Permanent port filling, alternative to welding

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Brad_AUS
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Permanent port filling, alternative to welding

Post by Brad_AUS » Mon Mar 22, 2010 9:43 pm

Hi Guys,

I had spent 3 weeks developing a port design for our Lamborghini heads, it involved an amount of putty on the floor of the intakes and some in the exhaust port to cover over and fill the EGR outlet in the SSR.

This was all ok, until I sent the heads for digitizing, and cnc cutting. Before anything went further, the machine shop tested their micro tig torch to see if welding was a possibilty.. I had assumed it wouldnt be an issue, but apparently it doesnt fit. They say the torch is overall 22-24mm high including tungsten, the i.d of the exhaust port is 24. So im stuck.

Heres my question, what have people used as a permanent port fill, as opposed to welding, we will still cnc them, but need to fill them. Remembering it needs to last on the exhaust side too..

Thanks for your time,
Brad

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Re: Permanent port filling, alternative to welding

Post by airflowdevelop » Mon Mar 22, 2010 10:49 pm

Find a new welder.

might be tough down under... But you need a guy that is good w/ a TIG pencil.

Brad_AUS
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Re: Permanent port filling, alternative to welding

Post by Brad_AUS » Mon Mar 22, 2010 11:43 pm

Have you got any suggestions for a good tig pencil torch to look up?? Im guessing you mean one thats not a 90deg end, but a flexible straight torch? The very smallest torch ive been able to find is no smaller than the size they say theirs is. Minimum cup sizes being 0.6in plus cap and tungsten, or the ones with a single piece cup (no cap) are a minimum 3/4in so thats 19mm plus tungsten protrusion. Of course, they are all for a 90deg torch

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Re: Permanent port filling, alternative to welding

Post by GregGood » Tue Mar 23, 2010 12:09 am

A Weldcraft WP-125 torch might possibly work.

I will be buying one soon myself.

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Re: Permanent port filling, alternative to welding

Post by airflowdevelop » Tue Mar 23, 2010 8:47 am

some guys like the weld-tec some like the weldcraft. The problem is being able to use the pencil especially when you can't really see what you are doing.

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Re: Permanent port filling, alternative to welding

Post by JBV-HEADS » Wed Apr 28, 2010 12:35 pm

I can't see depth with the pencil either. You might try one of these.

http://www.alvinproducts.com/Products/P ... ted%20uses

or

http://www.cotronics.com/vo/cotr/rm_putties.htm

These are about the best that I know of. Ceramic coat the exhaust ports. Good luck,

Joe

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Re: Permanent port filling, alternative to welding

Post by timdog » Mon May 31, 2010 4:47 pm

You might struggle to put the necessary amps through a very tiny torch. Ok at 150amps, maybe not at 250+
I've welded the pulsed air ports on heads with as small as a 22mm exhaust valve. Its super hard to do, a proper ball ache. Seats obviously have to be out if they are close to them like the ones i do. I have filled these holes with belzona 1111 once before but not put much mileage into it so don't know what durability you would get.
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Re: Permanent port filling, alternative to welding

Post by Piledriver » Tue Jun 01, 2010 9:47 pm

Plasma spray can be built up pretty thick... Common process.

penny
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Re: Permanent port filling, alternative to welding

Post by penny » Wed Aug 04, 2010 6:51 am

brad , paul in adelaide have you thought of adding "tongues " to your ports/. paul 0413987341

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Re: Permanent port filling, alternative to welding

Post by ALKYAL » Wed Aug 04, 2010 11:23 pm

With regards to welding, a very good friend of mine who has since past-away and was one of the best close quarters alum weldors. Used [he showed me the torches and cups] clear tourch ends so as to allow him to view what he was welding thru the quartz pcs [?] I remember him remarking to me as to how he ever did this before. I also remember him telling me that the whole tourch set-up was very costly, but a very worth- while purchase. He was an old master and we miss him. I hope this may put you on a path to find this type of torch. He also remarked how fragile the cups were/he used high amps as some of the welding was in the cam tunnels of alum race blocks.
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Re: Permanent port filling, alternative to welding

Post by SchmidtMotorWorks » Thu Aug 05, 2010 5:20 pm

Some aerospace welding is done in closed boxes with windows like sandblasting. I think they don't use cups at all.
http://www.schmidtmotorworks.com Aerospace Machine Work: Prototypes, Tooling, Molds.

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Re: Permanent port filling, alternative to welding

Post by dwilliams » Wed Sep 22, 2010 10:00 pm

Do the fill in body putty. When everything flows good, pop the chunks out - you might want to experiment with parting compound or mold release agents on a spare head - and take it to a modern machine shop that has a digitizer probe. They can probe the chunks and then machine 3D copies in the material of your choice, which you can bolt or weld into the ports.

Second choice would be to take the port chunks to an art metal foundry and have them cast copies. Most of them work in bronze or iron, but you might find one that can handle aluminum.

Yes, a bit more work than putty, but metal fillers will also work on the exhaust side, and on either aluminum or iron, and you can make sure they absolutely won't come loose during operation.

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