jclanin

Hi all,

I took off my engine tray this weekend at the recommendation of several RL's... I have to say I'm not sold on keeping it off. Looks like it protects quite a bit from general road rash.

What's the reasoning behind taking off the tray? (besides "everyone else does it" of course) I know it cuts down on engine heat - but I've never had an overheating problem... even in Hot-lanta traffic.

Just curious...

thanks,

JC

jimbo3

Keeps heat from building up around the heads resulting in a slightly less hostile environment for the valves/guides. You won't necessarily notice a lower oil temp, although some do report that. Can't imagine the engine getting any road rash- my tray wasn't scratched or damaged when it got pulled off after 40,000 miles. But, do whatever you are comfortable with.

-Jim

g_murray

Hi,
I take mine off for the summer months and then put it back on for the winter months.
My wrench is adamant about 'heat damage' to the engine as a result of leaving the cover on and then sitting in traffic.
Gerry

2ndof2

Somebody pass the butter please!

RallyJon

Not sure this debate ever covers the concept of actual physical protection, probably because most 993 owners would never drive their cars on loose surfaces. I know the underside of mine has some good dings and gashes, as does the gearbox undertray, from before I owned it.

Personally, I think the cooling issue outweighs protection in the summer, but my tray goes back on when the daily high temps are below ~60°.

Phil

LOL........

I have been wondering........How come my "front" engine mazda does not have an engine protection cover?

RallyJon

Think about it. Subarus have one.

jda407

not sure if I buy into any of this. Live in florida and have run with and without the cover for long periods of time....and paid attention to temp. No difference really.

TMc993

I can't put my finger on the exact reference but I think Paul Frere cited an aerodynamic advantage to having the cover on at high speeds ( 100 MPH + )...Something about minimizing lift in the rear I believe. I've also read posts on RL that cite high speed instability at DE events when the cover is off.

Again, this is just what I've read...I never exceed the speed limit when I drive.

Paddy

I think it had something to do with noise restrictions. Your Subie probably has a cover because it is designed with off road duty in mind.

black ice

I still don't buy the problem with valve guide wear and correlation with engine undertray. A quick search didn't help me find any 993s that had premature valve guide failure, except over and over I see it listed as a regular issue of concern with 993s.
My car in particular lives in FL and sees lots of hot weather driving in traffic. I don't have an extra fan, switch, etc and my car never exceeeds the 9 o'clock position on the temp gauge. If I interpolate from listed values for the nearby marks, this is 221 degrees fahrenheit. This sounds hot but we're used to water cooled engines, which work by design at a particular temperature threshold because the pressurized coolant has a threshold of its own. Is it possible air cooled engines are designed to run hotter?
My car typically runs closer to 190 fahrenheit and no doubt that's better than 221. But if I get 200 K miles out of the car with the tray on, why risk damage to the bottom of my engine, water splash on my cats, etc? Besides, at 200K it will be time to build a 4 liter motor...

Mark in Baltimore

It's alive!!!!!!!!!!!!!!!!

Mark in Baltimore

An urban interghettoweb myth. I've had my car up to about 145-150 at the track, with the stock spoiler, mind you, and have experienced zero stability issues.

chris322

This topic has been beaten up and rehashed over and over. Prior 911's never had an engine tray so Porsche was obviously not overly concerned with the motor getting beat up from the elements. The tray was reportly there for noise suppression. The other thing to note is that looking at the oil temp. gauge has little correlation with why removing the tray is beneficial. Removing the tray helps keep cylinder head temps down. Bruce Anderson and Steve W. and many others have weighed in on this topic and it appears that the benefits outweigh the downsides to removing the tray.

cabrio993

What took you so long?