Intake manifold tubes and intake plenum offset

[sasmith]

I am beginning the process of restoring my son's 83.5 water cooled 1.9. Planned on starting at sealing up the vacuum system. He has driven the van for 8 years before a clutch issue landed it at dad's repair shop. I have noticed since he has owned the van, that the intake manifold tubes and the intake ports on the plenum have never been well aligned. The plenum intakes on the left side sit ~1/4" higher than the intake tubes and the right side just slightly less, but the overall height of the plenum sits taller than the manifold tubes. The old hoses have just conformed to this shape but I don't see how new hoses could be installed without significant cussing, and air leaks. I have inspected the mounting tabs/bolts on the plenum to see if there is any reason for this and both tabs appear to be well seated with bolts tightened. Since he has owned the van, no work has been done that has required removal of the manifold tubes or plenum. Before I begin removal, I am trying to figure out how I will get the new hoses installed without this significant offset. This is a rebuilt engine that was installed prior to us purchasing the van. Would it be possible that the incorrect plenum or manifold tubes could have been installed on this engine? I just don't want to start into this repair and have overlooked something that may be obvious to others. Any suggestions or help appreciated.

[DanHoug]

new gasket sets come with a thick plastic spacer/gasket that sits on top of the intake port and seals between the head and the runner. that may be missing!
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-dan
60% of what you find on the internet is wrong, including this post.

'87 Westy & '89 Westy both 2.1 4spd

Past projects can be found at--
www.thefixitworkshop.com

[sasmith]

I have new manifold gaskets in the box but have not inspected them yet. Is it standard for these "thicker" gaskets to be included?, because the new ones look like they are standard thickness and would not nearly make up the difference in height. Is there a particular vendor that has those type spacer gaskets?

[DanHoug]

they are in both the Elring and Victor Reinz gasket sets, about 1/4" thick. i maybe reading too much into your post but these never come in a 'box'... but on a flat piece of cardboard wrapped in heat shrink plastic.
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-dan
60% of what you find on the internet is wrong, including this post.

'87 Westy & '89 Westy both 2.1 4spd

Past projects can be found at--
www.thefixitworkshop.com

[zimflux]

Take pictures of what you have here.
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84 1.9 Westy

[sasmith]

Yes. Sorry for the “box” description. The gaskets are in a sealed plastic bag but are sitting in a parts box. Ha. I will look again but the thickness sure does not appear to be able to make up that difference. I would have guesstimated slightly under 1/8” thickness. But I will take a closer look in the morning and provide update with questions I’m sure.

[dabaron]

the gasket is item "C" in this photo, from this post:

https://www.thesamba.com/vw/forum/viewtopic.php?t=716350
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1991 Vanagon GL Camper
i had no idea i wanted to be a mechanic
"burnin oil and cookin coils" -- Destructo

BiWerks Design, LLC

[sasmith]

Yes those are the gaskets I have. The thickness did not appear to be able
To make up the difference but I will take a closer look in the morning

[Tbob]

The 1.9 and the 2.1 use different size intake tubes and plenums. Is it possible that the rebuilder or a P.O. did some sort of mix and match mashup? I have never tried to mix and match em, so I don't even know if it is possible or how they would align if that was the case, but this possibility came to mind. Or, could the left and right sides be swapped? Once again, I don't know f this is even possible, but it came to mind.
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1969 Deluxe, owned since 1973
1973 Westfalia, owned since 1983
1980 Westfalia, watercooled conversion
1985 Westfalia, stock!
1986 Westfakia, Audi I-4 conversion
A couple of trucks and a couple of Jeeps

[sasmith]

[sasmith]

Finally made it out for some pictures and removal of plenum. Inspected the manifold and found that the plastic spacers are in place with original install. Upon removal of the plenum, I found that the front mounting tab was not bolted on the 17mm bolt/nut, but instead on another hole to the left and higher, at the center engine seam, with a separate bolt. The rear hook tab had been bent to fit this alignment. Initially I thought this would be an easy fix to just mount the tabs in the correct position but then found that no matter how I placed the tabs, or even attempting to bend the tabs, it would not align with the intake tubes. I compared my 85 1.9 plenum to the one removed and found that the front tab is a straight tab with a very slight offset that mounts to the 17mm bolt/nut, and the rear hook tab has an offset bend with ~3/4" shelf that rests on the engine block. The part numbers on the project intake tubes match the numbers on my 85 and they are mounted on the correct sides. I am now convinced that this is not the correct plenum but it has the identical ports as a 1.9. The angles of the intake ports also seem to be greater than the one in my 85. It seems I will need to source another 1.9 plenum. I looked at VC website, and the 1.9 plenum they sell from looking at the picture, does not have the same tab alignment as my 85 which seems to be the correct alignment and now has me a bit confused. I have found a matching set of intake tubes and plenum for a 1.9 from a seller and wonder if that would be my best option at this point. Any outside wisdom or thoughts would be much appreciated at this point. Here are some pictures that show the issue.

Offset with plenum in place

Offset L side

Offset R side

Mounting tab alignment when removed

part number of intake manifold

[MarkWard]

Would everything line up if the plenum was not secured? If so, modifying the mounts might be the quickest and cheapest fix.
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[sasmith]

Mark, the answer is almost. No matter how I tried to angle and position the plenum after removal, the ports were never aligned to my liking. It seems the angle of the plenum ports are slightly different than the tube alignment and definitely different than my 85 1.9 plenum to tube. That’s what is confusing because I figured I could just mess with the mounting tabs but the size of the plenum, even from front to back seems a bit off.

[Vanagon Nut]

[sasmith]

Neil,
There is not a part number on the plenum. I looked a few times making sure I wasn't missing something. I did check the part number on the intake tubes and it is the same number as on my 85 1.9, leading me to believe that these were 1.9 tubes, but at this point I am open to anything trying to figure this seemingly simple thing out. I even laid the plenum on top of my 85 plenum in place and neither the ports nor mounting tabs were well aligned. This is a rebuilt motor that was put in before we purchased the van 8 years ago and now I am wondering if it is actually built off a 1.9 or 2.1 block. Its running digijet so I never really have thought to look to verify. Hmmm...is that a silly thought?

[sasmith]

I know the 2.1 heads will interchange. And I just found a source that said the early 1.9 plenums, pre 85, had a different mounting setup, which would explain why my 85 is different (didn't know that before now). Hmm, maybe some cut and weld might be the best option like Mark suggested since there are a few variables that might take time to chase down.

[hdenter]

Check the engine number on the case and see if it starts with MV which would indicate a 2.1 case. Someone may have upgraded to a 2.1 or used a 2.1 case for a rebuild. The 1.9 accessories will bolt right on, for the most part. However the mounting tabs and bolt locations are not quite right for the plenum. The modifications you describe would fit the necessary steps to put a 1.9 plenum on a 2.1 case.

Hans
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'79 triple white convertible bug
'84 sunroof vanagon
'85 weekender

[Vanagon Nut]

[hdenter]

The thermostat does not dictate the case type. You can mount a 1.9 water pump and thermostat to a 2.1 case.
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'79 triple white convertible bug
'84 sunroof vanagon
'85 weekender

[hdenter]

My 1985 westie has a 2.1 block. To keep things legal here in California for smog, all of the 1.9 engine accessories are attached to it. My plenum a similar modifications, however, my plenum and runners are fairly well lined up.

Hans
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'79 triple white convertible bug
'84 sunroof vanagon
'85 weekender