johnbelk

With the exception of the bare block and heads. My assumption is that the race engine internals, fuel delivery and electronics are not what I'd find in my Porsche. I would expect the Corvette's competition engine to be different in many ways from the LS engine found in the street version, too.
If my assumption is correct, then what are we talking about here??? I just don't get it...
I love bench racing as much as the next knuckle head, but I'm not sure what's really being benched raced in this post...JB

A418t81

Amusing post. Sorry to say that the turbo version of the Mezger isn't nearly as special with all the "race parts" as the GT3s. The accountants got ahold of our motors. The Mezger is fun in its blend of new and old, but that also flaws it. The turbo 9A1 is increasingly being shown to be just as strong as the old engine, but with substantially better reliability and cost of ownership. The MA175 version in the GT3 like mine is still a work in progress with its own oiling issues, but that appears to have hopefully been solved with the latest revisions from PAG.

Own both and love both, though significantly less irritating owning the 9A1 so far.

Fishey

There isn't much between a GT3 motor and Turbo motor. The main difference is in the cylinder heads where the GT3 motor uses the traditional cylinder head and the Turbo uses the variable lift cylinder head. The variable lift head would never be used in motorsports but for a street application it makes absolute sense.

They are far more similar then you would think the main difference being cylinder head porting (GT3 Style) but no spring size modifications. (not sure of material) they use a forged Mahle Piston of a similar design not sure about the connecting rods but the crankshaft was normal 911 design but not sure about material used. The real interesting thing is that its not just the 911 GT1 its prior motors like the 962 which were very close to factory run parts that made the motor into what it is today.

Now, the Chevy *LS* motors I actually know alot more about and they are basically nothing like a factory motor. They do use a factory casting for cylinder heads but that is about the only similarity they are completely machined for different size valve springs (Nascar Cup Triple Springs) To do that they raise the rocker height and re-weld like a crap load of the head and use obviously solid roller rocker setup. They use Ti Valves/Pushrods and nothing is factory size or similar.The porting of the heads is also so extreme that they once again had to weld in extra material.

There has been multiple changes in the motor design as well and no place greater then the camshafts that had limitations put on overall lift. So the ramp rates of the camshafts were INSANE! We are talking 240+ duration at maximum lift they look almost like square blocks the ramp rate was so extreme which is why the motors wouldn't last much over 24 hours in racing conditions. You might be able to get 10,000mi out of a motor on the street.

However, the reality is though that all that work was because of the restrictions a street cylinder head with more extreme maximum lift would make similar power and last much longer. So sometimes race motors are only different because of rule restrictions and pretty much make them dumb.

The bottom end of the chevy motor was custom crank/block and drysump system all nothing similar to a street motor.

The Porsche V8/BMW/Ford V8/Toyota all are also very different from the street motors they represent but different reasons for each.

saabin

Did you get your 991 GT3 motor replaced of had it been done before you owned it? I'm not up to speed on the latest issues but I have a friend that is on his 3rd engine.

johnbelk

Very interesting post, I'd read of the major LS mods in order to compete...

Why do the Porsche engines not receive the same level of extensive modifications ( assuming is they don't)?

Is it because the base Porsche engines are far more superior when compared to the base Bow-Tie power?

How do the various manufacturers ensure there's a level playing field with respect to engine mods?

JB

Fishey

So it looks like the 2012 RSR motor is still going strong with new 2017 RSR

pissedpuppy

how 's the quality/reliability of the early 9A1 engines?

not trolling, curious

CodeRed

https://rennlist.com/forums/991-gt3-...t-blew-up.html

https://rennlist.com/forums/991-gt3-...-replaced.html

Rocco07

Please elaborate on the Mezger troubles you've experienced. I find this thread timely as I'm currently considering two cars, both 6 speeds, but one is a 2009, the other a 2010. 2010 has PCCBs. But I'm aware the last of the Mergers may be collectible.

CodeRed

i have a 2009 and put on 5k miles in a year, no problems except a leaking windshield spray motor so far...feels really solid to me, but will do the coolant line fix when my clutch goes at some point etc

golfnutintib

stout

spur911

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HellaHashTags

The Mezger engine had a run of how many years?
We'll just have to wait and give the 9A1 some time to see how it stacks up; it sounds like it'll have its own opportunity in the spotlight soon and keep in mind it's only about 6 years into production.

This is almost like people arguing about MJ vs. LeBron - it's still too early to tell at this point.

tcsracing1

The Mezger started out as a race motor.
The 9A1 started out as a street motor.

People tear down and build up Mezgers all day long.
I do not know of anybody tearing down 9A1 motors.

The 2017 Cup will be 9A1 like the 2016 GT3R GTD car.
The 2017 RSR will be 9A1. No turbo.

I have a Mezger turbo daily driver now, but at some point it will be replaced with a 9A1 turbo.
In 20 years the Mezger might be the motor to have in terms of rebuilding. But hopefully that will not be me as Mezger rebuilds are not cheap.

boxster-r

Most underated Genius. Hans Mezger.