overheated volvo penta 5.7GS , please help

[oneboat]

the cracks are in the end toward the riser . they were visibly only toward outside .
to avoid the water in the cylinders i will put a piece of flat rubber tighten between riser and manifold and put some pressure in the water jacket . if pressure holds for 24 hours manifold should be fine .
i just need to order new riser gaskets to replace them after test.

 

[Lou C]

Keep in mind that very small cracks that might not leak with a cold manifold can open up as the manifold heats up and then put water in the engine. What I did with mine was fill them with Acetone (which has a lower surface tension than water and will find small cracks but be careful, VERY FLAMMABLE) and let it sit to see if any appears at the exhaust ports that mate up to the cyl head. You dodged a bullet with the engine, don't risk manifolds if there are ANY cracks.