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#4 Exhaust port problems BB140A

R

repco

New member
Greetings,
I haven't posted here for many years and I am happy to report that the old 140A has been running well for the most part.
Three years ago I had an exhaust leak at the #4 port and I removed the head and had a welder add material to restore the flange face and a machine shop resurfaced the faces. Should have been a permanent fix, right!!! It lasted a year and the filler material had all corroded away. I next rebuilt the flange with high temp epoxy and that lasted two years.
Well my exhaust leak is back and I am wondering what my options are to put all this behind me. Can weld material be added successfully if the welder knows what he/she is doing and uses the right alloy? Can this port be cored out and a new flange installed, are there parts for that? Should I be looking for a used automotive head and go that route?
Any advice would be greatly appreciated.

Thanks,
Jon
 
repco said:
Greetings,
I haven't posted here for many years and I am happy to report that the old 140A has been running well for the most part.
Three years ago I had an exhaust leak at the #4 port and I removed the head and had a welder add material to restore the flange face and a machine shop resurfaced the faces. Should have been a permanent fix, right!!! It lasted a year and the filler material had all corroded away. I next rebuilt the flange with high temp epoxy and that lasted two years.
Well my exhaust leak is back and I am wondering what my options are to put all this behind me. Can weld material be added successfully if the welder knows what he/she is doing and uses the right alloy? Can this port be cored out and a new flange installed, are there parts for that? Should I be looking for a used automotive head and go that route?
Any advice would be greatly appreciated.

Thanks,
Jon
Click to expand...
In theory a welder can build this up and it should be a lasting repair, but you really need a welder who knows what they are doing, hence the high failure rate of welding a cast iron ( or is this an aluminum head ).

my suggestion would be to get another head as it is probably cheaper in the long run than trying to repair this one
 
Likely to be a recurring problem as I suspect that the root cause is the design/relationship between the exhaust elbow (water injection point/flow) and exhaust port #4.... just speculating...
 
Last edited:
Well, I got the exhaust manifold off today and the #4 exhaust flange on the head is so badly damaged that I doubt that any repair will work. So I guess I am in the market for a good used head.
Can someone confirm for me that any head (casting only)from a B21 automotive engine will fit my engine. The part number from this site is 463630. Is that a good number to source an automotive head? The casting on my head reads 100160 and 6770
IMP 85013
3
Any advise on where to look for a head?

Thx,
Jon
 
repco said:
Well, I got the exhaust manifold off today and the #4 exhaust flange on the head is so badly damaged that I doubt that any repair will work. So I guess I am in the market for a good used head.
Can someone confirm for me that any head (casting only)from a B21 automotive engine will fit my engine. The part number from this site is 463630. Is that a good number to source an automotive head? The casting on my head reads 100160 and 6770
IMP 85013
3
Any advise on where to look for a head?

Thx,
Jon
Click to expand...

these guys may help https://www.strandbergauto.com/about

they are a volvo oriented wrecking yard. They helped me with some NLA glass for my old Volvo wagon A few years back
 
Well, I haven't had much luck finding a good head. There's one or two on e-bay but they don't look too good. I have tried about a dozen Volvo auto wrecking yards with no luck.
Not surprisingly, the exhaust manifold has serious interior rust and leaks inside somewhere.

Anyone know of a good head available?

thx,
Jon A
 
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