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#60
by
RabbitJockey
on 08 Nov, 2011 07:45
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hmm that turbo looks just about perfect, i'd like to see a more detailed compressor map with efficiency islands. why so much work with the cam and porting then u are still using the stock intake manifold with that extreme bottle neck in the elbow.
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#61
by
Alleslowbuged
on 08 Nov, 2011 17:39
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Hi,
you are right about the intake manifold, i have start to build a dual plenum for more than one year, but a shop has make the welding wrong and so i have
to start again on that issue. Actual i only wand to bring this setup in a running status, before i try "big" numbers i will change the intake manifold.
Best Regards
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#62
by
Alleslowbuged
on 09 Nov, 2011 07:26
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Hi,
i was in a engine rebuilder shop today, but the told me that they could not weld it, because it is to difficult to get to the crack with the tig torch and the welding rod.
@Tobi,
many thanks for your suggestion, i will go on and will try to solder the crack. I have just speak with a retired alu soldering specialist, who means that this could work.
He recommended to use a 400°C tinning solder (soft solder) together with flux compount for hard soldering. From my personal feeling i would say hard solder should work even better as its getting capillary on the right temperature, but there could be the problem. How to ensure temperature above 560°C but below 650°C at this position.
I have allready ordered the solder material, next is to get clear how to heat up the head all-over up to 200°C - 300°C.
If you have successull repaired a cracked cylinder head with soldering?
Best Regards
Alleslowbuged
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#63
by
vanbcguy
on 09 Nov, 2011 10:33
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Since it's an intake port, epoxy is another option. Some race builders in fact will go in to the water jacket on purpose, and then use epoxy to rebuild the port to the shape they want.
If you search 'epoxy head porting' on Google you'll find quite a bit of info...
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#64
by
rabbitman
on 09 Nov, 2011 14:19
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Since it's an intake port, epoxy is another option. Some race builders in fact will go in to the water jacket on purpose, and then use epoxy to rebuild the port to the shape they want.
If you search 'epoxy head porting' on Google you'll find quite a bit of info...
It's actually the exhaust port
.......and yes I'd try getting it welded before just scrapping the head.
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#65
by
Alleslowbuged
on 21 Nov, 2011 14:07
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Hi,
i have tried to solder the crack last weekend. For soldering i have had to get temperature of min. 400°C, but even with preheating to hole cylinderhead up to 280°C and using two propan burner (each with flame temperature of 1900°C) i could not reach necessary temperature. By trying to solder i have open the crack, which is now a hole (appr. 7mm x 5mm).
I now look for a "new" AAZ cylinderhead, if any wand to sell one for a reasonable price please contact me.
Here is the crack:
Here is preheating (4,5 kW)
Here is the hole:
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#66
by
R.O.R-2.0
on 21 Nov, 2011 14:13
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you got it TOO HOT, and burned the material.. aluminum burns, it doesnt melt..
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#67
by
Alleslowbuged
on 21 Nov, 2011 15:19
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Hi,
no i did not get it too hot. The crack transform into a hole due to mechanical pressure from a screwdriver not due to heat.
There was no point at no time with a temperature higher than ~420 °C
I had scheduled to solder with "hard solder" at a temperature of 560 °C, but even with the two burner there was no chance to even reach 500 °C.
Best Regards
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#68
by
vanbcguy
on 21 Nov, 2011 15:28
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#69
by
BlueMule
on 21 Nov, 2011 17:41
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Alles, before trashing the head please look at this product. No preheating needed, oxy/acet might work best for your application. I have heard of some head builders here in the US using it to do port relocations, of course it just might be a vicious rumor
http://www.aluminumrepair.com/gas-welding.htmBlueMule
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#70
by
Toby
on 21 Nov, 2011 20:56
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The solder that I was talking about has a much lower melting temp. At 560C you would have had the valve seats and guides fall out, so it is good that you did not get it that hot.
http://www.alumaloy.net/alumaloy1.htmhttp://www.youtube.com/watch?v=TZ5sD9hQTywI use this stuff and it is PFM. Just make sure that you don't get the item to be repaired too hot before you put the solder to it. Put the solder to the work as it heats up. It will flow when it is hot enough. This stuff is great for repairing ICs and aluminum radiators.
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#71
by
Alleslowbuged
on 22 Nov, 2011 02:56
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Hi,
i think i did not wrote it very precisely, i had used a solder material with a melting temperature of aprox 380-400 °C.
Before we start i have scheduled to use the higher temp solder material, but than recognize that we will not reach
temperaures in that region. The solder i have used is normaly used without flux, but the expert from shop, where i have
get the solder from, means i would be good to use the flux material even with this solder, because i allready expected
that it will be difficult to get the necessary temperature.
Now i have the problem, that a nameable amount of the solder material is flowed into the water chanel i dont thnik i can
remove it from there, even if it is not really melded together with the head. At the end the problem was, the the hole was
so big, that the surface tension from the fluid solder material was not high enough to close the hole, specially because i
must remove the oxid layer of the head through the fluid soldermaterial.
Best Regards
Alleslowbuged
P.S.
I think i will get a "new" cylinderhead for a reasonable price at the end of the week.
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#72
by
MJF
on 22 Nov, 2011 06:04
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What is reasonable price? New empty heads are starting at 200€ in Germany.
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#73
by
RabbitJockey
on 22 Nov, 2011 07:16
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so how much were these opened up, just from the pictures those exhaust ports are huge, are they just gasket matched?
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#74
by
Alleslowbuged
on 22 Nov, 2011 12:58
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Hi,
the ports realy looks big on the pictures, but they are "just" gasket matched.
Even if i will buy another cylinderhead i will make a second try with this head
to solder it up tomorrow evening.
Resonable price will mean 120,- up to 150,- € for a good original VW head (empty)
incl. shipping.
Best Regards