Double-click here to change image
There are interesting questions from readers that can help others. 

Here is a selection of some of those questions and my effort to answer. If you think you can improve the answer please email me.


Engine size


Question: How can I know the engine size of my car: 2,0 or 2,3 litre?

Answer: Assuming that the car documents cannot provide you that information and there is no 2,3 written in the boot lid or in the engine's valves cover then, there's only a couple of ways to know it: If the car still has the original carb, remove the filter housing and the carb and then measure the inside diameter of the barrels in the bottom. The 2,0 litre engine has a 32mm inside diameter and 2,3 litre has 35mm. The final and most accurate way to find the engine size is to remove one of the engine heads and measure the cylinder diameter. The 2,0 litres engine has 84mm and the 2,3 litre has 90mm. If you check my specs page, you'll find that the stroke of both engines is 60,14mm. Now calculate the volume of a single cylinder (πr² x stroke), where r is the radius of the cylinder in cm (so 4,5 for 90mm and 4,2 for 84mm. Multiply the value by six cylinder and there you have 1998 or 2294 cm³ (3,14x4,5x4,5x6,014x6=1998 and 3,14x4,2x4,2x6,014x6=2294). There are also special devices that connect in the spark plug hole and measure the air displacement after turning the engine.

Wire wheels

Question: I want to install knock-off wire wheels on my OSI. What do I need to know?

Answer: According to Ford of Cologne, the admited tire sizes for the OSI 20m TS (beside the original 185 SR 15 Pirelli Cinturato mounted in 5,5J x 15 Fergat wheels) are:

  • 185/70 HR or SR 15 mounted in 5,5 K x 15 wheels
  • 195 HR 14 mounted in 6 J x 14 wheels
  • 205 HR 15 mounted in 6 J x 15 wheels

The 195 x 15 size is not admited in the OSI 20m TS.

The Geneva prototype used Borrani RW 4016 5,5 x 15 wheels 42 type mounting (62,5 mm diameter with 75 splines) with three eared spinners but you can also use the 52 type (73 mm diameter with 88 splines) because these wheels were used in Jaguar and are easyer and cheaper to find (The wheel type designation refers to the maximum size of the outer bearing in millimetres which can be used with that hub).The easyer solution is to find 5 stud bolt-on hub adapters with a pitch circle diameter of 112 mm, the same as Mercedes (the pitch circle diameter is an imaginary circle that passes in the centre of the holes or bolts). Depending on the adapters, it is very likely that you will have to shorten the studs and use thinner wheel nuts.

I will be back later on this issue with drawings and measures and even torque tightening values.

Exhaust System

Question: Can I use the exhaust system of the Taunus 20m in my OSI?

Answer: Yes, with minor changes. Up to chassis number 01878 the exhaust system is the same of the standard 1964-1967 Taunus 20m (P5) with only one resonator chamber and you only need to cut 90 mm to the muffler exit pipe (2 in the picture bellow). From this number up is the same as the Taunus 20m TS (P7 based) exhaust system with two resonator chambers and there is no difference between the 2,0 and 2,3 litre models. You must check the picture to see where to cut (three segments).


Question: I heard a couple of times that replacing the weatherstrip is a real nightmare because is almost impossible to put the aluminium trim in place. What do you know about this?

Answer: Well, it was a nightmare to find weatherstrips. OSI had special tooling to place the mouldings on the rubber but there is a good way to do it without special tools: Find a good safe stand for the windshield, mount the weatherstrip on it and just then apply the moulding. Finally apply the windshield complete with weatherstrip and moulding to the car. Do not try any other order. Anyway, this serves for both front and rear weatherstrips.

If you cannot find weatherstrips I can help you with accurate dimensions so you can find someone to extrude rubber for you or I can even find you quality weatherstrips.

10 front and rear rubbers ready to be cleaned up. contact me if you need one.