Smoky AD 41's Help!

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Nat

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Smoky AD 41\'s Help!

Friend of mine has a Targa 33 with AD 41s the problem is they smoke like hell just as the turbos come in before getting on the plane. also the air filters clog up with thick black dry soot in a very short time 2/3 days. removing the filters partially cures the problem they still smoke although not as bad. Whats puzzling me is how the air filters keep getting so dirty, I cant find any back pressure or such when revving the engines with no filters. Any one got any idea of the cause ? Im loath to start changing injectors untill I find out the cause of the dirty filters.
thanks Nat /forums/images/graemlins/confused.gif
 
Re: Smoky AD 41\'s Help!

There is an oil breather filter, silver can type thing next to the air filter. Take them of and clean or replace.

Watch them when they are running, this is the only place that I know of where the black 'soot' can be coming from. If you are getting a lot of crankcase oil from here then your engine needs looking at.

AD41's smoke anyhow. Are they the A's or the B's? If A's then your exhaust brakes may be faulty. I took mine off, including the flap inside the exhaust outlet. Much better.

Hope this helps....
 
Re: Smoky AD 41\'s Help!

I agree and would like to add I have 4 spare crank case breathers left over from my last boat and would like to sell them cheap so please feel free to pm me. or



Also check the exhaust solenoids are working , this will help start up and slow running smoke.

I used to add injector cleaner once a season.

Clean air filters make a big difference but if the crank case breathers are not doing their job then the air filters will not stay clean for long.

All this will help reduce smoke but there is only one way to stop a Volvo smoking

DISCONNECT THE STARTER BATTERY /forums/images/graemlins/wink.gif






Just read again and noticed the smoke is just before the hump so solenoid is not the problem.
Double check both exhaust bellows are fitted and not cracked.
If a split allowed loads of smoke out above the water line then maybe the boat is sucking it back instead of clean air.
Check extra air intakes have not been added causing dirty air to circulate.

Check all exhaust connections inside the engine bay for leaks, the cast aluminum exhaust elbows can corrode.
 
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Re: Smoky AD 41\'s Help!

Ha ... like it, That'll stop them somking alright!

I used to get a worried at my smokey 41's until I saw how my friends 43's and another's new 44's smoked.

Made a big difference running on white from the CI's. Also the new D6's had a smoke problem when they first went is due to the poor quality fuel.
 
Re: Smoky AD 41\'s Help!

Might be worth a check of the drive belts, just in case, doubt that would be a problem though. Whats the state of the primary filters like?
 
Re: Smoky AD 41\'s Help!

After running with AQAD41 for 6 years we have now gone to Cummins-Merc and the difference is unbelievable almost zero smoke.
All season with out the need to clean the tender, I used to have to scrub that every 100-200 nm.

AQAD41 are very fine engines and worth the hassle and occasional scrap with the Yachties over a bit of smoke /forums/images/graemlins/laugh.gif
 
Re: Smoky AD 41\'s Help!

[ QUOTE ]
After running with AQAD41 for 6 years we have now gone to Cummins-Merc and the difference is unbelievable almost zero smoke.


How do you think Cummins Merc achieve this?
Any ideas anyone?
I agree about cleaning my transom and rib is a complete pain!
But as you say-mine are reliable-and haven't let me down ....yet /forums/images/graemlins/laugh.gif
 
Re: Smoky AD 41\'s Help!

We will have to be careful not to start a Volvo/Merc argument between the old timers and the next generation.


My Cummins-Merc have also been 100% reliable and smoke free.100hrs.

I know the traditional 'flat cap' Volvo owners will say they are more reliable but I think this should be in a dedicated post and will not respond further on this thread as it is not mine and is about the wonderful Volvo aqad41 "Smokey but beautiful".
/forums/images/graemlins/smile.gif
 
Re: Smoky AD 41\'s Help!

Smoke, smoke!! Mine are famous for smoke. But only on start up, never once warm, we not much! One of the above could be the problem, or maybe it's just stuck on the hump because of dirty bottom or some such thing, causing the engines to over fuel and not reving.
 
