I need a new cam, I am looking at getting one like I had last time.
It is a crane hyd cam with 1 dergree of valve over lap.
It has 112 dergree lsa and good duration.
It is the crane H-272-2 cam.
I was going to run up to about 14 psi of boost on a 3.4 with this cam but it was in shop when the place burned down and now I'm making a new boostable 3.4L.
How much Over lap should I run if I want to boost?

 

It depends on the entire combination.

I've found that more overlap equals more top end power, at the expense of driveability, spool, and low end torque.

It would help if you listed your entire combination and goals.

 

First off the K03's are to small the idea is to build higher boost in the mid range and with a gretty boost controaler peak the boost in the mid range rpm and taper it off at the higher rpm.
I wanted to make about 300 hp peak and about 400 ftlb of torque in the mid range at most.
And it's setup for nitrous, just fuel taps so far I want to spary too.
With the K03's they can only make about 16psi on that engie and when I move up to K04's they could make over 20psi. at high rpms and blow those 300 and 400 numbers away and make near 500hp.
At least I won't be temped to make the near 500 hp till later on.
Then after a while I wanted to put forged pistons in there and after the K03's are used up repalce them with ball bearing K04's.
I'm in the market for a new cam because my engine got burned up in a shop fire.

 

On the other bords there saying less is good for a turbo that builds power down in the low RPM's.

 

Both statements are correct.

More overlap will build greater power at higher RPM's where less over lap will build more torque at lower RPM's.

 

Ive heard you want to keep it wide so you dont get reversion. Scavenging dosnt come into effect largley with turbo because theres so much backpressure. You might get a few deg of scavenging, if you have long and small dia primaries, from the momentum of the gasses. But dont expect much so keep overlap to a minimal.

 

The primarys are kind of big there all most 1''.
I'll get a pic of them on my cardomain site befor too much longer.