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SB8 Mystery Air Box??

 
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zombie



Joined: 10 Feb 2009
Posts: 272
Location: UK

PostPosted: Sat Oct 02, 2010 9:11 am    Post subject: SB8 Mystery Air Box?? Reply with quote

I am pretty sure this is not an SB8RS air box and probably not an SB8R does anyone know what it is? Is it from the Corse SB8?

http://cgi.ebay.co.uk/Air-Box-Carbonio-Bimota-SB8-/140459842661?pt=Ricambi_e_Accessori_Moto&hash=item20b40f1c65[/url]
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daotoys1



Joined: 29 Feb 2008
Posts: 202

PostPosted: Sat Oct 09, 2010 3:26 am    Post subject: Re: SB8 Mystery Air Box?? Reply with quote

zombie wrote:
I am pretty sure this is not an SB8RS air box and probably not an SB8R does anyone know what it is? Is it from the Corse SB8?

http://cgi.ebay.co.uk/Air-Box-Carbonio-Bimota-SB8-/140459842661?pt=Ricambi_e_Accessori_Moto&hash=item20b40f1c65[/url]


I believe that it fits the BIMOTA SB8K Santa Monica with the 52mm throttle bodies.

It is not for the SB8R/SB8RS with the ram air and 59mm throttle bodies. In the SB8R/SB8RS the air box is a molded plastic and the gas tank itself functions as the top of the air box.

Im not sure about the SB8K Gobert replica; it has the 59mm throttle bodies but did away with the ram air snorkels so the air intake came from under the tank rather than trough the tank via the ram air tunnels .

I do not know if this could be adapted to the other models. But it would require changing to the SB8K gas tank and air intake to make it work.....????

It would be nice if some SB8K owners gave use their thoughts. I happen to have a number of SB8RS bikes so I know the details of that model SB8 well. I do not own a SB8K so Im speaking from an educated guess rather than from direct experience.

As you know many of the parts of the SB8R/SB8RS can be traded for SB8K parts and the reverse is also true of many components but the fairing, intake, gas tanks, seat and tail sections as well as the radiators are very different, as are the throttle bodies.

Personally I like the way the SB8RS makes its power, but I like the looks of the SB8K Santa Monica more.......the SB8RS looks more functional, where the SB8K SM looks more like a piece of art.

This carbon air box is cheap enough that it might be worth buying just to see if it could be adapted to use on the SB8RS. But Im afraid Id have to change the gas tank, tail section and maybe other items to do so.

Smile
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zombie



Joined: 10 Feb 2009
Posts: 272
Location: UK

PostPosted: Sat Oct 09, 2010 10:30 am    Post subject: Reply with quote

That certainly would explain it.

The Gobert does not have an airbox but I always thought it should have from the regular leaf/grit/gunk clearout I have to do and there are the vestiges of the bottom half of the airbox including a rubber seal.

There is no top part for the airbox though even in the parts catalogue for the gobert/santamonica of the early 2000's.

Thanks for the explanation!!!

PS if anyone wants the sb8k parts catalogue/list pdf just let me know I will post it somewhere or post to email address.
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daotoys1



Joined: 29 Feb 2008
Posts: 202

PostPosted: Sat Oct 09, 2010 4:38 pm    Post subject: Reply with quote

zombie wrote:
That certainly would explain it.

The Gobert does not have an airbox but I always thought it should have from the regular leaf/grit/gunk clearout I have to do and there are the vestiges of the bottom half of the airbox including a rubber seal.

There is no top part for the airbox though even in the parts catalogue for the gobert/santamonica of the early 2000's.

Thanks for the explanation!!!

PS if anyone wants the sb8k parts catalogue/list pdf just let me know I will post it somewhere or post to email address.



In the SB8R/SB8RS the air box bottom is large blacl plastic tub. The top of this tub holds the air filter. The hollow inside top of the gas tank functions as the top to the air box and also holds the air filter down. And the air intake is via the 2 carbon fiber ram air tubes which are a true ram air system. ( with speed the air box pressure is increased by the "ram" air being forced into the system through the scoops in the front fairing nose piece, and through the 2 carbon snorkels into the sealed and enclosed air box).

In the SB8R/SB8K there are screens at the snorkel/gas tank junction to keep out debris. You can add extra screens at the air intake scoops, or even extra air filter foam to give more filtration if you are riding in really dusty areas.

In the SB8K Gobert and Santa Monica the ram air is gone and the air intake is in the front of the bike, but hidden under the fairing nose.

