Holy ****. . . .now that's a build! Look forward to seeing more of that develop just as eye candy.

 

They are Chevy Bearings as used in the high rpm NASCAR cars. They are about a 1.9998" bearing. I will look up who supplied them to us and post for you. Here are the crank specs.





You are correct about grinding the crank and there are two things you can do.

#1 - Grind the crank as a center grind and keep the same stroke.

#2 - Grind the crank as an offset and gain 2 mm of stroke. This was our choice. Our Arrow Precision crank started out as a 80.2 mm stroker from Arrow. We added the Oval bearings and did an offset grind to make it a 82.4 mm stroker. If we were to do it all over again I would have stayed with the 80.4 mm crank and could have obtained a better piston to rod ratio or piston speed. If I was dealing with a billet GT3 crank with a stock 78.4 mm stroke than I would have used the oval bearings and an offset grind to make it a 80.4 mm stroker.

 

I have priced some custom built cranks and I had a quote to build a pretty sweet billet forged crank for about $1500. The guy said he could do it stronger and lighter than factory. Did you ever consider anything like this?

Are you also saying the Spanish case is better than the 964 Germany case? Iv got one of each and prefer to keep the enter of the 2 for myself.

 

Spanish case is better as it's made for the watercooler's without provisions for oil return tubes used on the air-cooled's, IIRC some slight structural improvement inside...I doubt it makes much improvement until "perhaps" these 1000+hp mega builds...

 

A 80.4 mm Arrow Precision crank costs about 10K before you do any work to it. Saying stronger and lighter doesn't mean a thing. The crank should have full blueprints with detailed calculations for designed power/torque/etc.

The Spanish case has support ribs the other case doesn't. The Spanish case is in fact a stronger case.

Ribs on the Spanish case as well as tap and fitting for GT1 oil pump.

 

My Rturbo motor does not have any issues right now. I have close to 40 track days on it and it runs like a top. Very quiet, almost none of the typical IMS rattle, and burns virtually no oil, about 1/2 quart every 2000 miles. I am religious about proper warm ups and letting the engine idle about 10 minutes after each run. I change the oil every 6 track days which equals about every 1500 miles with some street driving mixed in. It blows me away how durable these engines are but I know the day will come when an overhaul will be in order and I'd like to have all the info on hand to get it done with limited downtime including having parts on hand. With all parts on hand I can get a rebuild done in about 10 days. I figure if I'm going to have the engine broken down than I might as well build it to make it even more bulletproof. From a performance standpoint, a raised redline to 7500 is something I would reeeeeally like as it would add a ton of flexibility at the track. I would much rather have a 550WHP motor that revs reliably to 7500 than a 700HP motor with a 7000 limit. I am just seeing if a reliable /durable 550WHP with a 7500 redline is a realistic goal with rods/GT3 crank/GT3RS oil pump. I don't even think that 3.8 pistons/liners would be needed. Any more power is pointless for what I use the car for. I've seen way too many guys show up at the track with 800HP cars and get spanked by Boxters or Caymans. Huge HP doesn't make an overall fast car, it's the whole package. Much greater gains can be realized through suspension tuning, brake optimization, and most of all, driver tuning..

 

That 7500rpm rev limit makes the 1 to 2nd shift so much more enjoyable..

 

lol! (driving tuning), happy motoring man and good luck with your quest.

 

Sorry to say but...
I just looked in a Porsche technical manual and it did say our cylinders are Nikasil coated....As my past water cooled 944 turbos were..
Also all the cylinder sleeves that I have treated our cast iron to begin with..
Just sharing info..

 

I call BS on the that. The 996 Non Metzger engines use nikasil because the cylinders and castings are aluminum and all one piece. With the Metzger engines the sleeves are steel(alloy) and separate from the water jacket which allows for wear and are replaceable. Why use nikasil? I think that was a typo. Of course I have no proof :/

 

I will take a picture of the info and post it for you..
Nikasil is used when ever long life is needed and when minimal material wear from sleeves is a concern for keeping oil from being contaminated from that sleeve material..

 

from Porsche..

 

Thanks for posting that showing the sleeves are coated...
Saves me a trip back to the dealer to prove it..

 

Interesting. Wouldn't be the first time I have been wrong. Thanks for sharing.

 

The stock sleeve's are Aluminum and coated..