GM Releases 2013 bogus HP ratings at PRI show

[Andrew Hill]

Originally Posted by Ken Miele

Andrew, the 352 has some great parts, but CNC’D Heads are not one of them.

This head is the part number listed in the engine blueprint guide
M-6049-Z304DA

http://www.roushyatesparts.com/ford-...049-z304da.htm

it talks about CNC porting at the bottom, so the accepted head is the non-CNC'd version?

[Ken Miele]

Correct Andrew, when the engine was submitted to NHRA it did list the cnc head, but NHRA said no.The 352 and 428 along with the new 363 and 427 all use the non cnc heads.

[Comp 798]

M-6049-Z304DA - 63cc CNC'd combustion chamber. NHRA allows 56cc

[Greg Hill]

Originally Posted by Andrew Hill

This head is the part number listed in the engine blueprint guide
M-6049-Z304DA

http://www.roushyatesparts.com/ford-...049-z304da.htm

it talks about CNC porting at the bottom, so the accepted head is the non-CNC'd version?

There's something screwy in this head deal because Roush says the heads have runner volumes of 204 and 85 as cast and the spec in the engine blueprint section says 230 and 91. Wonder where those extra cc's came from?

[Comp 798]

M-6049-Z304P - The ported head.

[Andrew Hill]

Here's all 3 listed with flow numbers
http://www.thefordsource.com/store/p...-6049-Z304.pdf

"Intake port volume as cast: 204 cc"
"Exhaust port volume as cast 85 cc"

In the Stock/Super Stock Cylinder Heads Volume list, both Z304D and Z304DA are listed with:
Intake CC's Max: 230
Exhaust CC's Max: 91

All have CNC'd combustion chambers, M-6049-Z304P has CNC ports as well.

Also, the engine blueprint guide has a 56 cc combustion chamber, while a 63 cc one is listed in the specs. What's the deal with that?

How can I go about getting an extra 26 cc's on the intake and 6 on the exhaust approved?

[Andrew Hill]

Originally Posted by Andrew Hill

Here's all 3 listed with flow numbers
http://www.thefordsource.com/store/p...-6049-Z304.pdf

"Intake port volume as cast: 204 cc"
"Exhaust port volume as cast 85 cc"

In the Stock/Super Stock Cylinder Heads Volume list, both Z304D and Z304DA are listed with:
Intake CC's Max: 230
Exhaust CC's Max: 91

All have CNC'd combustion chambers, M-6049-Z304P has CNC ports as well.

Also, the engine blueprint guide has a 56 cc combustion chamber, while a 63 cc one is listed in the specs. What's the deal with that?

How can I go about getting an extra 26 cc's on the intake and 6 on the exhaust approved?

So does anyone have any answers for this? Where did the extra cc's come from if they're not ported?

[art leong]

Originally Posted by Andrew Hill

So does anyone have any answers for this? Where did the extra cc's come from if they're not ported?

The same place they come from on all the other "stocker" heads?

[Ken Miele]

Andrew,

With all do respect, most head volumes listed by NHRA do not hold the factory volumes. The head was submitted and pored, just like many other heads.

I am not sure why you think the head specs listed by Ford Racing in their parts catalog has any relevance with what NHRA has posted. They also list flow number, but we all know they follow much better.