Reconditioning AD41s

DAVIDO

DAVIDO

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Evening all,
The sale of our boat has recently fallen through following not a very favourable survey ie a few blisters and the prospective buyers not liking the smokey volvos.
We are considering now keeping the boat and investing in getting her up to scratch. Question is who would you use to recondition the engines ? (AD41A,s)
Cheers
 
[ QUOTE ]
Whats wrong with the engines??

All 41's smoke. /forums/images/graemlins/confused.gif

[/ QUOTE ]

I agree. AD41's are generally bullet proof and all smoke.
 
Well firstly I'd be making sure that they really do have low compresion, less they have done umpteen thousand hours, or you forgot to put oil in.

Duno the local mechanics round Cardiff. I'd ask around the locals for a recomendation.
 
How low is "low" and what sort of hours have they done?.Mine have done around 2.500 and know of at least one example with at least twice that on the clocks.
 
Sorry for the delay needed the pub /forums/images/graemlins/smile.gif Down up to 30%.If i was to beleive the previous owner no more than 600hours. Which is either nonsence or mis-use. Researching the boats history it spent the first ten years of its life inland in Germany and as ive learnt tootling is not good for these engines. Im missing something though or missed something when i bought it, they have been repainted at some point you can see from the decals. Anyway whatever i beleive they need a recon now hence the question. Have had a quote from http://www.northgatemarine.co.uk/ at approx 8k for the pair,dont know how competetive this is.
 
Hi David,
I'd be surprised if your engines are worn out. Do they smoke all the time, or just until they warm up?

The 41's have a reputation for smoking, and you won't fix that by rebuilding them. Also, I don't believe the repainting indicates very much - it certainly doesn't add any argument to them being worn out.

If you have compression details/numbers from the test, please post them. Also, how are the engines running in general - do they smoke under load, are you low on revs at the top end, do they run hot etc? Are there any other indications at all that they may be worn other than some smoke from the exhaust?

We'd like to point you in the right direction and help you avoid spending money unecessarily. As I know from 1st hand experience, these little 6-cylinder lumps can absorb money if you allow them to ;o)

Cheers,
Paul
 
Hi Paul,
Am comparing our boat to a couple of neighbours with ad41s,yes they all smoke when cold but ours is excessive until completely warm. Apart from that when over the hump and usual lorry effect smoke has cleared all seems well achieves max revs (3900) and does 28knots WOT.

Compression test Book Pressure 355lbs/in2

PORT STBD
1 240 260
2 260 240
3 260 260
4 260 250
5 260 240
6 210 270

Port engine 30% down overall. No 6 cylinder 19.23% down compared to highest value.
Stbd engine 28.64% down overall with a difference of 11.11% between highest and lowest values.
Oiled bores and found a significant rise in pressures,but a high differential between individual cylinders.

PORT STBD
1 340 330
2 320 300
3 340 330
4 320 320
5 305 320
6 260 330

And the conclusions go on re cylinder wear and glazing bores etc.

Have been trying to convince myself that they are what they are but i think the problems are more serious. Could certainly do without spending the money at the moment, one in uni and the other on his way /forums/images/graemlins/confused.gif Happy Days.
Cheers
David
 
Running slow might damage the turbo's, but there cheap to mend.

Cant see it damaging the engines though.

I could understand one engine getting a problem for some reason, but not two.

As others have said, all these engines smoke like no tomorrow on start up. It's normal. What are the other symptoms. Are they using loads of oil?? Or is it just leaking?? Leaking is normal'ish.
 
I did try an additive earlier in the season with little effect. I got the compressions checked because of the excessive smoking compared to others.
 
I cant speek for the test figures. They may be right or wrong.

But nothing else points to a problem with the engines.

If as the figures say, both engines are down about 25% on performance. Then your speed and revs should be down 25%.

Speed is hard to quantify as it depends largly on hull clenlyness.

But there giving a bit more than full revs. 39000 instead of 38000. Sounds excelent to me. Dont know the boat or what it should do, but no boat does what the manufactures figures say.

Nothing says the engines are not working fine.
 
Sorry but a few more questions:-
1. When were the Injectors last serviced? Injectors Dribbling?.
This will cause increased smoke on start up as excessive fuel in cylinders.
2. Do the Exhaust brake assembly's operate (41a's only)
3. When were the Valve Clearances last checked?
A tight tappet would lower compression's.
4. Fuel Consumption ?
5. Oil useage, are you sure engine oil doesn't contain diesel from maybe injectors dribbling.
I think maybe you should double check compressions and be certain that the tester is sealing correctly on each cylinder.I have been using Soltron and have found a vast improvement in smoke, although i have just had injectors reconditioned and pumps are soon to be removed for testing. My boat has had limited use for 16 years with previous owner (4-500 hrs total) but i have done 100 hrs since april and 1250 sea miles since Nov 05. My engines are TAMD41A's i hope this helps. Geoff
 
Geoff,
1. Injectors were replaced after test with little improvment.
2. I have fixed the exhaust brake assemblies.
3. Will have to check with my service guy re tappets.
4. Fuel consumption appears normal.
5. No change in oil level all season but i cant be sure re mix.
Cheers
David
 
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