Ford 302 model 888 1977 riser bellows

[scubadoo73]

I have blowen a hole thru 2 riser bellows on the port side in the same spot i thought maybe it was the flapper but it is fine( just took it out) blowing a ton of carbon thru exhaust but what I am trying to figure out before i put another new one on is why
any suggestions.
thanks

 

[Bt Doctur]

your not passing water thru the riser into the exaust pipe

 

[scubadoo73]

There is water coming out of the hole both times but just thinking is it possible that there is a partial blockage only letting a little bit of water thru just enough to keep the engine from over heating but not enough to keep it from melting the bellows

 

[Bt Doctur]

coming out of what hole?

 

[scubadoo73]

The hole in the bellows

 

[Bt Doctur]

The hot exaust is not being cooled by water. Without sufficient water leaving the riser you will burn holes in the rubber couplings

 

[scubadoo73]

Ok thanks I will look further for a partial block

 

[scubadoo73]

Update cleaned the bottom of the block again checked all hoses cleaned riser ( new manifold) still burnt a hole thru riser bellows after 4 hours of run time only on the port side no over heating is it possible that there is a crack in the riser that only opens up when it gets hot