Captube length on Mach2 Modded

[martinakerman]

Well as everybody knows and can check in many forums
the cap tube add on a mach2 to R404a is 1,5m.
Same on R507, as uses same cap tube length.
But i heard some poeple using 1m or 0.60m add on-.
what is the difference so?
If sombody has a bowman´s mach2 modded or knows about
Mach2 GT cap tube lenght, please post.

[Gary Lloyd]

Cap tube sizing is a trade-off between capacity (the amount of heat load the system can handle) and evaporator temperature. Extending the cap tube will give you a little lower temperature, but will not be able to handle as much heat.

Without the extension, modded to R404A/R507, the unit can handle about 200 watts heat load. With the 1.5 meter extension, about 150 watts. With .6 meter extension, probably about 175 watts.

These are just rough estimates.

[Ragnarok]

Personally I'd prob leave it alone, as the newer processors really dump out a huge load when overclocked to the edge..

[bob(nz)]

I havent got my original workings handy but by memory....

A P4 3.4EE clocked at around 4300 generates 165W, while an Athlon 64 running at around 3100 would generate around 175W.

Maybe the 0.6m mod isnt such a bad idea - tuned for optimal heat removal :stick:

[Gary Lloyd]

It should be kept in mind also that a cap tube mod is much more complex and expensive than a refrigerant mod. IMO, a cap tube mod is not cost effective.

[Gary Lloyd]

To expand on this:

Consider why we change the drier and pull a deep vacuum on a system. We want to remove all of the air and its associated moisture from the system, because the system has been opened to the atmosphere. What if we can change the refrigerant without opening the system? We can.

We install a piercing valve near the end of the process tube on the compressor. This does not open the system to atmosphere. We then remove the R134a from the system and pull a vacuum. Then we charge the system with the new refrigerant.

How deep do we need to evacuate? R404A contains 4% R134a, so if we don't get it all out, it is not the end of the world, although we want to remove as much as we can.

What happens if a little R134a is mixed with R507? It becomes R404A at 4% R134a. Again we want to avoid the mix, but the result of not getting all of the R134a out is not earthshaking.

When we have the charge just right, we use a pinch-off tool to pinch the process tube near the piercing valve. Then we cut the tube between the pinch-off tool and the piercing valve and braze the end shut, just like they did at the factory, then remove the pinch-off tool and we are done.

At no time has the system been opened to atmosphere. No air/moisture has entered the system.

[wilso]

Originally posted by bob(nz)
Maybe the 0.6m mod isnt such a bad idea - tuned for optimal heat removal :stick:

I agree, I had my Mach II 404a modded with 60cm cap tube and works very well, especially when these newer CPU's are coming out with a lot higher heat load. :)

[martinakerman]

Thanks for posting...
I have decided mod my mach2 only changing the gas.
So it would be able to handle more W for future CPU.
And also the mod is chepear.
Well as soon i have my mach2 modded i will post the results.
Thanks all of you.

[jan]

Hey, does anyone know the original length of the captube. (machII) ?

[martinakerman]

1.5 meter.... i think

[Marci]

61.5" (1.562mtrs) of 0.028" ID CapTube for Stock 134a Unit

[jan]

THX.

Which ID ? I forgot to ask...

[Marci]

see edited post above... fer some reason I put the 404a length in before as the stock length!! S'been one of those weeks!

[jan]

Thank you :)

[CodeRed]

Originally posted by Gary Lloyd
To expand on this:

Consider why we change the drier and pull a deep vacuum on a system. We want to remove all of the air and its associated moisture from the system, because the system has been opened to the atmosphere. What if we can change the refrigerant without opening the system? We can.

We install a piercing valve near the end of the process tube on the compressor. This does not open the system to atmosphere. We then remove the R134a from the system and pull a vacuum. Then we charge the system with the new refrigerant.

How deep do we need to evacuate? R404A contains 4% R134a, so if we don't get it all out, it is not the end of the world, although we want to remove as much as we can.

What happens if a little R134a is mixed with R507? It becomes R404A at 4% R134a. Again we want to avoid the mix, but the result of not getting all of the R134a out is not earthshaking.

When we have the charge just right, we use a pinch-off tool to pinch the process tube near the piercing valve. Then we cut the tube between the pinch-off tool and the piercing valve and braze the end shut, just like they did at the factory, then remove the pinch-off tool and we are done.

At no time has the system been opened to atmosphere. No air/moisture has entered the system.

Hey Gary,
Thats what I did the very first time I modded my Mach I. It was really quick and painless to do.

Only thing is that I didnt pinch off the process tube and just left the piercing valve in place. It probably aint the best thing to do as it may leak, but its been a year now since that was done and it hasnt leaked yet.

[Gary Lloyd]

They don't always leak, but they are notorious for it. Maybe you got lucky. :D

The system runs in a vacuum, so if it leaks, you lose refrigerant while it is off, and suck air/moisture in while it is running.

[CodeRed]

Originally posted by Gary Lloyd
They don't always leak, but they are notorious for it. Maybe you got lucky. :D

The system runs in a vacuum, so if it leaks, you lose refrigerant while it is off, and suck air/moisture in while it is running.

well if that happens I am sure I'll find out very quickly :(

this weekend the prom is getting regased to %07 anyway, so I might as well replace the peircing vavles with Shraeder valves.