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AQ120B B21 head replacement

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pugetsounder

Advanced Contributor
As some of you might remember I had the dreaded #4 exhaust port corrosion causing an exhaust leak. I had the idea of a quick fix by JB welding it but it only took about 5 hours of running time to fail. I'm sure there are other products out there that can stand the heat better than JB weld but at this point I am going to fix it properly. Plus the PO gave me an extra B21 engine with a decent head without any corrosion problems. So I will take it in have it refurbished and cleaned up and all tolerances checked. I figure a long saturday and I will be back on the water with a quieter motor.

As I was researching how to replace the head on a volvo B21, I came across this series of videos on Youtube from a young guy changing out the head gasket on a Volvo 240 car. They are actually quite thorough and informative and thought I would share them with anybody needing to change out the head and gasket on a B21. I will start at the point where he is into the engine since the first series just pertains to the car parts. The vids will automatically progress.

http://www.youtube.com/watch?v=CFNUY4qMTZ8&feature=autoplay&list=UL96ZIOVghLpw&playnext=3
 
Did you know that Volvo Penta made a special tool that bolts to the rear cyl. exhaust bolt holes and has a cutter that cleans up the area, then a special sleeve gets tapped in and your done, fixed. No head removal or anything else. Check out a good V/P shop and an old mechanic, they'll know about it.
 
try finding one in the Seattle Area. No one around here even knows what it is or has ever heard of it. From what I've heard the kit costs about $300+ if you can find one. I can have the head rebuilt for that.
 
JB Weld,I had a 70' Pontiac as a kid.As for Headers if anyone knows about Pontiac headers know's that they aren't like a chevy.To install you have to bend to mount them always leaks.I tried JB Weld on exhaust.JB weld can't handle the heat.And stinks as well when heated.As you found can't use JB on exhaust.
 
I would consider replacing the leaky head with an automotive head from a 1976 to 1982 242 Volvo with a B21 engine (non-turbo). You can probably get one from an auto wrecker.
 
el_pesc, I have one already from an extra motor the PO gave me. I took it off the donor motor last night and looks really clean inside. So that's good. I really didn't want to remove the head from my boat as my compression was about perfect but looks like I am going to do just that. The instructional vids make it look fairly easy I figure one full days work after I get the extra head back from the machine shop and I will be back on the water. :)

boatdoc, I got a hold of a VP mechanic that while he doesn't have the tool he said if the port to too far corroded and has no surface left to mate a gasket and manifiold to, then it won't do me any good any how. My mating surface is pretty much gone.
 
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