Bowman Heat – Instant-G

The issue is that the flapper valves will not fit over this D because of the suspension casting (gray) being in the way.

The flappers were modified trimmed to fit and attached.

Cables

Cable

3M Seam Sealer was them applied to seal all

Then painted white. A top coat of Pearl will be applied which looks to be a good match.

Lastly the exhaust inlets and outlets for the heat exchangers need to be moved. There is no way to plumb them. The only way to get from the headers to the flappers I from the bottom middle of the headers like a factory 993.

Factory 993 Heat Exchangers, UP is toward the back of the car.

Old Outlets

Interference

Old Outlets

New Outlets

Here is the solution to heat plumbing, As shown above, the old inlets near the funnel have been removed. The old outlet is shortened and is the new inlet. The outlets are ovalized (slightly flattened) for clearance and welded to the inside of the heater boxes as shown in CAD and below.

Prototype coupler and mount

Junction – oval for clearance

Carbon fiber RS tube

Additional Photos:

Passenger Header with new outlet

Driver’sheader/heat exchanger with new outlet to the center under the engine.

Shot from rear on the lift

Rear view At ride height. Seeking black hoses to replace orange silicon.

Carbon tube

This photo shows the gap between the engine and the engine compartment surround. Normally sheet metal fills this area. None of the factory solutions will wort because we are usign a 1986 carrera engine mount/crossmember, a GT3 muffler mounted very high, and a 993 motor with 993 suspension, which changed the shape of the engine compartment closest to the rear seats.

The yellow crosshatched area is where the sheet metal is located. Under the distributor and coils and completely surrounds the engine.

Black Hose. I may spray paint or dye the cord black.

Heaters modified with original feed patched and new supply tubes for flappers

Capped hole and hose interference

Clearance for oil feed hose

Close up

Driver’s side close up.

A distribution piece was made of 304 Stainless. It is not visible.

304 Stainless heater distribution Bottom of heat splitter, breaks a 3.5″ stream into two 2.5″ streams for each side of the heat exchangers. THis will not be seen.