I was wondering....

[Red SLR]

On carbs you often just see mesh covering the air intake, no filter etc. Is this ok? Will all the bits that get sucked in get burn in the chambers????

 

 

 

X777CAT

[Graham Sewell]

Depends on whether you would like your engine to last more than a few minutes. On F3 cars they have what looks like a tea strainer in front of the air intake, but I would think that there is a proper filter further down the line - or do they just think that the engine only has to last 30 minutes?

 

Cheers,

 

Graham

 

Low tech luddite - xflow and proud!

[Simos]

Depends on how long you run between rebuilds. the gauze is to keep out big bits such as pebbles which will grenade the engine or block the inlet tract further down. Without an aircleaner to take out dust and sand etc these will cause accelerated wear on the rings and bore. However if you routinely rebore and re-ring it won't make much difference. Racing two strokes with an engine life of 20mins to 6 hrs we never ran air filters, sometimes didn't run gauze either and it's amazing what you'd shake out of the airbox at the end of a race !

[stevefoster]

Race cars perhaps do about 30 to 90 minutes running at a meeting.

Depends if 1, 2 or 3 races are entered for.

8 Meetings a year that is 720 minutes running at most.

Thats 12 hours running. At average circuit lap speeds of say 80 mph you would cover 960 miles in a season.

 

Fancy rebuilding every 960 miles? Perhaps a little longer if you are only on the road. I must admit I do not know the volume of stuff that needs to flow through an engine to wear the bores and rings enough for it to need refreshing.

 

Good free flow filters make sense.

All the clubman racers I have seen use filters. K&N or Pipercross etc... I just cleaned mine.... lots of small particle muck came out.

 

 

 

Steve

My racing pics hereid=red>

Hants (North) and Berkshire area club site

hereid=red>

 

[Red SLR]

Hi

 

Thats what I thought. Ta

 

Simon.

 

X777CAT

[Roger King]

The mesh only route is a very bad idea. It will act as a rockstopper only. Rocks cause instant damage whereas the small grit particles that get past will cause rapidly accelerated wear. There is no reason not to use an air filter these days because proper design leads to no restriction of airflow.

 

The mesh is best used as a tea strainer - after all, would you strain your tea with a K&N?

[kenny.]

I used mesh on the trumpets of my Jenvey's on VX XE on the Banks Europa. On the rollers it really knackered up the air flow and cost power....I could not believe it. Fitted K+N's and power loss was virtually zero to having no covers at all......the mesh was actually choking the motor,don't go the tea strainer route!!!!! K+N and ITG both claim something like 99+% airflow....mesh must hamper this loads.

 

Kenny SLR

 

 

[stevefoster]

Not if the mesh was of the same area as the filter!

BUT we don't want mesh do we....

 

Steve

My racing pics hereid=red>

Hants (North) and Berkshire area club site

hereid=red>

 

 

Edited by - stevefoster on 6 Jun 2002 18:18:35

[Coose]

With the mesh you suffer what is called seperation in each hole, which causes the effective area of each hole to be less its physical size.

 

Imagine the wake caused by a boat as it travels up a river - this is what happens to the airflow around each section which makes up the mesh. As these 'wakes' collide they reduce the physical amount of air which can pass through each hole, thus reducing significantly the amount of air which can pass into a bellmouth of a given diameter.

 

Next time you use a teastrainer (if anyone actually does still possess one of these) just run it under a tap first and you'll see for yourself! You could also try it with a sieve.

 

Fair enough, you could make the mesh the size of your average K&N, but you might as well use a K&N which has been specially developed for the job!

Also, your gran might get upset if she see's what you've done to her strainer.... wink.gif

[Jason Plato]

We rolling road tested a well used ( but cared for ) ITG filter vs no filter and there was no disernable difference in power .

 

Dave

[Morls]

Is this the same Cooose that didn't give me such good advice when my SS50 was filtered by a sock across the carb mouth wink.gif

 

I never noticed any power increase after it set alight.

 

Mark

[Morls]

How nice...

 

I'm a Windbag nowsmile.gif

 

Mark

[Red SLR]

Thanks guys, I am not planning on putting a tea strainer on my TBs EVER but I was just wondering why some people put the mesh over the trumpets.... it seemed to me that a filter would be better.

 

 

 

X777CAT

[Michael Peterson]

Then I will give my wife back her mesh stockingstongue.gif

[Coose]

I used to use tights to replace the filter on my rather quick TS50X. They worked a treat! (the supplier of said tights didn't seem to think so though..... RRAAAHHHGGGNNNN in a Sideshow Bob stylee!)

 

Mark - A sock being the shape it is will surely give a large filter area, not dissimilar to an AHU bag filter. The only problem being that there isn't the space inside an SS50 carb for the sock to fully open out.

Also, when the SS50 spent 3/4 of its life on one wheel (and the other 1/4 underneath a Mk2 Escort), the sock will tend to get soaked in petrol. Also, the fact that the timing on the SS50 was set using a hammer and a spirit level, it's not suprising that it spat back so much!

 

At least it removed the need for a toilet... wink.gif