OK, so what is the diameter of the wrist pin on the 996tt piston?

 

Stephen,

I just checked with Rob @ S Car Go Racing. He confirms what you said above. He added the GT3 uses 22 mm wrist pins and the 996tt uses 23 mm pins.

So to sum our situation up. We are using Woosner 104 mm pistons with 23 mm wrist pins. We are using the GT3R crank with the smaller radius and wider journals. We are usin Pauter rods sized for the GT3R crank and 23 mm wrist pins for the Woosner pistons. The difference on the different GT3 cranks is the dampener used or not used.

 

Sorry, just sat back at the computer. Yes, the 993 and the 964 as well as the 996TT is exactly 22.9mm. In fact even the same circlip that the 993 uses.

 

This is really crazy. Why is it so difficult to obtain information about these motors and what can and cannot be done?

We are definitely making progress, but boy is it slow.

 

Some of the crank stuff I was talking about over a year and a half ago

 

Stephen,

Agreed, some people were talking in non descript terms. Now we know the GT3 rods use 22 mm wrist pins while the 996 uses 23 mm pins. We know the GT3 rods are thirty thousands longer than the 996tt rods. We know the rod width on the GT3 is 17.71 mm while the 996tt is 14.68 mm. We know the rod journals on the GT3 are 52.99 mm while the 996tt are 54.96 mm.

To sum it up, most people believed because both motors were 3.6L the parts were readily interchangable. This is hardly the truth. They can be interchanged, with different approaches and it is expensive. Time will tell if was is worth it.

Do you know of anyone other than myself who as undertaken this type of work? If so I would like the name so I can talk to them.

What is even more frightening is, this is only the bottom end of the motor.

 

Is the rod big end diameter different?

 

Yes on the GTIII compared to the 996TT/993.

 

Thanks Kevin.

 

Thanks to Kevin, Killer Angel will be fitted with some special valves capable of approx. 2400 degrees.

Here are the difference in valve sizes.

Stock 996tt
32.0 mm intake, 37.0 mm exhaust

GT3 Cup Heads
35.5 mm intake, 41.0 mm exhaust

GT3R Heads
36.4 mm intake, 42.0 mm exhaust

I am using the GT3 Cup heads while Kevin is using the GT3R heads. The reason being I am staying with the vario cams and require my motor to be smog legal. This is really going to be interesting when these two motors are finished.

I really want to thank Kevin. The people who share such means and methods are few and far between.

Kevin has an excellent thread about his motor in the 996tt section of Rennlist entitled The Quest for Maximum HP.

 

I was told today that I will have the new valves by September 30th. These valves are custom built from a combination of Nonomic 90 and Nonomic 800. They will withstand 2400 degrees F and will safely rev to over 10,000 rpm's.

We are having both intakes and exhausts made.

 

Kevin,

I don't believe most people realize how knowledgeable you are! I'll take a back seat to you any day. In addition, you are only one of two people I know of who shares your information along with providing very fair pricing for the products you sell.

I have been trying for over two months to locate special intake and exhaust turbo valves. Out of the blue you are able to solve my problem.

Good luck with your own monster motor. Maybe when you are finished we can get our cars together for a Super Shootout. It really wouldn't make any difference who won. Second thought, maybe we could make it a three way exibition and get EL750 to join in on the fun.

In all likelyhood three of the faster 996tt's in existence. Again thanks for all your help.

 

Should have the new valves in another week. The case is being sent to Southern California to be aligned bored and shuffle pinned.

The GT3R crank is being knifed edged along with a little work on the oil passages. Then it will be micro polished. In addition a light weight aluminum dampener is being fabricated. The pistons, headers and turbo hot side have been sent to HP Coatings for some coating work.

So far, the biggest obstruction is the rods. We are not looking to see them for another six weeks.

Next hurdle, a billet intake piece for the injectors to mate intake to the GT3 Cup head intake ports. This will be interesting as we are going to incorporate six nitrous injectors on this piece.

 

Kevin,

When are you expecting to finish with your car? I would love to get together. Let me know what you think of the valves when they arrive.

 

The case has been sent to Southern Calif. In addition to the above described work, we have decided to o-ring the liner spigot where the cylinder fits into the case.