Vintage Mustang Forums banner

1 - 10 of 10 Posts

·
Registered
Joined
·
652 Posts
Discussion Starter #1
I haven't made a final decision on new heads for my 289, although I've been thinking
about getting my stockers reworked by PowerHeads. But I'm wondering if I shouldn't
be thinking about the GT-40P heads instead. They're almost half the cost, which I like,
but aside from that, what else have they got going for them compared to other iron heads,
(or aluminum heads for that matter)??



Rich
'67 C-code 'vert (Dees67)
'69 GT FB (project car)
Check out my band: Brickyard Blues
 

·
Registered
Joined
·
10,587 Posts
Read this article about a comparison of stock-based heads...

It opened my eyes....

I think I'll hang on to those C9 W heads layin' in the shop a while longer...*G*

IIRC, don't the GT P heads require some tweaking to the headers....?

Pat
http://albums.photopoint.com/j/View?u=1570936&a=11937754&p=42910787.jpg
 

·
Registered
Joined
·
2,217 Posts
'cause there cheap and flow WAY better then your stock 289 heads?

Hal
Love hard, drive fast, wear your seat belt.

PS, that's my 'bird...... My Mustang is too ugly to take pictures of yet........*G*.

http://www.teleport.com/~cosa/bird2.jpg
 

·
Registered
Joined
·
2,176 Posts
G

·
Guest
Joined
·
0 Posts
Great website-I bookmarked that one. Question for you: why on the street heads does the flow decrease at some point of lift whereas on the "strip heads" the flow continues to increase at higher and higher lift? Moreover why not run "strip heads" on a street car?

Raven Black 66 Fastback GT, 289 A Code, PS, C-4, AC
Pony w/Rally-Pack, TTD's
Cool Huh?
 

·
Registered
Joined
·
652 Posts
Discussion Starter #6
Thanks for that pointer Pat! Great article. As I expected, the GT-40P heads flow better
than even the Powerheads-ported stockers, but only on the intake side and only by about
8%. But the exhaust side, the Powerheads are over 12% better than the GT-40Ps! That's
kind of a surprise.

I guess, when all is said and done, I'll stick with my original plan to have Powerheads
port my stockers. I'll get better exhaust flow which will help offset the K-manifolds SWMBO
wants to use instead of tri-ys or shorties.

Thanks for the input!

Rich
'67 C-code 'vert (Dees67)
'69 GT FB (project car)
Check out my band: Brickyard Blues
 

·
Registered
Joined
·
3,047 Posts
Wait still, didn't you read the article about the guy porting heads for the first time and getting same flows as Powerheads. At least that got my fingers itching, luckily, I haven't spare heads or power tools, but those flow numbers are so impressive that maybe I should try. It takes time though.

Door handle first when cornering
 

·
Registered
Joined
·
652 Posts
Discussion Starter #8
I did see that article, and I was truly tempted, but then I used the handful of functioning brain cells I still
have and I realized:

1) Time - home porting takes a lot of time and I have to get the '67 on the road by Mother's Day (SWMBO's Day?)

2) Ooopsie! - If I screw up and bore through to a water jacket, I'm outta luck. If PowerHeads screws up,
they own the mistake and owe me a replacement.


Rich
'67 C-code 'vert (Dees67)
'69 GT FB (project car)
Check out my band: Brickyard Blues
 
G

·
Guest
Joined
·
0 Posts
I went with Power Heads and am a very happy customer. They are great people, especially Ralph. They do all they can to help you - even after you receive your heads and they have your money, which is something which seems to be getting more rare these days. I also like the fact that they did not try to sell me anything I did not need, and the general "old school" feel I got from them.

69 Royal Maroon Convertable
2001 GT Bullitt on order
 

·
Registered
Joined
·
10,587 Posts
Usually, flow characteristics are a function of port volume and shape....a larger, more aerodynamically shaped port will flow more...not necessarily better...

Street heads are designed to keep velocity up at low flow volumes to promote efficient mixing and delivery of the air/fuel mixture....that's because street engines spend most of their time at low rpm levels...

Racing heads are designed for maximum flow and velocity at high rpm's and airflows...

Just imagine putting a 1050 Dominator carb on a street 289...that carb would work great on a full tilt big block or screaming 351 C but would give you a gutless 289 because it would mix air and fuel inefficiently at such low velocities because of the enormous throttle and venturi volumes...
Conversely, and we see examples of this in NASCAR, putting a 4100 Autolite on a full race C engine or big block would restrict its performance because the carb wouldn't allow enough air and fuel to pass to develop the full potential of the engine's volumetric efficiency and air/fuel requirements...

Back to heads....it's often been proferred here that the 2V C engine head is more streetable than the 4V head....why? Simply put, because the ports are smaller, thereby promoting higher velocity and better mixing at lower, street, rpms....

The aerodynamic and engineering sides of this question are more the subject of a complete technical article.....you might read through the complete article from the URL I gave you...Joe Mondelo and his staff are much better than me at explaining these things in laymen's terms...

Hope this helps...

Pat
http://albums.photopoint.com/j/View?u=1570936&a=11937754&p=42910787.jpg
 
1 - 10 of 10 Posts
Top