T4 Engine tin: thermal design Options

[914werke]

So seeing a product recently got me thinking about the result of its application & my own observations of how well (or not) the T4 handles air flow, Engine block cooling & resulting oil temperatures. (IMG:style_emoticons/default/smile.gif)

Its somewhat well known that ...in the 914.. the T4 suffers from less than optimal cooling from the front mounted impeller/fan particularly to the #3 Cylinder
& that it is vitally important to seal the tins multiple openings to contain as much laminar air flow front to back over the finned cylinders.
In a gross approach, the goal was to seal the engine compartment "intake" air on top from the eng. heated "cooling" air below the tins.
When a motor is new and all its components serviced & refreshed, the design does, or did, a pretty good job.
After years of use (neglect), elements (oil dirt mice ext) conspire to restrict that air flow.
As well as eng. heat causing hardening of rubber pieces that are intended to help contain that cooling air below.
Now almost 50 yrs on I see fewer & fewer "STOCK" engine configurations which you can guess usually means more heat to deal with.
Jake addressed the cooling air via his(?) DTM solution, but IMO its not very practical for stock or near stock motors (& expensive)

The go-to response to eliminate that heat is usually an additional or a remote oil cooler which comes with its own set of challenges. (IMG:style_emoticons/default/confused24.gif)
How about KISS (IMG:style_emoticons/default/biggrin.gif) Has anyone used any of the Fiberglass based stick-on reflective heat shielding products on the engine-sides of the tin?
Idea being rather than allow heat absorption to all the those steel pieces reflect it back to carried away by the cooling air?

BTW Im not a Porsche engineer...but I did stay in a Holiday Inn last night (IMG:style_emoticons/default/happy11.gif)

[Lockwodo]

So seeing a product recently got me thinking about the result of its application & my own observations of how well (or not) the T4 handles air flow, Engine block cooling & resulting oil temperatures. (IMG:style_emoticons/default/smile.gif)

Its somewhat well known that ...in the 914.. the T4 suffers from less than optimal cooling from the front mounted impeller/fan particularly to the #3 Cylinder
& that it is vitally important to seal the tins multiple openings to contain as much laminar air flow front to back over the finned cylinders.
In a gross approach, the goal was to seal the engine compartment "intake" air on top from the eng. heated "cooling" air below the tins.
When a motor is new and all its components serviced & refreshed, the design does, or did, a pretty good job.
After years of use (neglect), elements (oil dirt mice ext) conspire to restrict that air flow.
As well as eng. heat causing hardening of rubber pieces that are intended to help contain that cooling air below.
Now almost 50 yrs on I see fewer & fewer "STOCK" engine configurations which you can guess usually means more heat to deal with.
Jake addressed the cooling air via his(?) DTM solution, but IMO its not very practical for stock or near stock motors (& expensive)

The go-to response to eliminate that heat is usually an additional or a remote oil cooler which comes with its own set of challenges. (IMG:style_emoticons/default/confused24.gif)
How about KISS (IMG:style_emoticons/default/biggrin.gif) Has anyone used any of the Fiberglass based stick-on reflective heat shielding products on the engine-sides of the tin?
Idea being rather than allow heat absorption to all the those steel pieces reflect it back to carried away by the cooling air?

BTW Im not a Porsche engineer...but I did stay in a Holiday Inn last night (IMG:style_emoticons/default/happy11.gif)

Wondering how to tell how well the tins are sealed? Is there a smoke test that can be used? With the engine idling, if I remove one of the tin seals (for example, the grommet over the CHT) what should the velocity of the escaping air be?