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)

[moto914]

Hi. My around town & ocasional 2 hr highway runs, avoiding traffic jams (getting a snack at an exit) head temps were ok.
The interest here is in the discussion.
"Upgrade the Floor Pan Air Deflectors" Nice point.
" Front ducting to eng. fan" Stated to work.
So how about some sort of scoop routing air through floor pan deflectors, for those who performance drive. Any thoughts?

[r_towle]

Hi. My around town & ocasional 2 hr highway runs, avoiding traffic jams (getting a snack at an exit) head temps were ok.
The interest here is in the discussion.
"Upgrade the Floor Pan Air Deflectors" Nice point.
" Front ducting to eng. fan" Stated to work.
So how about some sort of scoop routing air through floor pan deflectors, for those who performance drive. Any thoughts?

The firewall air deflectors create more “suction” under the car to help the fan blow air down.

[914sgofast2]

Hi. My around town & ocasional 2 hr highway runs, avoiding traffic jams (getting a snack at an exit) head temps were ok.
The interest here is in the discussion.
"Upgrade the Floor Pan Air Deflectors" Nice point.
" Front ducting to eng. fan" Stated to work.
So how about some sort of scoop routing air through floor pan deflectors, for those who performance drive. Any thoughts?

The firewall air deflectors create more “suction” under the car to help the fan blow air down.

Anyone know why the factory used two (2) under the car firewall deflectors instead of one longer piece across the bottom of the car at the bottom of the firewall?

When factories stared putting air deflectors/air dams under the front of cars to force more air into the radiator in front engined, water cooled cars, they used a long continuous piece of rubber/plastic below the bumper/radiator opening.

[wonkipop]

Hi. My around town & ocasional 2 hr highway runs, avoiding traffic jams (getting a snack at an exit) head temps were ok.
The interest here is in the discussion.
"Upgrade the Floor Pan Air Deflectors" Nice point.
" Front ducting to eng. fan" Stated to work.
So how about some sort of scoop routing air through floor pan deflectors, for those who performance drive. Any thoughts?

The firewall air deflectors create more “suction” under the car to help the fan blow air down.

Anyone know why the factory used two (2) under the car firewall deflectors instead of one longer piece across the bottom of the car at the bottom of the firewall?

When factories stared putting air deflectors/air dams under the front of cars to force more air into the radiator in front engined, water cooled cars, they used a long continuous piece of rubber/plastic below the bumper/radiator opening.

the deflectors are more or less lined up with the rear exit openings in the underside tin (if you have the lower air guides) or more generally lined up with the air exit areas either side of crankcase.

radiators in front engine cars are centrally located and wide. hence the dam needs to be across most of the front.

i'm sure the vw/porsche engineers had the optimum solution when it came to those deflectors and real word tested it.

[Superhawk996]

i'm sure the vw/porsche engineers had the optimum solution when it came to those deflectors and real word tested it.

According to conventional mythology, VW & Porsche had no idea what type of oil should be used, what size the oil pump should be, or at what oil temperatures the engine should operate at. (IMG:style_emoticons/default/happy11.gif)

[wonkipop]

i'm sure the vw/porsche engineers had the optimum solution when it came to those deflectors and real word tested it.

According to conventional mythology, VW & Porsche had no idea what type of oil should be used, what size the oil pump should be, or at what oil temperatures the engine should operate at. (IMG:style_emoticons/default/happy11.gif)

@Superhawk996 i enjoyed reading your post @ #8. (IMG:style_emoticons/default/biggrin.gif)
it got me thinking again.
about 15 years ago i took part in a professional forum on insulation and energy efficiency in buildings. i thought maybe the most vivid way i could get some notions across was to discuss the first "dwelling" on another planet. the LMs.
i had to bone up on what NASA and Grumman got up to.
i found it fascinating.
incredible technical object then (and still now!) and i was only really concentrating on the insulation and heat control aspects of it. mostly they addressed the issue with knowing what to do with radiant energy.
i hadn't realised there were two basic material and color schemes for the LMs.
the first batch for the early missions which landed on the moon equator. as a laugh you could call those tropical spec lunar modules. the second batch for the missions which landed much further north of the equator. temperate zone LMs. (IMG:style_emoticons/default/biggrin.gif) quite noticeable differences in areas of black material versus reflective external shields.

not to mention the problem of thermal expansion at monstrous levels that no earthly object ever endured on the rear face which was oriented towards the sun. which didn't go down and didn't stop shining on them like a blowtorch.

i am pretty sure the black tin on a VW aircooled engine is a similar study in the use of an absorbing and radiating dark surface for heat control and heat loss. one thing you can bet on is that its black for a reason that has nothing to do with aesthetics or engine dressing. i'm guessing a black or dark side down towards the engine itself is the most important dark surface and should be black no matter what. i'm still thinking about the top surface but if NASA logic is correct well it ought to be black too. we get the extra benefit on earth as you point out of convection cooling as well. heating the air carries the heat away from the surface.