" B " cast heads question

[dave-the-sparky]

g'day
this question has probably been asked a million times, i have had a search thru lots of pages and not found the answers i need.
i have a set of brock " B " cast heads with the HDT stamp on them and i also have the matching brock inlet manifold and a "QT" engine block.

my questions are...

can you use VN style heads and inlet manifold on the earlier QT block without modification?

or will a vn injection manifold work on the b heads?

my b heads my be better used on a brock vk as i am building a turbo/gas wb ute

 

[Immortality]

the early heads have a siamese exhaust port setup so you get a valve arrangement that looks like: int ex int ex ex int ex int

for the later VN heads they changed the arrangement to int ex int ex int ex int ex.

because of the differnt valve arrangements in the heads you ahve to either use all the early head bits i,e heads, intake and exhaust manifolds as well as the cam or late engine bits

late model heads will bolt onto a early block but would require the other bits to go with it. the VN heads do flow more and have more potential with porting.

if you have a matching numbers brock engine (block/heads intake etc) keep it together

 

[dave-the-sparky]

sweet, that makes sense. thanks for the reply,

 

[Reaper]

can you use VN style heads and inlet manifold on the earlier QT block without modification?
Yes however you will need a VN style intake manifold, exhaust and camshaft to suit. There are many options of each to choose from.

or will a vn injection manifold work on the b heads?
No - the port spacings are different and will not fit.

my b heads my be better used on a brock vk as i am building a turbo/gas wb ute[/quote]
Even stock VN style heads will murder the older style heads for potential hp unless your B casts have had some serious work done to them.

Reaper

 

[dave-the-sparky]

thanks for your reply, i might keep it all together.

 

[ari666]

Even stock VN style heads will murder the older style heads for potential hp unless your B casts have had some serious work done to them.

aint that the truth even just the simple fact that we can only go 1.94 inlet valves if we want unleaded seats, whereas VN have 2.02 from factory and have a tiny bit of room to move. (the 2.02 seats cut into a water gallery)

i shoulda just gone VN early in my build rather than finding out the hard way after buying extractors/manifold/cam to suit old heads. now i am stuck looking at 2 grand yella terras in the hope they will squeese more HP out.