Installing Heet Sheets

[PDACPA]

I looked under the car to see about the Heet Sheets that I ordered from Pelican.

Passenger side has easy access and looks very clean.

Drivers side has an obstruction (is it the cat?) but the place where the Heet Sheet is installed looks like its covered in oil. Where would this be coming from?

[Roland Kunz]

Hello

What are heet sheets ? ( Sorry I´m a stranger )

Are those the cool coolars to hang onto the valve covers ?

Oil comes mostly from the engine. On the passenger side it is possible leftovers from spill while fill but on the driver side it is mostly the valve cover.

Grüsse

[911pcars]

PDACPA ,
You didn't expect all 9+ quarts of oil to stay inside the engine did you? Many owners have completely dry engines. My hat is off to them as there are many avenues in our engine for oil to escape to the outside world. And due to earth's gravity, most of it moistens the bottom half of the engine on it's way back to the ground from whence it came. I suspect your oil is leaking from one or more (maybe all?) of these known areas:
- oil pressure switch
- engine thermostat
- cam housing oil lines
- upper valve covers
- crankshaft end seal
- flywheel end seal
- joint, engine case halves
- engine oil cooler seals
- oil drain tubes (4)
- cam housing-to-cylinder head joint
- camshaft chainbox seal
- rocker arm shaft(s)
- lower valve covers
- oil lines to/from oil tank
- oil sump plate

There's probably a few more areas I missed.

One way to find these leaks is to clean the engine (top and bottom), run the engine, then look for the fresh oil leak path(s). Another method, mentioned in a recent post, is to use a dye in the oil which is then easily seen with a black light. I had an oil leak that looked like it was from the driver's side cam housing-to-cylinder head joint. For months I was psyching myself up for an engine drop and D&A to fix this but soon realized the cam housing line was leaking at the hose fitting behind the distributor. I snugged it up (1/4 turn!) and now have one less leak source. Hey, it's better than plan A.

One nifty side benefit I've discovered (and what many customers don't like to admit) is that the lower bend of the HeetSheet acts as a gutter of sorts. Oil that once dripped indescriminately on the heat exchanger now collects in the sheet metal fold, flows in a fore or aft direction, then drips onto a specific area of the exhaust system. This is a definite improvement in external oil management over what the factory provides.

Roland,
I guess you haven't yet been blitzed (blessed?) by my multi-level product media campaign. Seriously, HeetSheets are modeled after the Porsche Motorsport versions to reduce the temperature in the lower valve cover area created by exhaust heat; in the case of 930s, heat generated by the turbo; in the case of later 911s, heat also generated by the catalytic converter. Temperatures can be 400ºF+.

Porsche Motorsports heat shield

HeetSheet on early 911 w/SSI heat exchangers

Regards,
Sherwood Lee
http://members.rennlist.org/911pcars
www.seinesystems.com

[Roland Kunz]

Hello

I see its a cool coolar thing

The Porsche Motorsports heat shield makes sense as it is a other situation then the normal angine has.

The background was that the aerodynamics didn´t allowed to much turbolence to cool the "hot spots" and on the other side the turbo chargers have a much hotter exhaust then the street 930. They became hot enough to draw enough heat to warp the thin aluminium valve covers wich would lead to higer oil consumption wich would lead to lose races
OK race engines are dual pluged and i think the powerloos by melting down ignition wires would avoid to overhat that area seriously

On the other side race engines don´t need to be cooled like street engines as they have a complete other thermodynamical layout and mostly run plenty oil trough giant coolers using efficient high volume pumps working at higher revs and having enough fresh air rushing trough abouve the average highwayspeed.

Something a normal 911 will not see to often to cool down.

( officer; Why where you driving that fast ?
You: I had to cool down the engine )

Grüsse

[JonT]

So are these a recommended add-on or not?

[island911]

Ouch! Foiled by an Absolute Beginner.

EDIT: . . .or is it Foil from an Absolute Beginner?

[Roland Kunz]

Hello

So are these a recommended add-on or not?

From my sight they look nice and are easy bolt ons for amatures.

But I wouldn´t use a comparson to a race car to justify there need.

Its a cool coolar thing.

The catalyt converter can become very hot under full load and should stay hot even at idle to work efficient.
In fact they are shielded to keep them warm at idle and avoid to burn something under the car if parked without care.
( japan versions needed full shielding )

So in fact at idle there is heat draped into the isolatin shielding from the catalyt and that heat also lowers the heat disapation from the lower left valve cover.

Now I still wounder how the heat sheet works. It is aliminim and mountet to the valve cover and just adds more heat sink and colling surface but it isn´t a full shield like on the race versons and so enough hot air will be drown behind it plus the upper area from the valvecover is still under direct heat radiation.

Grüsse

[PDACPA]

My personal opinion (and I bought them) was that they would provide a small useful function and I liked how they looked under the car (totally useless reason to spend $70 but I liked the little extra dress up touch even if u only see it by crawling under the rear bumper, but people do that to P cars).

[tshih]

Originally posted by Roland Kunz
Hello

So are these a recommended add-on or not?

