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)

[wonkipop]

@searunner

yeah the 911 "tin" ware is a whole other ballgame (as i conceded in an earlier post).

they are fibreglass anyway. non conductive.
and the engines are dry sumped and kind of super oil cooled.
+ the fan is massive.

there is other scientific stuff going down with the old 911 engine.
but interestingly its an upright fan blowing air down over the cylinders, kind of like the original beetle.

whereas the type 4 motor (leaving aside it being dropped into a 914) is actually designed to be a compact flat package. the old "suitcase" engine or as i think americans labeled it the "pancake motor". its real parameters are to to with its application in VW sedans and station wagons. and i'm sure metal for ducting was more economical than fibreglass which back in the 60s and 70s would have been exotic.

i'll just add that the space shuttle had black tiles on the bottom of it, which was the bit that got hottest during its missions. not silver and not white. also had various little areas of black tile dotted around its upper surfaces.

and the blackbird SR-71s that flew over russia on spy missions at fairly high speed back in the 60s and 70s were black despite the intense friction on their external surfaces.

its interesting stuff. heat and how to get rid of it. (IMG:style_emoticons/default/beerchug.gif)