thing for you guys who run crazy high RPM to consider is what oil filter you use. At very high RPM the positive displacement oil pump is putting out many GPMs of oil flow. If the oil filter is somewhat restrictive to oil flow, it will cause the oil pump to hit pressure relief sooner, which will result in less oil being fed to the engine. It can also cause the filter to go into bypass, and the bypass valve many not be able to flow as well, which just makes the filter seem even more restrictive to the oil pump. Using a heavier viscosity oil will make this situation even worse - ie, causing the oil pump to hit pressure relief much sooner and result in less oil being supplied at high RPM.

 

[Niz55]

Another thing for you guys who run crazy high RPM to consider is what oil filter you use. At very high RPM the positive displacement oil pump is putting out many GPMs of oil flow. If the oil filter is somewhat respective to oil flow, it will cause the oil pump to hit pressure relief sooner, which will result in less oil being fed to the engine. It can also cause the filter to go into bypass, and the bypass valve many not be able to flow as well, which just makes the filter seem even more restrictive to the oil pump. Using a heavier viscosity oil will make this situation even worse - ie, causing the oil pump to hit pressure relief much sooner and result in less oil being supplied at high RPM.

I am running oem 500 filter with my setup shifting at 7800-8000. I also use Castrol 0w-40 full synthetic.

What filter do you recommend?

 

[GT Pony]

I am running oem 500 filter with my setup shifting at 7800-8000. I also use Castrol 0w-40 full synthetic.

What filter do you recommend?

A filter that is a full synthetic media with wire backing because they flow with less pressure drop across the filter than typical cellulose media oil filters.

Fram now has an improved line of racing oil filters with metal end caps (like their full synthetic Ultra) that are designed for high flow in racing type applications. Filtering efficiency is still pretty high too. Might be one to consider, among many available full synthetic filters.

Sounds like the OP lost the bearing at the drag strip. Typically what I've seen at the strip is guys sitting in the staging lanes for a long time and the engine gets a burn out before going down the strip. I'm betting most of those cars don't have the oil anywhere near full operating temperature, and therefore the oil is thicker than normal (being cooler), and a run down the 1/4 mile at redline in that case is probably putting the oil pump into pressure relief really quickly, and therefore less oil flow is making it to the engine and bearings.

 

[mustang1]

Mustang needs a proper oil temp gauge like the GT350.

What type of oil filter is on the GT350 ?

 

[Jay159866]

Mustang needs a proper oil temp gauge like the GT350.

What type of oil filter is on the GT350?

Exactly.

Ran Mobil 1 5/20 for 16K miles.. Just switched to Amsoil 5/30.

 

[GT Pony]

What type of oil filter is on the GT350 ?

It's a special Motorcraft ... not sure if it would fit the 5.0L Coyote, it might. It's probably flows better with less pressure drop than the normal Motorcraft filter.

 

[sigintel]

My motor should spin a bearing very soon.
Babied until CHT has been 190+ for 5 min.
Then its on. At least 1200-2000 bounces off limiter.
Whipple at 1200 miles. 3.625". 93 Chevron.
5w20 Mobile 1 till 3000 miles.
QSUD 5W20 after.
9800 miles now.
Couple strip passes Seguin.
Driven hard in hill country back n forth to ranch. Very hard.
CHT upto 240F in traffic then I back off.
Stock tires done at 5k miles front and rear w rotation.
Front pads toast at 9800.
Avg MPG 11
Borrowed time?

 

[Roh92cp]

My motor should spin a bearing very soon.
Babied until CHT has been 190+ for 5 min.
Then its on. At least 1200-2000 bounces off limiter.
Whipple at 1200 miles. 3.625". 93 Chevron.
5w20 Mobile 1 till 3000 miles.
QSUD 5W20 after.
9800 miles now.
Couple strip passes Seguin.
Driven hard in hill country back n forth to ranch. Very hard.
CHT upto 240F in traffic then I back off.
Stock tires done at 5k miles front and rear w rotation.
Front pads toast at 9800.
Avg MPG 11
Borrowed time?

Why are you hitting the rev limiter so Often?

 

[mustang1]

... Babied until CHT has been 190+ for 5 min.
Then its on. At least 1200-2000 bounces off limiter.
...

what is the limiter set to ?

There has been a lot of discussion about OPG but not about the oil pump itself. What are the specs on the Coyote oil pump? Ford improved the oil pump for the Voodoo. Is the Coyote oil pump not good enough for 8200 RPM ? How about 7700 RPM ? Does oil pressure change from 6700 to 7700 ?

 

[Roh92cp]

what is the limiter set to ?

There has been a lot of discussion about OPG but not about the oil pump itself. What are the specs on the Coyote oil pump? Ford improved the oil pump for the Voodoo. Is the Coyote oil pump not good enough for 8200 RPM ? How about 7700 RPM ? Does oil pressure change from 6700 to 7700 ?

Not sure what your asking as the OPG is the oil pump gear, so are you referring to the pump housing? Also the voodoo has the same glass gear we have and I know of one GT350 that was unmod and broke his gear.

 

[mustang1]

Not sure what your asking as the OPG is the oil pump gear, so are you referring to the pump housing? Also the voodoo has the same glass gear we have and I know of one GT350 that was unmod and broke his gear.

Voodoo has a bigger oil pump, even though it uses the same gear. It looks like it will flow more oil. Coyote at 7700 RPM may not flow any more oil than at 6700 RPM.

 

[AutoX_GT]

I must be one lucky stang owner. Before I knew about the OPG issue I bounced off the rev limiter MANY times while being supercharged and have not had an issue so far. Which leaves me to believe that it's more of a high RPM issue as my limiter has always been at 7k max.

 

[Roh92cp]

I must be one lucky stang owner. Before I knew about the OPG issue I bounced off the rev limiter MANY times while being supercharged and have not had an issue so far. Which leaves me to believe that it's more of a high RPM issue as my limiter has always been at 7k max.

RPM may put more stress on it, but mine failed under 7k in 3rd gear.

Sponsored