Intake Manifold Heat Shield

[Tomnistuff]

My intake manifold heat shield looks like it was crumpled up, crammed between the manifolds, then flattened out again.  I guess that`s one way to install it.
I`ve decided to try to make a new one, using coiled aluminum flashing (14" x 10' for $13.00).  When I opened mine up, I see that the insulation inside is rigid and looks like 1/8" fibreboard.  Mine is probably no longer useable since it's pretty mangled and appears to have been wet at one time.  It swelled up and got a little fluffy like fibreboard does when it gets wet.  Mine is like the attached sketch that I stole and modified, from an old post by Alfred (66andblue).

Does anyone know just what the heat shield filler material really is or must I just start experimenting to find something similar that will stand about 1,000 degrees F ?

I know they are only about 120 Euro but this restoration is nickel and diming me to death.  $160 here and $160 there, and pretty soon were talking about real money, as Everett Dirkson could have once said (quote modified by me).

Tom Kizer

[IXLR8]

Hi Tom--

Mine was a bit sculpted, but I flatttened it out, polished it up a bit and reinstalled it.

I wouldn't want to testify in a court of law, but my guess is that the filler material could well be asbestos, given its year of manufacture and general knowledge and technology  at the time. It looks a lot like the wrapping I've seen on old furnace pipes.



the other Joe

[franjo_66]

Hi Guys

I was under the impression that the intake manifold heat shield was used on the late 250SLs & all 280SLs. But the other Joe has a 1965 230SL like mine. Does this mean that 230SLs should have these as well ?

Confused
Franjo

[paults1]

My early 230SL, engine #0000195, has the heat shield.

[jacovdw]

...but my guess is that the filler material could well be asbestos, given its year of manufacture and general knowledge and technology  at the time. It looks a lot like the wrapping I've seen on old furnace pipes...

I also thought the same thing when I gently persuaded a few wrinkles back straight on mine a couple of years ago.

The 230SL's should have a heat shield as well, but it is different from the one used on the 280SL's.
Sadly, the early version is NLA and if I remember correctly, only the later smaller version is available still.

[Tomnistuff]

I think mostly the difference between the 230SL and the others is the rounded end piece that folds down at the front of the engine.  It seems to be missing from the repros and the later versions of the heat shield.  The EPC still shows the rounded end piece when I look up my 67 230SL #017590.  I guess the NLA status and the later shield differences justify reproducing it myself.

I`ve attached a couple of photos of my heat shield disassembled.  You all (Y'all where I originally come from) are probably right in your assessment that it`s probably asbestos.  The insulation looks almost like it has been "painted" with something like a thinned out plaster of paris or ceramic paste.  Maybe that was to "encapsulate" the asbestos for handling safety purposes.  I am having second thoughts about replacing the "insulation".  At my age, I`m not worried about getting mesothelioma but I don`t need the extra work of finding a substitute material.  Given the work of replacing it, it's beginning to look in better shape than I thought it was.  I think I`ll reuse the old insulation but with new aluminum, since I already bought it.

I am making a dimensioned pattern and will eventually insert it into this thread and maybe the Technical Manual for all to use.  I`ll also document my construction process.

Tom Kizer

[rb6667]

Tom, I would give some thought to finding some used ones. I found some used ones on a 68 250 Sedan in the junkyard several years ago.  I don't know for sure if it's the same as used on our Pagodas, but it sure looks like it.

RB6667

[ja17]

Yes the fuel injected sedans of the era used the same and similar shields. All W108, W109 chassis (250SE, 280SE, SEL) 6 cylinder injected sedans of the era (except most of the 300SEs) used the exact same shield as the W113 250-SL and 280SLs. The 230 SL is a bit different and may be the same or similar to the injected "Finback Mercedes"  sedans of the era(220SE) .

These often pop-up on Ebay used.

[Jack Jones]

I have a really good shape used heat shield from a 1970 280SL if anyone is interested for $100.00 plus shipping.

[Cees Klumper]

I almost threw out about six of these last weekend, then thought: "Naah, let me just hold onto them, they don't take up a lot of space" ...

[jacovdw]

...The 230 SL is a bit different and may be the same or similar to the injected "Finback Mercedes" sedans of the era(220SE)...

The 230SL heatshield is the same as the ones installed on the 220SE fintail sedan and coupés.

[mbzse]

.../...  I guess the NLA status and the later shield differences justify reproducing it myself

For quite some time, the heat shield plate part for the M129/130 engines were indeed non-available (NLA).
However, since last year, both early and late style for 250 and 280SL became available, I know at least from from SLS company in Hamburg.
And, these freshly produced units are asbestos-free...

/Hans in Sweden
.

[franjo_66]

Hi Hans

I thought that the heat shields from SLS were only for the M129/M130 engines ?  If they had one for the M127 (different shape) I would get one myself

Regards
Franjo

[66andBlue]

I think mostly the difference between the 230SL and the others is the rounded end piece that folds down at the front of the engine.  It seems to be missing from the repros and the later versions of the heat shield.  ....

