Fan in engine bay?

[Narrowboat Jimmy]

Hi everyone,

 

My engine bay on my boat does not have any venting so i am going to be cutting a hole and fitting a vent on the side of the control piller so the engine heat can escape a bit. Would it be possible to fit a small fan inside of the engine bay also to help with air flow? Is this a done thing or are there other ways around this?

 

I should also point out the main reason i am wanting to do this is that my engine (kubota three cylinder) seems to be eating belts very quickly and i believe this is due to belt getting to hot and then i end up with lots of belt spray.

 

Thanks

 

Jimmy

[Albion]

Hi everyone,

 

My engine bay on my boat does not have any venting so i am going to be cutting a hole and fitting a vent on the side of the control piller so the engine heat can escape a bit. Would it be possible to fit a small fan inside of the engine bay also to help with air flow? Is this a done thing or are there other ways around this?

 

I should also point out the main reason i am wanting to do this is that my engine (kubota three cylinder) seems to be eating belts very quickly and i believe this is due to belt getting to hot and then i end up with lots of belt spray.

 

Thanks

 

Jimmy

 

What type of belts are getting eaten so quickly, vee or poly-vee? There may be another cause for the short belt life that isn't just heat.

Roger

[Narrowboat Jimmy]

What type of belts are getting eaten so quickly, vee or poly-vee? There may be another cause for the short belt life that isn't just heat.

Roger

I am pretty sure they are poly vee. I got them from beta marine who advised me it would be the right one.

 

As you can see in the photo the bottom belt is brand new and the top is after about 8 hours use.

[nb Innisfree]

I am pretty sure they are poly vee. I got them from beta marine who advised me it would be the right one.

 

As you can see in the photo the bottom belt is brand new and the top is after about 8 hours use.

 

The belt in the picture is a toothed V belt, not poly vee.

 

Are the pulleys aligned ok with each other + tensioned correctly?

[Narrowboat Jimmy]

The belt in the picture is a toothed V belt, not poly vee.

 

Are the pulleys aligned ok with each other + tensioned correctly?

 

Woops sorry about that

 

Yea everything seems to be lined up. I have to keep tightening the belt because as it wears down otherwise it will start to slip and squeak.

[Albion]

The belt in the picture is a toothed V belt, not poly vee.

 

Are the pulleys aligned ok with each other + tensioned correctly?

 

Yep, that's correct, they're the toothed vee belt type (came in to replace standard vees when better wrapping of the belts around smaller diameter pulleys on alternators became the norm). Vee belts are very susceptible to misalignment of pulleys (and tension) as Innisfree has said. If you are getting wear due to slippage or misalignment you'll find plenty of rubber dust around the place.

I'd look at the belts when mounted on the pulleys and sight along them looking for out of line belt runs first. It won't take much to cause sufficient misalignment to wear the belts rapidly. If in doubt try to place a straight edge across the belt pulleys to check alignment. Check that the alternator has been mounted correctly on its mountings and hasn't been moved fore or aft, check the water pump (if the pump is belt driven on this engine) and any other things like that. Tension to about a centimetre of movement in the longest straight run.

See what you find and report back if you can.

Roger

 

Edited to add:

If they are worn badly then they may be running on the bottom of the pulley vee and, in which case, you'll get squealing and further rapid wear. If they are running on the bottom of the vee then ensure that they are the correct section belts for the pulleys and replace anyway.

Edited June 30, 2009 by Albion

[Narrowboat Jimmy]

Yep, that's correct, they're the toothed vee belt type (came in to replace standard vees when better wrapping of the belts around smaller diameter pulleys on alternators became the norm). Vee belts are very susceptible to misalignment of pulleys (and tension) as Innisfree has said. If you are getting wear due to slippage or misalignment you'll find plenty of rubber dust around the place.

I'd look at the belts when mounted on the pulleys and sight along them looking for out of line belt runs first. It won't take much to cause sufficient misalignment to wear the belts rapidly. If in doubt try to place a straight edge across the belt pulleys to check alignment. Check that the alternator has been mounted correctly on its mountings and hasn't been moved fore or aft, check the water pump (if the pump is belt driven on this engine) and any other things like that. Tension to about a centimetre of movement in the longest straight run.

See what you find and report back if you can.

Roger

 

Edited to add:

If they are worn badly then they may be running on the bottom of the pulley vee and, in which case, you'll get squealing and further rapid wear. If they are running on the bottom of the vee then ensure that they are the correct section belts for the pulleys and replace anyway.

 

 

Thanks alot Roger i will have a good look tonight and get back to you.

