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Major malfunction - corroded exhaust port

D

discobayken

Regular Contributor
I removed the exhaust manifold to replace the leaking manifold gasket. The exhaust manifold was in near ferfect condition... the exhaust port on the head (#4 I think, farthest back) is all corroded and there is only about 1/16" left for the gasket to seal upon.

It is possible to have the head repaired or am I looking at replacing it? Does anyone have any suggestions? Mr. Ricardo... your advice / help would be greatly appreciated on this one.

Thank you!

Ken
 
I called around to some machine shops looking for answers to this problem today. A couple of them offered to weld it up but they also wanted to rebuild the head while they had it in the shop = pretty big $. Estimates ranged from $375 to 850 just for the repair and machine work. On top of that I would still have to R & R the head and buy the gasket set, etc.

One shop suggested I call a VP mechanic not too far way as he is the only guy around that will drill it out and put in a carbon fiber sleeve. I called the shop and the mechanic knew all about this problem and said it was very common for the 4cyl volvo engine. Bottom line is... I can bring the boat in and he will do the retrofit/repair without removing the head and have me back on the water for less than $300. Has anyone had this problem and tried this solution?
 
First im not the most experenced with ios however this ive seen there is a tool to cut the port a sleve is then instaled the head does not have to be removed. a ground cable should be added to the rear of engine.
 
This is fairly common on some of the OHC 4's, and is typically the result of a failing exhaust manifold.
Don't take any short cuts.
Remove the cylinder head and have the port machine cut for a steel sleeve.
(never heard of a carbon fiber sleeve, nor would I trust that)

The machine shop will mill out the port, and will make a friction fit sleeve for it.
The casting is then heated, the sleeve is chilled, and is then pressed in.

Afterwards the manifold mating surface is milled flat again.

.
 
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Ihad the same problem about 2 years ago.Took the head off and took it to a good head shop.He said no problem,welded the port back up and reshaped the port and ground the exhaust side port flat again.After 2 years it show no sign of problems.I am in Western Australia and the total cost was only $100.00 A$.We have pretty good machinist here.
Hope this helps
 
The procedure i mentioned was per volo the tool and sleves were brought to hollands marine in norfolk va by a volvo plant mgr also in norfolk. the carbide tiped volvo tool will cut out the port to accept the sleve and surficing is not required the manifold can be reinstaled. The aditional ground (per volvo) was added to prevent eloctrolisis. dissimler metles are prone to this condition the sleve from volvo was enginered to deal with this.
Ricardo i understand you concerns had i not seen this done sucesfully many times with no further problems i would also have had doubts.
 
Midnight Express, I went to see the VP mechanic and he showed me the volvo penta packaged sleeve and the volvo penta labeled tool. He said he had done dozens of them with no issues. He's a reputable mechanic and it seemed like a legit fix. He explained that he is the only volvo guy in the area that does it because the tool costs so much that most shops didnt think it was worth the investment. Anyway... he convinced me that it was the cost effective way to do this fix... so I had him go ahead and do it. I pick it up tomorrow (monday). i hope it works out. Thanks everyone for the input.

Ken
 
exhaust port.jpg
This is a picture of the port prior to the repair. I'm sorry to say that I dont have an after picture because I wasnt there when they put the exhaust manifold back on. A picture now would just show the manifold and not be useful.

The cost was 2 hours labor @ $100.00 per hour (good ole CA rates) plus $90 in parts. I brought it in with the manifold already off and that was the price just for the repair. I paid an extra hour labor to have the shop put the exhaust manifold back on and test it. so it cost me just under $400 out the door. I could have saved the $100 by reinstalling the manifold myself... but I didnt want the finger pointing if it didnt seal correctly. I had estimates for a hell of a lot more than that for the head repair and rebuild so I think I got away cheap (IF it works out).

He said it was guaranteed for a year but he's never had one come back. I asked it it was a lifetime guarantee. He laughed and said "no, but it will last longer than the life of the boat". I'm not sure if that was confidence in his work or an indictment of my boat. haha!

He also said "That motor runs better with that webber than any of the ones I've ever seen with the stock carb". So... I thought that was kind of good to hear coming from him.

I fired it up with the muffs on as soon as I got home and it does purr now. The real test will be how well it holds up under load. Hopefully I'll get her in by this weekend.
 
Ken, I'm sure glad that this worked out for you..... or should I say, I hope that it works out for you after a good testing.

Sounds like this guy was able to do this without removing the cylinder head.

.
 
Ricardo,

Yes he did it with the head in place. If the motor was tired I would have opted for the complete head job. He convinced me that this procedure was developed by VP and was not some kind of band-aid scam. His shop has a good reputation and has been around for over 30 years so I don't think he'd steer me wrong. I will let you know how it works out after a good long run. Thanks for the info and help!

Ken
 
Sorry for resurrecting this old thread but I'd really like to know the name of the mechanic/machine shop that did this repair. I have a head in the same condition and none of the machine shops around here can handle that repair.

I'm in Southern California but I could ship it I guess.

Thanks, Jim
 
JimS88 said:
Sorry for resurrecting this old thread but I'd really like to know the name of the mechanic/machine shop that did this repair. I have a head in the same condition and none of the machine shops around here can handle that repair.

I'm in Southern California but I could ship it I guess.

Thanks, Jim
Click to expand...

Talk to Harry @ Harry's Marine Engine Service in Orange, Ca. He has fixed many, many of them. When I worked for him years ago we did them all the time. The tool and sleave work great.
 
I tried to find an automotive head from a junkyard, problem is the 531 head I need was apparently never put on Volvo cars sold in the US, only Europe and Australia as far as I can tell. That left me with trying to find a fresh water used marine head. I found a rebuilder that had a pallet of them and I bought one. A few weeks later now, he's all out of them. But I found one in upstate New York.

What an adventure! I just need a V cam but you gave me the part number for that so I'm good there, except they're pretty pricey.

Gary, thanks for the info on Harry's.
 
If you persevere, you may find a used one reasonably priced. Also, have you tried searching at Turbobricks for parts? Just google the term.

Good luck.
 
The problem I found with the 'fix' is if your port is too corroded and not enough meat left to place a gasket flat against the head the fix won't do a lot of good. I was lucky and had a spare engine with a good head although this will be a winter time project swapping the heads. For now I wrapped muffler tape with muffler goo around the leaky exhaust joint and clamped it with a big hose clamp.

So far so good. I just want to get through the summer actually enjoying the boat.
 
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