1070 water manifold problem

[AFL]

Having some trouble with the 1070. The engine developed a knock during spring planting and we finally have time to tear it down and see what the issue is. We were trying to remove the water manifold from the heads and 4 of the 6 bolts attaching it broke off so we can't remove the manifold. First, is this a common problem? Second, what's the best way to move forward here? I'm assuming I'm going to have to try and drill the bolts out?

Thanks guys.

 

[urbancase]

afl : i redid the heads on a 1570 i bought this past winter, when i removed the exhust manafold i had 4 bolts that broke. i pulled the broken manafold over the bolts and i have a blackhawk stud puller. it has 2 diffrent hole in it and a wheel that you put a 12 drive on and it goes over center and locks on the broke bolt-stud and makes turning them out better. 2 or the 4 came out the other 2 broke again flush with the head and had to drill and retap. hope this helps.

 

[1370rod]

If you have the cast iron manifold you could try heating the bolt areas. If its the aluminum I don't know if there is a "good" way to remove it. I have seen 1 or 2 break, but not 4. The studs being stuck in the manifold generally come out of the head once the manifold is off. Not to common, seems to be caused from gasket seepage. I would think the manifold is a item salvage yards seldom sell and would be willing to sell at a very reasonable price. Before spending a lot of time trying to gently remove it I would see if a replacement manifold could be had at a bargain price. Rod.