General Zetec powered Caterhams/7's discussion

[pethier]

On 3/7/2023 at 12:11 PM, CarlB said:

The Zetec engine is very reliable in my experience. You are correct about its power potential compared to a Duratec . If you look at the bore and stroke difference and the size of the intake ports you will understand why the Zetec doesn't make as much power as the Duratec. The Duratec is lighter because of the aluminum block and the Zetec has a belt driven cam that is more tolerant to harmonics from high RPM and racing camshafts. Raceline would disagree but I think the reliablity goes away over 7500 GPM with the stock crank. You can have a very reliable 200 HP with a very wide torque curve and run pump gas. I turn mine 7200 RPM. You can put in bigger cams and raise the compression to get about 220 HP. You would need race gas and raise the speed to 7500 RPM. If you are looking at swapping engines, I would look at the new Ford turbocharged engines. There are people in the UK who are saying they get over 350 HP from the 1.6 L ecoboost. The stock 2.0 L ecoboost is 250 HP and the 2.3 L ecoboost is over 300 HP. Junk yard engines are available with all the power you need. Ford Performance sells ECUs and wiring. I have been looking for pictures of how the intercooler is installed in a 620 R but haven't found anything. Does anyone have pictures? If you really want to look at something different, The Polaris Sling Shot has its own engine now. It is a 4 cylinder version of the engine they use in their ATVs. The potential power of a naturally aspirated engine is determined by the size of the intake valves.  A bigger bore allows bigger valves. The Polaris engine has a 3.50 inch bore. It also has a forged steel crank and rods. The red line is 8500 RPM and the power rating in the slingshot is 200 HP. I haven't gotten any real information about this engine, but it looks very interesting.  

I am an autocrosser, and I have to have a car engine. Don't think the Polaris engine will squeak by.  

 

I am installing a Zetec in my Caterham because I had an opportunity to get one that had already been in a Birkin.  It has the fuel injection from a Suzuki Hayabusa on adaptors to a manifold previously used for Weber 40DCOE carbs.

Edited June 10, 2025 by pethier