Your 1975 MG Midget 1500 / air intake
Identify the air cleaner before choosing a filter.
IMG_6885–6887 show the metal case, two external latches, a painted elbow, and a rubber coupling with two clamps. The case is rusted and its inside, element marking, seal, mountings, and exact dimensions have not yet been recorded.
What the sources establish
The factory North American parts plate (PDF p. 122) lists a 1975 cleaner assembly CHA295 and one GFE1060 element; it lists a different assembly from 1976. This identifies catalog candidates, not the unit fitted to this car.
The WIX manufacturer interchange (PDF p. 674) maps GFE1060 to WIX 42151. That is a useful search term when looking for an element, but it gives no confirmed dimensions or seal fit for this car. A published 29.7 × 28 × 4.8 cm claim conflicts with the long, narrow product image and should not be used to scale the CAD.
Our CAD case and filter are separate, selectable studies. The factory plate shows a vertical panel between an outboard cover and carb-side backplate. The CAD follows that order with provisional 100 × 150 × 280 mm case and 30 × 120 × 250 mm panel envelopes. The virtual latch release, outward cover movement, filter seat, elbow and coupling clearances are illustrative.
The factory plate separates the case-to-carburetor flange (148006 gasket and two screws/washers) from an inlet temperature-control branch (BHH1163, CHA379 and CHA491 catalog entries). The paired-wire rubber joint in IMG_6885 has an unidentified remote component; calling it the carburetor joint was unsupported. IMG_6885/6886 show a separate rearward chamber beyond that sleeve; inspect its markings and the separate case flange before identifying parts. These catalog numbers do not identify the fitted components.
The CAD now follows a declared photo-layout estimate from the cover rear through the sleeve to a separately selectable chamber. Its fitted position and identity remain unverified. Legacy remote-clamp measurement identifiers do not assign a carburetor identity. Download the blank outlet survey ↗
The available workshop scan shows two round air cleaners in its UK maintenance section (PDF p. 31). That is not a verified removal procedure for this North American rectangular case. Record how the fitted case opens before relying on a service sequence.
The whole-car intake mounting study now separates the cleaner/backplate gasket and fixing roles from the carburetor/manifold gasket and paired studs. Its exposed mounting neck and coordinated poses are reference construction estimates; the detailed engine viewer retains the earlier pose and historical audit.
Factory topology / fitted endpoints awaiting confirmation
Trace two separate connections.
The factory plate MD0992, PDF page 122, printed 107-D50·01/02 draws the temperature-control inlet branch separately from the gasketed cleaner-to-carburetor joint. The chain below summarizes catalog relationships. It gives no fitted positions, dimensions, hose route or disconnection order.
Separate Federal branch: pre-heater → CHA491 connection (item 17) → air-temperature control device. The plate labels this connector Federal; it does not establish that the connector or pre-heater is still fitted here.
- Air-temperature compensatorBHH1163 · item 15
Catalog candidate; fitted unit unidentified. - Compensator-to-cleaner connectorCHA379 · item 16
The photographed sleeve is not positively identified as this part. - Air cleaner1975 catalog: CHA295 case, GFE1060 element.
Owner elbow and sleeve are on the inlet side. - Separate case flange148006 gasket · item 12
Two SH505071 screws and two WL600051 washers · items 13–14. - CarburetorDestination of the gasketed flange.
Do not label the sleeve’s remote end as the carburetor.
Three views that would resolve the routing
- One continuous inlet overview: show the case inlet elbow, both sleeve clamps, both metal ends and the entire remote component in a single view. Keep hoses in their installed state; use an additional angle around obstructions.
- Remote component from two sides: capture every opening, connection, bracket and marking. Trace any further duct to its actual endpoint. Check the compensator and pre-heater candidates against those observations; do not assign their identity from proximity.
- Case-to-carburetor flange: record the actual interface and fastening stack separately. During planned access, photograph its gasket and both mating faces with a scale; measure hole centers and named sealing planes. Keep these readings separate from sleeve insertion depths.
Photo markers identify visible surfaces only. The revised CAD inlet placement is a photo-layout estimate. No engine station, sleeve part number, valve operation, sealing fit or withdrawal path is established by this map.
