Cummins ntc 475

You are going to have an awful lot of low idle smoke if you do away with the MVT and keep the timing the same, when going fixed time it would be a good idea to advance the timing a bit, this will help with the low idle smoke.

 

How much is a bit? Inderjit suggest somewhere between .080 to .100. This sounds good to me but its definitely going to be a bit of trial and error I think.

 

I think that most that have changed them go to .090 or .095.

Your best bet if not wanting to take it down to pull it apart and change the key is to get the MVT off and then go to the maximum thickness of shims allowed under the followers which is .080" and check the timing there, this will be the most advance you can get without changing the cam key.

 

Sounds like a plan...I'm pretty sure I am going with a new camshaft as well. The camshaft that came out of this engine is a 3021589. I can't seem to find that number anywhere to cross reference it to make sure it's the correct camshaft to begin with. Thanks for all the info

 

So you figure the s400 is the turbo I need?

 

What was the orginal CPL number of the engine?

 

Cpl 330. I was in a bind, so I used that block and made it a cpl531 big cam 3. I currently have another block(cpl 554) that I am going to build the 475 with. This new block has much bigger main bearing bolts that the original 330

 

When the big cam 3 came out Cummins went from 1" main bearing bolts to 3/4" bolts.