Freddy the MK2 Twin Wheel — Getting Some Upgrades

[Trynader]

Freddy — MK2 Twin Wheel Transit Upgrade Thread

Hey all, time for an update on Freddy! For those who don't know, Freddy is an ex-Cologne fire engine MK2 Ford Transit twin wheel van. The plan is to get him running properly again and turn him into a weekend toy / occasional camper. Nothing too serious, just a van with a bit of character and hopefully some go to match.

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**The Head**

Started with the bad news: pulled the head and found two burnt valves. Not great, but honestly the perfect excuse to do something properly. Swapped over to a 1.6 head, had it fully ported, and fitted the Group Rally valves from a 2.0 head. Bigger valves, better flow, and with the higher compression of the 1.6 head we're targeting around 10.5:1. The head came back looking absolutely gorgeous — check the photos!

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**R1 Carb Conversion & Custom Inlet Manifold**

Next up — ditching the standard carb setup and going with Yamaha R1 throttle bodies. These actually came off a 2.0 Pinto already so they're no strangers to this engine family. To make it all work I've been designing and printing a custom inlet manifold in PAHT-CF (carbon-filled high-temp nylon) — should handle petrol and underbonnet heat without any drama.

First prototype already taught me a lesson: got the flange orientation completely wrong. That's exactly why you prototype and don't go straight to the final part!

The current version has some nice details sorted:
- Runner length optimised for torque around 2500 rpm — keeping the power in the useful range for a van
- Proper mounting points to bolt the carbs down to the manifold (no hose clamps!)
- Viton O-ring cord grooves for a gasket-free seal
- Inlet matched to the head gasket for a clean port match

Here's the carbs mocked up with the manifold and gasket for fit-checking:

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And for the nerds — I did a 3D scan of the engine bay so I could design the manifold properly in context. The scan renders show how it all sits in the bay:

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**Tuning**

Sticking with the stock camshaft for now — no need to go mad, this is a van not a race car. For tuning I'm fitting a wideband AFR meter so we can see exactly what the mixture is doing and dial in the carbs properly.

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Any suggestions welcome — especially on the manifold design while I'm still iterating. More updates soon!

[dumper]

Are you changing the pistons when i rebuilt the 2.0 L to fit in my mk1 to replace the V 4 I was recommended to fit low compression pistons and the 1.6 L pinto camshaft it ran well on this it had a 5.1 diff and would do 20 to 22 mpg on a 4 speed box when the local Ford dealership move to new location I got a brand new 4.56 completed diff fitted and re set the speedo it was a nicer drive much quieter but the mpg dropped to 16 to 18 mpg and this was on a regular run so knew it was correct for the amount of fuel put in the tank so changed it back which worked out well as I used it when I fitted a LSD to the mk 3

[Trynader]

No piston changes for now, the Transit engine already runs low compression pistons from the factory so that works out nicely with the 1.6 head upgrade. The goal is just to get Freddy driving again, not to rebuild the whole drivetrain.

The reason is that this is really just a temporary fix to get him mobile while I prep for a much bigger swap. I've got a Volvo B5254T3 with a ZF 8HP45 gearbox and a MK8 twin wheel rear axle waiting to go in. That's the real project! Just need the van to drive under its own power while I get everything ready.

Before I can do the engine and gearbox swap I still need to 3D scan the underside of the van so I can design a proper subframe to mount the Volvo engine and gearbox. Doing it that way means I can fab everything up beforehand and make the actual swap as quick and clean as possible, no trial and error with it sitting on axle stands for months.

Interesting data on the diff ratios by the way. With the 4.56 you would have expected better mpg since it drops the cruising RPM compared to the 5.1, but clearly the Pinto wasn't happy working in that range and ended up being less efficient. The engine probably just preferred to sit a bit higher in the rev range where it was in its sweet spot for torque. Good info to keep in mind when the Volvo goes in, getting the diff ratio right for that engine's power band is going to be important.

[dumper]

I think it was down to more gear changes and working harder it had the Webber carb and later fitted in a Serra worked well it wasn’t short of power