alexideways Posted May 7, 2006 Share Posted May 7, 2006 Just an idea here but.... I work at BMW as a mechanic and was looking at a baddly smashed 740il and noticed that some of the allu. body parts ar'nt wellded but glued together and the most surprising thing was seen on the crossmember, who have both bonding techniques on it, most of the welds were cracked but where it was glued, it was still perfect so, here is the idea: Glue the damn thing together, with some kind of torque plates on top and bottom and cams installed, to keep it sraight while it's driing. I'll checke if I can have access to this special glue. Quote Link to comment Share on other sites More sharing options...
Gollum Posted May 7, 2006 Share Posted May 7, 2006 I've done some research on the lotus cars (espirit exige) and have found out these tidbits of valuable information. They use an expoxy to bond the entire aluminium chassis together and rivet certain joins for collision proteciton so that if the glue gives out during an accident it doesn't just fall apart. The bonding is so much stronger than welds that they were able to use even thinner pieces. This is becuase the welds become the weakest points so normally you use thicker stock than you need in order to compensate. This bonding doesn't pose this problem. I just wanna find out what kind of bonding agent they're using. I've looked to no avail. Quote Link to comment Share on other sites More sharing options...
alexideways Posted May 8, 2006 Share Posted May 8, 2006 I'll try to take a look with the parts guys at work, BMW probably uses the same stuff as lotus so, we can at least get an price figure. Plus, I get everything at cost. Quote Link to comment Share on other sites More sharing options...
240hoke Posted May 8, 2006 Share Posted May 8, 2006 Check out this stuff guys: pretty sure this is what bmw uses: http://www.ashchem.com/ascc/specialty/automotive2.asp Quote Link to comment Share on other sites More sharing options...
Guest 1972_240z Posted May 8, 2006 Share Posted May 8, 2006 240hoke, i used some of that stuff on a body kit about 4-5 years ago. When i molded the kit into the body (of a honda) it never cracked, and sold it to a friend. To this day, which is about 5 years later, still looks like the day i did it with no cracks and the bond seems to be as strong as ever. worked good in my opinion, although i used it for fiberglass Quote Link to comment Share on other sites More sharing options...
alexideways Posted May 9, 2006 Share Posted May 9, 2006 pretty sure this is what bmw uses: Hummm, not sure, they don't mention alluminum anywhere Quote Link to comment Share on other sites More sharing options...
phantaz Posted May 9, 2006 Share Posted May 9, 2006 Hummm, not sure, they don't mention alluminum anywhere "Ashland entered the metal-to-metal panel bonding arena in 2004 with the launch of PLIOGRIP 5760B panel bonding epoxy. Available in 220ml and 400ml, two-to-one cartridge formats, PLIOGRIP 5760B epoxy is the first in a growing line of panel bonding adhesives" this was toward the bottom, ive used this stuff on my scale planes and boats... and they will bond aluminum together once its prepped corectly =) Quote Link to comment Share on other sites More sharing options...
AK-Z Posted May 9, 2006 Share Posted May 9, 2006 You are forgetting that what you are suggesting would be used in a engine. The harsh evironment of the head would cause it to fail miserably. The combination of oil, coolent and heat would cause epoxy to corrode and loos bonding. The best solution would be to weld the passages and then cryo treat it to even the metalurgy of the aluminum, so you would have stress cracks between different densistyies of aluminum. I don't know if this will work, but the aluminum welding stuff that was discussed on another thread might work, because the "filler" won't be in direct contact with the combustion chambers. Just use a propaine torch to melt the compound on one side and then put them torgether and heat the compound through the passages. Quote Link to comment Share on other sites More sharing options...
TheNeedForZ Posted May 9, 2006 Share Posted May 9, 2006 They are talking about gluing the body parts, not the head. Read before you post. ""The best solution would be to weld the passages and then cryo treat it to even the metalurgy of the aluminum, so you would have stress cracks between different densistyies of aluminum."" Are you sure what you are talking about? Quote Link to comment Share on other sites More sharing options...
Sparks280zt Posted May 9, 2006 Share Posted May 9, 2006 actually YOU should read ahead, the adhesive was brought up as a way to glue this 24v DOHC head together. Just an idea here but....I work at BMW as a mechanic and was looking at a baddly smashed 740il and noticed that some of the allu. body parts ar'nt wellded but glued together and the most surprising thing was seen on the crossmember' date=' who have both bonding techniques on it, most of the welds were cracked but where it was glued, it was still perfect [b']so, here is the idea: Glue the damn thing together, with some kind of torque plates on top and bottom and cams installed, to keep it sraight while it's driing.[/b] I'll checke if I can have access to this special glue. Quote Link to comment Share on other sites More sharing options...
Zhadman Posted May 9, 2006 Share Posted May 9, 2006 They are talking about gluing the body parts' date=' not the head. Read before you post.[/quote'] TheNeedForZ, They are referencing an adhesive that is used to bond body panels. They are referencing it to Mack's post: the head is not welded yet, and I am not sure if we are even going to weld it, or if we will just be using gaskets with press fit pins inbetween the halves (thirds, I guess) to keep them aligned. Take it easy! Edit: Sparks and I posted at the same time Quote Link to comment Share on other sites More sharing options...
