jonzi22

Has anyone run Imco powerflow manifols with S/S risers with a ZZ502 and had reversion issues ? Has anyone had success ? Thx

1BIGJIM

iTrader: (1)

Are you asking about the short risers used with silent choice?

28Eliminator

Not sure about the cam profile on the ZZ502, but It could be a problem (silent choice riser?) because of the cam 110 lsa. I am running the PowerFlows W/silent choice SS riser on stock cam, 509mpi and have no problems but the cam is much smaller. A friend is running the 741 cam with the long risers and has no problems. Not exactly what you are asking but some similar comparisons for you.

jonzi22

Yes , short risers with silent choice . I've run the boat for 2 seasons with stock merc manifold/risers with no issue but uncertain of making this change without talking with you guys , I appreciate the help thx

28Eliminator

If those work ok, I can't see how Powerflows would create any more reversion issues than stock Merc manifolds. I guess it would depend on the type of manifold & risers you actually have. The gill ones seem to be pretty good. Are the risers the cast iron type or rolled steel with a long reach?

jonzi22

Old risers are the cast iron really heavy ones . Imco ones are s/s they call Short SA

airjunky

iTrader: (2)

The zz grind is outside the gm marine grind box has a idle rumpity rump similar to hp500 ,if you have closed cooling you may be able to manipulate the idle water dump.to the minimum ,otherwise its going to be close if you want to put it together and forget it ,I did a zz dump at the tips cmi headers with 3rd overflow never reversion lots of idling and it was complicated .everybody will know its not a 502 mag when you start it .did I just read your zz502 went 2 seasons with cast manis and no problems ? You have aluminum heads on that ?

airjunky

iTrader: (2)

2 years on a zz502 with merc risers ? I was about to fall asleep . Awake now.. .you will get a power bump with imco's . If you have any valve seats left .

Baja Rooster

iTrader: (1)

I'm running ZZ502 cam and have many members advise me to go with only the longest risers possible, and have posted pictures of what happens if you don't. It gets ugly.

jonzi22

Thx guys . Sounds like I'd be dancing with the devil eh ? I will re think this for sure ! What a difference in weight though ..... I was hoping the runners were long enough to get away with no reverson issues