New cam for TS head?

[Richard48Y]

I had my original TS cam welded and ground.
Not altogether happy with it as the cam grinder made an assumption instead of looking at my notes.
Lift is over 10mm despite his insisting it is a match to an original Gordini grind.
He also did not relieve the cam heels as we had discussed.

I am giving up a couple of distractions to concentrate on my S2.
I have been warned that some of the billet cams are poor quality.
Looking for a suggestion to get a good billet cam that is not full-race.

[Mecky]

Hi Richard,

I can recommend CatCams for sporty Renault cross flow engines. I used 310° (11.6 mm lift) with a fixed sprocket in the past. That was already great. Next I'm aiming for the full 318° camshaft (12.05 mm lift) with adjustable sprocket do find more peak power. At the same time, I'm planning on gearing my 5 speed box a lot shorter to be able to use that peak on the circuits.

If you are planning on building a sporty - yet tame - road going engine, you should go with a camshaft between 280° and 293°. I think, the 280° could be the Gordini grind, or at least close to that. Have a look at this link: http://www.catcams.com/engines/camshaft-setup.aspx
I never tried one of these three camshaft, but I can assure you of two things:

1.) Catcams delivers great quality camshafts for this engine type. I never had an issue with mine and the engine ran better that ever with it.
2.) The 310° is not suitable for road use. It only runs well close to full-throttle and above 4000 RPM. At lower revs and low throttle, it jumps like crazy. The overlap between inlet and outlet valves is much too big for a road going engine.

[Richard48Y]

Anyone have a ready means to translate Euro cam specs to US measurement or vice versa?
Hard to compare with the systems being different.
Sorting the cam should be my last major engine expense.
Car needs to be sporty but street-able so I have to curb my enthusiasm.

[Richard48Y]

At CAT Cams I find these,

5500525, 280°/280° - 236°/236° - 10.00mm/10.00mm - 2.15mm/2.15mm

Also,
5500526, 287°/287° - 244°/244° - 10.45mm/10.45mm - 2.85mm/2.85mm

The second may be essentially the same as what my cam was ground to.
Wishing the cam grinder had followed through on relieving the cam blank where it will hit the lifter.
Not sure I am confident in doing it myself.
Use the Vertical Mill or do it at the Lathe?
Any billet cam should avoid the heel rubbing issue entirely.

Need to restrain myself, I tend to go a bit overboard and this will be a street car most of the time.
Not certain how well the second cam would work off the track.

[jbcollier]

Talk to Cat Cams directly.  They will have recommendations.  Use a lathe to reform the base of the lobes.

[GavinT]

If it's any guide, the 125HP cooking version of the Renault 12-G had 10.25 compression (same as the Alpine A110 and Oz & Euro spec R-17TS) & used a cam with timing of 40/72/72/40 but I don't know what lift was specified.

The more powerful 160HP versions of the Renault 12-G and Alpine A110 1600GS had 11.5 compression & used a cam of 53/83/83/53. I measured mine at a cam lobe lift of 0.253".

The Renault Sport philosophy seems to reflect relatively modest lift but with lots of overlap.
So, I'd say depending what compression you're aiming for, that probably indicates an appropriate cam spec. At least that's the way I'd go.

Folks also hold Salv Sacco in high regard. Maybe get him on the blower.

[Richard48Y]

I have sent an email to Salv, waiting on a reply.
I bought my pistons from him so he is familiar with my build.