Porting to reach high rpm breathing

[Fahlin Racing]

So once I had seen the size of the ports on these Dmax heads I purchased to investigate. Being the operation range is very low, these engines need to breathe if I decide to go high flow breathing.

Here is my idea and I will post pictures of what I am going to change. I doing it just to do it and see what happens. I am sure everyone is aware of the basic smallblock chevy intake port, Even though the LML heads have slightly different port /runner configurations front to back of the engine, I and going to cut some intake ports out of a SBC and rotate it so the height of the runner is changed to a wider runner when installed into the Duramax head. I know there will be quite a bit of cut, fit, cut fit etc etc but I guess you could say building a port will help understand the induction flow itself. It should be a good learning experience, hopefully I can find a reputable flowbench once I am finished.

I will be measuring the current circle ports, hopefully get something to CC the ports too before I cut the runners off. Dimensions will come later since I have not measured them yet.

How high have the stock heads been operated at before? granted the heads I have are different from others, mine are from a 2011 engine and are iron.

 

[slipclutchms]

Lml heads are iron?

 

[blk smoke lb7]

Lml heads are iron?

I believe he is refering to the sbc heads as the cast iron heads.


I would like to see what you find out.The guy that ported my heads has completely moved the intakes on lsx heads to be in the valve covers to give the straightest shot into the cylinder with great results so i think your on the right track i just dont know about reving these engines real high and the heat factor that comes with it.Good luck ill be watching for thread updates.

 

[ctrump90]

Subd

Sent from my MB865 using Tapatalk 2

 

[Hot COCOAL]

I would be afraid that my efforts would not yield such a great result, the dmax does not spin as fast as a LQ, LS, LSX, nor does it develop torque in the same rpm , therefore the flow of the head is less an issue, right? This is what i have come to understand anyways, coming from a slightly modified LS to a duramax

its forced induction v.s N/A parts comparison and thought process, two different " doctrine's" so to speak...

Still, one would think that doing this would yield massive gains, cuz if an ls motor can see a gain of say 60bhp or more, you would think a dmax would see gains of 150, i would give guy at So Cal a call and see if he would share some of his experience

Im curious to see what you would find out from this experience:thumb:
also is this something, or process that you plan to be repeatable? Or just like one off custom for your truck only? Just curious.

 

[hondarider552]

What are you going to do different than what Guy does?


I feel there is zero need to even mess with the LML heads because of limited tuning.

 

[blk smoke lb7]

What are you going to do different than what Guy does?


I feel there is zero need to even mess with the LML heads because of limited tuning.

So just because guy ports alot of heads do you think there is no improvement possible ?

Sometimes a fresh look at things is a good thing and if he is doing the r@d and shares his findings more power to him.

 

[juddski88]

what if they are not going on an LML?

 

[hondarider552]

So just because guy ports alot of heads do you think there is no improvement possible ?

Sometimes a fresh look at things is a good thing and if he is doing the r@d and shares his findings more power to him.

No, I think there is always room for improvement, but like Guy said, you can only take so much away form a aluminum head before it doesn't seal water anymore.

But from what we already have out there, I doubt there is anything the OP is going to do different. LML head is same as LMM with slightly diff injector bores.

JMO..

 

[blk smoke lb7]

All im sayin is im open to anyone trying to improve on what we have

 

[Fahlin Racing]

Lml heads are iron?

Yes, the heads I have are IRON and they weigh enough lol I was told they are off a 2011 Duramax mill. The SBC heads I will be using for parts are iron as well.

If my heads aren't a LML because they are iron, I must be misinformed for a 2011 Duramax engine from what I have read I guess. I can post the casting number if anyone would like, it doesn't bother me guys!

Hot CoCoal wrote:

I would be afraid that my efforts would not yield such a great result, the dmax does not spin as fast as a LQ, LS, LSX, nor does it develop torque in the same rpm , therefore the flow of the head is less an issue, right? This is what i have come to understand anyways, coming from a slightly modified LS to a duramax

its forced induction v.s N/A parts comparison and thought process, two different " doctrine's" so to speak...

Still, one would think that doing this would yield massive gains, cuz if an ls motor can see a gain of say 60bhp or more, you would think a dmax would see gains of 150, i would give guy at So Cal a call and see if he would share some of his experience

Im curious to see what you would find out from this experience:thumb:
also is this something, or process that you plan to be repeatable? Or just like one off custom for your truck only? Just curious.

If you view flow from anyview, airflow known has reactions similar to fluid flow within a port which is why its classified as a fluid. As far as N/A compared to Forced you have the same general active area between the two situations. Forced induction however you have more than just that and thats where you get some complications in improvemnt because if you create flow seperation you create vorticies and therefore you create a louder, less efficient port. Boost goes up, turbulence goes up!

Dry flow systems IMO seem to be slightly easier to deal with because we don't have to worry on fuel suspension, we just have to make sure our flow does not seperate from the walls roof or floor or with a circle port the runner surface in general. Like I said before, I am doing this to learn not only flow but to understand it more completely and its behavior just like all of you of fellow gearheads!

