Difference between airfilters

Cosmo · #1 (**permalink**) 06-13-2007, 05:49 PM

My Spider was built in 1968 and has had an engine swap at some time. I have the standard air filter located on top of the carb plenum but the original engine looks to have been the cross-over air filter type, like a duetto, judging by the location of the washer bag and the canister mounting point on the LHS of the engine bay.

I'd like to have an original car, not point perfect but correct for the year it was built. Is there any technical reason why I cannot go back to the cross-over air filter, was it any less efficient? Does the cross over filter sit on top of the same plenum chamber and is there anything else that would need changing?

**Bill S** · #2 (**permalink**) 06-13-2007, 06:46 PM

I believe the reason that they got rid of the crossover air filter was because of the area encroachment when they went to hanging pedals on the LH vehicles. No reason not to switch back to the original. It is a different plenum from the one you currently have but they aren't too hard to find. I've got the plenum, top, and cannister if you're interested. Might also be interested in a trade for the one you've got. PM me if you're interested, otherwise keep an eye on ebay - they turn up pretty regularly although shipping from the US is libel to be expensive. Maybe you'll luck out and find one locally, especially since the system you have works and doesn't put you under a time constraint. Good luck.

Bill Sinclair Hagerstown, MD USA

**Tifosi** · #3 (**permalink**) 06-13-2007, 08:49 PM

Something like this is what you're after then? FS:105 series airboxes

Cosmo · #4 (**permalink**) 06-14-2007, 08:13 AM

After some asking around it looks like the parts are available, should I want to do this. I'd need the older style cam cover with the dip in it as well. However there would be a 5-7 BHP drop in power

Alex · #5 (**permalink**) 06-14-2007, 10:15 AM

Quote:

Originally Posted by Cosmo

However there would be a 5-7 BHP drop in power

Cosmo · #6 (**permalink**) 06-14-2007, 10:49 AM

From two independent sources, both long standing Alfa specialists. Just from looking at the two designs I wouldn't be surprised if the old cross over filter is less efficient.

Alex · #7 (**permalink**) 06-14-2007, 10:56 AM

And they are ............. ??

Cosmo · #8 (**permalink**) 06-14-2007, 05:07 PM

Alfaholics & Classic Alfa.