Ninemeister Cylinder Heads
02-23-2007, 09:27 AM
#61
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Originally Posted by Red rooster
Colin,
Unfortunately there is no 98RON here ! or in quite a few areas of the USA .
Maybe a North America version with a little less compression ?
Geoff
Unfortunately there is no 98RON here ! or in quite a few areas of the USA .
Maybe a North America version with a little less compression ?
Geoff
The secondary factor is that because of the improved chamber design with improved squish of the 9m head, the combustion process is better controlled and as a result there is a lower % of the wasted fuel (and by inference a higher % of used fuel) in the chamber, indeed all customers who have had the conversion done on their 993 have commented on the improvements in running economy.
02-23-2007, 09:33 AM
#62
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Originally Posted by C2MED
Thanks for the explaination Colin. Do you have different heads for 993 and 993RS?
If I was to just replace the stock head with the (m item, leaving the cam stock, (if that's possible) what sort of figures (cost and output) are we expecting as a rough guess? Whay I'm thinking is that I really like the idea of the 9M head but I don't fancy having the engine changed too much from stock. Not just for the power gain but also for the torque and durability of the head.
If I was to just replace the stock head with the (m item, leaving the cam stock, (if that's possible) what sort of figures (cost and output) are we expecting as a rough guess? Whay I'm thinking is that I really like the idea of the 9M head but I don't fancy having the engine changed too much from stock. Not just for the power gain but also for the torque and durability of the head.
At the moment we have not tested the heads on an engine with standard or RS cams so I would not really want to guess the performance potential. However from our work on the 964RS with Motec and the Motec +1, the same Sport camshaft gives useful gains in the 6000-7000rpm range and makes an additional 10-12hp, so it seems reasonable to assume that a 993 engine with the billet heads would make in the order of 330-340 on our dyno if it was running on stock cams (but still with the 100 cell cats). However this is an estimate and we have not verified the result, ok?
02-23-2007, 10:24 AM
#64
Originally Posted by Red rooster
Colin,
Unfortunately there is no 98RON here ! or in quite a few areas of the USA .
Maybe a North America version with a little less compression ?
Geoff
Unfortunately there is no 98RON here ! or in quite a few areas of the USA .
Maybe a North America version with a little less compression ?
Geoff
02-23-2007, 10:49 AM
#65
Three Wheelin'
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David,
Lucky boys ! We have 91 as the best . I thought that was also true on the USA east coast ?
With the inlet cam closing number it works out that the dynamic compression is
in the correct area so maybe 91 is OK.
Porsche have flagged that the 993 is OK (ish ) running on Euro 95 gas but
Euro 98 is correct for the DME calibration.
Thats why I wondered whether a gentle compression raise on lower octane gas was a good move ?
I have started to think about fitting RS cams to lower the dynamic compression .
Takes you back to the old 2.4 days when the motors would run on anything !!
Geoff
Lucky boys ! We have 91 as the best . I thought that was also true on the USA east coast ?
With the inlet cam closing number it works out that the dynamic compression is
in the correct area so maybe 91 is OK.
Porsche have flagged that the 993 is OK (ish ) running on Euro 95 gas but
Euro 98 is correct for the DME calibration.
Thats why I wondered whether a gentle compression raise on lower octane gas was a good move ?
I have started to think about fitting RS cams to lower the dynamic compression .
Takes you back to the old 2.4 days when the motors would run on anything !!
Geoff
02-23-2007, 10:55 AM
#66
Nordschleife Master
My 993RSR tyep engine with the 9M cylinder heads and 12:1 compression runs on 93 octane street fuel with as much power as a PMNA 993RSR Sprint engine with slide valves.
02-23-2007, 01:31 PM
#67
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Originally Posted by C2MED
Thanks Colin, will have to have a chat with you in Oulton, assuming you'll be there?
Get yourself a cheap flight Geoffrey and you can come and join us if you like, it's our annual RS trackday and we are expecting to see around 40-50 RS's take the circuit amongst some other fast Pork.
02-25-2007, 08:33 PM
#70
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Originally Posted by NineMeister
...Provided that you can afford to fit them (!) there is no downside to using 9m billet heads. They are made more accurately (completely CNC profiled including ports) from a better homogenous material and are fitted with sintered steel long life valve guides and seats that outlast the stock bronze guide by more than double. They will run with Porsche valves, springs & retainers and are a direct replacement for all production 964, 993 & 993RS engines, even the SAI port is available as an option to cover the US 993 n/a engines.
I'm going to follow this thread because although my engine only has 65K, it's inevitable it will need to be rebuilt, and I want the 6 Million Dollar Man treament..."Stronger, Faster, and Better Than Before" when this day eventually arrives. 
07-15-2007, 09:23 AM
#75
Instructor
Currently in the UK. I sent Colin an email before I left requesting a visit to his shop. Have not heard from him yet. Also contacted a UK member who already has the heads installed and is willing to take me for a ride in it. Hope to still visit ninemeister and take shots before returning. Will provide update on status of progress with US cylinder heads also. Regards.