28/36 Weber Filter that will clear fuel pump & shelf?

oli · Post by **oli** » Tue Jul 24, 2007 10:56 pm

Hi there everyone, does anyone have, or know where I can get a reasonale air filter for the 28/36 Weber that I have fitted to my temporary engine that will clear BOTH the standard fuel pump, AND the solenoid/ parcel shelf? I have seen suppliers of the 'Ram Flo' type, and these would appear to fit, (have checked the dimensions) but it is really only needed temporarily, and I don't want to fork out £25+ for one for just until I get the 1040 and the 40 Weber back in. I am hoping that someone will have something suitable kicking around the garage that I could find a good home for!

ImpManiac · Post by **ImpManiac** » Wed Jul 25, 2007 9:06 am

I have a Weber 28/36 and suitable filter somewhere but it's not in the garage with the car. If at all possible, I'll try to find it but I wouldn't count on it.

With the postal chaos, I doubt I could get it to you anyway. Which region of the country are you in?

IM

Lotus-e-Clan · Post by **Lotus-e-Clan** » Wed Jul 25, 2007 9:51 am

I haven't played with a 28/36 in an IMP body so I'm not sure about the exact clearance issues...but I have played with a "tuned" air feed system to a 28/36 in my Clan a few years ago with good results...

...if you want the engine to produce power at high revs then *don't* fit a pancake filter...it baffles, and severely restricts the air flow...obviously the shallow filters are the worst ..and this applies to sidedraft carbs too.

Any plate at 90 degrees (directly in front) of the chokes (or trumpets if fitted) need to be as far away as possible (>50-60 mm) and clearance issues above the28/36 in the imp may restrict this distance. Better still, NO plate at all...

...so I made a "top hat" tube adapter (out of thin ally sheet re-enforced with fibreglass) fitted to the top of the 28/36 to take a flexible pipe (about 75mm diameter, 350 mm long) terminating with a power cone (from any boy-racer tuning outlet). The in coming air now has a direct, unrestricted path into the chokes.

At part throttle medium to high revs, the air in the 75mm pipe has enough inertia from the vacuum of primary choke to provide a ram effect into the secondary when you floor it!

Result is a much more responsive, unrestricted high revving engine!

And this works on a std L4 as well as a tuned engine (you may have to rejet to get the best effect - but my 28/36 had been jetted for a bigger engine and was running rich until the air induction moddification)

Peter

ImpManiac · Post by **ImpManiac** » Wed Jul 25, 2007 9:58 am

Peter is right. Pancake filters are no good for maximum power. Indeed, some people think that they are not much cop at filtering either.

I had them on the Strombergs of my old Imp and the engine wore out its bores in short order.

Maybe see if you can come up with something like he has described first.

IM

oli · Post by **oli** » Fri Jul 27, 2007 9:54 am

Thanks for the advice guys, I wouldn't allow my Imp anywhere near pancake type filters!! I have opted to try the 'Ram Flo' type of filter, as this eliminates the plate problem, and seems to have a curved outer casing which should clear the shelf too.

skamanfrank · Post by **skamanfrank** » Fri Jul 27, 2007 11:57 am

I've just bought a ramflo, not on the car yet, but it certainly looks like a nice piece of kit