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Premium Member
1983 380 SL
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3,194 Posts
Discussion Starter #781
Does anyone have any recommendations for which gasket sealer should be used on the intake manifold to head?

Also... is there sealer used on the donuts between the plenum and the intake manifold?
 

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Registered
1989 560SL
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156 Posts
Does anyone have any recommendations for which gasket sealer should be used on the intake manifold to head?

Also... is there sealer used on the donuts between the plenum and the intake manifold?
As a dealer tech, I always installed both dry (no sealant).


Sent from my iPad using Tapatalk
 

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Premium Member
1983 380 SL
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3,194 Posts
Discussion Starter #785
Wow! I never would have thought dry on either the intake or the donuts. Just goes to show how little I actually know about re-assembling a vintage Mercedes alloy engine.
Thanks guys... dry is a lot less messy.

I bought all new bolts for the intake... there are 16 of them, 8 on each side. The two long ones on each side are a no brainer... they are 104mm and 80mm in length so there is no confusing where they go, but that leaves 6 on each side that initially appear to be the same length but on closer examination I found that five of them a 40mm in length and one on each side is 45mm in length, but I can't figure out for the life of me why. All 6 appear to take the 40mm length very nicely so why is one of them 45mm? :unsure:

If the two were just randomly 5mm longer I'd say it was just providence... there were some 45mm bolts in the bin they used to install the intake origianlly, but in this case one from each side is 45mm so that doesn't appear to be a random occurrence, Mercedes probably intended one of the bolts on each side to be 45mm. Does anyone know which one should be 45mm?

Now if I could only remember what I did with that throttle position switch. :)

.
 

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Premium Member
1986 560SL with M120 V12 Engine, 1988 560SL Stock
Joined
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10,686 Posts
Wow! I never would have thought dry on either the intake or the donuts. Just goes to show how little I actually know about re-assembling a vintage Mercedes alloy engine.
Thanks guys... dry is a lot less messy.

I bought all new bolts for the intake... there are 16 of them, 8 on each side. The two long ones on each side are a no brainer... they are 104mm and 80mm in length so there is no confusing where they go, but that leaves 6 on each side that initially appear to be the same length but on closer examination I found that five of them a 40mm in length and one on each side is 45mm in length, but I can't figure out for the life of me why. All 6 appear to take the 40mm length very nicely so why is one of them 45mm? :unsure:

If the two were just randomly 5mm longer I'd say it was just providence... there were some 45mm bolts in the bin they used to install the intake origianlly, but in this case one from each side is 45mm so that doesn't appear to be a random occurrence, Mercedes probably intended one of the bolts on each side to be 45mm. Does anyone know which one should be 45mm?

Now if I could only remember what I did with that throttle position switch. :)

.
Where did you get the bolts. Belmetric has the original Mercedes type. I'm sure they are cheaper than MB. But looking at the pictures some seem to have a knurled head and some do not?

 

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Premium Member
1983 380 SL
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3,194 Posts
Discussion Starter #787
Where did you get the bolts. Belmetric has the original Mercedes type. I'm sure they are cheaper than MB. But looking at the pictures some seem to have a knurled head and some do not?

I buy 90% of my bolts from McMaster. The bolts I buy are zinc plated some with clear conversion and some with blue dye. The blue dye is almost clear. For non-stress applications I buy SS.
I bought the head bolts from Autohauz. They are supposed to be MB originals and they came with a price tag to match. I didn't replace all the head bolts, only the ugly ones.
 

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Premium Member
1983 380 SL
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3,194 Posts
Discussion Starter #788 (Edited)
I have the air plenum mated to the intake manifold and I'm in the process of installing the air intake boot. New clamp and strap (strange design) and of course the rubber boot is new. I bought the cheaper option even though some people have reported fitment problems. I too had a bit of a problem getting the lip on the rubber to find the slot in the metal flange but some fender washers and a temporary joining of the rubber to the metal flange solved that problem. The fit looks perfect now.

Pictures tomorrow.
 

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Premium Member
1983 380 SL
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3,194 Posts
Discussion Starter #789
Here's a picture showing how I solved the problem of the inexpensive (read cheap) boot fitment issue. I connected the boot to the new metal flange and stretched the rubber boot to fit. While holding the boot lip in the grove it needs to go in, I screwed in the bolts with large washers to hold the boot captive. I did this all around (see photo) and left it that way for months. Once I removed the bolts and washers, the rubber boot lip stayed engaged in the grove and I could easily attach the air metering assembly without worrying about the boot pulling out of the grove. Worked perfectly.
The white you see that makes the boot look like crap is actually powder they use to protect the rubber boot. I have no idea if it works.

MercAirDuctBoot.jpg
 

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Premium Member
1986 560SL with M120 V12 Engine, 1988 560SL Stock
Joined
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10,686 Posts
I buy 90% of my bolts from McMaster. The bolts I buy are zinc plated some with clear conversion and some with blue dye. The blue dye is almost clear. For non-stress applications I buy SS.
I bought the head bolts from Autohauz. They are supposed to be MB originals and they came with a price tag to match. I didn't replace all the head bolts, only the ugly ones.
Most of the engine bolts are 8.8 grade. The ones from McMaster will be 12.9 and they will be less likely to strip the heads.
 

