996 GT3 4 Liter
09-22-2011, 12:35 PM
#121
Rennlist Member
Thread Starter
Time to install the cam housings. On top of new seals between the chain housings and cam housings, a layer of Drei Bond is applied to ensure there are no leaks.
Brand new lifters (tappets) are soaked in Swepco and positioned.
Cams are placed with the cylinder 1 lobes on the exhaust and intake cams facing each other. The crank is just off TDC. Porsche special tool is utilized to prevent the chain from falling in.
Cam gears are positioned onto the cams. This is where we realize we received Cup intake cam bolts, which are half the length (no variable valve timing on cup). We will time bank 1 once we get the bolts and then move on to bank 2.
We’re getting close to having a complete long block.
Brand new lifters (tappets) are soaked in Swepco and positioned.
Cams are placed with the cylinder 1 lobes on the exhaust and intake cams facing each other. The crank is just off TDC. Porsche special tool is utilized to prevent the chain from falling in.
Cam gears are positioned onto the cams. This is where we realize we received Cup intake cam bolts, which are half the length (no variable valve timing on cup). We will time bank 1 once we get the bolts and then move on to bank 2.
We’re getting close to having a complete long block.
Last edited by Serge944; 09-29-2011 at 09:18 PM.
09-30-2011, 10:14 PM
#128
EPIC.
Thanks for sharing this with us, amazing build.
Not sure I understand how the smaller wrist pins increase compression... isn't the piston still in the same place, with the wrist pin rotating about the same axis? I must be missing something...
Edit: Went back and read your compression post, is it the actual piston that increases compression and the wrist pin just happens to be smaller for it?
Thanks for sharing this with us, amazing build.
Not sure I understand how the smaller wrist pins increase compression... isn't the piston still in the same place, with the wrist pin rotating about the same axis? I must be missing something...
Edit: Went back and read your compression post, is it the actual piston that increases compression and the wrist pin just happens to be smaller for it?
09-30-2011, 10:54 PM
#129
I think it looks like money well spent. The 996 with a 4.0 should get point bys from 997.7 RS and they cost more than 50K doner car + 50k in upgrades. This is a sticky for the pictures alone.
10-01-2011, 01:06 AM
#130
Rennlist Member
Thread Starter
EPIC.
Thanks for sharing this with us, amazing build.
Not sure I understand how the smaller wrist pins increase compression... isn't the piston still in the same place, with the wrist pin rotating about the same axis? I must be missing something...
Edit: Went back and read your compression post, is it the actual piston that increases compression and the wrist pin just happens to be smaller for it?
Thanks for sharing this with us, amazing build.
Not sure I understand how the smaller wrist pins increase compression... isn't the piston still in the same place, with the wrist pin rotating about the same axis? I must be missing something...
Edit: Went back and read your compression post, is it the actual piston that increases compression and the wrist pin just happens to be smaller for it?
My idea was killed when we did a test fit and the deck height measurements simply wouldn't allow anything like that. This also means I wouldn't be able to shave the piston housings (water jackets), as it would again, raise the piston relative to the head.
I have no interest in shaving the actual head, so, we left it at the nominal 12.0:1 compression.
10-01-2011, 01:12 AM
#131
Rennlist Member
Thread Starter
Undoubtedly, the car will be quicker in a straight line than any OEM GT3, short of the factory 4.0.
10-01-2011, 09:48 AM
#132
The smaller wrist pin = larger rod bushing. In theory, you could offset the bore (eccentric) and actually push the piston up.
My idea was killed when we did a test fit and the deck height measurements simply wouldn't allow anything like that. This also means I wouldn't be able to shave the piston housings (water jackets), as it would again, raise the piston relative to the head.
I have no interest in shaving the actual head, so, we left it at the nominal 12.0:1 compression.
My idea was killed when we did a test fit and the deck height measurements simply wouldn't allow anything like that. This also means I wouldn't be able to shave the piston housings (water jackets), as it would again, raise the piston relative to the head.
I have no interest in shaving the actual head, so, we left it at the nominal 12.0:1 compression.
PS: I think you should video the first start
10-04-2011, 01:07 AM
#133
Rennlist Member
Thread Starter
Got my intake plenum back from the machinist. It has been bored out to match the 997 throttle body. There is plenty of material thickness remaining below the flange...over an eight of an inch.
10-05-2011, 06:57 AM
#134
8th Gear
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Amazing build! I just read full thread and it's really nice to see pro clean water cooled hot rod engine build from crank to heads. Waiting to see final results.
May I ask what rod bearings you used? Are those OEM/Motorsports or do you have some special coating on them?
May I ask what rod bearings you used? Are those OEM/Motorsports or do you have some special coating on them?
10-05-2011, 12:48 PM
#135
Rennlist Member
Thread Starter
Those are Porsche Motorsport CUP rod bearings. PMNA doesn't sell them to just anybody as they want to keep all CUP engine rebuilds in-house.