Kevin

Zippy;

I have been on vacation, when I get back I will post my results on my camshaft selection.. It is very interesting to see the specs on our engines and what Porsche has done..

Kevin

Chad;

With regards to the GTR heads, there are diffrences in the ports. All the ports have been CNC'd. Also with regards to the heads.. I'll take the larger valves, most people don't know that Porsche changed the design by installing a smaller spark plug to gain some more room..

Neil@Orton

Chad what hp are you upto now?

Neil@Orton

Chad.
we have just had one on the dyno making 816hp

m42racer

Kevin,

Very interesting project. I to have looked at the GT3 engine platforms as a performance engine. Some information you may or may not have.

The Ti rods are a way better choice over Steel, (Carrillo's) for performance. The down side is that in a high perfromance Turbo engine, they will require more attention. Also if the "standard" steel rod is used, they are usually made to size, and not to a weight requirement. Most of the Pankl Rods used have Ti Fasteners. Do yours? If the Fasteners are installed correctly, they are stronger than the Rod for size. In cases where failures have occurred, it has always been the Rod that has failed not the bolt. Where the Fastener has failed, its been the installation that was incorrect. Most Fasteners can be stretched 7 times, but ask the manufacturer for their recommendation here.

The R and Cup Heads are diiferent, but for a Turbo use, be careful of the Heat treat. If you are not going to run high boost and temp's, you will be ok, but if you put to much heat into them, expect problems. Problem you MAY encounter are seats moving, Guides losing their press ets. You can check the Heat Treat and you want to be above 95 on the B scale. Its continual high heat and heat cycles that will cause you problems. If you stay away from these, you should be OK. The problems that can occur are Seat Inserts moving and Guides losing their press. You will need to change the Exhaust Valves. Ti Valves will not live on the Exhaust side, and if used on the Intake side, will require regular service. The R heads have Beryluim seats which will help the heat transfer, but an increase in seat pressure will be required to help in the transfer. The R heads flow more on the Exhaust side than the Intake side, which will help your Turbo application. At 0.350in they flow around the same, but from there on out, the Exhaust is way better. You can calculate the HP potential from the Flow numbers per Cylinder, and for Turbo's, convert the manifold pressure into inches of water, then calculate the flow numbers on this value of pressure, then do the math for NA engines. You will be very close. Thats a great upgrade. The Throttle response will be amazing. Forget the HP, big deal, the Torque and response will be incredible.

Duane in Miami

Kevin,

Very interesting project. I to have looked at the GT3 engine platforms as a performance engine. Some information you may or may not have.

The Ti rods are a way better choice over Steel, (Carrillo's) for performance. The down side is that in a high perfromance Turbo engine, they will require more attention. Also if the "standard" steel rod is used, they are usually made to size, and not to a weight requirement. Most of the Pankl Rods used have Ti Fasteners. Do yours? If the Fasteners are installed correctly, they are stronger than the Rod for size. In cases where failures have occurred, it has always been the Rod that has failed not the bolt. Where the Fastener has failed, its been the installation that was incorrect. Most Fasteners can be stretched 7 times, but ask the manufacturer for their recommendation here.

The R and Cup Heads are diiferent, but for a Turbo use, be careful of the Heat treat. If you are not going to run high boost and temp's, you will be ok, but if you put to much heat into them, expect problems. Problem you MAY encounter are seats moving, Guides losing their press ets. You can check the Heat Treat and you want to be above 95 on the B scale. Its continual high heat and heat cycles that will cause you problems. If you stay away from these, you should be OK. The problems that can occur are Seat Inserts moving and Guides losing their press. You will need to change the Exhaust Valves. Ti Valves will not live on the Exhaust side, and if used on the Intake side, will require regular service. The R heads have Beryluim seats which will help the heat transfer, but an increase in seat pressure will be required to help in the transfer. The R heads flow more on the Exhaust side than the Intake side, which will help your Turbo application. At 0.350in they flow around the same, but from there on out, the Exhaust is way better. You can calculate the HP potential from the Flow numbers per Cylinder, and for Turbo's, convert the manifold pressure into inches of water, then calculate the flow numbers on this value of pressure, then do the math for NA engines. You will be very close. Thats a great upgrade. The Throttle response will be amazing. Forget the HP, big deal, the Torque and response will be incredible.




Wow

Kevin

M42

Thanks, Pankl is the factory rod, there are many differences between the Pankl rod and the Ruf rod.. You are correct with the rod bolt situation.. They suggest 3 total stretch torque applications. I am not going to risk it, so I am buying a new set of bolts at $840.00..

I am aware of the head differences, I am going to ceramic coat all the chambers and valves.. These heads have been CNC machined. I will post the differences between my stock TT head and a stock GT3 head vs the LATE "R" head...

Sameer

Friends,
Ruf offers a 100,000km warranty on their titanium conrods. Now if the titanium rods are'nt that good, I dont think they would warranty it for 100,000km.

