volvo penta 5.7gi cracked block

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frankym3

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Hi all, this question im sure has been asked before and I really appreciate your combined expertise!

The engine is a 1997 vp 5.7gi with a duo prop drive. Shes in for her summer service at the mo and needed... i thought some minor works as she has been a great boat reliability wise so far... or so I thought...

The mechanic reckons the block has cracked due to the severe winter (-15deg) in December in two places, how severe I dont yet know. He says that if its cracked here there could be more cracks also that are as yet unseen. From talking to him it sounds like it would be very unwise to try to repair the block and better to replace.

Ive looked on VPs ponline shop and they say you need a full longblock, from the images it looks like a lot more parts than are required, but im no expert either! they are quoting £4,000 odd for the part plus delivery!

The boat pre cracked block I reckon was worth around maybe £8,000 so I dont know what to do as the repair cost could easily top £5,500 grand!

Is there anyone who sells second hand blocks you know off?

Also I read somewhere that the 5.7 bottom end is basically a Chevorlet Corvette item. Would this mean a 5.7 motor car block would work or would the marinised version be different?

Finally our local boat shop sells 5.0 Mercruiser engines at a reasonable price, would this be compatable with the Volvo duo prop rear end drive?

Maybe I should sell as is, how much less would I have to take? (Four Winns 195 sundowner 1997, low hours)

I really appreciate your help and am totally gutted that I dont think ill get out on the water this summer! and the holiday abroad fund is going to be despatched on repairs too!
 
If its just cracks in the water jacket, try cleaning and wire brushing it and degreasing it thoroughly, then push chemical metal into the cracks, i repaired a volvo penta MD21 that had a 4 inch long crack that was caused by frost damage and last time i saw it, it was still going perfectly well 7 years on !!, the owner was delighted that i had saved his engine.

Sounds like you've got nothing to loose by trying it if your thinking of a replacement engine already !
 
We had a landrover which had a cracked block. My mechanic (we had a garage) suggested having the block welded. we rang round Engineering shops which did welding, found one, towed the landrover there, and 3 days later drove the landrover back. They had "Stitched" the crack together. And that was in the 1960's. Today this sort of job must be easier to do as in those days they did not have the wonderful welding equipment which they have now.
And with respect to the mechanic, he probably hasent suggested having the block done as either he has not had had experience of this being done, or wants the job for a block replacement.
PS. I forgot to mention, they did the welding while the engine was still in the landrover.
 
Last edited:
Thanks all!

Sorry only getting a reply now, when you say the water jacket, does this mean theres a second skin to marine engine or is this on all engines? Excuse my ignorance!

Have spoken to a metal work specialist today and hes to get back to me ref the welding! That could be great news if it can be repaired! Its a very simple engine I think and a cast iron block not aluminium so may be easier I hope!

Also what do you mean by stitching and welding?

Thanks a million for all the help guys!
 
Engines do have 2 layers, the cylinder has the piston in and holds back pressures of about 2000psi, then you have a layer of cooling water around this cylinder, then around the layer of water is the water jacket which only has to hold back about 15psi, its this water jacket which cracks if the block freezes and causes the damage.

stitch welding is a good way to repair it, but i'm not sure if you will find someone to do it in situ, because heatsoak could warp other components, but if a welder if confident they can do them, then thats the way i would go !, but if they want to strip the engine, then chemical metal is worth a try as it will probably last longer than the engine if its put on properly.

Going for a new block just because you have a cracked water jacket is a very very expensive way of repairing your engine !!
 
Thanks top donkey!

We have the engine out already, so wont be hard to work at! (Just found this out, thought it was still in)

Fingers crossed we can get her well fixed at a reasonable cost now then! If I do then ill definitely be singing YBWs praises to anyone who will listen!

Thanks to everyone who replied and ill keep you updated! Francis.
 
frankym3 said:
Thanks all!
Also what do you mean by stitching and welding?
Click to expand...