Make the next inspection useful
- With the engine cold and unable to start, take square-on photos of the whole assembly, both latches, the seam, mounts, elbow, coupling and each clamp. Include a ruler in the same plane as the surface being measured.
- Record any legible case, elbow, coupling or carburetor marks exactly as seen. A tiny mark near the seam in IMG_6886 is not readable enough to identify the assembly.
- Measure the complete case outboard depth, vertical height and long-axis length; note which face each dimension spans. Measure its distance to nearby parts separately so a future CAD build can check access.
- When the case is opened for service, document each latch before and after release, the cover’s actual movement, gasket position, inner seat, element orientation and any loose hardware. Photograph before cleaning or moving the element.
- Read every element marking, then measure the removed element’s long-axis length, vertical height, outboard thickness and seal lip. Compare its shape and markings with a supplier listing before ordering.
- Measure both metal tube outside diameters and the rubber coupling inside diameter, length and clamp positions. Check for corrosion, cracking and loose joints; keep the routing photo with the measurements.
Dimensions that would improve the 3D model
| Part | Record directly | What it unlocks |
|---|---|---|
| Full case | X outboard-to-carb-side depth, Y vertical height, Z long axis; note cover seam and measurement faces. | The CAD inspector accepts these three direct outside dimensions and can preview a resized case. Exporting the log can generate a separate owner STEP build. |
| Cover and clips | Cover outboard depth; lip and gasket section; both latch stations from one end; hook and pivot views. | A real split line, latch geometry and a removal path. The current virtual motion is not validated. |
| Filter and seat | Element length, vertical height, outboard thickness, marking and seal location; inner case opening and seat dimensions. | Direct outside dimensions can resize the filter in a separate owner STEP build after its case envelope is recorded; a defensible replacement number still requires the marking and seal match. |
| Intake joints | Case outlet and elbow diameters, bend-center offsets, coupling bore/length and clamp stations. | A dimensioned air path with testable joint clearance instead of the present visual route. |
| Mounting and access | Fastener centers, bracket bends, nearby obstruction distances, and clear direction of removal. | A replacement rehearsal checked against this car rather than a floating assembly study. |
Use Measurements and model details in the CAD inspector to save direct case dimensions. The owner build accepts only values marked “Measured directly on this car”; photo estimates remain reference notes.
Keep case and element readings independent
Record the removed element’s thickness, height and length, including its seal or frame, separately from the case. The owner builder preserves those readings even when they conflict with the current case study. Its static model check reports element/case and element/lid overlap without shrinking the input or treating guessed margins as fitted clearance. Recheck identity, installed/removed configuration, measurement faces and the estimated seat when a conflict appears.
The browser case preview keeps the element’s source-build size and moves only its estimated case-relative position. Rebuild with the measurement log to apply the element’s own dimensions and obtain current native pair checks. Older exports without the independent-size record remain unchecked. Neither a non-overlap result nor a preserved size proves the seal, retention or a withdrawal path.
Decision after inspection
Write down the fitted case number if found, the element number and dimensions, the seal condition, and whether the elbow and coupling are sound. If any identity or fit remains unresolved, keep the parts order open and add the missing measurement or photo to the planner.
The rear inlet branch is now separate
The revised 3D study replaces the old carburetor-relative right-angle cue with a hollow rear-cover bend, straight terminal, paired-wire sleeve/clamps and a separate observed chamber. The cover has its own inlet opening; the carb-side backplate outlet remains distinct. This follows the branch order visible in IMG_6885/6886 and adds a substantial surrounding obstacle behind the case.
All centerline stations, bend, necks, sleeve, insertion and chamber dimensions are estimates. BHH1163 and CHA379 remain catalog comparisons. The chamber has an open rear omission boundary; its hidden ports, flap and pre-heater route are not modeled. The separate 20 mm backplate-to-carburetor gap is unchanged and unresolved. The current source audit retains about 151 mm³ of cover/bend overlap and 165 mm³ of chamber/heater overlap. These are reconstruction conflicts, not measured car interference. Static reference joints do not establish sealing, operating flow or a disconnection/removal path.
Inspect the chamber and connected inlet branch ↗ · Inspect the rear-cover bend ↗