LS4 Accessory Drive & LS3 ??
Thread Starter
On The Tree
Joined: Jun 2017
Posts: 119
Likes: 17
From: Lynden Washington
LS4 Accessory Drive & LS3 ?? I'm building a LS3 Porsche Cayman and am using a Chevrolet Crate LS3 / 525. Is there a way to use the beautifully LS4 crank pulley, Water pump etc ??? 
Thread Starter
On The Tree
Joined: Jun 2017
Posts: 119
Likes: 17
From: Lynden Washington
If your using the ls3 the crank wont line up because the ls4 crank is shortened 10mm on the accessory side to line up with the ls4 accessory drive. So you'll have to work a solution for that.
LS4 crank pulley has been used on a lot of RWD engines, so it will work, but there are several things you need to work through.
The LS4 crankshaft is shorter, but it is still recessed bellow the surface of the LS4 balancer - the crankshaft doesn't need to be as short as the LS4's. Worst case, just use a stepped washer to clear a protruding crankshaft.
Belt alignment to the LS4 pulley will require relocating every accessory closer to the timing cover, which can cause more fitment issues in the engine bay.
The LS4 water pump is a wide monstrosity that limits space at the lower portion of the engine for the accessories. It also wont clear a lot of forward facing intakes, and the normal belt path is right through the throttlebody location.
I extensively modified the one in my Fiero to change the location of the hose connections to make room for the low mount alternator and to allow the belt path to go below the water pump.
The LS4 crankshaft is shorter, but it is still recessed bellow the surface of the LS4 balancer - the crankshaft doesn't need to be as short as the LS4's. Worst case, just use a stepped washer to clear a protruding crankshaft.
Belt alignment to the LS4 pulley will require relocating every accessory closer to the timing cover, which can cause more fitment issues in the engine bay.
The LS4 water pump is a wide monstrosity that limits space at the lower portion of the engine for the accessories. It also wont clear a lot of forward facing intakes, and the normal belt path is right through the throttlebody location.
I extensively modified the one in my Fiero to change the location of the hose connections to make room for the low mount alternator and to allow the belt path to go below the water pump.
Thread Starter
On The Tree
Joined: Jun 2017
Posts: 119
Likes: 17
From: Lynden Washington
LS4 crank pulley has been used on a lot of RWD engines, so it will work, but there are several things you need to work through.
The LS4 crankshaft is shorter, but it is still recessed bellow the surface of the LS4 balancer - the crankshaft doesn't need to be as short as the LS4's. Worst case, just use a stepped washer to clear a protruding crankshaft.
Belt alignment to the LS4 pulley will require relocating every accessory closer to the timing cover, which can cause more fitment issues in the engine bay.
The LS4 water pump is a wide monstrosity that limits space at the lower portion of the engine for the accessories. It also wont clear a lot of forward facing intakes, and the normal belt path is right through the throttlebody location.
I extensively modified the one in my Fiero to change the location of the hose connections to make room for the low mount alternator and to allow the belt path to go below the water pump.
The LS4 crankshaft is shorter, but it is still recessed bellow the surface of the LS4 balancer - the crankshaft doesn't need to be as short as the LS4's. Worst case, just use a stepped washer to clear a protruding crankshaft.
Belt alignment to the LS4 pulley will require relocating every accessory closer to the timing cover, which can cause more fitment issues in the engine bay.
The LS4 water pump is a wide monstrosity that limits space at the lower portion of the engine for the accessories. It also wont clear a lot of forward facing intakes, and the normal belt path is right through the throttlebody location.
I extensively modified the one in my Fiero to change the location of the hose connections to make room for the low mount alternator and to allow the belt path to go below the water pump.
The LS4 water pump is an amazing structure, just try to make that at home LOL>
I likely don't have the same space issues you have but surely your setup is the narrowest around.
