trailtoy83

Hey guys im gathering parts for my new race truck. As much as I would love a LS3 or a L92 money makes all the decisions. I currently run a sereis 2 SC3.8 (awesome engine) and was just gonna put a series 3 SC3.8( around $1300) and put about a grand into engine for more HP. While looking for a SC3.8 i cam across the LS4(36K miles for $1000). I know they have the 60* bellhousing which works great for me, seeing i have a built baby 700R4. My plans for the LS4 would be a LS6 intake, LS6 fuel injectors, flow though rails, headers, manual 85mm TB, DOD delete with a cam, and a new water pump. Thinking 400HP? My question is can i use any LS cam? thinking something is different with oil pump, whats the difference on 2 or 3 bolt cam. Seen a few builds but they keep the DOD cam?


Also can i use a regular LS water pump?

Im sure most would say why not just get a LS1, a complete LS1 seems to be in the 3K range, plus i already built the 60* 700R4. Also if i blow up a LS4 they are cheap to replace. Any info is greatly appreciated!!

neilownz

I think you need to change the oil pump when doing a dod to non dod swap.

I've seen some cams drilled for both 1 or 3 bolt. Basically you have more choices by going to a three and a 05 or 06 will already be a three. Look to see what the current ecm is. If it has 2 big connectors it's setup for a 1 bolt.

Good luck.

fieroguru

iTrader: (1)

You can use any LS(x) cam in the LS4, just need to make sure it fits the cam sprocket with the engine (1 or 3 bolt) or more importantly the ECM. The 3 bolt LS4's ran the E40 ecm and the 07+ LS4's used the 1 bolt with the E67 ecm.

If you try to mount a RWD LS(x) water pump to the LS4, the camshaft sensor will interfere (it is in a unique place on the LS4):




You can swap timing covers to move the cam sensor location, but then you also have to swap to a RWD application in the ecm to match up the cam sensor timing to the ecm program.

The other issue using a RWD water pump is the LS4 crankshaft is 10mm shorter on the snout. So if you install a RWD balancer (to drive the RWD water pump), you may have some issues keeping it tight the the shorter length of the press fit on the shaft in addition to the belt drive being a few inches further away than the LS4.

But running an electric water pump should allow you to keep the LS4 balancer (but clearance is very tight):


You biggest issue will be the starter. The LS4 has no provisions for one on the engine side, and the required use of the 142 tooth ring gear (only one that fits inside the GM Metric (V6) bellhousing) does not protrude far enough past the block to engage a starter. So you will need to fab up a starter mount like this and notch your transmission case for the starter gear. This is all assuming you have room in the transmission tunnel for the starter to be transmission mounted.
Here is the stock transmission starter mount for the original LS4 transmission:


Here is a bolt on bracket to mount the starter to another transmission (once the transmission has been clearanced).