Complete Exhaust Manifold & Riser Kits
Dry Joint versus Wet Joint Exhaust Systems - Finally You Can Upgrade
In 2002 after many years of fighting WATER INGESTION problems, Mercruiser changed the V6 and Small Block V8 engines from the standard style of exhaust to the newer Dry Joint Exhaust systems. The purpose of this was to reduce the risk of leakage at the gasket between the manifold and exhaust riser. It should also be noted that the height and down angle of the exhaust elbow changed as well. It was felt that the overall height of the exhaust elbow should be raised to meet the total height of the engine. Therefore Mercruiser created the 1.5" taller exhaust elbow which included a 14 degree down angle versus the standard 7 degree. This then created an issue regarding the use of risers. For example when 3" risers/spacers are installed along with the taller elbow this means the overall height of that installation was taller than the previous installation with 3" risers. Therefore Mercruiser created the 1.7" and 4.5" riser/spacer to account for these installations where the standard 3" & 6" spacers were already at a package height limit.
Short Dry Joint Elbow p/n 864309T02 s/n 309999 and below (pre 2005 models) - Measures 5.2 from elbow flange to mounting bolt bass pad. SELECT THIS LINK TO VIEW EXHAUST DRAWING.
Tall Dry Joint Elbow p/n 864591T02 s/n 310000 and above (post 2005 models) - Measures 6.7 from elbow flange to mounting bolt bass pad. SELECT THIS LINK TO VIEW EXHAUST DRAWING.