Thread: Porting Question.

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whats the correct term for this finish??

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Originally Posted by BigTruckDriver

whats the correct term for this finish??

http://www.clubhotrod.com/forums/att...lish-20006.jpg

I would call it "as cast"

The heads I did before these . Were a set of 1972 350 #993 heads . That time I had more time then money to . Well that set took 60 Hours to finish . But man you should have seen how that car ran and sounded . That engine was a Low C/R 350 in 1978 Z-28 with a 450 Lift cam a 2800 stall and a 3.42 Posi . Even had a ported iron non-EGR intake from a truck on that build . I did the curve kit on the HEI and had a set of headers . That car ran 13.80s right of the high way . But not long after that a rod bolt failed . On some things you don't want to cut corners ! Rod bolts being one of them things . Add photo 11.48 pm

Both Tango and Denny are good. I ported my 305 heads(first time I did it) and just spent 9hrs. doing it with a hand held grinder. Showed it to a mechanic friend of mine who does it for a living and he suggested I take it down a little more but otherwide he said not bad. He said with the cam I had in my 305, the engine would breathe a hell of alot better. If I really had taken my time, I could have done alot better job after looking at some porting jobs done by my friend. I picked up alot on the higher end after 5,00 rpm's.

porting is not that bad i just hate the iron in the eye here one for you tango and ported the heads to and smooth out so much more but no photos of all that i do most of my big blocks this way the screens were not epoxy in the photo

Them 305 heads need a lot of porting . The bowl area or also called pockets . And all them casting bumps Never again will I do a set of these 305 heads . But the 355 they are going on will make 400 HP when I am done with them And that will be COOL .

Here's a little more about it;

A common thing that porters like to do is gasket match the heads and intake. First
for this to work it assumes that the manifold fits perfect to the heads intake face. This also
assumes that the gaskets size is right for the application. Gaskets are not designed with
airflow in mind. Remember that the majority of the port flow is on the port roof not the
port floor. Therefore removing lots of extra metal from the port floor isn’t going to do
anything other then increase port volume, which will decrease port velocity. It has also
been shown that gasket matching if not done right (i.e. proper size etc) can decrease
overall flow across the board. In a wet flow manifold (i.e. Carb or TBI) it is also actually
best to leave about a .050” step from the port floor of the intake to the port floor on the
head. The port floor on the intake should be higher. This step gives the fuel which has
puddled on the port floor a chance to re-introduce itself into the air intake stream. It acts
as a fuel shear point.

Originally Posted by camaro_fever68

Here's a little more about it;

A common thing that porters like to do is gasket match the heads and intake. First
for this to work it assumes that the manifold fits perfect to the heads intake face. This also
assumes that the gaskets size is right for the application. Gaskets are not designed with
airflow in mind. Remember that the majority of the port flow is on the port roof not the
port floor. Therefore removing lots of extra metal from the port floor isn’t going to do
anything other then increase port volume, which will decrease port velocity. It has also
been shown that gasket matching if not done right (i.e. proper size etc) can decrease
overall flow across the board. In a wet flow manifold (i.e. Carb or TBI) it is also actually
best to leave about a .050” step from the port floor of the intake to the port floor on the
head. The port floor on the intake should be higher. This step gives the fuel which has
puddled on the port floor a chance to re-introduce itself into the air intake stream. It acts
as a fuel shear point.

Makes since , the heavier "solids" will naturaly go to the bottom since they are heavy.......

There are a lot of theories to how it works. Some proven and some not. I've found that you do better if you do a lot of research and create your own theories. Or trust a good head porter and let him figure it out for you.

Originally Posted by camaro_fever68

There are a lot of theories to how it works. Some proven and some not. I've found that you do better if you do a lot of research and create your own theories. Or trust a good head porter and let him figure it out for you.

I did the research in books photos and racing . Don't have the ca$h to burn on a Pro head porter . I am very old School carb only race cars . Have had EFI-TPI 5.7 F-body street / strip cars . Pulled all that new EFI stuff off and installed a Carburetor and High Rise intake . Every time the cars were Faster

Hey guys, great discussion. I am currently learning cylinder head porting. The great thing about the class is having access to a flow bench. I am able to see the changes I am making in regards to flow and velosity. I was surprised to learn that even some of the high dollar after market heads still needed porting to reach their potential.

thats a foundry (razor back) finsh