Anyone have any experience with Imco Powerflow manifolds and SS risers ? The water goes in the manifold and thru the riser flange without the use of manifold to riser hose, correct ? Any problems with internal water leakage around the flange gasket ? Thanks..

I never had any problems with my powerflows, and they were 8 or so years old. You are correct, There is no hose for the riser. Water flows through the manifold flange into the riser. The riser gasket is pretty thick and there is also like a rubber o-ring built onto the gasket. Freshwater use, if it matters. Hope this helps.

I also have them with stainless risers with no problem. I have not taken the risers off in 7 years.

10 years no problems.


GREAT STUFF
I have a pair on my 90MPH 406 Tunnell hull
Big D has a set on his cole superhawk

Teague uses them(good enough for Bob Teague- good enough for me,) Boostpower use them.

(Teauge also stocks between 50 and 100 CMI full header systems at any given time as well.)


I posted a comprehensive breakdown on these.
Do a search on small block headers or exhaust and uncle dave.
I Highlight inner runner diameters and lengths vs others and discuss these vs headers and - show pictures of an install

Honestly there are a few great headers and a llot of mediocre ones. Imco makes great ones.

Its a GREAT little company.

Uncle Dave

Thanks for your input. Found a couple used sets with the 6" long risers, hope they're for TRS.

Hello! The Powerflows are great lightweight manifolds for marine engines. Of course it will always depend on the entire package to determine the optimal choice, but we like and use them in several applications for fitement and weight. On all the big HP stuff, we always use headers with 2" or larger primary tubes. I must say though--In the past, we have made big power with some manifolds as well. Good Luck!

IMCO Powerflows are great systems offered at great price, great power gains over stock and save tons of weight over cast iron. IMCO's and many more on our website http://www.keitheickert.com/exhaustsystems.html

Prices on systems for my application, Thanks

What is the size of the primaries on the Powerflows? Any opinions on using them on 900 + HP applocations.

Anyone using them with 900 +HP?