A very common issue that we receive calls about is "oil starvation" stemming from track activities. In this tech article I'll hit the highlights concerning "oil starvation" and also go over some myths that we have busted through our development.
First off the primary reason that engines fail on the track and are found to have symptoms of "oil starvation" when torn down is directly related to engine oil temperatures and the subsequent themal breakdown of the engine oil more than anything else.
Sure things like accusumps, larger scavenge pumps, X51 oil baffles and other "fixes" help bandage the issue the main issue is directly related to engine oil temps that can reach 270F while on track. We have datalogged temperatures even higher on super hot days at the track.
When we receive our routine failure call of the week from the person who has experienced "starvation" they magically never have the failures at the beginning of any track session as they always occur at the end of a session.Now, If G forces were the root cause of these issues as they are often blamed wouldn't we hear about them occurring at any point of a session and not just near the end?
The fact is it takes the majority of the session for the oil to get to the point of thermal breakdown and for the viscosity to drop enough for the failure to occur. This is why we NEVER hear of engine failures occurring near the start of any DE session. We also never hear of these failures occurring in Autocross competitions even with G forces HIGHER than most "big track" activities. I feel its directly related to the sessions being short and the oil doesn't see the temperatures high enough to start the snowball effect.
Remember: Your favorite "flavor" of over the counter generic engine oil might be a 10/40 or 20/50 but it's viscosity is measured at a mere 212F. What will the viscosity of that oil be at 250, 270 or even 290F? What if your 40 grade oil was less than a 20 grade when operating above 260F? Some are!
When operating your engine on the track it is being overworked just like a race engine. This is one of those situations where you need a full "race oil" to properly protect your "street engine". Race oils have a life span of less than 1,000 miles with their additive packages being depleted completely. True race oils make horrible street oils so those that are serious about engine protection aren't generally worried about cost or convenience. These people are paid dividends of longevity and reliability over their peers.
Basically what we have found is G forces are simply "the straw that breaks the Camel's back" on the track. Hot oil leads to pressure losses, G forces aggravate the issue and things scatter.
I won't make brand or viscosity recommendations in this tech article and please don't email me with questions like this. I simply wanted to stimulate your thought before going to the track for another hot summer of track activities~
Those that want to keep their engine alive on the track should couple a proper race oil with higher volume scavenge pumps, better oil control baffles and a higher volume oil filter. All of which LN Engineering and Flat 6 Innovations have teamed up to develop and manufacture.
Till next time....
The Engine Surgeon