OldGuy

Whats the differences between the two motors besides the blowers and ECU?. I am trying to figure out how good this standard new 3.8 motor is. So what are the internal differences between the two? Anyone know?
I have searched this site (ALL of Rennlist) Googled it, Looked at Porsches web site and looked at the two in the technical specification area and did see much besides the Compression ratio 12.5:1 vs 9.8:1

Land Jet

I'm no expert but I believe I read that they are the same engine, the internals were built to be able to use with the turbo or the NA variant. Others please correct me if I'm wrong.

eclou

does the 9A1 have the newer quasi-dry sump oiling system of the turbocharged 9A1?

TT Surgeon

I think they are exactly the same other than compression ratio.

OldGuy

WOW, thats what I am thinking. I think Porsche really worked hard to build this new 9A1 to be the be all, end all motors for the whole line.
I dont see however they are going to modifiy them to be GT car motors that spin upto 9K RPM

911SLOW

Find attached information about the 997 NA engines for S and non S MA.101 and MA.102 and for the 997 turbo engines (including turboS) MA.170 MA.170S.

herman maire

I was also looking into this, after finding out that porsche really went cheap with internal engine components/ materials on the 996/boxster engines they better have overbuilt these new engines.

The biggest problem for me is that they are using " powder metal" for crank shafts , rods, cams and fragile camshaft gears and I cant help but wonder ...... WHY!!! just to save a few $$$ on machining VS a forged metal crank and rods.

The 996 turbo and GT3 ect... all have forged crankshafts .

Macster

I question your info. My info is the Boxster and NA 911 engines all came with forged crankshaft, rods. The cams are cast -- I may have a pic of my Boxster's cam that shows the casting mode parting line -- and the gears could be cast.

Even if the camshaft chain sprockets are made of powder metal that is a perfectly good process which in some cases delivers more consistent and uniform metalurgy than casting or even forging.

Now the rods are fractured rods which is a better process than the old way of slicing the big end across and then bolting the two pieces together and boring/honing the diameter to size.

Sincerely,

Macster.

OldGuy

Well when you consider the 9A1 uses 40% less parts than the previous motor you figure Porsche could spend a few more quid in building this engine. The 996 motor is a $8K crate motor replacement.

I am just hoping this new 9A1 motor is the bomb. It sure drives like it

Thanks John I should have known you would have the info.

OldGuy

Looking over SLows Data it appears the only differences are forged pistions in the Turbo, and the turbo has three radiators. This is outside of all the timing and other data you would expect from different air flow mixtures. And of course the stuff associated with the turbo like intercoolers and turbos.