Fan shroud "oddities"?

[congerz83]

I decided to re-paint my tinning. When I took it apart, I noticed some things. The two areas circled in red were LOADED with RTV. While the green area had some kind of metal tape over it. Can someone give me a clue to why this may have been done? I want this to fit back together perfectly. Does anyone have any tips.

[Tim Donahoe]

The green and red circle on the right ordinarily have rubber seals to seal that exit chute (for your off-set oil cooler). The red circle on the left? Maybe the PO thought that needed a seal. But it shouldn't.

Tim

[Eric&Barb]

The green circle should have foam seal tape that you can get at almost any hardware store.

Same foam seal tape needs to be over the oil cooler to seal cooler to the shroud. All cooling air goes thru the cooler, not around it.

Red circle should have a rubber seal and two seals where the DH exhaust tube goes out thru the front engine tin,

The 1971 DH diagram thru the link below. "F" is the pair of seals for where the exhaust tube goes out the front tin.

http://www.bus-boys.com/aircoolsystem71.html

Measure your cooling fan to make sure it is a DH one or hopefully the really big 35 mm fan last used.

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In Stereo, Where Available!

[61SNRF]

[bluebus86]

[congerz83]

[KTPhil]

[Joel]

Its a cheap repro shroud that has gaps everywhere which is why its loaded up with sealant and tape.

Best thing you can do with that is bin it, it doesn't even have the internal air deflectors which will shorten engine life dramatically.
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Quick little bug, you got a Porsche motor in that?
1974 Germanlook 1303 2.5 Suba-Beetle

[Rome]

Hi R; it's Roland with the green '77 Beetle from Chris' (ClassicVWBugs) open houses.

Here's a shot of a good German doghouse shroud from the gallery. The chute coming out the bottom right bolts to the shroud first (AFTER the shroud is down in place on the engine). The thin rubber seal that goes between the top of the chute and the triangular piece- you can make one by taking a rubber vacuum or fuel hose, slitting it along its length, and fitting the cut over the chute's top edge. The left edge of the triangular piece has a thin piece of foam. Like mentioned above, you can get a strip of regular weatherstrip foam, like 1/4" wide, at a HW store. Just wipe the surface of the triangular piece with mineral spirits to get rid of any dirt. The triangle piece is the last one to install.

When you fit that chute into the opening in the front cross-tin, make another rubber seal for the top of the tin's opening. It'd be shaped like a sideways "D".

Here you can see the three seals-

The foam strip on the oil cooler itself is visible here. You can extend the foam more if you want, but the section shown on the vertical edge of the cooler is enough to direct cooling air into the cooler rather than past it.

Your left red circle- you can try fitting a slit rubber hose to the top of the cylinder tin's edge, going from the side above the spark plugs then going around the FRONT of the tin's edge (near the firewall). This will close the gap between the aftermarket shroud and your cylinder tins.

Silicone/RTV remnants are hell for paint. Wipe that edge really well with spirits so that your spray can paint adheres. You'll still probably see fisheyes develop almost immediately when the fresh paint is misted on. Don't worry much- nobody will see the front of the shroud.

[crvc]

For years I used aluminum tape to seal the two areas on the right. But pressurized air from the fan would blow through the tape quickly.

[congerz83]

Hi Roland...

I realize, after cleaning and repainting, that these gaps are pretty bad. I guess I need a whole new shroud and triangle piece.

My engine is an 1835cc (so says the previous owner)

Would it be easier/more efficient to purchase an external oil-cooler kit?

[Rome]

Nah, I suggest reducing the air losses like you've learned here, and carefully fit the triangle piece to get your engine going again. You can look for a German doghouse over the winter, or at the latest, down at the Englishtown NJ VW meet in April. Also, your HPMX kit's manifolds supposedly won't work with a German doghouse shroud because the manifolds will cause the inner faces of the carbs to hit the sides of the shroud. The German doghouse shrouds are wider than the one you have because they have the fresh air outlets coming out the sides like "puffed cheeks".

I really don't think you need or want an external oil cooler! You've learned enough here to modify your current shroud enough to increase the cooling effect through the doghouse. Routing your oil through an external cooler in our "moderate" NY climate is a waste for a street-driven near-stock Beetle.

[Aussiebug]

I agree with Rome.

the 1600 doghouse cooler setup has quite enough cooling capacity to cool a 2000 type4 engine when converted to upright cooling system, so an external cooler is not normally required.

The original cooling system (German fan shroud with all it's internal guide vanes - not an aftermarket shroud which are sometimes "empty" inside), together with the foam around the cooler itself and the Hover Bit at the bottom to stop air spilling out before it goes through the cooler, works VERY well.
_________________
Rob
Rob and Dave's aircooled VW pages
Repairs and maintenance for the home mechanic
http://www.vw-resource.com

[congerz83]

[bluebus86]

[Rome]

R, your engine ran for the entire time you've had the car so far with that "oddity" shroud. I suggest reassembling it with the fan shroud you now have and just repainted, and also implement some of the air sealing tips we've provided. I know you are really eager to see how the HPMXs work. Then once you have them tuned/adjusted, etc. keep a lookout for a good German shroud to install during the winter. Then at least you have the benefit of having the basic adjustments done on the carbs so that you can pull the engine and swap shrouds over a weekend. If you find a shroud that also has the thermostat flaps intact, consider it a bonus. It's not difficult to fit a thermostat (and bracket) on the right side of the engine case, and adjust it so that you have factory-efficient engine cooling.