Porting to reach high rpm breathing

[EDP]

empire did this a while back

Been porting this way since 2008 and still to date. As well as a few larger versions running on a few big motors in the sled pull world.

Mark, great addition to the thread. Ben, thats in the general idea of what I have planned. Joining them until they must split.

From the picture it looks like they removed a couple inches into the head. The radius itself shows me they are still using a plenum type of intake like the factory one, I could be wrong with my assumption though on what manifold is ran on these heads. What I want to determine is where the main flow path is and go at it in that respect. I will not actually be employing a radii around the runner entry.

Brings up some interesting thoughts.

We have ran all kinds of different manifolds to date and have yet to see real world performance gains to justify the high dollar bling intake manifolds that have been coming out lately.

Have a small question here, I found a firing order for these mills. Just want to verify this is the correct firing order for a Duramax, 1-2-7-8-4-5-6-3. With the passenger side as the leading bank.

Some are changing the fire order to help relieve crank shaft failures

 

[Fahlin Racing]

Thanks for some insight on the realm. What other firing orders have you seen EDP?

 

[boominator]

12734568 is one it is a powerstroke firing order
he wont tell us about the other one or ones there a trade secret :secret:

 

[Fahlin Racing]

Bump, should around a week or two before I see my carbide.

 

[Fahlin Racing]

Ok, forgetting once again that moving your stuff in photobucket removes photos. I will use the same picture I highlighted flow routes as my picture to point of areas i would like to remove. As well as repost the picture from Danville I asked about the oil feed hole for those that haven't seen it.

First the oil feeds with the red arrows.

My first things in mind that I will do in pointed in Yellow w/ the runner routes in red.

This bend pointed in yellow I plan to make more gradual which is probably going to entail material removal to the point of need to fill in the outside void and shape accordingly. Once I remove the divider which many have done thus far already I plan to do some filling, not a lot though.

To make filling easier at the present moment I will be using Splash zone epoxy which I bought from Reher-Morrison in Texas. The stuff has worked great on my other head project so I recommend it if you need an epoxy. It just doesn't last much at all on the exhaust side due to extreme heat.

Would anyone happen to have a picture or measurement of how close the pushrod is to the runner of the right side 'L' like shaped runner I am pointing to?

 

[Fahlin Racing]

Nobody has a picture with a pushrod installed on these? Oh well.

Anyone's thoughts on what you want me to disect on these? I have 2 heads from Guy @ socal so I can chop up whatever.

 

[Fahlin Racing]

Since we don't have to worry much about flow velocities, more of just overall mass flow (pounds of air) we can simplify certain things however runner texture will still play a role as well as using a valve job that will hinder reversing intake flow. Not sure how well this will turn out, but, I have 8 cylinders worth of ports to modify and hopefully score something for us weekend warriors to let the breathing more freely begin and turn up the heat at the strip, sled pull or off-road race :thumb:

 

[Burn Down]

Looking forward to seeing what you do.

 

[Fahlin Racing]

I hope I can find something new as well, positive thinking buddy!!

This one was a labor of love yesterday evening, no band saw so whats the next best thing? hacksaw! lol

This last one is kinda blurry which I will have to get a better one but I figure I wiould post it anyways to give the angled shot.

As I go I will use paint markers and arrows etc etc for pointing things out. I will probably have some questions for some of the Dmax gurus arond here who work with these things day in and day out. Any ways, here are some pictures to chew on.

 

[Fahlin Racing]

My first perspective of the straight runners here is the floor for about the first couple inches should be lowered and the roof a few inches inward should raised to match it to the opening and roof by the bowl area for the first immediate portion of the port. The SSR looks a little rough which should be a smooth transition to the valve seat angles other than that the rest of the port maybe just texture it for starters possibly.

My reasoning behind the two spots in the roof and the beginning of the floor, is to produce a linear runner with the top and bottom surfaces to start with. If you remove the area that droops in the roof you free up a little room for higher rpm flow IMO. With the roof surface at a higher point, the easier, flow itself, can adjust within the GFA (geometrical flow area) of the runner and approach the bowl and seat area more efficiently. With that, the flow sees the valve at a better angle and in turn we see a climb in CFM (w/ everything being in the right situation). Not sure how much it will be worth with just doing these two areas but time will tell for me. Each cylinder I will have tested when able but for now, The sections of the roof and floor and the SSR are my concerns.