TheNeedForZ Posted May 9, 2006 Share Posted May 9, 2006 heh, MY BAD. Quote Link to comment Share on other sites More sharing options...
turbobluestreak Posted May 10, 2006 Author Share Posted May 10, 2006 Why are you guys arguing about welding verses gluing the decision was made to weld it all of you that are talking about gluing it need to reread thread on the custom 24 head Its been talked about. Besides when was the last time that myself, 1fastz, or Mack have updated this thread with progress. That’s right there are two almost heads done out there and I don't think mine will ever get done it was a great effort but interest and time are fading. I'm sorry but maybe it not meant to be. Thank god AK-Z knows what’s going on, WELD it lol. tbs Quote Link to comment Share on other sites More sharing options...
Mack Posted May 10, 2006 Share Posted May 10, 2006 yeah, been busy with other things. 1 fast Z has been busy with his head proting business. and its hard to get timne to work on it since I moved back to minenapolis. It will get finished, one way or another. Im not going to let this one go. Quote Link to comment Share on other sites More sharing options...
AK-Z Posted May 10, 2006 Share Posted May 10, 2006 ""The best solution would be to weld the passages and then cryo treat it to even the metalurgy of the aluminum' date=' so you would have stress cracks between different densistyies of aluminum."" Are you sure what you are talking about?[/quote'] Sorry that was a typo "would" should of been wouldn't. I should of reworded the last phase differently. I should of said that by cro treating, the defference in the welded areas on the base metal would lessen and would be less likely to form stress cracks. In cryo treating, they heat up the item(s) in a 400 degree oven and slowly bring down the temperature to (I think) -150 degrees, all in the same chamber. and they repeat the process 2 more times. Its tempering without pounding and forming. And Yes I was reffering to the post of someone suggesting on "glueing" the heads together. I kinda read the post backwards, because I was wondering why the recent posts were talking about epoxy. Thank god AK-Z knows what’s going on, WELD it lol. Thanks. Haha I was the one that brought up such an old post. Just wanted to know what the progress was, if any. haha. Quote Link to comment Share on other sites More sharing options...
evildky Posted May 10, 2006 Share Posted May 10, 2006 with all the effort and maching people have tried in this why not just copy the OS Giken design and make your own castings? I know casting alumnum is more difficult but I read on a guy that cast his own out of production engine for an old triumph or alpha or something, it was a lot of work but once the cast is made a run of 100 or so could be made and sold off to pay for the cost of setup, they would still be expensive as hell I am sure but it woud be a complete solution and not some peiced together frankenhead Quote Link to comment Share on other sites More sharing options...
TheNeedForZ Posted May 10, 2006 Share Posted May 10, 2006 AK-Z, I know what cryogenic treatment is. It's not for the purpose you are talking about. It is used to extend wear life of metal objects or to improve sound of music instruments. If you weld the seams with a slightly different alloy, that's as homogeneous as it ever will be. Cryo the head like you said will not "blend" the boundaries or bond the discontinuities. Quote Link to comment Share on other sites More sharing options...
AK-Z Posted May 10, 2006 Share Posted May 10, 2006 AK-Z' date='I know what cryogenic treatment is. It's not for the purpose you are talking about. It is used to extend wear life of metal objects or to improve sound of music instruments. If you weld the seams with a slightly different alloy, that's as homogeneous as it ever will be. Cryo the head like you said will not "blend" the boundaries or bond the discontinuities.[/quote'] Yes I know. tempering is used for the same purpose, but kinda hard to do on a already formed object. If you read how I reworded it in my last post, I didn't say blended. You should also know when you weld, it doesn't just affect the part of the base metal that its welded to, the surrounding area of the metal is also affected because of the heat change. And also welding something like aluminum valve head for that long to have the passages sealed would cause some considerable warpage because of the AC current involved with welding aluminum. Weighing the head down and cryo treating would solve that. Well anyways, it was just a suggestion, not to taken too seriously. Quote Link to comment Share on other sites More sharing options...
AK-Z Posted May 10, 2006 Share Posted May 10, 2006 with all the effort and maching people have tried in this why not just copy the OS Giken design and make your own castings? I know casting alumnum is more difficult but I read on a guy that cast his own out of production engine for an old triumph or alpha or something, it was a lot of work but once the cast is made a run of 100 or so could be made and sold off to pay for the cost of setup, they would still be expensive as hell I am sure but it woud be a complete solution and not some peiced together frankenhead I just wish someone would be willing to put tha much effort. If I recall the positive forms that OS Giken used to make the negative molds from were carved out of wood, correct? Makes me want to go do some carving ,haha. But then I realize that I'm lazy and would fail miserably in my attempt. haha:mrgreen: Quote Link to comment Share on other sites More sharing options...
TheNeedForZ Posted May 10, 2006 Share Posted May 10, 2006 Yes I know. tempering is used for the same purpose, but kinda hard to do on a already formed object. If you read how I reworded it in my last post, I didn't say blended. You should also know when you weld, it doesn't just affect the part of the base metal that its welded to, the surrounding area of the metal is also affected because of the heat change. And also welding something like aluminum valve head for that long to have the passages sealed would cause some considerable warpage because of the AC current involved with welding aluminum. Weighing the head down and cryo treating would solve that. Well anyways, it was just a suggestion, not to taken too seriously. Why is tempering hard to do on a already formed object? You didn't get my point, I wasn't asking why use cryo, I was saying cryo will not magically make two different alloys blend at the boundaries. You said cryo will "even out the metallergy", I said it is not going to make the boundary "blend" then you said you didn't say blend....and then you said weighing the head down and cryo will cure warpage, where did you see that cuz I never heard of it. Quote Link to comment Share on other sites More sharing options...
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