Porsche Enthusiasts Club Forum

If I remember correctly, the thicker gasket is NLA *but guys correct me if I am wrong*

The head has a relief dot in the face showing maximum skim depth. My head had some pretty deep corrosion but retained the dot - just - even after two skims (don't ask).

As it is NA the extra compression might bring about a little more hp.

Hi Dave,

Thanks for your input. My local OPC is offering the thicker gasket which is 1.4mm. The standard is 1.1mm. I've done a bit of reading this afternoon. There is a reference point on the front of the head (according to the Porsche manual). The new head distance from that reference shelf to the machined face of the head is 24mm +/-0.1mm. The manual says that if you go to 23.8 or less you need to use the 1.4mm thick gasket and the bottom wear limit is 23.6mm. I'm told that my head had 0.2mm removed in the skimming process but when I measure it with a couple of different vernier gauges I'm measuring between 23.8 and 23.9 but I'm not feeling too confident. I think I'll order the thicker gasket and see how it goes. Hopefully the improvements from the valve re-seat, new guide inserts etc will give at least the same level of performance that I had previously even if the compression ratio is likely to be slightly lower than before.

If anyone else can shed more light on this I'd be grateful. If there are power gains to be had by going for the 1.1mm gasket without the risk of valve to piston contact I'd prefer to go that way.

Thanks in advance

Matt

Having checked, I got it the wrong way round - I got the 1.4mm one (Victor Reinz set). After the second skim mine was close to, but thankfully above the lower limit and so the thicker gasket was needed. Admittedly, I did ask Jon @ JMG just to be sure.