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Engine top access in convertible, good idea?

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Old 03-06-2015, 05:04 PM
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DrBrain
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Default Engine top access in convertible, good idea?

I am no engineer. While refilling my convertible hydraulic today I looked at the enclosure tub where the engine is located. It is a metal inverse tub. Would it be possible to cut out an access port into this structure to similar to the ones in 986's. Does it contribute to the structural rigidity of the convertible? If possible changing the AOS would be simpler. Just a thought, I am sure people much smarter than me considered this already.
Old 03-06-2015, 05:10 PM
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RRTEC
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I can't speak to it through my own experience but some of the V8 conversion guys have done it. Not sure if it was coupe or cab.
Old 03-06-2015, 05:16 PM
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TSMacNeil
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Just a hunch, but I'd be concerned that it would affect the structure of the cab.
Old 03-07-2015, 08:48 AM
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Hurdigurdiman
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I would be more concerned with the alteration of the air flow around the engine compartment. I suggest you read Chapter 7 of Porsche 996 Essential Companion before you start removing any body work from the car. The aerodynamics of the airflow around the engine would be greatly compromised leading to an engine over heating. Your idea sounds good at first but further thought is defo a NO NO. The heat of that engine would come into the cabin around the back window sill via the cut out panel. Please think again on your move.
Old 03-07-2015, 12:01 PM
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DrBrain
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I did not mean to remove it permanently, but rather create a hood or latch that can be temporarily removed for access and fastened back in place once done. See 986 for concept.
Old 03-08-2015, 07:47 AM
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Hurdigurdiman
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Originally Posted by DrBrain
I did not mean to remove it permanently, but rather create a hood or latch that can be temporarily removed for access and fastened back in place once done. See 986 for concept.
A replaceable part would be a great idea if it could be achieved.
Old 03-08-2015, 09:28 AM
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ditto
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Well I am an engineer. It certainly could be made to work. The structural issues could be offset with stiffeners, pins and bolts. However, the end result would not be simpler, less expensive or make the car go faster.
Old 03-08-2015, 08:27 PM
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DrBrain
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I was not aware of asking about increased speed but good to know.
These people did it (Not a convertible, though)
http://ls1tech.com/forums/attachment...n-dscn2120.jpg
There is no mentioning of alternative stiffening measures.
Old 03-08-2015, 10:40 PM
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ditto
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Even though you did not ask, I will point out that the picture shows an incomplete job. I know that because the engine bay is empty. Stiffeners may be on the way, along with an engine.

Pulling greasy engine parts through a small hatch with sharp edges and into the cabin is less than desirable. Go for it.
Old 03-09-2015, 12:24 AM
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Spokayman
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Originally Posted by ditto
Pulling greasy engine parts through a small hatch with sharp edges and into the cabin is less than desirable. Go for it.
As pointed out above, the Boxster/Cayman cars have an engine access behind the front seats.
It's how the serpentine belts are replaced as well as access to several other major front-of-engine accessories.
http://www.knoxvilleperformance.com/...2/DSC_0900.jpg

IIRC it is an aluminum cover with just a handful of bolts attaching it. There is a seal around the perimeter.
No stiffening that is obvious, though I am sure the engineers looked at the effect of the opening on overall stiffness of the car.

Last edited by Spokayman; 03-09-2015 at 12:27 AM. Reason: clarification
Old 03-09-2015, 03:28 AM
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DrBrain
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Not to sound combative but the "engine rear access panel" has been done before (see post 70 for pics):
http://ls1tech.com/forums/conversion...version-4.html
And this is how the final construction looks like (no sharp edges):
http://ls1tech.com/forums/attachment...n-dscn2200.jpg
And this gentlemen put in a LS3 engine (engine installed, see post 137 and 139):
http://ls1tech.com/forums/conversion...version-7.html
See post 250, first picture, no stiffeners.
But also look how accessible the engine is. In a convertible no greasy parts would get into the car, there is plenty of space to remove the engine parts through the opening where the rear window is once you put the top in service position and fold back the rear window (again, I am talking about the convertible here).
I talked to a reputable body shop here and the fabrication of a "rear access panel" similar to the links listed above would be about $350-400 (including a seal, sound proofing, attachement of latches for the panel). Much cheaper than dropping the engine.
Old 09-18-2023, 03:50 PM
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Default 996 access panel

did you ever install the access panel?