You should have a sealed air box in both SB8K models. The air inlet track into the airbox should be well defined and the air filter(s) should be filtering out any debris that could enter the airbox.

Debris must be kept out of the throttle bodies as entering "dirt" will damage the engine.

Debris should also not enter the enclosed airbox because if it does it can interfere with the smooth function of the linkage that operates the intake system, plus a dirty airbox puts the engines clean air at risk ( risk of dirt eventually being inhaled into the intake).

If you are getting dirt into your airbox you need to find out why. It should not happen. Maybe you are missing a filter, pre filter or screen. Or maybe your airbox intake seals are letting outside unfiltered air in.

In the SB8R/SB8RS for example; there is a large rubber seal that encircles the top of the large plastic airbox and the top inside of the hollow gas tank sits down over the air box and is sealed to the airbox by this rubber seal. BIMOTA recommends lightly grease this rubber seal to maximize the seal and minimize air leaks. An ungreased seal will make a dry fit and allows extremely tiny particles of dust to enter the air intake system via tiny leaks. This does not happen if the rubber seal is correctly in placed and lightly lubed.

If you are getting stuff in the air box I suggest you track down the source and fix it. I seriously doubt that BIMOTA did not design these bikes to have sealed air boxes.

Just some thoughts to share

Smile
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zombie



Joined: 10 Feb 2009
Posts: 272
Location: UK

PostPosted: Sat Oct 09, 2010 7:00 pm    Post subject: Reply with quote

I agree about the dirt etc.

You are absolutely right - someone has gone to a lot of trouble to design a loverly carbon intake snorkel which buts up against an air filter which protects the velocity stacks from incoming crud. But then they forgot to seal between the base of the airbox and the cross beam and various places where cables come into the 'clean' area.

The half-an-airbox arrangement is shown in this picture from the parts manual - http://s1228.photobucket.com/albums/ee460/bimotapix/?action=view&current=airbox.jpg

The tank is supposed to form the mating half but it does a very poor job...looks like the top of the airbox was abandoned from the design late for some reason or just forgotten about!

I do try to block up the leaking areas with foam etc with some "success" but after a few hundred miles you have to bodge it up again. Even then dirty water seems to find its way in leaving crud when it dries up.

I have posted an annotated picture so that you can see what I am on about...

http://s1228.photobucket.com/albums/ee460/bimotapix/sb8k%20burnout/?action=view&current=IMAG0145-1.jpg&t=1286647227729
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daotoys1



Joined: 29 Feb 2008
Posts: 202

PostPosted: Sun Oct 10, 2010 9:00 pm    Post subject: Reply with quote

zombie wrote:
I agree about the dirt etc.

You are absolutely right - someone has gone to a lot of trouble to design a loverly carbon intake snorkel which buts up against an air filter which protects the velocity stacks from incoming crud. But then they forgot to seal between the base of the airbox and the cross beam and various places where cables come into the 'clean' area.

The half-an-airbox arrangement is shown in this picture from the parts manual - http://s1228.photobucket.com/albums/ee460/bimotapix/?action=view&current=airbox.jpg

The tank is supposed to form the mating half but it does a very poor job...looks like the top of the airbox was abandoned from the design late for some reason or just forgotten about!

I do try to block up the leaking areas with foam etc with some "success" but after a few hundred miles you have to bodge it up again. Even then dirty water seems to find its way in leaving crud when it dries up.

I have posted an annotated picture so that you can see what I am on about...

http://s1228.photobucket.com/albums/ee460/bimotapix/sb8k%20burnout/?action=view&current=IMAG0145-1.jpg&t=1286647227729




Ive seen people do away with the velocity stacks and mount K&N style ( woven cotton ) air filters right onto the top of the throttle bodies.

K&N and other aftermarket companies make these stand alone air filters that are made to rubber mount right onto the back end of a carb, or the intake side of a throttle body.

You could even keep the existing air box to keep out the large bugs and larger debris and the K&N air filters would be extra security to allow only filtered air to enter the engine.

The only other option that comes to mind would be to make your own air box cover and duct tape or some how mount and seal it air tight if you can. Your modified air box would be hidden under your gas tank unit and would do what you need without messing up the cosmetics.

I know that this is a sad thing.

Even the SB8R/SB8RS with draw in supper fine dust if you dont seal the air box top with grease. The first time I took off the tank of a used SB8R it had tiny bits or dirt in the air box and a completely dry ( not greased) air box rubber seal.

