Hello,
I have inherited from my granddad 23 foot boat with GM small block V8 (originally AQ271C) mated to Volvo DP290A outdrive. In late 2020 I have started rebuild of boat and engine. Now almost 3 years later everything is ready for boats return to sea, but one big problem emerges to bite me.
It is alignment of Y pipe horns to exhaust risers. On port side alignment is actually spot on, but on starboard it is not even close, as seen in pictures, and it buffels me hard...
I put engine two weeks ago, and I have installation manual for aquamatic series engines. Because of the tight engine room, engine has to go in without exhaust manifolds and accessories.
Tried to do my best aligning the engine according to the manual and lining up markers on bell housing and transom shield. Gaps between marking (picture for reference) are as follows: port side 2.5mm, starboard side 4.5mm, top side 5.0mm, so it is two and half millimeters discrepancy almost within the spec in manual (2 mm difference between each other). Also worth noting is engine naturally came to this position when clamp ring was tightened to spec so I called it good (mistake?).
in this picture is port side
Also 3 years ago when started to tear into it, I didn’t draw much attention to exhaust alignment, because everything was corroded and in bad shape and it wasn’t obvious that time that there is some problem. I also repaired exhaust Y pipe horns because they were corroded.
Worth noting is exhaust manifold are new (HGE 5804), and risers are little bit older but in OK shape (GLM 51510). Old manifolds are original Volvo Penta and are in bad shape. Does aftermarket manifolds have to be machined or something, because with quick measuring between old and new manifolds, new manifolds are ¼” further out from block on riser mating surface than original old manifolds
So kind and knowledgeable folks of this forum please help
Have I been doing something wrong or what should I try to do to rectify this problem. Also I’m kinda hastefully writing this down, so I will provide additional info if something is not that clear.
thank you
I have inherited from my granddad 23 foot boat with GM small block V8 (originally AQ271C) mated to Volvo DP290A outdrive. In late 2020 I have started rebuild of boat and engine. Now almost 3 years later everything is ready for boats return to sea, but one big problem emerges to bite me.
It is alignment of Y pipe horns to exhaust risers. On port side alignment is actually spot on, but on starboard it is not even close, as seen in pictures, and it buffels me hard...
I put engine two weeks ago, and I have installation manual for aquamatic series engines. Because of the tight engine room, engine has to go in without exhaust manifolds and accessories.
Tried to do my best aligning the engine according to the manual and lining up markers on bell housing and transom shield. Gaps between marking (picture for reference) are as follows: port side 2.5mm, starboard side 4.5mm, top side 5.0mm, so it is two and half millimeters discrepancy almost within the spec in manual (2 mm difference between each other). Also worth noting is engine naturally came to this position when clamp ring was tightened to spec so I called it good (mistake?).
in this picture is port side
Also 3 years ago when started to tear into it, I didn’t draw much attention to exhaust alignment, because everything was corroded and in bad shape and it wasn’t obvious that time that there is some problem. I also repaired exhaust Y pipe horns because they were corroded.
Worth noting is exhaust manifold are new (HGE 5804), and risers are little bit older but in OK shape (GLM 51510). Old manifolds are original Volvo Penta and are in bad shape. Does aftermarket manifolds have to be machined or something, because with quick measuring between old and new manifolds, new manifolds are ¼” further out from block on riser mating surface than original old manifolds
So kind and knowledgeable folks of this forum please help
Have I been doing something wrong or what should I try to do to rectify this problem. Also I’m kinda hastefully writing this down, so I will provide additional info if something is not that clear.thank you
