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-Alex77- Samba Member
Joined: December 09, 2008 Posts: 513 Location: Finland
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Posted: Wed Jun 19, 2013 2:40 am Post subject: Billet heads |
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I am working 3D version of vw billet head.
Plan is to offer bare heads with
-94 or 4" bore
-Stock headstudspacing or wasser 88x83mm studspacing.
-heat treated aluminum
-Cosworth style intake ports,
-Large fullwidth rockerpad
-NGK D8EA plugs fits
-Spring pocket OD 36mm, ID 16.8mm
-10 mainfins
-Throughboles for coolingair
-Max valvesizes around 52x40 for 4" bore
-Max valvesizes around 50x38 for 94 bore
-Custom features possibly available, 6-studding, 54x40 valvesizes, dual plugs etc.
[/img] _________________ Lasercut parts and CAD design
Last edited by -Alex77- on Thu Feb 08, 2018 2:06 am; edited 4 times in total |
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CLKWRK Samba Member
Joined: October 02, 2001 Posts: 566 Location: Toronto
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miniman82 Samba Swamp Donkey
Joined: March 22, 2005 Posts: 9515 Location: Southern Maryland
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Posted: Wed Jun 19, 2013 3:06 am Post subject: |
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How you gonna get around the pushrod tubes? _________________ Build thread: http://www.thesamba.com/vw/forum/viewtopic.php?t=212747
Glenn wrote: |
satterley_sr wrote: |
I just wanted to bitch but I'm getting no sympathy. |
Welcome to the Samba. |
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Quokka42 Samba Member
Joined: December 02, 2010 Posts: 3117 Location: Melbourne, Australia
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Posted: Wed Jun 19, 2013 3:18 am Post subject: |
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Yeah, I wondered about the through drilling, too. This kind of depth is a problem for most CNC. Though I suppose you could actually just leave the outside of the exhaust ports open, as they don't actually need cooling themselves.
Changing too much from the original design opens up a whole world of engineering issues to allow for expansion, cooling and tension though so be careful - maybe the CB 044 idea of adding a heap of metal around the combustion chamber will help you out there.
Just my 2c. I don't recall the stud spacing, but I'm sure it's here on the Samba if you search. _________________ There has only ever been one man who was perfect, and they nailed Him to a cross. |
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Jimmy111 Samba Member
Joined: October 05, 2006 Posts: 2643 Location: Wyoming
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Posted: Wed Jun 19, 2013 5:32 am Post subject: |
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Good luck.
I made 2 sets using 6065 and 7075. The 6065 melted and the 7075 corroded and delaminated.
Last edited by Jimmy111 on Wed Jun 19, 2013 5:42 am; edited 1 time in total |
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Jeff_Birt Samba Member
Joined: June 06, 2012 Posts: 315 Location: Rolla MO, United States
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Posted: Wed Jun 19, 2013 5:35 am Post subject: |
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Ah 'billet' the magical automotive metal. So why would a 'billet' head be superior to a cast one? I'm not trying to pick on the OP but I do get annoyed at how putting the word billet in front of something makes it automatically better.
(For those who don't know a billet is just a large chuck of metal that you machine something from.) |
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mxracer Samba Member
Joined: April 09, 2011 Posts: 568 Location: NC
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Posted: Wed Jun 19, 2013 5:55 am Post subject: |
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Jeff_Birt wrote: |
Ah 'billet' the magical automotive metal. So why would a 'billet' head be superior to a cast one? I'm not trying to pick on the OP but I do get annoyed at how putting the word billet in front of something makes it automatically better.
(For those who don't know a billet is just a large chuck of metal that you machine something from.) |
A billet "chunk of metal" (in this case aluminum) is either forged or formed using continuous extrusion, either of which is stronger than cast since either process produces a finer, stronger, more uniform grain structure than casting does.
Similarly forged cranks, pistons etc. are stronger and "better" than cast. |
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Jimmy111 Samba Member
Joined: October 05, 2006 Posts: 2643 Location: Wyoming
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Posted: Wed Jun 19, 2013 6:15 am Post subject: |
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Not true MX racer.
Dont confues forged steel with forged aluminum. Completly different animals.
A forged steel part comes from a previously rolled, grain refined bar of steel.
Aluminum extrusions arent forged. They are for the most part castings with large grain size. Some are further rolled for added strength. But the strength is linear and in the long direction only. Castings may have lower ultimate strength but they have hig compressive and expansive strength so they deal better with shock and thermal cycling.
A extrusion is a lousy material for a part such as a cylinder head. |
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mxracer Samba Member
Joined: April 09, 2011 Posts: 568 Location: NC
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Posted: Wed Jun 19, 2013 6:53 am Post subject: |
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Agree Jimmy...my statement was way to broad.
Agree that aluminum billets are rarely forged and are for the most part rolled, and all start out as a cast ingot.