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Premium Member
1983 380 SL
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3,194 Posts
Discussion Starter #791
Most of the engine bolts are 8.8 grade. The ones from McMaster will be 12.9 and they will be less likely to strip the heads.
The minimum grade I buy from McMaster is 8.8. The socket heads are generally higher at 12.9. The SS are whatever they have available but I never use SS in high stress areas. For example, I used SS for mounting the water pump.

I know I'm guilty of overkill and I've spent a bunch of money on new hardware (McMaster doesn't sell onesie-twosie ) but I just can't stand putting an engine together ( I have meticulously cleaned) using filthy pitted hardware. I even ordered new 5mm screws to attach the FD to the air metering housing. The originals are slotted... who uses slotted anymore? I replaced them with socket head screws.

One thing I must admit about the original MB hardware, the plating and conversion appear to have done their job on the 37 year old hardware. The exposed heads are ugly and pitted but the shafts still show the chromate conversion in good shape. What more can you ask of a plated bolt but to have the plating intact 37 years later?
 

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Registered
1979 450SL UK spec
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1,606 Posts
You guys are so fortunate to have suppliers like McMaster and Belmetric is the US with such a massive choice, there is nowhere in the UK to find a good choice of yellow passivated fasteners.

Jyuma, you should make up "R107 bolt kits" with all yours spares to recoup the cost.
 

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Premium Member
1983 380 SL
Joined
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3,194 Posts
Discussion Starter #793
You guys are so fortunate to have suppliers like McMaster and Belmetric is the US with such a massive choice, there is nowhere in the UK to find a good choice of yellow passivated fasteners.

Jyuma, you should make up "R107 bolt kits" with all yours spares to recoup the cost.
Not a bad idea. I'll consider it. (y)
 

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Premium Member
1983 380 SL
Joined
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3,194 Posts
Discussion Starter #794
Wow! I never would have thought dry on either the intake or the donuts. Just goes to show how little I actually know about re-assembling a vintage Mercedes alloy engine.
Thanks guys... dry is a lot less messy.

I bought all new bolts for the intake... there are 16 of them, 8 on each side. The two long ones on each side are a no brainer... they are 104mm and 80mm in length so there is no confusing where they go, but that leaves 6 on each side that initially appear to be the same length but on closer examination I found that five of them a 40mm in length and one on each side is 45mm in length, but I can't figure out for the life of me why. All 6 appear to take the 40mm length very nicely so why is one of them 45mm? :unsure:

If the two were just randomly 5mm longer I'd say it was just providence... there were some 45mm bolts in the bin they used to install the intake origianlly, but in this case one from each side is 45mm so that doesn't appear to be a random occurrence, Mercedes probably intended one of the bolts on each side to be 45mm. Does anyone know which one should be 45mm?

Now if I could only remember what I did with that throttle position switch. :)

.
Update: I found the reason why 5 of the 6 bolts that secure the intake manifold on either side are 40mm and one is 45mm. One bolt on each side of the intake manifold also secures the throttle linkage brackets... thus the extra 5mm length. Putting this intake, air metering assembly, injector, air tubes and sensor wiring together is like doing a 1000 piece jigsaw puzzle.
 

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Outstanding Contributor , Bob's Your Uncle!
-----'83 280 SL----- 5 speed....The PIG
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29,626 Posts
I guess you are not ready for the Great Barrington show this year.........oh wait.

Nevermind.
 

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Premium Member
1983 380 SL
Joined
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3,194 Posts
Discussion Starter #798
I guess you are not ready for the Great Barrington show this year.........oh wait.

Nevermind.
We lost a year of everything this year. It started with Sun & Fun being canceled... a yearly pilgrimage to Lakeland Florida at the end of April for a huge airshow. Then there was Oshkosh... the worlds largest airshow at the end of August... cancelled. And then there was Great Barrington... cancelled. Not to mention all the stuff in-between that was cancelled. I'm going through withdrawals.

What next... no Macy's Thanksgiving Day parade followed by cancelling Christmas?
 

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Premium Member
1986 560SL with M120 V12 Engine, 1988 560SL Stock
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10,686 Posts
I told my wife that I would not be going to Bonneville this year since my car was costing a fortune. I never told her it was canceled.

2651092
 

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Registered
1987 560 SL, 1990 300E 4Matic
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608 Posts
[QUOTE="Jyuma, post: 18068985, member: 1088954"

What next... no Macy's Thanksgiving Day parade followed by cancelling Christmas?
[/QUOTE]

Funny you mentioned this. My wife told me that she heard that this year's Thanksgiving parade is only going to run for one city block, with no live viewing allowed. Instead viewers will have to watch what there is of it on TV. I know you'll be glad to hear that Santa will still make an appearance. :)
 
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