lb7 cylinder head questions

[dmaxvaz]

i was wondering what are the pockets for in between the intake ports? i was thinking about filling them in before i port the heads. any ideas?

 

[McRat]

My guess is they are there to help keep the casting wall thickness more uniform. When designing cast objects, a uniform wall thickness distorts less than one with thick and thin areas.

Filling them in can't hurt I suppose, but I'd be surprised if it would make any measureable difference.

 

[dmaxvaz]

my guess is they are there to help keep the casting wall thickness more uniform. When designing cast objects, a uniform wall thickness distorts less than one with thick and thin areas.

Filling them in can't hurt i suppose, but i'd be surprised if it would make any measureable difference.

my thinking was that maybe less turbulance in the intake manifolds by being smooth would make a little difference(every little bit adds to alot in the end, right?)

 

[duratothemax]

I thought they were "hollowed out" on the california [emissions] LB7's? (and "filled in" on the federal emissions) I know the EGR LB7 heads are different than federal emissions heads on the LB7's.

ben

 

[dmaxvaz]

I thought they were "hollowed out" on the california [emissions] LB7's? (and "filled in" on the federal emissions) I know the EGR LB7 heads are different than federal emissions heads on the LB7's.

ben

My heads are not california emissions ones and they have the pockets in between the intake ports

 

[duratothemax]

My heads are not california emissions ones and they have the pockets in between the intake ports

no, I know...but I thought on the cali heads, those pockets were actually deep ports instead of just ~1/4" deep craters...

I could be completely wrong tho, maybe im thinking of something different.

 

[juddski88]

what are the differences in the fed and cali heads? does one flow more than the other? they are interchangeable correct?

 

[UPS DRVR]

I would like to know the same thing. I have a Cali Lb7 and would like it to be a 500 hp motor for daily driver. Will I need to change my heads to get to 500 ?

 

[duratothemax]

I would like to know the same thing. I have a Cali Lb7 and would like it to be a 500 hp motor for daily driver. Will I need to change my heads to get to 500 ?

nooo, not at all.

 

[JMK777]

I would like to know the same thing. I have a Cali Lb7 and would like it to be a 500 hp motor for daily driver. Will I need to change my heads to get to 500 ?

You can hit 500 with just tuning your going to need a trans build to hold it.

 

[delong_1]

Guy told me the feds flow 30 cfm more than the Cali heads.

 

[juddski88]

thank you. i wish i had both sets to compare side by side to see where i could port if i can indeed port them to make them the same

 

[Micheal Tomac]

The intake ports on the California heads are two different sizes and the intake ports on the federal heads are the same size.

 

[juddski88]

awesome, thanks Micheal, i've wondered for a long time and never had the two to look at

 

[Micheal Tomac]

here's a link to an Diesel Power article about SoCalDiesel that shows pics of the egr and federal heads

http://www.dieselpowermag.com/tech/chevy/0704dp_socal_diesel_duramx/photo_04.html

http://www.dieselpowermag.com/tech/chevy/0704dp_socal_diesel_duramx/index.html

 

[UPS DRVR]

Thank You Micheal. That gives me a much better idea of where my restriction is in my heads.