1-Output Improvement

This exhaust was designed in order to increase the engine output:

Photo Primary pipe, 4 branch manifold

Every cylinder outlet tube - primary tube - is 880 mm long. This is the optimal length considering the data from the manufacturer (length, bore, valve opening, etc.), and the available space inside the engine compartment.

Each pipe has the same volumic length, and neutral fiber. Identical lengths of primary pipes ensures an equivalent output for each cylinder, reduces fuel consumption, diminishes engine vibrations by approx. 60%, which leads to a higher level of comfort.

The 4 branch manifold – 4 primary pipes linked to a collector and to an outlet – enables a good mix of the gases, increases available torque and power.

Cylinder head flanges are made from 316 L stainless steel. Primary pipes and collectors are made from inconel 625 sheets. With a high thermal resistance, this alloy insures an excellent reliability to the exhaust.

Photo Cylinder head flange.

2-Le silencer

The silencer works along two principles :

A chamber made out of a drilled sheet of metal ensures the diffraction.

Padding around the relaxation chamber, made from layers of insulating material, enable the absorption.

The acoustic gain, of approx. 15%, due mainly to the loss of high frequencies, significantly improves the acoustics’ onboard.

3-Silencer mounting

The available space inside the engine compartment is not sufficient to receive the silencer: it is fastened under the cockpit.

The cylinder head flanges insure the rigidity of the collector’s fastening on the engine.

The engine mounted on silent blocks has a certain mobility compared to the cockpit, during cruising for instance.

All the conditions put together imply a specific stud, and the right build between the collector and the silencer.

Photo Screw and fastening bolt of the silencer Vertical tie rods Silencer clamp.

A twin ball joint pipe between the outlet pipe and the silencer compensate vertical and lateral movements

During manufacturing great care is taken for the sealing of the twin ball joint, without reducing the mobility

Small vertical tie rods link the silencer clamps with the cockpit. They compensate lengthwise movements of the silencer.

Structural elements which support the silencers are made out of 15CDV6T, which is used in aeronautics for mechanic-welded components. Surface treatment prevents them from corroding

Paulstra type supple ball joints enable a vibration free link up between the tie rods and the under cockpit supports.This combination of mechanical elements enables mobility between the collector and the silencer, limits mechanical constraints, and improves global reliability

Cette combinaison d'éléments mécaniques autorise une mobilité entre le collecteur et le silencieux, permet de restreindre les contraintes mécaniques et améliore la fiabilité de l'ensemble.

Exhaust manifold

Remove upper cowling

Remove lower cowling

Install the front left primary pipe (2), without forgetting the original exhaust joint, and the two support washers (22). Tighten.

Install the rear left primary pipe (2), without forgetting the original exhaust joint, and the two support washers (22). Tighten.

Set up the carburetor heating box (18) on the left front primary pipe. Screw on all the round headed screws M4 (23) and washers (24) on the carburetor heating. Tighten.

Put in place the carburetor heating boa (12) onto the bend of the heating box (18). Attach the tightening clamp (21), and then tighten.

Install the front right primary pipe (2), without forgetting the original exhaust joint, and the two support washers (22). Tighten.

Install the rear right primary pipe (2), without forgetting the original exhaust joint, and the two support washers (22). Tighten.

Install the 4 branch manifold, by matching the numbers on the flanges (see photos)

(suite)

Set up the M5 fixing screws (16) and the tightening nuts M5 (17), then tighten.

Install the support structure to the 4 branch manifold (6) onto the engine crankcase. Prepare a longer screw on the side where the fixing bush is. Tighten the crankcase screws.

Set up the 4 branch manifold support clamp (7), onto the outlet pipe (4). With the ChC screw (25) and the braking screw (15).Tighten all the clamp screws.

Set up the cabin heating box (8) onto the outlet pipe (4), corresponding with the position on the photo. Screw on all the round headed screws M4 (23) and washers (24) . Tighten.

Put on the exit cabin heating boa (29) onto the incoming cabin heating tube.. Attach the tightening clamp D44 (21), then tighten.

Fit the cabin heating bend (19) onto the front right primary pipe with the tightening clamp D44 (21), corresponding with the position on the photo.

Put on the fresh air boa on the end of the cabin heating pipe. Attach the tightening clamp D71 (20). Tighten all the clamps.

Move all the spark plug wires that might be in contact or near hte primary pipes.

Check that all the fuel pipes or electrical cables are far away from the exhaust manifold. If not isolate with thermal protection every part that might be deteriorated.