The Cabby k20 conversion thread

So as the title implies I am thinking of swapping the vw engine for a K20 engine. Do you know what is involved?

I have done a p38 range rover with HMMWV 6.2l diesel swap before.

Afraid i have no idea, assume youve seen the one/ones on utube

Can't offer anything more than vague/general stuff but it boils down to the following issues, when you put an engine from a different maker in. This is why the conversions such as the 16V, G60, 20Vt etc are popular, because things like the engine/transmission are near-identical dimension and shape, so can take up the same or very similar engine mounts and the popularity leads to the availability of parts (such as 16V conversion manifold) etc

1. Transmission - you'll pretty much be obliged to use the tranny with the engine, which means custom driveshafts to adapt this to the Mk1 Golf; and using/adapting the linkage from the donor car too.

2. Engine mounts - you'll be, essentially, "copying" the locations of the donor car, and doing an amount of custom fabrication to replicate the strong points the drivetrain mounts to. Note that the front panel of the Mk1 is not particularly strong, its used as a torque-reaction mount but isn't really weight-bearing - so it would need strengthening to put a proper mount there.

3. Exhaust - basically you'd need a custom downpipe

4. Electrics - basically you'd need an aftermarket ECU of some kind, and the relevant technical info of the engine to be able to interface the necessary sensors. Then an amount of experimentation/guessing to do the initial mapping.

I'd not worry too much about the physical dimensions - bigger engines (and transmission) will tend to fit, or be able to be made to fit, but the original engine had space around it to be a part of the well-engineered crumple zone (for example, the chassis legs have deformable sections and the front panel doesn't have tons of strength - deliberately). Your custom fabrication, without extensive engineering/testing behind it like a car manufacturer would do on the body, would mean this is compromised but that's just part of it being custom. Width may be an issue - the big block Mk1/Mk2 used an arrangement of clutch inside the flywheel to save on space. So, altering of chassis legs might be necessary. Also, obviously, if your filling up existing space around the engine then things like changing the water pump, or timing belt, etc etc later on are going to be impacted.

It would be a really good help if you're able to take on a lot of the welding yourself, and have the tools (ie an engine crane….or A frame to lift the car, or 2 post lift or something like that) to remove and install the engine a number of times. If you can't do this then you'll be paying someone else £££ to do it.

Very good considerations and you made some strong points, thank you.
What leads me to this is the fact that the engine in my blue Cabby will need to be rebuild.
-I can find a K20 engine all day long for $300 on ebay even. I would buy a crashed car, however and pick the parts I need.
-I cannot find any VW engines that would be considering the swap, no GTI or 16V or anything later model with more HP's

This makes the swap a lot more feasible. I want to turn this car into something that will make it a lot more fun to drive. And something that will shed the stigma that comes with the cabriolet (at least here in the US).

Honda engines seem to be quite reliable and get a lot more gittyuppiness than a VW engine will have.
Of course that comes with some structural considerations and adaptations to make it not just fit , but also be safe.

I would imagine the $300 or so for the engine forms a very small percentage of the overall spend. If this is for cost-saving reasons, it won't work out - there's a lot of stuff which would need to be made or bought to do this kind of thing.

As I mentioned earlier, I can't find any worthwhile VW replacement here in the US.

I want to turn this car into something fun to drive. There not just an economical factor involved.