996 GT3 4 Liter
05-25-2011, 08:04 PM
#50
Nordschleife Master
Join Date: Oct 2004
Location: Vacuuming Cal Speedway
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Along with piston and wrist pins weights, I'd love to see how balanced Porsche has your rods if you get the chance to weight them. Do anything with the crank?...
05-27-2011, 06:06 PM
#51
Rennlist Member
Thread Starter
I'll try to weigh everything this weekend - I'm curious myself.
In other news, I just dropped off the cylinder housings and case at the machinist. I was pleasantly surprised that the owner of How Tek, Howard, is also quite a Porsche enthusiast. A Cayman S was parked inside his facility and he had Flying Lizard posters everywhere.
Apparently, he does a lot of machine work for the Flying Lizard ALMS team - brake rotor hats, suspension parts, etc. It was very cool to see. I was also really impressed with the shop itself.
The machining will be a three stage process:
1. The cylinder housings and case get machined as one unit. There are two bores associated with this - the upper mating surface where we have the single o-ring attached to the cylinder lines and then the bore at the lower mating surface where we have two o-rings in the cylinder housings. Due to the shape of the liners, the same bore extends into the case.
2. The cylinder housings are separated and the cooling channels are bored out approximately 2.5mm, in order to maintain roughly the same cooling gap. In reality, this actually gives you a little more volume due to the cylinder liners fined profile.
3. The two o-ring grooves are machined deeper to accommodate the larger o-rings, since the lower mating surface bore is enlarged approximately 1.5mm.
In a couple weeks, the machine work should be done and we can start assembly.
In other news, I just dropped off the cylinder housings and case at the machinist. I was pleasantly surprised that the owner of How Tek, Howard, is also quite a Porsche enthusiast. A Cayman S was parked inside his facility and he had Flying Lizard posters everywhere.
Apparently, he does a lot of machine work for the Flying Lizard ALMS team - brake rotor hats, suspension parts, etc. It was very cool to see. I was also really impressed with the shop itself.
The machining will be a three stage process:
1. The cylinder housings and case get machined as one unit. There are two bores associated with this - the upper mating surface where we have the single o-ring attached to the cylinder lines and then the bore at the lower mating surface where we have two o-rings in the cylinder housings. Due to the shape of the liners, the same bore extends into the case.
2. The cylinder housings are separated and the cooling channels are bored out approximately 2.5mm, in order to maintain roughly the same cooling gap. In reality, this actually gives you a little more volume due to the cylinder liners fined profile.
3. The two o-ring grooves are machined deeper to accommodate the larger o-rings, since the lower mating surface bore is enlarged approximately 1.5mm.
In a couple weeks, the machine work should be done and we can start assembly.
05-28-2011, 04:09 AM
#54
Burning Brakes
Are you going to be at sears point tomorrow? I'm taking my son out to see the TMR event and the autocross.
06-08-2011, 05:31 PM
#56
Rennlist Member
Thread Starter
Guard LSD parts arrived. Let’s go.
Ring gear comes out.
Time to split the housing.
Out come the guts.
Oops. My beer got in the way of IPB's photos. Sad really - light beer - gotta get in shape for summer.
This measurement determines the thicknesses of the friction disc spacers to achieve the correct preload.
Spider gears.
Guard rebuild parts.
OEM vs Guard.
Friction disc spacers.
Belleville washers. You can see that the Guard parts have more curvature and greater thickness to achieve a higher spring rate.
LSD is held in place with the aid of the output flange and a vice. We actually had to fix the upper flange as well to achieve the 148 ft/lb required. Although, the preload alone almost did the job.
Rebuilt unit.
Ring gear comes out.
Time to split the housing.
Out come the guts.
Oops. My beer got in the way of IPB's photos. Sad really - light beer - gotta get in shape for summer.
This measurement determines the thicknesses of the friction disc spacers to achieve the correct preload.
Spider gears.
Guard rebuild parts.
OEM vs Guard.
Friction disc spacers.
Belleville washers. You can see that the Guard parts have more curvature and greater thickness to achieve a higher spring rate.
LSD is held in place with the aid of the output flange and a vice. We actually had to fix the upper flange as well to achieve the 148 ft/lb required. Although, the preload alone almost did the job.
Rebuilt unit.
Last edited by Serge944; 09-29-2011 at 08:14 PM.
06-08-2011, 08:54 PM
#58
Question on your measurement... Looks like you measured the core of the unit. Is there a pre-determined overall thickness desired? Do the friction disk spacers come in different thicknesses? Looks like you can only tell what you need after you take unit apart and measure. Your other thread going on mentioned ~1/4 gap before closing unit. Were you able to adjust? Or did you just used what GT Gears sent you? After doing a number of engine and trans rebuilds, this looks plug-n-play, assuming you don't mess with bearing spacers for ring/pinion clearances. Thanks for the pictures!
06-08-2011, 08:58 PM
#59
Rennlist Member
Thread Starter
Question on your measurement... Looks like you measured the core of the unit. Is there a pre-determined overall thickness desired? Do the friction disk spacers come in different thicknesses? Looks like you can only tell what you need after you take unit apart and measure. Your other thread going on mentioned ~1/4 gap before closing unit. Were you able to adjust? Or did you just used what GT Gears sent you? After doing a number of engine and trans rebuilds, this looks plug-n-play, assuming you don't mess with bearing spacers for ring/pinion clearances. Thanks for the pictures!