From my sight they look nice and are easy bolt ons for amatures.

But I wouldn´t use a comparson to a race car to justify there need.

Its a cool coolar thing.

The catalyt converter can become very hot under full load and should stay hot even at idle to work efficient.
In fact they are shielded to keep them warm at idle and avoid to burn something under the car if parked without care.
( japan versions needed full shielding )

So in fact at idle there is heat draped into the isolatin shielding from the catalyt and that heat also lowers the heat disapation from the lower left valve cover.

Now I still wounder how the heat sheet works. It is aliminim and mountet to the valve cover and just adds more heat sink and colling surface but it isn´t a full shield like on the race versons and so enough hot air will be drown behind it plus the upper area from the valvecover is still under direct heat radiation.

Grüsse

I agree with Herr Kunz,

The fact that aluminum can act as a heat sink makes this a dressup proposition. I personally prefer to attach a different piece of aluminum sheeting that would be designed to scoop cool air and channel it over the valve cover areas like the COOL BRAKES products racers use for their brake cooling enhancements.

[widebody911]

So why not make them out of titanium?

[island911]

Hey, even better; I have a piece of titanium honeycomb about the right size.
That's it! and at only $1200 per side I'll be rich . . .muhaahahah

[5axis]

I tend to think these may be much more beneficial than the CC.
If I recall correctly they are constucted of SS #?? for it's thermal properties. I think they may help some of us. I bet it would help this turbo

Hot Turbo Engine!!!


david 89 turbo cab

[Superman]

From time to time Boeing sells sheets of .040" titanium from their 'surplus' store for I believe $8 per pound. Sheets between 2 and 3 feet per side weigh about 7 lbs, according to my recollection. Machinists hate to work with this stuff, but those thinner sheets might not be too bad. And titanium shields heat like nothing else (except space shuttle tiles).

[5axis]

Originally posted by Superman
Machinists hate to work with this stuff, but those thinner sheets might not be too bad. And titanium shields heat like nothing else (except space shuttle tiles).

Hey Super, Ti and SS both tend to be a PIA to machine. They are what we describe as GUMMY . The material loads up on the cutting tools and the cutting edge fails. They make lots of specialised tooling for this stuff that costs a lot and only works a little better.

[tshih]

Guys,

The only real way to settle all this heat shielding and necessity of additional cooling is to attach a thermocouple heating sensor to the valve cover (with and without the heet sheet attached and run the car under normal conditions and see what the temperature says on the probe. Then you can all see the real effect of the modification.

[911pcars]

tshih,
I have done what you suggest with heat sensitive thermal strips. I installed a short length of metal off of one valve cover stud to help isolate engine vs exhaust heat, then stuck the thermal strip onto it. My preliminary results: front of shield = 260º, back of shield = 220º. During long term testing under hotter weather and extended driving conditions: front of shield = 300º, back of shield = 220º. Engine tested is 2.7 w/RS P&C, Webers and E cams. Your results may vary. BTW, surface temps from my factory heat exchangers next to the valve cover were close to 400ºF at idle. Engines with catalytic converters and turbochargers will most likely be hotter (though not tested).

Similar testing was performed at the driver side chain box cover. Heat coming off the muffler is not as hot and I measured 220º at that location as well which means a shield at this location is not necessary. However, I did have to fashion a shield between the muffler and the rear license plate panel (proximity much closer) as the paint was bubbling.

Aluminum can act as a heat sink if there is a cooler area for the heat to go. Unfortunately, compared with the exhaust system, the cooler area is the engine itself which is largely aluminum, and we know how well it dissipates heat by the oil temperature inside of it.

Titanium is a nice material for a shield, but there is a cost/benefit equation for stainless steel that Ti doesn't provide at this point (for customers). A Ti HeetSheet does sound racey though.

Sherwood Lee
http://members.rennlist.org/911pcars
www.seinesystems.com

[tshih]

Sherwood,

You're right about SS being better for economy than titanium but the best flat sheet shielding material would be ceramic (non-conducting!) and lightest of all. I still think installing a bigger front oil cooler and letting the engine oil and dry sump system do its job of moderating metal temperature through out the engine area is the best solution for engine longevity.

Tom

[jpachard]

Hmm, I have had no problems machining Ti. You just need to RTM(read the manual ie. Machinery's Handbook). I used to machine 6Al-4V for the bicycle and aerospace industry as well as CP(commecially pure) and 6Al-2.5V. It's actually easier than some of the high grade stailness steels(17-4pH comes to mind). Where do I go to get these surplus sheets from Boeing???

Cheers, James

[911pcars]

[b/]"....I still think installing a bigger front oil cooler and letting the engine oil and dry sump system do its job of moderating metal temperature through out the engine area is the best solution for engine longevity."[/b]

I agree. I have no issues with that. However, the exhaust system, which transports approx. 60% of the heat energy from the combustion process, is not doing the cooling system any favors due to its close proximity to the engine. Wouldn't it be nice if the temperature of the bottom of our engines was the same as the top end?

Sherwood

[Hellgate]

I heard that if you buy two of these they will throw in a sequencial ERAM to boot!