My replacement short block build is a little ahead of the tuning. My existing block was built over 5 years ago when there were only cast cranks, so I have been having a new block assembled and I need to decide where to install the cam between 0-4 degrees advanced.

My iron RT heads flow 288 cfm & 239 cfm at .600
The existing block has a 4" stroke and 408 cu. The cam is a 284-284(232-232) .556-.556 ground on a 110 cl and installed +4. The compression ratio is 7:5-1

The new block is also a 4" stroke, but a larger bore for 440 cu. The cam is a 272-272(224-224) .573-.573 ground on a 113 cl. The compression has been raised to 8:5-1
I am using a Milodon fixed idler gear drive and can install the cam straight up or 1,2,3 or 4 degrees advanced. Any recommendations on where to install the cam? Since the new block has more compression and cubic inches, but a smaller cam, should it make less or more power?

 

Actually advancing the cam timing helps out on the low end, retarding it extends your power higher and later............

 

It was ground on a 113 centerline without any advance built in. I was told that it could be installed anywhere from zero to 4 degrees advanced.

 

Even moving it back and forth 4 degrees is negligable. Most lsx cams are ground with 2-4 deg advance in them to accomodate for a sloppy timing chain. I vote for slightly advanced only because it will shift your power down ever so slightly and as the chain wears it'll be right where you wanted it

 

Split the differents and go with 2*

 

Thanks for the suggestions so far. The engine will be using a Milodon fixed idler gear drive so the timing isn't going anywhere. Are there any negatives releated to advancing the cam, like detonation or higher EGT's? If not I will probally advance it so I don't have to spin the engine so high to acheive peak hp.

 

What is the recomendation of the cam manufacture? They will tell you on the cam card where to install the cam. When you advance the cam you will gain some lower end and when you retard the cam you will gain some top end. Either way you will need to ckeck your valve to piston clearance as this will be affected by advancing or retarding the cam.

 

The cam card says to install between 0-4 advanced. I have always heard that advancing the cam gives you power sooner in the lower rpm's, a lower power peak and a smoother idle, but are there any negatives?

 

lose power up top, if you advance it. the way i understand it, is itll move the power band down.

 

When you advance the timing it will decrease the valve to piston clearance, so make sure you have enough room. What is the installed degree of the cam? ( ie. cam installed at 106* )