Inline fuel filters

Post by **foggyjames** » 02 Feb 2007 06:42 pm

Let me try to clear it up a little.

Most carb-powered cars have a single fuel line from the tank to the carb. 300s are a bit wierd, in that they have two lines - send and return, like a injection car. Why? I have no idea.

Injection cars need a return line because the fuel is 'circulated' under high pressure, while carb pumps run much lower pressure, so it's safe for the pressurised fuel from the pump to be 'piled on top of' that already in the lines. I believe there may be a heat issue involved, as well as implications for the lifespan of the pump. I'm not that clear on this, but certainly the default for carb setups is 'no return'. My 360 is now plumbed like this (because of the twin carb setup), with the return line blocked off.

IIRC, the return line is handled by the pump on a B14, but on the B200K and 1.7 cars, there is this vapour separator which does this job. It has three connnections:
Fuel in (from pump)
Fuel out (to carb)
Excess fuel out (back to tank)

I'm very confident that this isn't a filter, and doesn't need replacing like a filter. It wouldn't be a surprise if it were referred to as a filter, as that's what it would be on most cars...and it looks like (a wierd) one!

cheers

James

Post by **Chris_C** » 02 Feb 2007 06:48 pm

Foggy's right, apart from a niggly point.

Not all 1.7's got the front mount thingy, infact, few did afaik. If it doesn't have one, then the fuel pump has 3 noozles, like the 1.4.

Post by **foggyjames** » 02 Feb 2007 07:29 pm

Ah, fair play

I bow to Chris' superior knowledge of all things French

cheers

James

Post by **redline** » 02 Feb 2007 07:32 pm

be interesting to know if cornholio has one on his redline GAVIN !!!!!!!

Post by **pettaw** » 02 Feb 2007 08:12 pm

We don't have one on our 1.7, just a simple inline jobby.

Post by **foggyjames** » 02 Feb 2007 08:29 pm

3-port pump Andy?

cheers

James

Post by **pettaw** » 03 Feb 2007 12:20 am

Post by **fume** » 03 Feb 2007 09:41 am

So i could fit an inline in between the separator and the carb then, as i always prefer running cars with a fuel filter on them. I apologise for causing hassle!!!!

Post by **foggyjames** » 03 Feb 2007 10:42 am

Yup, sounds like a plan.

cheers

James

Post by **fume** » 03 Feb 2007 01:04 pm

Thanks for your help

Post by **Chris_C** » 03 Feb 2007 01:19 pm

Don't worry about hassle, thats the point we're here for

I'd reckon that an inline would be ok between the pot and the pump.

Is there anyway of looking inside the 1.7 pot? Sounds like a tiny swirl pot, I remember MJ's car had one, and it wasn't big enough to be much use as a swirl pot!

Post by MJ » 03 Feb 2007 02:22 pm

Yeah, I remember at the Taunton meet some of you guys were looking at some Red Bull can sized thing at the front *gets idea*.

Luckily I seem to have caught it in the corner of a photo unintentionally. Here it is.

I also spotted this in another photo. Is it something to do with fuel? It says: FB 629/24/5
Made in Austria (I think it's Austria not Australia) Gotta love good cameras

Post by **redline** » 03 Feb 2007 04:41 pm

haha well done MJ ( or should I say David Bailey ) thats the chap ,oh well whoever has my redline now has a nice new one of these whatever it do's.
the second pic looks like an in line fuel filter to me