I wanted to know how can you prevent reversion from taking place, other than changing a cam? Does reversion take place only in injected header applications or can it happen in manifolds as well? I was thinking about installing those 3" spacers below the risers to create a shorter angle to help the water get out quicker. Anyone experienced this and fix it?

A lower idle rpm will also have a higher chance of reversion than a slightly higher idle.

The best way to prevent reversion is to throw out the stock manifolds and get a set of good aftermarkets. Adding spacers will make the water mix with the exhaust a little further away from the cylinder heads, but the way I see it, the downside to spacers is another set of gaskets to cause a leak. We all know that the chance of a riser gasket leaking into the engine is prety good. Thats why Gil doesn't let water flow through the gasket, they use a by-pass system. Leaps and bounds better.


US1Fountain

I believe that you have that reversed. The chance of reversion lessens when you raise the idle.

Miguel , When you say "injected header applications" are you talking about the kind of headers that are found on jet boats where they inject water right in the header??? Those headers cant be installed under a engine hatch because they get to hot , and they can have the tendency of reversion. What you need is a Water jacketed header. this is where the header tubes are jacketed by another tube that flows water around it to cool them off. The water is then mixed with the exhaust at or after the header collector. some are completely jacketed all the way through the transom and the water never mixes with the exhaust. this is called a dry system, they are very loud due to the lack in the exhaust. The further away from the heads that you mix the water in the exhaust the less chance for reversion. You can have more of a chance of reversion on a manifold than say a long tube header. but put a long set of risers on the manifold and they can be just as good as the headers. But There is no substitute for a good set of headers.

Ahh, read again. I just worded it differently.

US1 Fountain,

SORRY. I misread your post. I guess my eyes read it but my brain must have farted and understood it backwards.