Author Topic: Sump Guard - Thumbs up  (Read 1896 times)

September 28, 2017, 12:35:42 PM
Reply #15

Veneficus

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Hehe I agree

The thing is the stock plastic cover blocks allot larger area compared to the after market sump guard.
The aftermarket ones leaves the edges open where the plastic one closes that down as well

It only has the furthest rear section open
And hell even that connects to the plastic cover under the gearbox

So during slow driving the metal ones should technically allow more air to escape (in theory at least)

If it was during high speeds then I would say that it could be because the sealed front lip may create a low pressure enviroment at the rear helping it suck more air through

But that would not work at low speeds
« Last Edit: September 28, 2017, 12:37:37 PM by Veneficus »
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September 28, 2017, 04:21:38 PM
Reply #16

jbh

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Even with my LSS Sump Guard I had exactly the same problem. That is why I fitted the "BIG" radiator with all the ensuing problems that I had. Luckily everything is now sorted. Even at slow speeds in thick sand we stay "cool".  ;)
jbh
Southernmost point of Africa
Ex:2003 Forester XSel Dual Range
Now: 2009 XS Dual Range. LSS sump guard.
Pedders Suspension. Aluminium heavy duty Radiator.

September 29, 2017, 07:25:15 PM
Reply #17

Starfire69

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I have a sump guard from someone other than LSS on my Outback.
I do not wish to badmouth anyone or their product, but in my opinion, a lot more effort could have gone into the design and fitment.
A person fits such a sump guard because of wanting to protect the engine while off road, yet the guard I fitted decreased ground clearance by at least 5 cm.
I was quite miffed, so I cut it up and made it better.
In the process I got back my ground clearance, as well as add a good venting solution.
I will take some pictures tomorrow and post here.

September 30, 2017, 03:14:50 PM
Reply #18

Starfire69

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Right then, a few pictures of my sump guard.
First off, the area you see those bolts in was one piece, which I cut in half and bolted together so there is a 10mm gap between the two sections.
This aids in venting air.
Used different mounting rubbers for the front, combined with the cut I made, I gained 5cm back in ground clearance.
When I fitted it originally, there was loads of space still under engine, that

September 30, 2017, 08:17:58 PM
Reply #19

jbh

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The LSS gaurd is as good as you can get without letting sand and rocks damage your engine.
jbh
Southernmost point of Africa
Ex:2003 Forester XSel Dual Range
Now: 2009 XS Dual Range. LSS sump guard.
Pedders Suspension. Aluminium heavy duty Radiator.

October 01, 2017, 08:24:59 PM
Reply #20

berndp

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Right then, a few pictures of my sump guard.
First off, the area you see those bolts in was one piece, which I cut in half and bolted together so there is a 10mm gap between the two sections.
This aids in venting air.
Used different mounting rubbers for the front, combined with the cut I made, I gained 5cm back in ground clearance.
When I fitted it originally, there was loads of space still under engine, that

And then the pics did not arrive..................
Subaru Forester 2005 2.5 Xsel
Always looking for a tar free "road"
Brackenfell, W'Cape

October 01, 2017, 09:01:06 PM
Reply #21

berndp

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Have you tried the same without the sump guard on? Will be interesting to see if the temps differ?
I would also like to know what the differance is

Technically the primary cooling is on the radiator which is supposed to suck cold air in the front and blow that out the back
Which the fans implement when there is not enough air flow

The amount of cooling coming from air running over the engine should be minimal in such cases in anycase

Now don't get me wrong if the factory fited or aftermarket sump guard stopped the air from flowing then it would be a issue.

But I suspect that would generally have been picked up by Subaru intially

So would be interesting to see the equivilant results without the sump guard

Maybe 3 different tests would have worked best

1 factory fitted plastic sump guard
2 aftermarket metal sump guard similar to Loop's aluminuim ones
3 no sump guard

Then on the same the test would probably have to have 3 sections
1 slow crawling off road driving
2 city traffic
3 open highway

That would then give a better result

If only we could now call Mythbusters to do full test :P

You think Subaru would be thinking about us hooligans that want to take their cars into the sand?
Surely then they would have figured out the problems with the radiators, headgaskets, ringlands,......

The bottom tupperware stuff is mainly for fuel efficiency, emissions control,...., in city/highway driving. Surely not for offroading.

Anyway, I tried to get a baseline with my old sump-guard yesterday in the Sandveld. But, the sand was still too moist & cool, and no uphills..................
However, before returning home today, I fitted my new mini sump-guard, just because............
My initial feeling is that the engine intake temperature seems to have remained lower than before. It was about 34'C outside, and the intake temp stayed at approx 10'C above that, not the normal ~ 20'C. Maybe a good sign, maybe just wishful thinking.

