Plus 2 airbox or K&N

[Gazm]

Hi, looking for guidance from the collective about which way to go with our ?70 Plus 2S.
Engine currently has ?socks? over the Webber trumpets. We would like to change that to either K&N filters or source original/replacement airbox and trunking.
Any thoughts on pitfalls, effect on car value source and cost of parts would be appreciated.
Cheers
Gary

[JonB]

Well first off I'd say that you'll lose no value by fitting K&N if you already have "socks" fitted.

As to original covers, they tend to be expensive but:-

• You get cold air from the nose cone rather than hot air from the engine bay. You probably know that cold air is denser and leads to better combustion and thus performance.
• You get somewhere to put the outlet from the oil breather. The standard air box has an inlet pipe welded into it that connects via a rubber pipe to the breather hole in the cylinder head so that oil vapour can be drawn into the inlet for No. 4 cylinder (although there is the problem of oil fouling the spark plug occasionally). Maybe your car has a catch tank?
• It's original. I'd consider this especially important if your engine bay is otherwise original.

[Gazm]

Thanks for the reply Jon,
I do lean towards originality as I have a Turbo Esprit HC that is very original.. but this Elan has had a few mods over the years from previous owners. It has electric fan, a battery cut out switch (to stop the battery going flat when the lights come up in the garage) and the interior has had a few replaced items...
I presume my year car would need a 3 bolt fixing airbox.

[JonB]

Well - mine's a '73 and it has three holes in the airbox.

[Matt Elan]

I'd also go for the standard airbox - I get nervous with the distributor below the carbs with lots of HT ready to set fire to the car At least the standard airbox won't be burping petrol gas all over the dizzy if you have a backfire or similar problem!
Also the lights coming up when its in the garage shouldn't drain the battery unless there is an issue with the wiring. The lights should not be on if the vacuum has leaked and the pods raise - I'd do a check over the wiring for the headlights to see if there is anything wrong.
HTHs
Matt

[Gazm]

Thanks Matt,
We haven?t had time to explore the switching of the lights, I think it?s the parking lights that illuminate when the pods extend, regardless of switch position.
I?m pretty sure the function of the original switch isn?t as OEM, we have 2 rocker switches at the bottom of the offside dash that also control light functions..... an addition by previous owners.

[Bigbaldybloke]

Personal choice, but I?ve gone for a replica of the original system, I had the one bolt airbox on the carbs but nothing else. I bought a replica of the original pattern air filter housing and mounting brackets and the trunking. I got mine from Kelvedon, but I think they buy them in and they all originate at the same place whoever you buy them from. Does make distributor access difficult but as I have electronic ignition that shouldn?t matter. The trunking can make locating the coolant bottle tricky, but it also depends a bit on what radiator you have. The workshop manual has instructions on a revised location for the air filter housing. There is quite a bit on here about these original air boxes restricting airflow to cylinder 4, but not sure how relevant this is unless you intend to race or have a highly modified engine.

[Davidb]

I agree with all of the above reasons plus one more-the original cold air box makes the car quieter! And that makes it more pleasant to drive on a long trip.

[McBiter]

I logged in to post a near identical request- an airbox- but for a Stromberg rather than Weber setup.

I don't know if they're available but they car came with a pair of 60's pancake type airfilters with a thin foam filtration which must have both throttled the engine and allowed everything bar lumps to be ingested.

If someone has one for sale I'd be interested but failing that some illustrative pictures would help in re-constructing a replacement.

Good luck with the Weber air filter. Like you I'm in favour of a quiet engine without inlet roar- the noise should be at the back end.

[69S4]

The Stromberg airbox is a one piece moulding rather than the backplate and front cover Weber arrangement. They are available from the big name dealers - SJ list them at ?83 +vat but if you've only got pancake filters atm you'll also need trunking, filter box and a filter to complete the set.

[McBiter]

Many thanks.
I guessed I'd need the trunking and air filter.

[JonB]

In that case, then..

https://www.ebay.co.uk/itm/LOTUS-TWIN-C ... 2082816809

https://www.ebay.co.uk/itm/Mk-1-ESCORT- ... 2082812412

No affiliation, etc...