The top of the SB8R/SB8RS air box has a rubber seal around it. The air box is designed to seal with the under side of the hollow gas tank ( the underside of the gas tank is designed to act as the top cover of the air box).

This rubber sealing gasket will not seal very well unless you grease it. Its as simple as that.

If you dont do this your engine will prematurely wear out.

If you are looking at buying a used SB8, then I strongly suggest that you look into this before you buy. Other wise you might be buying a nice bike with a poorly treated engine interior. Even a low mile used bike can have a lot of engine wear with even a tiny amount of dust added into the fuel mix.

Smile
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zombie



Joined: 10 Feb 2009
Posts: 272
Location: UK

PostPosted: Sun Oct 10, 2010 10:16 pm    Post subject: Reply with quote

Hi Daotoys,
I totally agree with the general principles. I wish I could fit some magic K&Ns onto the stacks but of course this is a shower injector system. If there was such a thing as an aftermarket sealed air box I would go for it.


Although I have done my best to seal up the worst of the leaks, I have a nightmare that too much bodgery will end in disaster with bits of foam, tape and silicon sealer etc being displaced after hitting a bump, then being sucked through the gaping velocity stacks into the combustion chamber.

So I have adopted a fatalistic attitude of accepting what Bimota have designed and accepting that I may need to do some premature engine work.

I dont know if dust ingress really is that much of an issue in temperate climates, remember the old dukes and BSAs Tritons etc with just wire gauze on the bellmouth intakes and the guzzis with wire strainers instead of oil filters. As per the SB8K it was not the engine wear which needed attention it was all of the other bits...

Thanks again for the interesting counterpoints,

Zombie
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daotoys1



Joined: 29 Feb 2008
Posts: 202

PostPosted: Tue Oct 12, 2010 8:48 pm    Post subject: Reply with quote

zombie wrote:
Hi Daotoys,
I totally agree with the general principles. I wish I could fit some magic K&Ns onto the stacks but of course this is a shower injector system. If there was such a thing as an aftermarket sealed air box I would go for it.


Although I have done my best to seal up the worst of the leaks, I have a nightmare that too much bodgery will end in disaster with bits of foam, tape and silicon sealer etc being displaced after hitting a bump, then being sucked through the gaping velocity stacks into the combustion chamber.

So I have adopted a fatalistic attitude of accepting what Bimota have designed and accepting that I may need to do some premature engine work.

I dont know if dust ingress really is that much of an issue in temperate climates, remember the old dukes and BSAs Tritons etc with just wire gauze on the bellmouth intakes and the guzzis with wire strainers instead of oil filters. As per the SB8K it was not the engine wear which needed attention it was all of the other bits...

Thanks again for the interesting counterpoints,

Zombie



Two thoughts;

Maybe you could somehow tape on over lapping side walls ( one one the sides of the lower box, and the other hanging off the upper cover)????

The other thing is a trick we used back in the good old days ( 1960s and 70s).....we literally applied a light layer of grease on the entire inside surface of the air box. The idea is to have the grease catch and hold the ingress of debris and dust and keep it out of the intake into the engine.

It then would require plugging the intake and cleaning out the "dirty" grease as needed, and do it again. This we used on lots of bikes that had "unsealed" air boots and/or air boxes. It is a little messy but it actually works well.

The worst case is that you will need an early engine rebuild, but the parts for Suzuki TL engines are still easy to get and cheap compared to the cost of parts for a European mill.

I love the Santa Monica; and even knowing about this fault, Id still buy one......in a heart beat. In fact the Santa Monica is on the top of my next to get list of bikes. Its a beautiful piece of art, no doubt........and like most exotica, there are the "little things" that makes perfections ever present flaw.....even the best natural diamond will have flaws.....that how you tell them from the man made ones..... Smile
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zombie



Joined: 10 Feb 2009
Posts: 272
Location: UK

PostPosted: Wed Oct 13, 2010 12:11 am    Post subject: Reply with quote

i agree with all your points, some v high temp grease should do it the bottom of the air box would be the place to trap the grit etc.

My leaky airbox whinges are not the order of today though, I am celebrating today as my reborn/rebuilt SB8K (after the fire) hit 129bhp at the back wheel today (with legal exhausts) while the TPS setting was being optimised after the rewire and rebuild. Long flat torque curve too - will post it in my album of rebuild pictures later.

Cheers,
Zombie
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