The current mini version sits fairly close to the sump sides. On normal tar/gravel roads, the sump seems to have never touched the sump-guard. I still need to try and let the engine rock to max (launch or stall.............)

The "mini" still has some adjustments required, then I'll make a final prototype, regardless of any tests I might undertake. It's cheap enough to make a prototype(thin material) and throw away if not successful.(for me)

One thing I thought of while driving home today, is to make it so that any stones that can possibly get in above the bash-plate, can easily get out again. Otherwise they might just sit there and rub a hole into the sump. That won't do any good.


Stay tuned (DSTV channel 15596,98,37,28 :D for scenes (info/thoughts) from our next episodes................ ;D
Subaru Forester 2005 2.5 Xsel
Always looking for a tar free "road"
Brackenfell, W'Cape

October 05, 2017, 02:51:36 PM
Reply #22

Starfire69

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Right then, a few pictures of my sump guard.
First off, the area you see those bolts in was one piece, which I cut in half and bolted together so there is a 10mm gap between the two sections.
This aids in venting air.
Used different mounting rubbers for the front, combined with the cut I made, I gained 5cm back in ground clearance.
When I fitted it originally, there was loads of space still under engine, that


October 05, 2017, 03:13:23 PM
Reply #23

dreamerza

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My LSS guard has quite a lot of gap too, was wondering about cutting the rubber spacers down a bit too
SG9 XT 
LSS Sump Guard
LSS Diff Guard
WRX 4 Pots
3"Turbo Back from A.C.E Performance
PSPerformance Tuned
Romic Motors Maintained
Willing to get muddy!

October 07, 2017, 12:26:52 PM
Reply #24

FuzzyFozzie

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Just to throw my fuel onto the overheating fire...

I'd get the aluminium anodised[1], raw aluminium reflects a fair amount of heat straight back up onto the engine. At higher speeds where airflow is not an issue, it would make little to no difference as cooling is almost entirely due to convection. I'd surmise that at lower speeds radiation starts to play a larger part, the aluminium plate starts acting as a heat shield, with it effectively just shielding the ground from radiant heat.
If it were closer to being a black body[2], it would be absorbing more heat from the engine[3], and radiating it out in all directions, which includes away from the engine and towards the ground.

[1] Interestingly, and according to https://web.archive.org/web/20120919150451/http://www.electro-optical.com/eoi_page.asp?h=Emissivity%20of%20Materials the colour of anodising makes little difference to the emissivity, just having it anodised greatly increases it's emissivity. This wikipedia has an example of a Leslie's cube demonstrating polished aluminium, vs painted white, and painted black: https://en.wikipedia.org/wiki/Leslie_cube

[2] This is the reason that the big radiator thing for fridges is black, barring commercial fridges which rely on forced convection.

[3] Increased emissivity increases a surfaces ability to both absorb, and radiate heat, with direction of heat flow depending on the surrounding environment.

Caveat lector:
I'm no expert. It's quite possible that the aluminium plates have already been anodised, but I can't confirm that. While I'd love to get aluminium squares anodised in various colours and test this vs raw aluminium in a semi-controlled environment, I have neither the funds, nor time at present. I have a back log of projects for years as is. Having said that, if I were fitting a sump guard which was not supplied anodised, I'd be getting it anodised, painted, or coated before fitting it.

October 07, 2017, 04:02:12 PM
Reply #25

Starfire69

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So what would you reckon would be the best colour to paint it if anodizing is not an option.

I have to add, I just towed two jetskis to Moz.
The last 50km is thick sand and the trailer is a wheel width wider than the Outback, so it was plowing all the way.
It was 32C outside, and the car showed no signs of getting hot.
« Last Edit: October 07, 2017, 04:05:13 PM by Starfire69 »

October 08, 2017, 07:47:34 AM
Reply #26

berndp

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So what would you reckon would be the best colour to paint it if anodizing is not an option.

I have to add, I just towed two jetskis to Moz.
The last 50km is thick sand and the trailer is a wheel width wider than the Outback, so it was plowing all the way.
It was 32C outside, and the car showed no signs of getting hot.

On a new car, or newer model, the problem may not be there.
Not being familiar with an Outback... maybe this car has more space in the front for the hot air to go somewhere?

In the short while that I have used my mini protoype, on normal roads, it seems as if the engine is maintaining lower temperatures, but it could be wishfull thinking.
I must take it to the dunes (soon) to test.
Subaru Forester 2005 2.5 Xsel
Always looking for a tar free "road"
Brackenfell, W'Cape