Kevin

Sameer;

I nor anyone here is slamming the Ruf TI rods.. They are very good, however, I am building an engine that is designed out of the "Normal design parameters" I am going to exceed the HP limits for the Ruf rods.. I have and own all the different stock rods, Carrillo rods and now Pankl rods... When ringing out 800-1000 HP with or without laughing gas, as individuals we have to make our own choice.. I just have went with the Pankl setup..

m42racer

Kevin,

The Valves in the GT3R Heads will not last in a Turbo engine, even coated. They are coated on the Stems, and under the temps you will see, will cause problems. This among all the other problems. The material is not rated for these Temps. The manufacturer will tell you this.

Also, the Cam you use, needs to be designed for the Ti Valves.

Also, be very careful with coating internal engine parts. Using ceramic as a heat barrier is great on Pistons, but a Cylinder Head, its a whole different ball game. Getting the heat out is the name of that game.

Kevin

I have since gotten back from vacation and have dove into my project alot further.. I will report my camshaft findings shortly... Right now I am mocking up my turbochargers and headers.. I am going to post the raw measurements.. One interesting fact is that the Exhaust Ports on the GT3R heads are Larger than the Intake port... Now I didn't say that the valve sizes were that way. They are the traditional Intake Valve being larger with the Exhaust valve being smaller, and for those that don't know why this is, it's because after the compression stroke then ignition of the air/gas mixture, the volume of spent fuel/gas is alot less.. Now with Porsche manufacturing the outlet port larger than the intake they really are reducing the backpressure placed back into the cylinder.... Now for a turbocharged application, I do not want the exhaust velocity to slow down. I will mimick the 996TT design and speed the air flow up a little by a reduction of my primary header tubes. In looking at the factory headers, I will have to increase the sizes overall.. I haven't yet figured out what I will do, but I will remanufacture the factory headers with new tubing.. I personally like the factory design and factory flat collector... It flows well and the primary pipes are very short... For a turbo application we want as short a distance from the exhaust port to the turbine housing.. Yeah, I have heard all of the arguments about equal length headers. It just doesn't work on an turbocharged engine if you want a low lag-broad power band engine.. The design for the headers is for short tubing runs.. On a seperate note.. I am posting a DIY header topic for the 996TT boys...

Kevin

It's been awhile since I have posted anything on my little project.. This is my new GT3 crankshaft. I have taken the time to show the titanium Pankl rod mounted to it.. An interesting note when I got the factory bearings, Porsche has spec'd out moly coatings on the bearing surfaces.. Infact when I took the engine apart, I noticed that the shells were coated, but I though that it was just sent out prior to the engine build.. I'll post a picture showing the coated bearing.. There has been alot of talk about what is what with the 996TT engine vs the GT3 parts.. I've taken the time to list some of the facts..

1) The 996TT rotating assy is the same as the 993TT, the GT2 shares these components.. The rod widths are the smallest that Porsche has ever used.. The measure roughly 14.68mm wide and a diameter 54.96mm

2) The GT3 crank uses 930, 3.2ltr, & 964 width bearings of 17.71mm. The kicker is that the diameter of the rod journals are infact smaller than the 964-993-996 rods, it is 52.99mm..

#) With the Pankl rods the wrist pin dimensions are 22mm vs the 23mm of the 930-996TT..

Edit: In my haste I mistyped the correct rod diameter.. Basically the GT3 rod bearing journals are 2mm smaller than the 996TT.. Main journals are tradition 930,964,993 and 996TT..

Kevin

Here is the GT3 oil pump. Please note the additional oil pickup.. located at the bottom of the pump housing.. For the money this is a huge improvement to prevent oil starvation. The 996TT and GT2 share the 964 oil pump.. Which isn't a bad unit, this is just a better pump, and it is inexpensive.. Anyone that is in a hurry and needs one, I have a spare one..

Kevin

This was a hard decision for me.. Finding a clutch that would be able to handle the power that this engine will put out.. and being streetable to a degree.. I searched for over 2 weeks to find this 7.25" lightweight 60-2 flywheel.. This baby only weighs 5.5 lbs.. I weighed it twice, I couldn't believe it.. The pressure plate is going to be Tiltons carbon/carbon unit.. I should get it tomorrow, and will post pics..

Kevin

I promised that I would post the cmashaft spec of this engine.. I was couldn't believe the lift of the intake and exhaust cams..

Intake cam lift is .492 with the duration of 256 degrees measured at .050 (I have the entire range)
Exhaust lift is .472 with the duration of 241 degrees measure at .050

The stock 996TT for comparison

.402 Intake lift and a duration of 230 degrees

Interesting the vario cam lobe is .118 lift with a duration of 120 degrees..

For a comparison the 993TT specs are

Intake lift of .454 with 252 degrees durations
Exhaust is .430 with 218 degrees measured at .050

These specs are from my camshafts used for comparison.. Another note is that the GT3R camshaft are billet forged, then milled to remove the center area out of the camshafts.. They are basically hollow and very light.. I have been comparing these spec to the normal GT3 grind, and most likely will use the exhaust profile for my intake and will use a 928S grind for my exhaust.. I will probably pull some more duration out of these profiles..