[mikevye]

I haven't seen this type of belt since the old king died but the wear rate is phenominal and is symptomatic of the driving pulley not correctly engaging with its corresponding tooth on the belt so the metal impinges on the rubber grinding it away.

[RobinJ]

My engine bay on my boat does not have any venting so i am going to be cutting a hole and fitting a vent on the side of the control piller so the engine heat can escape a bit. Would it be possible to fit a small fan inside of the engine bay also to help with air flow? Is this a done thing or are there other ways around this?

Engine bays are normally vented, but occasionally your find one that isn't?

If the control pillar is open to the engine bay then it is a simple job to fit a computer type fan (square about 7" diameter) to suck hot air out, but you may need to let air in on the other side?

The fan can be run from a switch or connected to the ignition or alternator.

[blackrose]

I haven't seen this type of belt since the old king died but the wear rate is phenominal and is symptomatic of the driving pulley not correctly engaging with its corresponding tooth on the belt so the metal impinges on the rubber grinding it away.

 

I use the same type of toothed belt - I thought lots of boats did, but I don't think there are usually teeth on the pulleys?

 

The teeth on the belts are just there so that the belt can be driven around a smaller diameter pulley.

 

Engine bays are normally vented, but occasionally your find one that isn't?

If the control pillar is open to the engine bay then it is a simple job to fit a computer type fan (square about 7" diameter) to suck hot air out, but you may need to let air in on the other side?

The fan can be run from a switch or connected to the ignition or alternator.

Not a bad idea - I think I'll vent the control pillar on mine and put a fan in it (init)

I'm also going to have a 12v fan pointing at the skin tank to try to solve my overheating problem and if that doesn't work I'll install a car radiator and point the fan at that.

Edited June 30, 2009 by blackrose

[Sir Nibble]

I use the same type of toothed belt - I thought lots of boats did, but I don't think there are usually teeth on the pulleys?

 

There aren't.

 

 

Not a bad idea - I think I'll vent the control pillar on mine and put a fan in it (init)

I'm also going to have a 12v fan pointing at the skin tank to try to solve my overheating problem and if that doesn't work I'll install a car radiator and point the fan at that.

If you are going to install a fan to drive air out of the engine bay, you will need corresponding ventilation to allow air IN.

[CampinGazz]

i'd say from the photo's of the worn belt, one of your pulleys has the wrong size vee, or your using the wrong width belts to start with, can't see heat being the cause of belts wearing like that, if it was then i'd expect the hoses and any other rubber components to suffer similarly, and you'd have no paint left on the engine as the heat we're talking about would be bloomin hot,

[AlanH]

Hi everyone,

 

My engine bay on my boat does not have any venting so i am going to be cutting a hole and fitting a vent on the side of the control piller so the engine heat can escape a bit. Would it be possible to fit a small fan inside of the engine bay also to help with air flow? Is this a done thing or are there other ways around this?

 

I should also point out the main reason i am wanting to do this is that my engine (kubota three cylinder) seems to be eating belts very quickly and i believe this is due to belt getting to hot and then i end up with lots of belt spray.

 

Thanks

 

Jimmy

I don't think that over heating is the problem although your engine bay should be vented to provide the engine with fresh air. If you put a fan in a vent then you will have to provide another vent for the air to either enter or leave the engine bay depending on whether your fan is sucking or blowing. We have a 3cyl Kubota and don't seem to have a problem with the belt. Our belt is a Volvo one 11.9mm x 1010mm and has been on for at least 500 hours. Maybe the water pump or the alternator is seizing or at least giving too much resistance.

[blackrose]

"If you are going to install a fan to drive air out of the engine bay, you will need corresponding ventilation to allow air IN."

 

Yes I already have vents in the sides of the engine hole - I thought all boats did to allow air to reach the air filter/intake?

Edited June 30, 2009 by blackrose

[nb Innisfree]

The belt in the picture is a toothed V belt, not poly vee.

 

Are the pulleys aligned ok with each other + tensioned correctly?

 

The belt seems to be a rather thin section (10mm?) for driving a reasonably large alternator, 13mm would be better preferably twinned, I have a 24v 100A alt. on twin 13mm belts, hardly ever needs adjusting,. perhaps every 500 hrs or so even then its only slight. Just to add to that alt pulley is quite large (4")

 

Edit to say sorry for replying to my own post, it's my age!

Edited June 30, 2009 by nb Innisfree

[Albion]

The belt seems to be a rather thin section (10mm?) for driving a reasonably large alternator, 13mm would be better preferably twinned, I have a 24v 100A alt. on twin 13mm belts, hardly ever needs adjusting,. perhaps every 500 hrs or so even then its only slight. Just to add to that alt pulley is quite large (4")

 

Edit to say sorry for replying to my own post, it's my age!

