Volvo Engine Rebuild ?

[svcattales]

Originally Posted by Ex-Calif

Doing the bottom end in situ is possible but but at this point, were it my engine, I would haul the block out, disassemble and install new rings, bearings, a new #2 piston and get the block machined.

I took the head to a shop that specializes in cylinder head repair. He found a crack in the head radiating from exhaust valve of #2 piston and penetrated into the cooling water jacket. So the oil analysis was right on... they said to check the cylinder area and check for coolant leaks. That also explains the compression on #2. The crack caused the corrosion on exhaust valve which leaked badly. The shop is repairing the head for @ $450 and that includes a valve job.

After looking closely at #2 piston, I decided it needed replacement. I lifted out the block, but positioned it on top of the wood floor of the berth. From there I could evaluate further. We took out the #2 piston, plastigauged all the crank bearings, and looked carefully at all the cylinders. Everything looked great and the bearing wear tolerances were well within limits. My plan is to replace the #2 piston/rings, hone the #2 cylinder with a "flex hone" and put it all back together. One of my cruising friends is a skilled mechanic and he concurred with the plan.

[Ex-Calif]

Sounds like a good plan. You might want to get a parallel block and shim and see how flat block surface is before remounting the head.

[svcattales]

Originally Posted by Ex-Calif

Sounds like a good plan. You might want to get a parallel block and shim and see how flat block surface is before remounting the head.

Good idea. Thanks.

I got the head back and the shop did a nice job on the crack repair and the valves. Since I had the injectors out, I had them rebuilt and the nozzles were out of tolerances. I'm still waiting on some parts before I can put everything back together.

The machine shop shared some good info with me. Although the engine is labeled Volvo Penta, it is the same as a Perkins M30 which are both made by Shibaura, a Japanese tractor company. No wonder Cat Tales plows through seas so well! Looks like a trip to the "tractor store" for parts next time.

[barnakiel]

BTW,

I have quickly looked thru our options (@MD7) and it shows many vital parts are simply out of production and out of stock. Sort of like rebuild / repower issue solved here. It will be a very sad day when the beast dies, because it goes like a sewing machine.

b.

[svcattales]

I just finished putting everything back together and ran the engine for the first time today. There was no exhaust smoke and engine ran more smoothly than before. The water temp stayed in normal range even though the sea water temp is about 90 F here.

I did another compression check of #2 cylinder before starting and got 400 psi. I was disappointed because manual calls for 435 psi and other cylinders were 450. I'm hoping pressure will come up after rings break-in and get properly seated. After the head was milled there was still some pitting above #2 cylinder (see pics) so the extra volume may also contribute to the lower pressure. I'm not going to lose any sleep over that since it is running well.

The before and after pics show the pitted/cracked/repaired head (can't see the crack), the old & new piston, and a couple stages in the rebuild. I did all the work on the engine block in the boat due to the weight. I raised the block high enough to set it down on the aft berth and that served as a good work bench. I used standard sized piston and rings since #2 cylinder was in good shape. The last pic was taken with the engine running. Sure glad this project is over!

[Stillraining]

Wow well done...but yes you will never get speck compresion with that head...I will have to go back and read as to why you went with it again...I thought you were switching out engines...

Going to read now.

Carry on

[DeepFrz]

Nice work.

[Stillraining]

OK ..back up to speed.

I had you confused with another poster leaning toward scraping the volvo for a re power option.

Still a little surprised with going with that head again...but I don't know the cost or availability of a new one either so don't mind me.

Again well done..........................it was sort of fun though wasn't it?.............now that its done...

[Chief Engineer]

That's how we like to see it done.....

[never monday]

400 psi in #2 doesn't surprise me. There is a good bit of increased volume with the lost material.
I am concerned that cylinder is going to run hot with all the funny contours in there. In all likely hood. The eroded area will fill in with carbon and bring the compression up.

[svcattales]

Originally Posted by Stillraining

OK ..back up to speed.

I had you confused with another poster leaning toward scraping the volvo for a re power option.

Still a little surprised with going with that head again...but I don't know the cost or availability of a new one either so don't mind me.

Again well done..........................it was sort of fun though wasn't it?.............now that its done...

It was kind of fun and it was a great opportunity to remove the rusty spots and paint everything. I painted it blue instead of green since it has more Perkins identification than Volvo (see pics).

I checked on the cost of a new head and it was $1400 before a valve job. I feel pretty good about the machine shop that repaired the head and did the valve job for $450. They have been doing that business in Tampa since 1961 and they have a long term contract with Yanmar to fix a pallets full of heads as Yanmar needs them. A new head would be nice, but the "boat unit" saved will be put towards other priorities. Besides, sailboat engines are only auxilaries for those rare occasions when the wind doesn't blow....right?

Never Monday: My first question to the machine shop was "Is the pitting going to cause a problem and will it crack again?" They assured me that they have seen many heads with this kind of pitting and their repairs held up fine. I guess time will tell. I believe the head crack was caused by overheating the engine due to an exhaust elbow restriction that happened on our last cruise.

[sigmasailor]

That was some good 'old school' workmanship demonstrated.
Good for you!

[svcattales]

We motored out in Tampa Bay this week and started to break in the new piston/rings. After 2 hours of running under load at various RPMs the engine ran smoothly and temps were normal despite 89 degree bay water. I developed one small oil leak from the aft gasket of the sea water pump, but that was the only problem. Fortunately, this gasket is easy to access.

This will be my last input on this thread unless something breaks.

Thanks for all the great inputs!

[Ex-Calif]

What a great success story. Well done and good looking work. Thanks for taking time to document things.

[svcattales]

Originally Posted by Ex-Calif

What a great success story. Well done and good looking work. Thanks for taking time to document things.

Thanks for the moral support. I've received lots of good advice from you and others. When cruisers take the time to help out, the least I can do is post the results.

PS. We had another sea trial today and ran the engine up to 3000 RPM under load. Still running smoothly, normal temps and no leaks...YEAH!