996 GT3 4 Liter
05-12-2011, 01:27 AM
#33
Rennlist Member
Thread Starter
Found some more time to work on the engine today after work.
Oil pump and shaft are out.
Note the dual pick-ups on the oil pump.
Crank comes out with the rods.
All bearings are pulled and a bare case half remains on the engine stand.
Sleeves are pounded out with a rubber mallet out of the cylinders.
Case and cylinders are pressure washed. Nice and shiny. Although, getting all the cosmoline off the exterior will take additional effort.
Here’s the interesting part. Note the recesses in the cylinders to accommodate the coolant. The sleeves maintain an opposite profile. When the machinist bores out the sleeve mating surfaces for the larger 4 liter sleeves (at the tops and bottoms), the rough cast surface will also need to be bored to maintain an adequate coolant passage and prevent flow restriction. The 2 rubber gaskets in the cylinders prevent the coolant and oil from mixing. An additional gasket is located at the top of the sleeve.
Oil pump and shaft are out.
Note the dual pick-ups on the oil pump.
Crank comes out with the rods.
All bearings are pulled and a bare case half remains on the engine stand.
Sleeves are pounded out with a rubber mallet out of the cylinders.
Case and cylinders are pressure washed. Nice and shiny. Although, getting all the cosmoline off the exterior will take additional effort.
Here’s the interesting part. Note the recesses in the cylinders to accommodate the coolant. The sleeves maintain an opposite profile. When the machinist bores out the sleeve mating surfaces for the larger 4 liter sleeves (at the tops and bottoms), the rough cast surface will also need to be bored to maintain an adequate coolant passage and prevent flow restriction. The 2 rubber gaskets in the cylinders prevent the coolant and oil from mixing. An additional gasket is located at the top of the sleeve.
Last edited by Serge944; 09-29-2011 at 07:39 PM.
05-20-2011, 02:00 AM
#40
Rennlist Member
Thread Starter
An old 930 flywheel is bolted up to the crank so we can place it into a vice and remove the con rods.
Out they go.
Bare crank.
While we are waiting for pistons and sleeves to be shipped, we start working on the gearbox. Onto the stand it goes.
Drain plug is pulled and oil drained. Looks like it’s doing its job.
Output shafts are pulled.
So is the differential cover. LSD is out and you can see the huge pinion gear.
We are ordering LSD rebuild parts from the now world-known Guard Transmission. LSD will be rebuilt once we receive parts from Matt.
Out they go.
Bare crank.
While we are waiting for pistons and sleeves to be shipped, we start working on the gearbox. Onto the stand it goes.
Drain plug is pulled and oil drained. Looks like it’s doing its job.
Output shafts are pulled.
So is the differential cover. LSD is out and you can see the huge pinion gear.
We are ordering LSD rebuild parts from the now world-known Guard Transmission. LSD will be rebuilt once we receive parts from Matt.
Last edited by Serge944; 09-29-2011 at 07:50 PM.
05-25-2011, 01:53 AM
#42
Rennlist Member
Thread Starter
Pistons and cylinder sleeves (left) for the 4 liter conversion are finally in. Mahle 105.4mm pistons, steel cylinder sleeves out of the UK from a Formula 1 supplier, stronger wrist pins, and Mahle ring sets. Pistons and sleeves were developed and sold by Wrightwood Racing in Southern California.
One look at the new piston (left) and you know it’s all business.
The 4 liter sleeves are a work of art themselves. They are finned in the cooling channels to provide greater surface area for heat conduction. More power requires better cooling.
Wrist pins are heavy duty.
Piston rings from Mahle. Only the best here.
The case and cylinder housings go for machining this Thursday at How Tek in Cameron Park. The owner, Howard, was the machinist for Comptech racing.
Meanwhile, we are waiting for new clutches from Guard Transmission to rebuild the limited slip differential.
One look at the new piston (left) and you know it’s all business.
The 4 liter sleeves are a work of art themselves. They are finned in the cooling channels to provide greater surface area for heat conduction. More power requires better cooling.
Wrist pins are heavy duty.
Piston rings from Mahle. Only the best here.
The case and cylinder housings go for machining this Thursday at How Tek in Cameron Park. The owner, Howard, was the machinist for Comptech racing.
Meanwhile, we are waiting for new clutches from Guard Transmission to rebuild the limited slip differential.
Last edited by Serge944; 09-29-2011 at 08:03 PM.
05-25-2011, 02:04 AM
#44
Rennlist Member
Thread Starter
I need to get an accurate scale before I can post official numbers - my drug dealer was busy today. 
I expect them to be heavier as it's a substantially larger piston.
I expect them to be heavier as it's a substantially larger piston.