Is this Guy from So Cal on any forums at all? All I am doing is chasing power, like any of you, and what is limited on any engine is only by its own design parameters but if its possible, adding welds and material isn't outta the question One thing though I thought if, the rocker box on these heads may get into my way. I will just tackle that obstacle when I decide to go through with practicing that runner position change.

This first project I am going to attempt I will make it easy as I can, probably being able to duplicate it on each port but you have to remember look at the runners before anyone even attempts a job like this. Also changing the runners will change the intake manifold design. I think from this engine outta the 2011 the OEM intake is 3 pieces. I never got to see it though so I couldn't tell you how much different it could be!

Some photos will be posted soon. Its should be a interesting project for everyone.

 

[duratothemax]

Yes, the heads I have are IRON and they weigh enough lol I was told they are off a 2011 Duramax mill.

uhh yeah you were told wrong.......the LML heads are definitely aluminum.......just like every other duramax in the world......

GM hasnt made an iron-headed engine for like 10 years.

 

[duratothemax]

Its should be a interesting project for everyone.

I would start over again....this time with actual duramax heads.


Im still not sure why you are so hellbent on reinventing the wheel. And/or what you think really "must" be done to heads that can already do well over 1000hp without any porting or "work" at all. This isnt the gasser race cars you are used to working on. You really dont "need" to touch the heads on a duramax. I mean you do, but you dont, kinda. People who have been in the high-hp duramax world for a while know what I mean by this.

Im not trying to be an ass, but if you really are looking to pour all sorts of new outside knowledge into the duramax platform, it would be more useful to take a look at areas that actually do need help and are still "wild cards". Such as the crankshafts and/or pistons. Im not saying there is "nothing" to be gained by messing with the heads, but really, the heads are the last thing that needs super technical attention and "thinking" when building a high hp duramax. In my opinion.

ben

 

[RPM Motorsports]

Nice...! Can we get a pic of the heads?? Be interesting to see what your working with.

 

[Stingpuller]

Pretty spot on

Verywell said Ben. You must have woke up on the right side of the bed today. LOL

 

[Trippin]

Fahlin is on the right track. Sounds like a fun experiment.

The Duramax head is pretty disgusting airflow wise. Even after porting and big valves they still don't flow as well as good as a set of SBC aluminum street heads, let alone a race head. The factory casting is just limited. Sure, you could weld a set up and then re-heat treat the casting, re-machine every surface (because it warps during heat treat), and you would end up with a very expensive set of heads that probably won't last a season of sled pulling or drag racing while holding water. The factory material is just really bad.

An engine doesn't know if it is a SBC or SBF or LS1, it basically comes down to the physics of the engine. Bore, stroke, rod ratio, airflow, length of runners etc.

I actually ran a set of LS1 heads on a small block Ford once just to prove a point. The two engines have very similar bore centers, bolt patterns etc. fabbed up an intake and exhaust to fit in a Fox body mustang and off to the races we went.

I look forward to seeing and encourage his progress.

Guy

 

[Fahlin Racing]

I would start over again....this time with actual duramax heads.


Im still not sure why you are so hellbent on reinventing the wheel. And/or what you think really "must" be done to heads that can already do well over 1000hp without any porting or "work" at all. This isnt the gasser race cars you are used to working on. You really dont "need" to touch the heads on a duramax. I mean you do, but you dont, kinda. People who have been in the high-hp duramax world for a while know what I mean by this.

Im not trying to be an ass, but if you really are looking to pour all sorts of new outside knowledge into the duramax platform, it would be more useful to take a look at areas that actually do need help and are still "wild cards". Such as the crankshafts and/or pistons. Im not saying there is "nothing" to be gained by messing with the heads, but really, the heads are the last thing that needs super technical attention and "thinking" when building a high hp duramax. In my opinion.

ben

No problem Ben, and I am not necesarily reinventing the wheel, if you have followed any high competition racing there have been people whom have repositioned ports etc. in heads.

I actually turned something up on this set of heads through google and these happen to be 6.0L Ford heads!! Danit Ben why do you have to get a downer lol Just kidding, I enjoy your straight shooting attitude man. I really wish these were Dmax heads though!!! I will have to look around for some now!

For now, this thread will be on HOLD as far as pictures, but ideas can still be thrown around!!!

O well, looks like my first major porting project will be a 6.0L ford head, I knew the casting number looked odd with the C as the second to last digit for a GM piece, oh well a victim of assumption lol made an ass outta me! dun dun dun. This is funny.

Where to find junk Dmax head(s)? hmmm

 

[Fahlin Racing]

Sorry everyone about the mislead on this one!

 

[Fahlin Racing]

Hey, theres Guy! Just noticed you there posting the last before my last replies, anyways I must zip on to work now.

 

[Trippin]

After buying, selling, and porting these things for 7 years I've got a pallet of unported junk Dmax heads. Literally.

Pay for the shipping and I'll send you a couple.