Type 3 Oil Coolers and Seals

Misunderstandings here abound, so let's go over this again:

VERY early type 3s (61-2) used a steel 40hp cooler and a right angle adaptor. I've never seen one of these.  
For simplicity, let's just ignore them. I don't know which seal they use, although it appears to be a Beetle seal.  
I suspect that these very early cooler assemblies could be replaced with the later (63-9) cooler to some advantage.

All the rest of the type 3s use one of 2 different coolers. Both are right angle, made from aluminum, and look pretty much alike; 
I'll call them early (-69) and late (70-).

Early coolers have 8 mm oil inlet and outlet holes. These have no part number marking anywhere.

Late coolers have 10 mm oil inlet and outlet holes AND have the part number stamped on the top of the body, 
just to the right of the pressure switch boss, so you can identify them while installed.

Both coolers are IDENTICAL in vertical dimensions.

Early cases (-69) have 8 mm oil cooler inlet and outlet holes and just one oil pressure relief valve (on the bottom of the case.)

Late cases (70-) have 10 mm oil cooler inlet and outlet holes and 2 oil pressure relief valves (on the bottom of the case.)

So the cases can also be identified without disassembling the engine.
 
Seals: From 63-on there are 3, only 2 of which ever came installed on factory new engines.

Early seal: 8mm/8mm, has a thick flange (~1/4") and requires that spacer washers be installed to permit the use of these thicker seals.  
I have only seen these in the color black.  This is a type 3 part only.

Late seal: 10mm/10mm, has a thin flange (~1/8") and requires no spacer be installed. I have seen these in black and red.  
These seals were used in all type 1, 3, and 4 engines from 70-on.

Adapter seal: 8mm/10mm, has a thin flange (~1/8") and requires no spacer be installed.  
This seal is ONLY for use if it is necessary to use a late case with an early cooler, or vice versa.  
This seal is referred to many places as the "green" seal, but lately it has been reported in different colors.

The mm seal dimensions are the ID of the bore on each face. Most FLAPS will never have noticed that the seals they sell have 
the tapered bores that make them the adaptor seals. You should note that the ODs of the end faces are also different.

Aftermarket gasket kits only came with the early seals for decades after the late seals were introduced, but now include both early and late.  
I have never seen a gasket set that included the adaptor seals.  Spacer washers, ONLY if called for, should be installed between the case 
and the cooler on each of the 3 6mm studs/bolts that secure the cooler to the case. These washers were about 1/8" thick.  
Note that this is approximately the difference in flange thickness between the early and late OE seals.

There was a VERY long thread on this just a few months ago. After measuring a number of parts I concluded that there would probably be 
no harm in using a THIN (as in a wavy washer) washer as a spacer with the thin seals, but the important thing is to understand exactly 
what the possibilities are and just exactly which parts you have in YOUR engine.

It is common to find the wrong parts installed in engines rebuilt by almost any source. Installing the wrong parls can lead to oil leaks, 
restricted oil flow, or oil starvation, depending on the particular situation. This is a very important point to pay attention to.

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Jim Adney, jadney@vwtype3.org
Madison, Wisconsin, USA
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