Air filter fitment

[efnfast]

Sooo, changing my air filter. Brand new AC Delco. Bought on line, but looks like an official GM sticker on it. It appears the filter is about an inch taller than the plastic half of the air box. It's not too thick, but too big. It doesn't fit properly and won't seal. The K&N I took out wasn't great, but better. I bought three filters and they all appear to be the same. Is it the part, or the operator? Maybe my air box is too small???

[secondchance]

Try installing the filter with the assembly out of the car.

[CamP]

Try installing the filter with the assembly out of the car.

This^^^

[GOLDCYLON]

This^^^

Yep as stated ^^^^^^^^^:cheers:

[efnfast]

I am. If I lay the filter in the opening, it is clearly too big.

[secondchance]

Then it?s a wrong size. Never had this issue.

[efnfast]

Anybody have an air box laying around they can measure the opening for me?

[WARP TEN]

Someone must have a stock AC Delco air filter that fits and could measure it. Maybe ask Marc or Bob H to do so as they have some in stock I am sure. I do know that a stock AC Delco air filter was what I used (after an unimpressive period with a K&N) and it fit fine. --Bob

[efnfast]

My filter measures correct, yet the hole in the plastic air box, from the raised edge measures 9 3/8th by 16. How can that be? The mounting flange (the raised edge) is no longer flat, like it's heat distorted.

[efnfast]

I can't even get the cover on.

[secondchance]

My filter measures correct, yet the hole in the plastic air box, from the raised edge measures 9 3/8th by 16. How can that be? The mounting flange (the raised edge) is no longer flat, like it's heat distorted.

Holly s**t Steve, you seem to have an incredible shrinking air box!

[efnfast]

Holly s**t Steve, you seem to have an incredible shrinking air box!


Right? Might be time to call Mark at Mirrock.

[Dynomite]

I can't even get the cover on.
My filter measures correct, yet the hole in the plastic air box, from the raised edge measures 9 3/8th by 16. How can that be? The mounting flange (the raised edge) is no longer flat, like it's heat distorted.
Steve, you seem to have an incredible shrinking air box!

The Air Filter Installation

The outside filter gasket (part of the filter) that fits into the cover is.....
17-3/8" by 10-5/8" outside dimensions and inside dimensions of the cover.....

The Air Filter fits up into the Cover.......not down into the Air Filter Housing.

A. K&N 33-2035 High Flow Air Filter (http://www.ebay.com/sch/i.html?_trksid=p3984.m570.l1313.TR0.TRC0&_nkw=K%26N+33-2035&_sacat=0&_from=R40)

B. K&N 33-2035 High Flow Air Filter (https://www.ebay.com/itm/334158427745?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=w3Y_ffHfSR-&sssrc=2349624&ssuid=gx6Ad465TOC&var=&widget_ver=artemis&media=MORE)

This is for a 1990 ZR1 or 1995 ZR1....I assume for all ZR1s 1990 to 1995.

The Air Filter total height can be up to 1-1/2".
I show the Air Filter Housing, two ZR1 filters and the filter cover in the photo.
The 1990 Air Filter Housing has the hose connection on the Drivers side for the Air Injection Pump.

https://cimg6.ibsrv.net/gimg/www.corvetteforum.com-vbulletin/600x600/80-img_3572_8a80ef9ee0d5eb92e3da93554f4c06fa94e1c3f6. jpg

1. General Installation

There are three cap screws.....the Center Cap Screw is shorter than the other two on outside. The Center Cap Screw is inserted into the filter housing after the the filter is installed in the cover (Tighten the center Cap Screw before the complete filter housing is placed in front of the radiator). The Center Cap Screw screws into the filter housing only.

Make sure the five tabs are inserted into the filter cover. The five tabs are part of the filter housing (not the air filter).