I do stand behind the statement that a billet (when further processed via extrusion) is stronger than a pure cast.
I also can't argue with the statement that the cast is better for ACVW heads. |
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CLKWRK Samba Member
Joined: October 02, 2001 Posts: 566 Location: Toronto
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Jimmy111 Samba Member
Joined: October 05, 2006 Posts: 2643 Location: Wyoming
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Posted: Wed Jun 19, 2013 7:19 am Post subject: |
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Yes.
But most of the extruded billet out there is not rolled. It is extruded only. Finding rolled billet is difficult unless you order it from the mill yourself or have access to a forge or aerospace company that stocks it for their own use and just happens to have the right size you need.
This is what makes things like forged pistons better than cast. They start out as a grain refined piece of billet, are heated almost to the hot shortness point then pressed into a mold. It is not the forging process itself that makes them better. It is the superior form of the aluminum that was started out with. The grain size of the forged piston is much longer and uniform than the cast one. The cast one will slowly cool from liquid to solid and have small grains on the outside and in small profiles and large grains in the thick sections. The forged one will almost instantanious go from solid to liquid then back to solid with little change in structure. The structure will almost be the same as the billet you started out with. |
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mark tucker Samba Member
Joined: April 08, 2009 Posts: 23937 Location: SHALIMAR ,FLORIDA
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Posted: Wed Jun 19, 2013 7:32 am Post subject: |
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everytime somebody says billet!! my bank account gets smaller. so how about a forgeing a head.
nice pic jimmy, where is the rest!!? wish I still had cnc equipment at my fingertips. darn life gets in the way of fun. |
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mark tucker Samba Member
Joined: April 08, 2009 Posts: 23937 Location: SHALIMAR ,FLORIDA
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Posted: Wed Jun 19, 2013 12:30 pm Post subject: |
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miniman82 wrote: |
How you gonna get around the pushrod tubes? |
move the pushrod over.... but I dont see any advantage to just moving the port to aim downward.just give it a better smaller port&wider header. |
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-Alex77- Samba Member
Joined: December 09, 2008 Posts: 513 Location: Finland
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Posted: Wed Jun 19, 2013 1:59 pm Post subject: |
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You know, there is few type 4 heads with type 1 exhaust. Type 1 exhaust is not that bad, just not well cooled around it on some heads..
Here is basic all necessary dimensions containing drawing:
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modok Samba Member
Joined: October 30, 2009 Posts: 26743 Location: Colorado Springs
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Posted: Wed Jun 19, 2013 5:28 pm Post subject: |
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CLKWRK wrote: |
I have always wondered why no one points the exhaust ports downward on a custom type 1 head, like a type 4 cylinder head.
Seems like there is a missed opportunity to add more cooling surface area. |
Where? through the pushrods or through the head stud?
The angleflow is not a bad idea. The shorter the port then less heat it absorbs, as the motorcycle crowd has always known, but then again you still have to have enough material around there to keep it stable. |
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mark tucker Samba Member
Joined: April 08, 2009 Posts: 23937 Location: SHALIMAR ,FLORIDA
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Posted: Wed Jun 19, 2013 10:22 pm Post subject: |
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looks nice, but fix the ex port, fill the floor atleast1/4 angled at the same as the valve angle.you could fill it about half and raise the roof a bit & widen it some too. befor you go to wacking make it as good as it can be.add teardrops on both sides of all guides so the charges blend back togeather. dont leave any thing on the table or to chance . you could also change the valve angle a few degrees less too. do all your homework,dont make something that is already out there that needs reworked. have fun and getter done. I miss that kind of work. |
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Der6VoltFahrers Samba Member
Joined: April 15, 2009 Posts: 84 Location: Hannover Germany
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-Alex77- Samba Member
Joined: December 09, 2008 Posts: 513 Location: Finland
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Posted: Thu Jun 20, 2013 4:50 am Post subject: |
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Sorry, not really a copy, because we could offer two bore and port sizes, 6 studding and exhaust is normal and height of the head is standard
Basically just another cosworth port head with lots of fins
I started desing these last summer before found Thorstens heads to my engine and i got the updated version of Thorstens head, much better now intake port.
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Der6VoltFahrers Samba Member
Joined: April 15, 2009 Posts: 84 Location: Hannover Germany
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Posted: Thu Jun 20, 2013 5:33 am Post subject: |
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Just kidding, looks good |
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-Alex77- Samba Member
Joined: December 09, 2008 Posts: 513 Location: Finland
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Posted: Sun Jun 23, 2013 6:33 am Post subject: |
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I'v been suggested by professional head porter to use calculated valve positions for both bores, 94mm and 101.6mm, but then again, the result may be that stock style rockers dont fit:
I would use this spacing on both heads, just to give possibility that you dont have to build totally new valvetrain.
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