Originally Posted by DrBrain
Not to sound combative but the "engine rear access panel" has been done before (see post 70 for pics):
http://ls1tech.com/forums/conversion...version-4.html
And this is how the final construction looks like (no sharp edges):
http://ls1tech.com/forums/attachment...n-dscn2200.jpg
And this gentlemen put in a LS3 engine (engine installed, see post 137 and 139):
http://ls1tech.com/forums/conversion...version-7.html
See post 250, first picture, no stiffeners.
But also look how accessible the engine is. In a convertible no greasy parts would get into the car, there is plenty of space to remove the engine parts through the opening where the rear window is once you put the top in service position and fold back the rear window (again, I am talking about the convertible here).
I talked to a reputable body shop here and the fabrication of a "rear access panel" similar to the links listed above would be about $350-400 (including a seal, sound proofing, attachement of latches for the panel). Much cheaper than dropping the engine.
Old 09-20-2023, 06:40 PM
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irontmp
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Originally Posted by DrBrain
I am no engineer. While refilling my convertible hydraulic today I looked at the enclosure tub where the engine is located. It is a metal inverse tub. Would it be possible to cut out an access port into this structure to similar to the ones in 986's merchant services? Does it contribute to the structural rigidity of the convertible? If possible changing the AOS would be simpler. Just a thought, I am sure people much smarter than me considered this already.
I'm going back and forth on the vert vs. coupe. If the vert has some structure under the buttresses and will pass HPDE tech I'm getting one most likely. (ask me again tomorrow). However, based on what we've seen of the oil fill on the coupe, how will you access it? I assume the tonneau cover lifts to allow the top to stow over the motor and the rear most panel is a trunk lid like a C5/6/7 vert. Any thoughts to how you'll add or check the oil and coolant or get to the top of the engine bay?
Old 09-21-2023, 02:43 AM
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There is no real difference between a coup and convertible as far as the engine, oil is serviced from the back,
the biggest advantage adding a small door under the top would have is that you might be able to get at the starter bolts..

For many items instruction #1 , loosen motor mounts and lower engine (You get about 2 or 3 inches)
For several things, #1 instruction is drop engine out of car. (Its a 3 hours job with decent tools, and a basic lift and table. )
In most cases you will spend more time dinking with short cuts than just giving in and dropping the motor..
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Old 11-10-2023, 09:01 PM
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996fix
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Default 996 ACCESS PANEL INSTALLED

I did cut an access panel in my 1999 996 convertible. pictures attached. Was able to replace the AOS from the top without removing all the plumbing and dropping the engine.



prep for cut

first cut. expanded the cut later for easier access to AOS

Installed heat/noise barrier and trim around the edge

finished panel.
Originally Posted by DrBrain
Not to sound combative but the "engine rear access panel" has been done before (see post 70 for pics):
http://ls1tech.com/forums/conversion...version-4.html
And this is how the final construction looks like (no sharp edges):
http://ls1tech.com/forums/attachment...n-dscn2200.jpg
And this gentlemen put in a LS3 engine (engine installed, see post 137 and 139):
http://ls1tech.com/forums/conversion...version-7.html
See post 250, first picture, no stiffeners.
But also look how accessible the engine is. In a convertible no greasy parts would get into the car, there is plenty of space to remove the engine parts through the opening where the rear window is once you put the top in service position and fold back the rear window (again, I am talking about the convertible here).
I talked to a reputable body shop here and the fabrication of a "rear access panel" similar to the links listed above would be about $350-400 (including a seal, sound proofing, attachement of latches for the panel). Much cheaper than dropping the engine.



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