 

It's a good point about the size of the alternator, and yet this should be a reputable marinisation(?). The alternator size would definitely be a factor after some considerable discharge from the domestic battery system (I'm assuming that the belt in question drives the domestic alternator or the only alternator with a split charge system) as the alternator struggles to put the charge back into the battery, particularly first thing in the morning. Does the belt squeal on first start-up after some considerable domestic battery discharge?

The photos look as though the belt has been running at the bottom of the pulley by the very rounded innermost edges compared to the new belt held alongside HOWEVER we can't tell whether this is cause or effect. Did the belt wear so much that it started to run on the bottom of the pulley after a while or did it always run on the bottom of the pulley? We can't tell from a picture and description I'm afraid.

Roger

Edited June 30, 2009 by Albion

[AlanH]

The belt seems to be a rather thin section (10mm?) for driving a reasonably large alternator, 13mm would be better preferably twinned, I have a 24v 100A alt. on twin 13mm belts, hardly ever needs adjusting,. perhaps every 500 hrs or so even then its only slight. Just to add to that alt pulley is quite large (4")

 

Edit to say sorry for replying to my own post, it's my age!

As I said, ours is 11.9mm and has been working fine for at least 500 hours on the same engine.

[Eeyore]

I am pretty sure they are poly vee. I got them from beta marine who advised me it would be the right one.

 

As you can see in the photo the bottom belt is brand new and the top is after about 8 hours use.

Hi Jimmy

The wear pattern is also very similar to that obtained when running a 13mm (1/2") belt on at least one 10mm (3/8") pully. This can occur when a replacement alternator with the wrong width pully has been fitted.

Two part (pressed steel plate) alternator pullys can also cause accelerated wear if the belt is run too tight. The belt will spread the pully locally where it enters, and the pully then closes back up as the belt exits. This causes radial movement of the belt in the pully groove, and increased wear. The use of a pully machined from solid will eliminate this.

When sorted use a premium grade of belt (for Gates belts xxxxMC is standard xxxxES is extra service)

Adequate static vents will almost certainly be all you need.

And just for interest: the lower front cover of most Kubota 3 cylinder engines has cooling fins, which when in the flow of air from the radiator fan.........

Which sugests that they may be a little hotter in boats, but not so that they would damage the belts.

Steve

Edited June 30, 2009 by Eeyore

[Narrowboat Jimmy]

Hi Jimmy

The wear pattern is also very similar to that obtained when running a 13mm (1/2") belt on at least one 10mm (3/8") pully. This can occur when a replacement alternator with the wrong width pully has been fitted.

Two part (pressed steel plate) alternator pullys can also cause accelerated wear if the belt is run too tight. The belt will spread the pully locally where it enters, and the pully then closes back up as the belt exits. This causes radial movement of the belt in the pully groove, and increased wear. The use of a pully machined from solid will eliminate this.

When sorted use a premium grade of belt (for Gates belts xxxxMC is standard xxxxES is extra service)

Adequate static vents will almost certainly be all you need.

And just for interest: the lower front cover of most Kubota 3 cylinder engines has cooling fins, which when in the flow of air from the radiator fan.........

Which sugests that they may be a little hotter in boats, but not so that they would damage the belts.

Steve

 

Thank you everyone for your help and comments so far

 

I have taken a few more pics this morning.

I am starting to think that like some of you have said it is the wrong size alternator which is eating my belts!

 

 

 

As you can see in the pic the pulley is very deep, alot deeper than a new belt. (pic is shown with old worn belt)

 

 

 

Belt spray!

 

 

The belt that beta marine sent me.

 

[nb Innisfree]

Thank you everyone for your help and comments so far

 

I have taken a few more pics this morning.

I am starting to think that like some of you have said it is the wrong size alternator which is eating my belts!

 

 

 

As you can see in the pic the pulley is very deep, alot deeper than a new belt. (pic is shown with old worn belt)

 

 

 

Belt spray!

 

 

The belt that beta marine sent me.

 

 

 

 

 

Looks as if all your pulleys could accomodate a wider belt, I would fit one straight away as a temporary solution and look to replacing alt pulley in the future

Edited July 1, 2009 by nb Innisfree

[Wiltshire Moonraker]

Hi

 

Looks like the wrong width alternator pulley for that belt, the XPZ series belts are nominally 10mm wide see here for spec

 

I would try your new belt in the other pulleys & if it fills them to the top but it does not fill the alternator pulley then change the alternator pulley (I have a number of 2 1/2 inch diameter pressed pulleys to fit A127 alternators if you want one)

 

However.. if the new belt is low in all the pulleys you probably need a wider belt, probably 13mm wide e.g. Optibelt XPA series.