The other two cap screws are inserted into the filter housing after the filter housing is placed in front of the radiator. Those two Cap Screws screw all the way into the radiator housing and are tightened after the complete filter housing is installed.

https://cimg5.ibsrv.net/gimg/www.corvetteforum.com-vbulletin/600x600/80-img_3573_cc5cb0b0c1a2484a530fae183be93f895b82748c. jpg

2. Connecting the Air Filter Housing to the Plenum

Lastly the Corrugated Flexible Air Connection between Filter Housing and engine Plenum air intake (Leave the Corrugated Flexible Air Connection connected to the Plenum Air Intake. The Filter Housing end of the Air Connection is slipped onto the Filter Housing before the Filter Housing is screwed into place with the two outside Filter Housing Cap Screws. The Air Corrugated Connection is tightened with a Band Clamp (Screw Band Clamp....use 7mm 1/4" socket with extension or flat head screw driver).

Post 276 - Air Filter Installation (https://www.corvetteforum.com/forums/c4-zr-1-discussion/3005470-tech-info-lt5-modifications-rebuild-tricks-500-hp-14.html#post1594190815)

3. Details for Installing the K&N Air Filter

Installing a K&N 33-2035 is a bit complicated for the simple reason K&N provides foam spacers that can be compressed to different thickness which should cover the alignment issues of the "Plastic" Air Box........but an Air Box that is not flat at the Air Filter Cover interface flat within 1/4" presents a problem when the interface is warped significantly more than 1/4". A NEW AIR BOX IS THEN REQUIRED unless the gaps between the box and Air Filter Cover can be filled with Silicon Seal or some other filler.

Use the provided K&N lubrication on the filter gasket (flat part) with the filter inserted into the Top Cover facing into the Top Cover. I then remove the filter from the Top Cover and set in place on the K&N foam gasket of the Filter Housing (which Foam Gasket is glued in place with Gorilla glue) if the foam gasket does not stick in place.

The "Trick" is to lubricate the Filter Gasket rubber facing the cap screws (towards rear of car). The Filter Top Cover is then positioned by inserting the five Tabs into the Top Cover (while keeping the Filter positioned on the Filter Housing). Then while keeping the five Tabs inserted, press down on the rear of the cover as it "slides" (the reason for the lubrication at that location) down in place on the filter as you tighten the middle front Cap Screw (THIS IS THE MOST DIFFICULT PART).

https://cimg9.ibsrv.net/gimg/www.corvetteforum.com-vbulletin/800x800/80-img_3588_17d9aff75dc54429f9ab52de96ada2a6fb0c298c. jpg

Documentation of the Installation of the K&N 33-2035 Air Filter.........It is a bit complicated to install a K&N 33-2305 Air Filter. These instructions come with the K&N 33-2035 Air Filter.....

https://cimg8.ibsrv.net/gimg/www.corvetteforum.com-vbulletin/800x800/80-img_3585_0db47e40f046f41df6693a154ddc91a528c08040. jpg
https://cimg1.ibsrv.net/gimg/www.corvetteforum.com-vbulletin/800x800/80-img_3587_94143bb9b5f74db8c64493c0e0a6f934f23adc7f. jpg

[efnfast]

I ordered one from Mirrock. We'll see when it arrives.

[efnfast]

Got my new air box in. They are kinda a pain in the *** even when they fit properly. New one fits better. I think the heat distortion in mine was the culpret. The annoying factor might justify the SLP.
Then I was looking at my old one and decided to put it with all the rest of my 'Vette parts. What's on the shelf? You guessed it, an air box in good shape.

[secondchance]

Got my new air box in. They are kinda a pain in the *** even when they fit properly. New one fits better. I think the heat distortion in mine was the culpret. The annoying factor might justify the SLP.
Then I was looking at my old one and decided to put it with all the rest of my 'Vette parts. What's on the shelf? You guessed it, an air box in good shape.

Not only me?! :cheers:

[dredgeguy]

Sounds like the Wazoo storage area at Jim's. Glad you got everything fixed up.