Exhausting Exhaust Port Divider Question

[rayell]

Epoxy would be out the question, for me in that much heat. I would use Nirod on that cast iron.

 

[Anonymous]

I was talking to my dad about tacking in the port divider. He welds for a living, so he said it'd be no problem. His only concern was the possibility of a wayward spark getting inside the exhaust port and ruining the valve. So, I'd like to hear of how any of you installed your divider. I'm assuming 3 tacks at each point of the "T". Any special precautions taken?

 

[ludwig]

The welder stuffed a rag way down inside. Pulled it out afterward. My welder ground off little wedge shaped reliefs at the three points that open to the outside for the weld bed. Tapped it with the hammer after. No slag or spikes; all smooth.

 

[CobraSix]

Here is my opinion on the port divider question:

1) SAVE YOUR MONEY!

2) SAVE THE HEADACHES!


Okay, here is my reason for those opinions.

I've run 2 heads with the port divider installed. Originally I had one installed on my Offy 3x1 head. Since I did it at the same time as the other modifications, I couldn't tell if there was a difference.

Move to head #2. When I bought my Aussie head a few years ago, I installed a Port divider using my high temp epoxy (no, not JB Weld...real 3000* turbine exhaust epoxy). This method had worked great on my US head where there was still the "ww" intereferences on the head. My Aussie head was smoothed out on the 3-4 port so I had to use the epoxy to build it up. 2 years later the epoxy broke down and for 2 years I dealt with an annoying rattle until one day last summer I couldn't take it anymore and pulled the thing out. Any anyone with a Aussie Head with Pacemaker 1 peice headers knows, that is no small task (which is why I left it for 2 years).

Result...I've been a happier man since. Power? I've not noticed any significant changes. I did not run any dyno tests, so my only results are seat of the pants and I can honestly say I felt no difference on the Aussie head set up with coated dual out headers. The exhaust note is still very nice, but sounds a little bit smoother now.

I'm not debating that the port divider may improve things as the theory behind it does support that conclusion. And I'm sure it does help some, but I seriously doubt it'll increase power then 1%.

As far as the "burned out exhaust flanges", I haven't blown out my gasket yet and the head still appears to be fine.

My other concern is even with wielding them in place, how are they being welded as you can't weld cast iron to cast iron. Sure, you can temporarily, but it will eventually result in corrosion inside the head or broken welds or both.

So in short, if you really want it...wait until you pull the head for other work. It simply isn't worth it to pull the head just to get this item installed.

Slade

 

[Bort62]

you can't weld cast iron to cast iron.

Bs

Port Divider still isnt worth crap...

 

[CobraSix]

you can't weld cast iron to cast iron.

Bs

Port Divider still isnt worth crap...

Let me clarify,

You can...but it won't work great...but since I guess it's not a structural wield, it doesn't matter too much...

 

[jamyers]

If all that heat didn't make a difference between 3 aqnd 4, how come all the original stock manifolds have a burnt through choke air tunnel? Put the divider in on the motto of 'a licking to nothing'. Meaning: the best you will get it nothing at all, which is better than almost certain damage to an expensive part.

Fixed that for ya.

Good point about the blown-out manifolds - just about every one I've seen is eroded there.

 

[CobraSix]

If all that heat didn't make a difference between 3 aqnd 4, how come all the original stock manifolds have a burnt through choke air tunnel? Put the divider in on the motto of 'a licking to nothing'. Meaning: the best you will get it nothing at all, which is better than almost certain damage to an expensive part.

Fixed that for ya.

Good point about the blown-out manifolds - just about every one I've seen is eroded there.

But that could also just be a symptom of worn out exhaust gaskets the people never replace. I know I rarely do...especially on my slightly newer truck that has a leak at the manifold but I'll never dig in there to replace it.

I actually had more problems around the #6 port then the 3-4 port.

 

[ludwig]

Not the gasket. The wall between outlets 3 and 4 in the exhaust manifold [sic per asa] across from the two ports, where the air travels to be warmed for the choke pull off.

 

[CobraSix]

Oh, I only had one head with the choke port.

Still could be caused by condensation sitting in the port and wearing out the iron. 40 years is enough time for water to burn throw that metal.

 

[jamyers]

Oh, I only had one head with the choke port.

Still could be caused by condensation sitting in the port and wearing out the iron. 40 years is enough time for water to burn throw that metal.

The couple I've seen were eroded from the exhaust side. Not that water in the choke passage wouldn't contribute. (shrugs)

 

[ludwig]

The two I saw were charred, actually burned like as a cinder. I believe that it gets super hot right there, starts to glow and begins to spall. This yields more little tips that glow and it eats through from the exhaust side.

 

[Bort62]

Mine is wasted - but who cares? I just ground it flat w/ the rest of the flange and put it back on. I'm not running a choke anyway.

I don't see how the port divider would effect this. You will still have a chunk of metal with a small local mass in a high velocity hot gas stream. Erosion may occur...

 

[Anonymous]

Wow! I wish there were just a simple answer. I just can't make up my mind. Those of you who did install one, were you able to just weld them or did you have to preheat the head and such? My dad said that probably wouldn't be necessary. Also, what size rod did you use?

 

[CobraSix]

Well, to even try to wield cast iron correctly, you have to bake the head to the right temperature for the rod. And even then, you really can not do it to the degree of success as wielding Steel, AL, etc.

Slade

 

[Bort62]

Well, to even try to wield cast iron correctly, you have to bake the head to the right temperature for the rod. And even then, you really can not do it to the degree of success as wielding Steel, AL, etc.

Slade

That depends entirely on the quality of the cast iron. I've welded my block, exhaust manifold, and turbo turbine section all with varying degree's of success.

 

[CobraSix]

I'm not saying it can't be done with some success...but it is not a true and proper weld. Sorry, can't happen with cast iron no matter what you do. I mean, doing spot welds around the house on fences, attaching stuff to blocks, filling in thin spots on cooling ports (which I've done) is one thing. Getting good, proper, structurally sound welds with cast iron can't happen.

 

[Junk-Falcon]

ppp

 

[jamyers]

braze it in place n it will stay for ever
braze it in if ya gona use it

+1 8)

 

[BIGREDRASA]

braze it in place n it will stay for ever
braze it in if ya gona use it

Verrry interesting......