??? about reversion

[LAC_STS]

I dont have any reason to believe I have an issue with water reversion but I was just wondering.

If the manifolds and risers are straight up from where the exhaust goes out of the engine then what stops water from going back down into whatever cylinders exhaust valve is still open after shutting the engine off?

 

[Lyle29464]

Re: ??? about reversion

visualize a small pipe inside a larger pipe. the small one discharges the exhaust and the larger one discharges the water. The "water pipe ends just a bit before the exhaust pipe so the water can not flow back up the exhaust. " hopefully

 

[wire2]

Re: ??? about reversion

The riser discharge (exhaust and coolant water) is in the large hose, which is inclined down. Water would have to flow uphill to get back into the exhaust portion.

 

[Alpheus]

Re: ??? about reversion

Should be an expert when your done reading this...

Read All About Reversion Here...

http://www.michel-christen.com/ExhaustElbows.pdf

 

[John_S]

Re: ??? about reversion

Should be an expert when your done reading this...

http://www.michel-christen.com/ExhaustElbows.pdf

Or just totally confused.

This "vibration" resonance to cause the water to walk up the inside of the exhaust, would seem to be a problem at a particular rpm, given a certain manifold and engine. ie they should have no issue recreating, but don't see that sort of proof being talked about.

 

[Philster]

Re: ??? about reversion

Water is sent out, going downhill. Problem is that water can be sucked back towards the engine during low RPM because of the cam duration that sees the piston going down slightly while the exhaust valve is still open. This creates a sucking action, which can pull water back toward the engine.

High performance cams are more prone to this happening. The operative word is 'prone' and the relative words are "high performance". The longer the duration on the exhaust stroke, the more prone to reversion an engine is.

Good solutions are high and long risers/elbows which discharge water as far as practical down the line, and keeping cams from getting too aggressive (although I don't have the numbers near me).

Even some mild cams can cause grief if the setup is basic and the water is not discharged far down the line. Lots of idling and a rhythmic sucking action can pull water back into the cylinders.