Question on solex air filter

[Gary Hudson]

I would like to know some options people are using to replace the stock air filter. I contacted Stan Chernoff about the reuseable foam filters he carried and he no longer has them. Does K&N or anyone else make something that is easily adaptable? How hard is it to use the itg filters, and do the velocity stacks have to be changed out?

Thanks,

Gary

[SLOroadster]

I have one word. ITG. They are the best, Formula 1 uses them, WRC uses them, and they do so for a reason. It is a reusable foam filter that filters far better than a K&N, or any paper filter. Coast Fabrication has them, it will set you back about $160 but they are worth every penny. You want a JC50-65 with a blank mounting plate. You will have to cut the intake holes and mounting holes but they work really well. Dean has them already cut out for more $$ but it wouldn't be hard to make the backing plate.

Will

[spl310]

You can still get the OEM elements, so you could keep the original. I have not done any specific measuring, but it should be fairly easy to find a K&N that can be deformed to fit the OEM housing.

If you want aftermarket, a lot of folks like the unit Will recommended. If you prefer a K&N type, then I would suggest that you shop CB Performance. They sell an air cleaner assembly that fits the Weber DCOE (same footprint as the Mikuni Solex air cleaner) and is of superior construction. The K&N uses chromed steel stampings. The CB Performance units are cast aluminum. I have a pair and everyone that has seen them really liked them. The price is right too - $27.95 each. You need a pair, but for less than $60, it is a hard setup to beat!

You can see them here: http://www.cbperformance.com/catalog.asp?ProductID=557

[spl310]

Oh, I forgot to mention this, but it should be evident if you hit the link - they are an almost identical match to the R-16 valve cover design, so they are PERFECT for a Solex carbed 1600 (or 1500 such as I have planned...)

[Gary Hudson]

Thanks guys,
Just the kind of responses I was hoping to get. I have a couple of follow up questions.

Will, do you have to swap out the velocity stacks with the itg setup the way you are doing it? I've seen Dean's offering online and he recommends the shorter stacks that he also sells. I haven't priced this setup but if your way is $160 then I know it's considerably more than that. Whew!

Spl310, the filters you linked to look nice. Can you tell me which model number is the correct match?

For the record, my stock filter is still fairly new and I found the vendor replacements. I just wanted to let the carbs breathe a little better, even though I don't get anywhere near redline with MY mechanical skills. (usually)

Thanks so much for the advice.

Gary

[spl310]

Gary,

I have not actually fitted the aircleaners to the car, so this may be a bit premature. I did a fair amount of measuring and it looks like the 2 1/2" units should work (part number 3378). I have seen some photos of solex powered cars with some rather thick aircleaners, so they should not pose any significant issues. The thicker units (3377)may just be too thick. The thinner units (3379) do not offer much difference in the way of thickness of the element, so they would not seem to be a big improvement - plus you could not run velocity stacks in those.

Now on the point of stacks, the OEM open element unit had stacks built into it. The later closed units did not (well, those stubs may be stacks to some folks - not to me). I have some shorty chrome Mikuni velocity stacks inside the 2 1/2" units and they have ample clearance.

[sgriffin]

Hi: The air filter is readily avaible throught the nearest avaible Nissan dealership for $15 . Good luck. Sam SP3111L27158, SPL31129004

[oilleak]

You'll need 50mm velocity stacks to fit under the ITG. If you've got 75mm stacks, you should be able to trade them for 50s. The only way I know to use 75mm stacks with a filter is to use the sock type filters over each stack or cut the inner fender.

[SLOroadster]

I have the K&Ns now, the reason I am getting rid of them is that they don't filter until they are really dirty. They fit ok, if I don't trade them to a friend I will sell them.

Will

[Gary Hudson]

The more I think about it, the more hesitant I am to change out from the OEM filter. I like the idea of better breathing, but not at the expense of letting more stuff through. I'd rather give up some performance in exchange for longevity. Is this wrong thinking?

I'm not handy at repairs. My goal is to be on the road as much as possible. I know some of you enjoy the rebuilding almost as much as the driving. If I shared your talents I'd probably be among you.

Gary

[SLOroadster]

The SOLEX filters are a pain to remove. I think the ITG is the way to go, IT is an open cell foam filter that you spray with oil to capture dust particles. I think it might actually filter better than the stock ones, but I have no proof to base that on. Everyone I know who races a 510 has them so that might say something.
Will

[spl310]

I don't know if they filter any better, but they should allow a lot better air flow. The stock solex aircleaners (even the early ones) don't have much filter space. They only got worse as the designs progressed. The best is of course, the open. The next would be the closed with the high hole count. The close with the low hole count (last type that was available and the one that is shown on Rallye's pages) had the least airflow. The French version would be interesting with it's stack, but I have never actually seen one of those...

The gauze type is probably fine for street use. If you live in a dusty, dirty area, or travel those kinds of roads frequently, the OEM is the better choice.

So, Gary, you gonna bring that thing to the next Road Atlanta meet?

[Gary Hudson]

Mine is an older version. I think it is closed, but it is covered with holes, not like the one on Rallye's site.

When is the next Road Atlanta meet? You mean something is actually on my side of the country? I'm still afraid of driving that far (about five hours) especially with fifth gear gone, but I might be able to find a trailer.

Gary

[spl310]

There is a spring meet at the Historic races (the Walter Mitty Historics) which usually occurs in April. There was a fall meet in September, but that may have been canned for this year. I drove mine from Jacksonville up there - about the same distance - but I did not have transmission problems. You should get that thing apart and find out what gives. It is relatively cheap to fix now - not so later.

On the aircleaner, the open unit is pretty easy to identify. The entire perimeter of the element is visible. The base plate has veloctiy stacks built into it as well as studs for the lid. The lid is retained by wing nuts. The closed units are bigger in circumference (so that the lid can clear the element). The lid actually touches the back plate. The velocity stacks are no longer fluted, but rather are sort of flat (not really efficient) and the lid is retained by wing studs that completely unscrew (making filter removal a bit easier.) The closed units are usually marked with a stamp signifying UP on the face of them. There are also black plastic/rubber locaters for the element in the lid.

[Gary Hudson]

I checked and mine is the older, open version. Thanks for all the help. I hope I can make Atlanta next April.

Gary