rbahr

Hi All,

I need to completely tear down my motor to fix stuff, and will be doing some maintenance while I am in there. I don't have the budget to do the 3.8l upgrade :-( as the tranny is also being redone (one lousy PP can ruin your whole day - but that is a different story).

At this point I will:

• Get the block fixed
• Have the block checked and line-bored if necessary
• Replace all bearings
• Micro polish the crank
• Check rods, rebush small end, replace bolts
• Break the glaze on the cylinder walls
• Replace rings
• Clean block, replace all seals

Questions:

I want to use ARP con rod bolts -- there are no listings for the GT3 - suggestions?

What else should I do while in there?

Thanks

Ray

32krazy!

nikasil lined cylinders and pistons. dont think you can hone them changes the thickness of the nikasil

rbahr

Does that include just breaking the glaze? If one wants to change rings - how does that happen?

Thanks

Ray

Viperbob1

you need to find a machine shop that has a special hone for Nikasil. Not many machine shops will have this.

rbahr

Ok, Thanks.

The shop I am looking at is a well known Porsche machine shop - but will confirm.

Ray

32krazy!

my understanding is the liner piston and ring are sold as a set. the manufacturer sets the thickness of the nikasil at the factory. if the wear is beyond specs the entire cylinder setup is replaced

rbahr

Hi All,

Pulled the motor apart - 1st time in one of these monsters and found the following:

The vibration from the pressure plate failure really beat the tar out of this bearing...




The following is one of the con-rob bearings - they all looked like this. One theory is that the car sat for a long while and perhaps some moisture got in...



I will publish highlights of my build - will likely stay with a 3.6l build since I am rebuilding the tranny at the same time and the budget will not support both extravagances...
Although I found that the 3.8l motor is all about the pistons & cylinders (and heads and cam...) but....

Ray

Viperbob1

Whats a PP?

rbahr

Sorry: Pressure plate. My problems started when I lost several rivets on an older style pressure plate which cut up the bell-housing. I saw an oil leak, I pulled the motor & tranny to fix the clutch / pressure plate and saw a crack in the block...

Ray

32krazy!

Does the gt3 run titanium rods? It might be time to replace them since the age of the car is over 15 yrs?

The 3.8 kit with new rods would run about 4k$.

Full gasket kit runs about 1000$. 16 hrs to remove /reinstall engine and 40 hrs labor to tear down and rebuild engine. May need an oil pump as well if metal was found. 1800$.

rbahr

GT3 does run the Ti rods. $4K sounds cheap BUT - doing the tranny as well, so that will be a stretch...

No metal found, motor is already out and torn down.

Ray

32krazy!

might be time to change the rods then. theres pauter , carillo and silly rabbit motorsport rods avialable and much stronger then any oem setup. maybe not as light but lasts longer and allows for every bit of torque to be used . also consider stronger head studs while its apart. srm 12mm studs and machine work are about 2000$ and hold over 1200 ft/lbs without lifting

Rickard 993 Turbo

CRex

Thanks. Helpful to all of us trying to learn the right stuff here.

Performance Developments

Your bearings both look pretty normal for these engines. Most rear mains look similar as the cranks in these engine move around a lot. The rod bearings in these engines are really hard as they tin coated. This is for long life and a lower wear. The rod shell shown shows normal wear. The wear pattern is higher up the shell towards the parting line but this is typical as these bearings have less eccentricity than race bearings have. These are a "street" bearing.
The back of the bearing tells a lot here too. If the heavy mark shown was from a foreign object it typically will show up on the back side as well. If not, this is more from some sort of overlay impact or fatigue. This can happen when the crank twists from harmonics, creates a momentary high spot on the journal and briefly touches the bearing when it loses its oil clearance. All very typical. Best to fit a damper to help stop the twisting.

As for fitting steel rods and 12.0mm head studs, that is way over kill for this engine. I guess the person who suggested that did not realize this is a GT3 engine. When steel rods are fitted to one of these engines regardless of make, you are going backwards. The Ti rods should be checked, measured and the bolts replaced. It is recommended that this is dome by persons who know about the care and any repair work required for Ti rods.

Mains come in 3 sizes so be sure you measure the case housing bore and the crank so you fit the best bearing to give you the clearance you want.