Originally Posted by Porsche964FP

I have a question about 964 cylinder heads. As I understand it the real performance gains from bigger valves is down to exhaust ports... although presumably this would ruin the ceramic lining?

I read that Cup cylinder heads are around £3,500?! What are the options regarding cylinder heads and prices?

Thanks in advance.

Cheers,

Originally Posted by m_a_saunders

Hello Grant,

With a compression ratio of ~12:1, if not more, it's better to be safe than sorry. The engine builder races cars with the same engine in Dakar and the additional oil cooler reduces the oil temperature by up to 20C. If I'm not mistaken it can be ordered from FVD - part number FVD 207 035 00. Fach Auto Tech may have used two for 3.8l Cup cars if I have understood things correctly... When sitting in a traffic jam on the motorway at 30C+ outside temperature, the oil temperature rarely exceeds the half way mark...
Cheers, Mark

Originally Posted by m_a_saunders

- enlarge the throttle body;
- drop in Wössner 3.8l PC kit with ~12.1 compression, i.e. no machining of the crankcase;
- wide Carrillo RSR conrods;
- ARP headstud kit;
- ARP case through bolt kit;
- Schrick titanium valve retainers;
- Eibach valve springs;
- new valve guides and valves;
- boat tailing of the crank case;
- suffle pinning of the crank case;
- welding of additional aluminum material on the cylinder heads à la 964/993 Cup;
- ADDITIONAL OIL COOLER;
- replacement of the old oil cooler as well as all oil lines;
- 993 3.8 RS fuel injectors, as well as
- lots of other items I cannot think of right now.



Am I happy with the result - yes, definitely.

Would I do anything different - yes, consider installing 993 Cup cylinder heads with the 8mm valves while the engine is apart...

Originally Posted by Cheeksyboy

Hi Frank

When I was having my engine built I was advised that the 964 had superior port angles to the 993 (and that's before you start opening them out), hence why my engine is 993 bottom/964 top.....

of course there's the 9Meister heads which according to Geoffrey have a design which is much improved over the original factory design...…

Originally Posted by m_a_saunders

Before I forget Cartronic Motorsport in Germany modify original 964 and 993 cylinder heads whereby the flow is apparently 7.5% better than the RSR cylinder heads

Originally Posted by m_a_saunders

Hello Frank,

It's probably best to give Marc De Siebenthal a call regarding HP figures - I was focused on torque and am very happy indeed. If I'm not mistaken torque levels should be comparable with the 3.6l turbo.

Regarding the valve sizes, they are stock - bigger is not always better...

Cheers,

Mark

Originally Posted by m_a_saunders

Regarding the valve sizes, they are stock - bigger is not always better...

Originally Posted by m_a_saunders

Regarding Cartronic and the flow levels, I honestly do not know whether 7.5% applies to the intake and exhaust. I obtained this information from their website.

Originally Posted by m_a_saunders

I'll ask Mecacomponents for the power and torque chart and will post it.

Originally Posted by m_a_saunders

Hi Grant,

Boat tailing and the compression ratio probably explain a lot... I'll ask Mecacomponents for the power and torque chart and will post it. Piston skirts are also mooned...

Cheers,

Mark

Originally Posted by hockenheimr

Your car is clearly the Standard for all 964 rebuilds on here, and you've done a great job at documenting it. From what I can see, unless you made updates that I missed, you are using the stock crank and oil pump and running above 7,000 rpm. Just curious to hear your reasoning behind this, and any issues that might have come up.

Thanks