 

Regards

 

Chris

 

 

 

Thank you everyone for your help and comments so far

 

I have taken a few more pics this morning.

I am starting to think that like some of you have said it is the wrong size alternator which is eating my belts!

[Albion]

Thank you everyone for your help and comments so far

 

I have taken a few more pics this morning.

I am starting to think that like some of you have said it is the wrong size alternator which is eating my belts!

 

 

 

As you can see in the pic the pulley is very deep, alot deeper than a new belt. (pic is shown with old worn belt)

 

 

 

Belt spray!

 

 

The belt that beta marine sent me.

 

 

Looking at your further pictures it would seem that the belt is definitely riding too far down in the pulleys. Normally the belt outer surface is approximately level with the 'outside' of the pulley vee.

Also I've never seen such a corroded looking alternator pulley. Where is the shiny surface where the belt has been running?

It may just be the distortion from the photography but in the picture from above the engine the alternator looks as though it might be slighlty forward of the other pulleys. Have you checked out this alignment?

As suggested try a wider belt.

Roger

[sentinel]

Looks as if all your pulleys could accomodate a wider belt, I would fit one straight away as a temporary solution and look to replacing alt pulley in the future

 

Agreed.

 

A "Z" section belt, as shown, (the Z part of XPZ) is too small for those pulleys. the crankshaft pulley looks as if it sized for an "A" section, standard automotive belt.

 

For further sectional and length details go to the Gates Power Transmission website, you will have to generate a user i/d etc then go to "industrial power transmission" then "catalogues in pdf" and then "heavy duty belts". This will give you dimensions of all available belts "Z" thought to "E" section

 

As an aside and probably at a tangent, I have disliked "Z" sections ever since coming across them on Roll's C8T engines fitted to a few Hunslet loco's, they had 4 of them fitted to drive the coolant pump and alternator instead of 2 or 3 A section belts and they were always trouble.... I fitted banded belts in the end out of frustration.

[nb Innisfree]

Agreed.

 

A "Z" section belt, as shown, (the Z part of XPZ) is too small for those pulleys. the crankshaft pulley looks as if it sized for an "A" section, standard automotive belt.

 

For further sectional and length details go to the Gates Power Transmission website, you will have to generate a user i/d etc then go to "industrial power transmission" then "catalogues in pdf" and then "heavy duty belts". This will give you dimensions of all available belts "Z" thought to "E" section

 

As an aside and probably at a tangent, I have disliked "Z" sections ever since coming across them on Roll's C8T engines fitted to a few Hunslet loco's, they had 4 of them fitted to drive the coolant pump and alternator instead of 2 or 3 A section belts and they were always trouble.... I fitted banded belts in the end out of frustration.

 

Standard A sec belts are quite forgiving IMO will take a degree of misalignment and abuse, provided they are sized properly and correct pulleys fitted, toothed ones for smaller pulleys.

Edited July 1, 2009 by nb Innisfree

[Eeyore]

Thank you everyone for your help and comments so far

 

I have taken a few more pics this morning.

I am starting to think that like some of you have said it is the wrong size alternator which is eating my belts!

 

 

 

As you can see in the pic the pulley is very deep, alot deeper than a new belt. (pic is shown with old worn belt)

 

 

 

Belt spray!

 

 

The belt that beta marine sent me.

 

Hi Jimmy

(edited to say - agree with the last few posts)

I stand corrected.

You have the wrong width belt fitted - its too narrow in all of the pullies.

The belt you have is an XPZ1000 which from memory is 1000mm long by 10mm (3/8" ish) wide.

The belt you need is an XPA1000 which is 1000mm long by 13mm (1/2" ish) wide.

Any autoparts shop, even Halfords, can supply againt a description of 1000mm x 13mm vee belt.

Everyone would have spoted it if these had been the first photos posted - wonderful thing hindsight

Beta employ human beings, and we all know the sort of mistakes they are capable of.

Best to give them a call (I know how much you paid!). Ask for replacements for the used and unused belts.

Give them the directions to your photos on the forum if nessesary, although I wouldn't expect any problems.

Your setup would tolerate a smaller alternator pully if needed, but if it charges ok leave along.

The first new belt will need checking soon after fitting, when its finished knocking the rust off the upper surface of the pullies

Steve

Edited July 1, 2009 by Eeyore