 Water boxer
Yes, the term exists in automotive technology and anyone who is only somewhat familiar with it knows immediately what it means, namely a boxer engine that has been converted from air to liquid cooling.
| Beetle engine - air cooling |
Why aren't there similar terms when converting other engine types? Because they usually had this type of cooling already directly or relatively shortly after 'birth'.
Why was the boxer engine linked to air cooling for so long? Not easy to answer, because the boxer engine was mainly presented to us by VW and Porsche.
There it works in the rear and that place is a problem for the liquid cooling. Just look at the in-line engines in small vehicles after the war. Radiator in the front with long pipes or a lot of rear weight.
No, we don't want to rattle off the advantages and disadvantages of air cooling, we just want to rebuild it. It can't be that difficult to get a cooling jacket for the air-cooled cylinders and their heads.
But it is, if you first look at the individual parts and the assembly of an air-cooled boxer engine. In contrast to the Wasserboxer, there is a separate housing for the crankshaft.
The consists of two halves that are screwed together with additional sealant, with only the connecting rods sticking out.
You either put the pistons on it alone or directly with the cylinders. This consists of two halves that are screwed together with additional sealant, with only the connecting rods sticking out. You either put the pistons on it alone
or directly with the cylinders.
Completely different with liquid cooling. Here the two housing halves for the crankshaft are cast together with the cylinders. But here, too, you can only push in the crankshaft with the connecting rods.
The method with the in-line engine, namely pushing the pistons with the connecting rods into the cylinders and then screwing them to the crankshaft, doesn't work because you can't get at the other side, at least when
assembling it.
| In case of the VW Waterboxer with wet liners, the hole on the far left is sufficient to mount the two piston
pins of this side. |
It is also impossible to pre-assemble the crankshaft with the connecting rods and pistons because the boxer engine does not have enough space to push the pistons into the cylinders from below.
And not only with a Porsche six-cylinder, which has a crankshaft with seven (!) bearings. In any case, the question now arises as to how the middle pistons can be combined with the connecting rods.
In any case, there must be openings that can be closed later in the cylinder wall, which is no longer double at the bottom, through which the piston pin is pushed and secured in the piston bore that has already been closed
with a safety device.
This becomes a challenge with the middle pistons because the outer cylinders have to have an additional borehole on one side. Of course, the middle pistons have to be mounted first here as well.
So through the first opening on the housing past the connecting rod and through the additional first hit the bore of the piston pin together with the small connecting rod eye and lose nothing on the way there.
In principle, the assembly of the cylinder heads does not differ from that of the other engine types.
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