In the event of a crash/spin, unless the clutch is depressed the engine of a car rolling backwards at speed can be spun up in its reverse direction. Opinions vary re the potential for resultant damage. Obviously the bearings will be starved of oil with the typical range of possible results as the filter, cooler and lines are also drained. With a dry sump engine plumbed for crankcase vacuum and lacking a pressure relief valve, the scavenge stages will also pressurize the entire engine internals, potentially resulting in blown gaskets, major leaks and oil fires.
Seems to me the only remaining concern would be potential timing chain tensioner issues causing jumped teeth and resultant piston/valve contact.
Any Speed Talkers with data, theories or anecdotes to contribute?
<OK, as soon as I posted, as seen below, the 'similar topics' function kicked in like a more effective 'search' tab. I'm leaving this post as is rather than editing based on below entries.>
Effects on an Engine Spun Backwards in a Crash
Moderator: Team
Effects on an Engine Spun Backwards in a Crash
Felix, qui potuit rerum cognscere causas.
Happy is he who can discover the cause of things.
Happy is he who can discover the cause of things.
Re: Effects on an Engine Spun Backwards in a Crash
We deal with this in our dirt midgets due to being direct drive. Usually air filter is loaded with methanol but not much else happens. I know in the division 2 cars and the motorcycle powered cars ocasionally will jump time since they’re timing chains are so long and not always tensioned properly. They usually only turn the wrong direction a handful of times though.
-
- HotPass
- Posts: 9406
- Joined: Tue Nov 22, 2005 5:41 am
- Location:
Re: Effects on an Engine Spun Backwards in a Crash
The Ford Kent engine (twin cam in the Lotus and others) is known for bending the bronze tensioner bracket when the engine is rotated backwards.
https://www.semasan.com/breaking-news-archives?utm_campaign=DrivingForce_DF272&utm_content=SeeAllLeg