I know Guy has CNC'd majority of what can be removed from a stock head, however I am after what areas can be worked and how much work it will be for the weekender that can't afford a set of heads that wants to go faster of pull a load with more confidence in his engine. In turn can afford a set of porting abrasives and the time put into the project. This project will be one port at a time, if I can I will make some silicone molds of the runners too.

 

[Fahlin Racing]

Here is a clearer picture with markings.

With the two colors I should have done 3 colors to seperate the sections of the runners in terms of airflow importance througout the runner as it approaches the bowl. Any ways, as far as the roof and floor, the two areas I spoke about as immediate removal areas within the first couple inches on the floor and few inches on the roof. The outside edge of the paint marker is what I would like to raise the roof to and lower the floor to.

The least crucial portion of the runner is near the entry of flow, next, near the middle we not only approach the bowl, but, we are at a higher level of crucial flow influence and concern. This area is where the flow itself kind of initiates itself to flow across the SSR and move around the valve stem. What is happening ahead, in a way, influences the upstream flow approaching the valve. I have been looking more at the SSR and it is a little on the flat side actually and about as wide as my pointer finger, which is about 1/2" maybe a little more in width. I marked the short-side-radius in red meaning the congervgent side of the valve is VERY important. Everything I have been told and everything I have learned we need to shape not just the port, but we must develop a port/runner that changes (hopefully) in the correct flow direction and physical shape in a way that gradually changes from one plane and turn as its shape has changed to not only flow between the seat and the valve but flow into the chamber as a system at all lift incriments both against the firedeck of the head and around the chamber side of the valve.

I have mentioned before on another forum that the flowbench can help you tune your cylinder heads, I believe this only because I understand this unit as a tool only however without flow balls or velocity probes etc you can't without the additional tools all you are doing is chasing numbers. Some may not agree, this is just what I believe.

Notice I have also marked the stem guide too. This protruding into the bowl without any meat to make a tail to provide a flow recovery landscape, will it do any good to remove it or would this particular application improve from its removal?

 

[RPM Motorsports]

empire did this a while back

Since the heads are off the Chevelle, I've spent the last two days doing this for the hell of it. It makes it nice porting around the corner inside for sure. I also cleaned up the bowls, some guides and left the exhaust alone. We will be racing next Sat, and I'm curious of any ET/MPH change over a stock head.. I'll post any findings.

 

[blk smoke lb7]

Since the heads are off the Chevelle, I've spent the last two days doing this for the hell of it. It makes it nice porting around the corner inside for sure. I also cleaned up the bowls, some guides and left the exhaust alone. We will be racing next Sat, and I'm curious of any ET/MPH change over a stock head.. I'll post any findings.

The intake on mine only picked up 30 cfm Russ,theres 60 cfm to be had on exhaust side atleast gasket match and manifold match.

 

[RPM Motorsports]

Not sure that I've got enough time this go around. I didn't plan on spending as much time on the runners and bowls as I did.

 

[Fahlin Racing]

Anyone have some thoughts on the flattened SSR? I am wondering if it passed its optimum angle going to the bowl. Maybe its not.

 

[JoshH]

Russ, are you guys still coming to Texas this week?

 

[Fahlin Racing]

So I have decided to fill the floor from where it drops to the short side radius for a consistent floor and work from there for higher rpm breathing range efficiency.

 

[Fahlin Racing]

Now the more I think about these heads, I haven't spent much time viewing the floors of the inboard runners, they may have the dip or they may not. I will need to look at them next time I am able because there just may be a different 'equation' of sequences to port these heads.

I just love the thinking involved !!! (no sarcasm) :thumb:

 

[RPM Motorsports]

Russ, are you guys still coming to Texas this week?

Just saw this Josh, no we aren't coming . Rick got into some oil at the top of the track and kissed the Guard Rail @ 132mph. Motor is already out, and body work/paint in progress.

 

[Fahlin Racing]

As far as what this head looks like on the floor with a flatter SSR, the Dmax head may just seem to be developed to work well in a mid-range operation range, but, the height of the runner-roof I would say limits this. If anyone would care to voice what they feel about the head flow, I am all ears to view your point of view. I think there is still something left, I won't be doing many major mods for more flow here. Albeit we must think of enhancement of swirl quality within out combustion space too so we can not neglect the chamber side of the valve seat not just for the purpose of swirl but for the purpose of relieving the upstream flow characteristics that appear to be a negative.

Are there any posted flow numbers for stocker heads here? I tried a search and nothing really dedicated to flow rates.

What about CC of the runners? Has anyone really thought about that in terms of overall flowing capacity of the runner within adequate flow velocities?