Tom,
it sure looks like that this is the major difference.
Franjo,
I combined Tom's photo of his shield with a photo of the shield in my 230SL and it is clear that the others sold by SLS do not have the rounded end piece and are different from the original 230SL shield.
Perhaps Cees will find one in his stash?

[Tomnistuff]

So far, it doesn`t seem to be a big deal to replace the aluminum and reuse the insulation.  I`m not finished yet but here`s where I am so far.  The 1/4 inch fibreboard is the mold for forming the rim of the larger lower aluminum piece to a 90 degree angle before installing the insulation and the upper aluminum piece.  I'll then fold the lower rim down onto the upper aluminum piece to complete the "sandwich".  The last step is bending the appropriate flaps to the appropriate angle and installing the manifold clamps.  To give it a nice sheen, I`ll probably give it a very light glass blast.  Wish me luck.  The total cost so far is about 5 hours and $13.00 for the aluminum flashing.

The inside of the shield aluminum pieces, next to the insulaton, will be white because aluminum roof flashing comes in a roll with one side painted white.

Tom Kizer

[mbzse]

I thought that the heat shields from SLS were only for the M129/M130 engines ?

Franjo and others,
You are indeed right, there are three variants and the earliest, for M127 type III engines (230SL) is not currently available.
But, if you are missing the item on your engine, it is a positive thing the part can now be obtained (benefit of heat insulation for the inlet air)
/Hans in Sweden

[franjo_66]

Aside from the rounded end piece, the other aspects of the 250SL/280SL heat shield look virtually the same as the 230SL heat shield.

Since I don't have one, and haven't been able to source any used ones from local salvagers/wreckers here in Australia, I am thinking that I should be able to use the M129/M130 version sold by SLS. Would you guys agree ?

Regards
Franjo

[jacovdw]

Just be aware that there are 2 different sizes for the clamps that hold the shield to the manifold as well.

[franjo_66]

That's right, my 230SL has the early style tubular headers, so I think the clamps on the 250SL/280SL shield would be larger as they have the later square style exhaust manifolds

Rgds
Franjo

[jacovdw]

The heat shield is not clamped to the exhaust manifold, but to the inlet manifold. Therefore it does not matter what kind of exhaust manifold your pagoda has.
It has to do with the differences between the earlier and later inlet manifolds. 

[114015]

So far, it doesn`t seem to be a big deal to replace the aluminum and reuse the insulation.  I`m not finished yet but here`s where I am so far.

Hey Tom,

That surely looks really great so far !
Let's make a production series out of that.

I'll order to sets (i.e. 2 shields).

Best regards,

Achim
(only with late 280 shields in stock)

[Tomnistuff]

Just keep dreaming, Achim.  I only do it for myself when I don`t have any other choice.

I made a little progress today.  One step backwards and two steps forwards.  To make the shield exactly like my old one, but without the wrinkles of course, I planned to fold the lower surface over the edge of the upper surface.  Even though the aluminum flashing is thin and soft, the corners still wrinkle or tear when trying to hammer form it.  It really needs a factory-type stamping die to do all the fold-overs in one stroke.  There`s just too much material in the outer corners and too little in the inner corners.

To solve the "appearance" problem, I decided to swap the two pieces, that is to fold the upper surface down over the edge of the lower surface.  That way I can notch the material in the corners and relieve the "bunching".  There won`t be any joint visible on the top surface.  It will be underneath.  There`s nothing I can do about the mild tearing in the inner corners, but they won`t be visible from above anyway.

I have almost finished folding the edges of the larger (now upper) piece to a 90 degree angle.  It is working quite well but in order to avoid recutting new pieces, it means that the white inner surfaces of the aluminum are now on the outside, not inside next to the insulation.  When It is finished, I`ll provide photographs so this explanation will be easier to understand.

Anyway, I`m now once again making progress.  I`ve got a couple of hours work left, plus sanding or light sandblasting to remove the white paint.

This is so much fun, I could just make lots of them --NOT!  Just kidding, Achim.

Tom Kizer

[Benz Dr.]

The differences between the old and new style heat shields is because of the header pipes. The old style header pipes would be right in the way of the new style throttle linkage so they made a small bracket to move forward into a different spot, which means it also comes through the heat shield in a different location.
You would be unable to use the late heat shield on an engine with early header pipes. Fortunately, I was able to locate a proper heat shield to go with the header pipes installed on my engine.
BTW, those little brackets and pieces you need to convert to the header pipes are VERY hard to find.

[wwheeler]

To keep the fresh aluminum look, you could powder coat the shield with ceramic. Same thing they use when coating the manifolds. Most shops should have an aluminum color.

[Tomnistuff]

Well, I finally finished it.  I haven't yet bent the tabs to fit the manifolds, since my car is still at the body/paint restorer's shop.  It's better than what I took off, BUT, it could be a lot better if "real" tooling were used instead of hammering it by hand.  I'm no metalworker.  If someone could convince SLS or someone else to make this shape instead of the later model shortcuts with features missing, it would be a lot more satisfying.  Their quality looks incredible, but they're just not the right part for the restoration of an early car.

In addition to not being good enough from a fold-and-crimp point of view, it was also a ROYAL PITA to make.

I would much rather have bought one, but of the right design.

Tom Kizer