This is how I imagine I would do it. Say you have a crack which is 6" long. I would get an angle grinder and run down the crack to clean it out (like a V groove) and make the crack wider so the weld goes in deeper, You weld the crack and every 1" down (or along) you go either side of the crack by at least half an inch so that the finished weld looks as if the weld has been "stitched". This Land Rover was still running 20 years later.

Unless people have had experience in "Arc Welding" they would not realise how easy this sort of job is. It seems that in these days of "Tig" and "Mig" welding the original art of "Arc" or "Oxygen and Acetylene" Welding has been superseded.

But to bring an old joke to life. "Did you hear about the Welders Daughter" Answer " She had "Acetylene" legs. Boom Boom.
 
Hi Francis, I have just been through this with the VP AQ 231. The block is cast, and to weld it with mig or arc the entire block needs to be heated to reduce the risk of cracking the cast.
Personally I would get a long block engine. The £4k is VERY steep for a long block (where you put all your bits on it, alternator, intake manifold, exhaust manifolds etc) Repower marine will supply a complete engine for £3,300 IIRC but if you go for a remanufactured long block, you can get them for £1500-£1600 with warranty.
The VP block is exactly the same as mercruiser and OMC.
Try these guys:
http://cgi.ebay.co.uk/New-5-7L-V8-M...at_Engines_EngineParts_SM&hash=item3cb856ad73
or
http://cgi.ebay.co.uk/MERCRUISER-5-...at_Engines_EngineParts_SM&hash=item33692c9b64

I hope this all helps, and if there is anything I can answer, just drop me a line and I will do what I can :)
 
Prospect and Sunray said:
Hi Francis, I have just been through this with the VP AQ 231. The block is cast, and to weld it with mig or arc the entire block needs to be heated to reduce the risk of cracking the cast.
Personally I would get a long block engine. The £4k is VERY steep for a long block (where you put all your bits on it, alternator, intake manifold, exhaust manifolds etc) Repower marine will supply a complete engine for £3,300 IIRC but if you go for a remanufactured long block, you can get them for £1500-£1600 with warranty.
The VP block is exactly the same as mercruiser and OMC.
Try these guys:
http://cgi.ebay.co.uk/New-5-7L-V8-M...at_Engines_EngineParts_SM&hash=item3cb856ad73
or
http://cgi.ebay.co.uk/MERCRUISER-5-...at_Engines_EngineParts_SM&hash=item33692c9b64

I hope this all helps, and if there is anything I can answer, just drop me a line and I will do what I can :)
Click to expand...

Yep was in with guy doing welding today, he mentioned about heating the block already. /has one side done and made a great job and is starting on the other side tonight.

If it goes ok, when its finished and the block painted it should look like new... Juts hope it performs that way too!

Thats great piece of info on the long block, hope I wont need it, but good to have a cheaper price all the same!

Thanks again everyone!
 
SUCCESS!.... or so I hope!

UPDATE!

Good news! (To be confirmed for definite on Tuesday when I get time to put her in the water!)

The boat is ready for collection, the block has been successfully (and extremely well!) stitch welded, cleaned down, painted and the entire engine is back in the boat and running perfectly! Holding water pressure, no leaks and running sweet as a nut again!

In addition to this she now has all 3 belts changed, new elbow gaskets, new 20w 40 oil, new oil filter, brand new starter motor, brand new impellor pump and fully serviced! All parts genuine equipment Volvo Penta and supplied from England to Ireland within 2 days! Big thanks to Keyparts for all their help and speed of service! Brand new wiper motor ordered from Four winns to arrive on Tuesday and thats her complete!

Cant believe how much was got done in a week, engine out, parts ordered, parts arrived, block fixed, engine in, full service and as if there never was anything wrong!

It is indescribable how much can change in a week and thanks to everyones advice on here I hope now (Dont want to jinx it until I test her on the water!) that I can enjoy another great summer on what has been a great boat to own!

As its stands parts cost circa £500 and labour something the same! So all told I managed to reduce a potential 5K bill to 1K and get back on the water unbelieveably quickly! Plus Im now confident that the boat is in tip top condition! (Subject to final test!)

Cant thank everyone enough and if I can be of help to anyone else I will certainly try!
 
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