Re: Smoky AD 41\'s Help!

isn't it due to the fairly low compression of the early Volvos? That plus overcooling when idling = smoke. Once the Turbo's are spinning there is plenty of compression.

Just a thought .... You can adjust the injection pump for rate of fuel delivery at a given turbo pressure.
 
Re: Smoky AD 41\'s Help!

I have twin volvo's AD41's on my Cranchi cruiser 32....suffer the same problem of smoking and not getting up on to the plane. Found out the turbo blades had jammed against the casing so no compression. Had to strip the turbos and clean the gunge from the casing.
 
Re: Smoky AD 41\'s Help!

Get the injectors tested. Dirty air filters are caused by them "breathing in" the soot from the exhausts. I suspect injectors are "hosing" as the fuel rack opens up for turbo boost. This happens at about hump speed.
 
Re: Smoky AD 41\'s Help!

Thankyou all
I've changed the crankcase filters, checked the turbos are spinning, solanoids are clicking in & out ok,engines do not burn any oil no visable back presure, boat was lifted & antifouled 4 months ago ect Will check the exhaust bellows & other sugestions next week when I go out to Spain.
Its a real pain at moment, running with no air filters is not going to do it any good in the long run but its practically unusabel with air filters in.........Nat
 
Re: Smoky AD 41\'s Help!

can you get washable/reusable airfilters for that motor? K+N do many types, and it cuts out that expense at servicing time.

If the filters are getting smoked up, then they are breathing in the cack either (hopefully) from outside recirculating as others say whilst at standstill or if whilst moving then it could be the exhaust pipework and hole (which could be tiny) needs fixing. From cold exhaust startup you can feel or detect with tissue paper.
 
Re: Smoky AD 41\'s Help!

I'm curious, how might you know if enough air is getting into the engine bay? Having added more soundproofing I suspect this may not be the case at >10 knots. Its tempting to reverse wire the old blige fan from when the boat was petrol but a mix of sloth and iggerunce has so far stopped me.
 
Re: Smoky AD 41\'s Help!

Hi TCM
They hardley smoke at all on start up, but with filters in just before it goes over the hump its like a bloody smoke screen coming out the back, once its on the plane, no smoke.........Nat
 
Re: enough air in the engine bay

Piston engines are fabulous air pumps. They usem in series (driven by lecky motor) creat near-total vacuums frinstance.

You would have to block up all the inlets very well indeed to stop the thing pumping air and stop, and even then a decent diesel would try sucking in the hatch seals rather than give up pumping air. Of course, there would be pumping losses if the inlet hole was v small. But as an example of how irrelavnt the vent is above a certain size note how the motor doens't run much better with hatch open than shut, it doesn't go oh phew, some air at last. Look at the inlet maifold diameter and i suppose make the enginerroom vent twice that - which will still be small and the engine will get alll the air it wants, imho.

The twiddly lickle fans are mainly there cos it the regs to have twiddly fans, supposedly to change air if gas or fumes are there etc, and with bigger fans that don't go pop after a season the engineroom air temp can be hauled down when the motor is stopped and hence the air and water cooling also stops. Mind you the air is hot so you can just open the hatch and that cools the engineroom as well.
 
Re: Smoky AD 41\'s Help!

[ QUOTE ]
can you get washable/reusable air filters for that motor?

[/ QUOTE ]


I found these non standard filters fitted better ( smaller circumference OD) and cost less than a £5 each.

As they were so cheap I changed them twice a season (every 1000 nm or so) as they fitted better the job was half the time of trying to fit the Full size one that bent, ripped and snagged several times en route to the filter housing.

FRAM CA 4306






If anyone wants 4x crank case breathers for £50 (less than half price)
pm me or
 
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Re: Smoky AD 41\'s Help!

Talking of crankcase vents, anyone else using the Racor CCV system? I've heard of a number of Cummins installations using them now (though mine doesn't).

Rick
 
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