sierra ex manifolds

[Divecaptchris]

so I had OSCO 994 manifolds on my 350 chevy inboard with closed cooling system, not thinking i ordered SIERRA 18-1953-2 manifolds and risers, problem no is my old manifolds have fitting holes at both ends and the new sierra ones only have a fitting hole at one end! will these new manifolds not work for a closed cooling system, or is there a way to make it work? i have searched the internet best i can for a diagram but have not found any so far, any experiance would be a great help! thanks

 

[jboaty]

Re: sierra ex manifolds

so I had OSCO 994 manifolds on my 350 chevy inboard with closed cooling system, not thinking i ordered SIERRA 18-1953-2 manifolds and risers, problem no is my old manifolds have fitting holes at both ends and the new sierra ones only have a fitting hole at one end! will these new manifolds not work for a closed cooling system, or is there a way to make it work? i have searched the internet best i can for a diagram but have not found any so far, any experiance would be a great help! thanks

Yes, the 18-1953-2 can be cooled with coolant. The inlet is the 3/4" NPT hole on the bottom center of the manifold. The outlet is the 3/4" NPT hole at the top of the manifold right in front of where the riser/elbow mounts. You will need a gasket and perhaps a stainless plate to block the water flow from the manifold to the riser/elbow. The raw water discharge from the heat exchanger goes into the 3/4" NPT hole in the front of the riser/elbow.

The Osco 994 manifold does have fittings on both ends but if you were using one as a coolant inlet and the other as a coolant outlet it probably did not work so well. Manifolds generally work with gravity to fill up. So as a general rule the water exits the manifold at the highest point. The highest point on the 994 manifold is at the top in front of where the riser/elbow mounts, not either end.

I hope this helps.

 

[Divecaptchris]

Re: sierra ex manifolds

Yes i figured it out right after i posted but thanks alot!