Sigma 150 Cam spec

[dan4182uk]

I've recently picked up some throttle bodies from Stef on here that are from a Caterham Sigma 150 upgrade.

I don't have the cams so I'm currently looking into options.

Does anyone know the spec of the cams that would have originally been paired with the 150 throttle bodies?

 

[Domus]

A very good question.  Mine is a 150, I changed the cam belt and water pump over the winter.  Not 100% sure that I got the cam timing spot on due to the fact that the Ford alignment tool is not supposed to match up with the 150 cams.  The cams are Piper with 150 stamped on the end.  I asked Piper for the spec and they replied that as the cams were exclusive to Caterham they could not help me.  If you do find out please post on here.  The car runs well but I would like to make sure that the valves are opening and closing at the right times.

[ChrisC]

Domus, if you have set the cams according to the ford aligment tool, I a 100% sure you have set the cams wrong.  The problem is I don't know what the correct setting is.  It seems to be a very closely guarded secret the exact settings :-(    I had to find a caterham expert (ex factory) that know the setting to get mine done.   Its exactly the same problem with the 125, but I not even sure its the same setting   

[Domus]

I locked the crank with the Ford pin and the slots in the cams were level enough for the tool to go in (with a slight tap)  It was after doing the job that talk on here led me to believe that the timing may be out.  I have a timing disc and DTI but these are uselesss without the data required.  Someone on here must know surely.

[7 wonders of the world]

Why on earth won't CC offer L@TDC data for these to ensure customers can get the timing correct, do they honestly expect every customer to go to them for service and repair?

'It's my ball and I'm going home'............ springs to mind, they'll be taking the tyre pressure date out of the build manual next  

[dan4182uk]

It's really not on that they don't give out the timing specs, every cam manufacturer does.

We can work it out though, here is what we know:

Piper make the “150” cam to Caterham spec (so the best starting point should be other Piper cams for the Sigma engine).

The rocker ratio on the Sigma engine is 1:1. (ref newman cams: http://www.newman-cams.com/pdf/ford.pdf)

It's a reasonably “hot” cam as it needs the valve springs changing.

What we need to know:

The lift & duration of the “150” cams.

This is not secret information, the cams exist and can be measured, we need someone with some cams that aren't currently fitted to help out.

As the rocker ratio is 1:1 then the lift is easy, just accurately measure the size of the lobe vs non lobe and the difference is the lift.

Duration is not so easy to get accurately, but an estimation should be possible by holding them up against a timing disc in profile.

Once we know lift & duration we should be able to find a similar spec and timing from one of the aftermarket manufacturers.

Here is a load of info direct from Piper:

http://www.pipercams.co.uk/pipercams/www/tech.php

Cat Cams is also a good resource,

http://www.catcams.co.uk/acatalog/Ford_Zetec_1600_16v.html

 

Alternatively someone could just state the timing for these 150 cams.