cylinder porting/flow experts?

This is tough to explain but I am gonna try.

ex valve ************X ex valve
**
**
**
**
exit

Imagine this is a port configuration top view. The ports are very crude on the old head and I think this setup is poor for flow due to the sharing of the exhaust port between the two cylinders. Do you think a triangular shaped spoiler between the two exh valves in the middle of the shared port would help? It just seems like a cavernous dead spot. I'll try to illustrate.

valve ****X V ****** valve
**
**
**
exit
The V is an epoxied or bolted in air dam. Top view once again.
I wish I was better with a pc as some of you. Hope I got my point across. JP IMPORTANT When I posted the thread it moved the port exit. Please imagine the exits in the center of the illustrations.

 

Saw - Want kinda motor is it?

 

Here's a pic of the head, 28 chevy. Two ports for intake, two for exh.From left to right it's exh, int, int, exh, int,int, exh

 

Epoxy and exhaust ports don't mix.

 

I would let a flow bench tell me if a modification would help or hurt.

 

I have no camera today. I think it would help by keeping the exh from traveling down a dead end hallway and and or fighting the opposing cylinder exh. before it exits. I missed a payment on my superflow 9000 flowbench so now all I have left is my limited knowledge of aerodynamics to go by if i wanna improve this dinosaur.

 

Check the Tractorsport.com flowbench board
for lots of good info on building your own.

Not saying your idea won't work,but it's kinda hard
to visualize from your description when i don't have
a '28 Chevy head here to reference.

One big lesson I learned on the flow bench,is things
don't always work exactly the way you might like them to.
-------------
For adding inserts into the ports,my first choice is bolting.
Second choice is welding or brazing.

What application is the fire breathing monster for ?

 

My model a ford. I am gonna try and see what happens. It's an experimental engine.

 

Street motor ?

 

yep.

 

I would think that it would depend on the timing sequence between the two valves. If they are firing one right after the other it might be an issue. If not, the flow would tend to go in the line of least resistance, and probably not be a source of major gains. But stay away from epoxy in that area.

 

depending on the firing order of the cylinders is going to depend on if the modifications will help. if the cylinders fire in sequence with each other then there may be an issue with the current flow. the exhaust is going to flow wherever it can reguardless if there is a divider or not. if you are worried about how well it is or isnt flowing right now i wouldnt add any metal or anything else for that matter to the port. the only thing thats going to do is add a restriction to the port and make it smaller. i would just leave it as is.

 

The key word here is "Application"
There are epoxy style products available designed especially for head modifications.

http://www.mondello.com/Catalog/cyl_head_tools.htm

 

And did you read the text beside that picture on the Mondello site ?

"Professional epoxy kit for filling,repairing & shaping all
intake ports & intake manifolds. (Do not use on exhaust ports)...."

The first post in this thread refers to modifying the exhaust ports.

 

I used that stuff underwater when I was a diver, tough stuff!

 

Hey Sawracer, Take a pic from the port side of the head. I'm a cylinder head guy and now you got me thinkin' but, more info is needed. I'm not familiar with the early Chevy deal but, it has me intriged. Smokey

 

Here's some pics, For the record we are discussing the intake port, sorry if I screwed this up earlier. I have a head on pic. It shows the dead end, dead spot I want to put an airfoil in. The other pic shows where the airfoil would be in yellow and the yellow lines outline the intake port shape in the head. I am sorry if the pic has a nutsack look to it. Can you see the portwork?

 

Just like a Diver I bet you got some poly rope and ductape on your ride to huh All kidding aside we still use the **** out of it,but I don't know if i would on a head.

 

I used to work for Global Diving out of Louisiana (New Iberia)

 

Splash Zone (above) is supposed to be good on intakes.

Search on the Speedtalk.com engine forums for "Splash Zone".
Some of the guys have specific ways of preparation and applying it.

 

She's running again so we can speak hypothetically till it blows another head gasket.

 

One line of thinking,is you want the air to slow down,
so it can change direction.

 

For the record, it's running great with the improvements. As usual the power goes right thru the clutch. I am not into any more top speed runs for now, gonna enjoy it for a while. I can't find my GPS anyway and I'm pretty sure I can pin the speedo. When I am willing to break it again to figure out what she is capable of I'll time her. Till then Happy Hot Rodding. A little before and after porting. There was an ignition upgrade also so it screws up the mix, but it seems to have more snap to me.

before


after

 

After a few Heinekens I don't if i can tell the ****** difference. Can You? I guess a GPS is the only true measure, or a dyno.