928 Stroker Crank Drawing or Model
10-23-2010, 03:04 PM
#1
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928 Stroker Crank Drawing or Model
I just bought a double chuck 5 axis CNC machining center and was thinking about turning out a stroker crank as an exersize to become familiar with the programming and capabilities of the machine. My draftsman is in the process of mdeling the original 5.0 liter crank in inventor. I know its a long shot but I was wondering if any one on here might have a stroker crank DWG or already done up that they might be willing to share. I have been an Industrial machinist for 30yrs but know absoultly nothing about machining crankshafts. I would gratefully accept any advise on this project. If any one would care to have input into the crank design please let me know your thoughts.
Thanks
Sean
Thanks
Sean
10-23-2010, 06:15 PM
#3
Race Director
sounds like a great project....so you could make it anyway you want.....very nice.....
I did read an engine building article a while back and they talked about billet vs forged cranks & how NASCAR engines run billet cranks & a forged crank wouldn't work for their application it was quite interesting......
I did read an engine building article a while back and they talked about billet vs forged cranks & how NASCAR engines run billet cranks & a forged crank wouldn't work for their application it was quite interesting......
10-23-2010, 07:04 PM
#4
Nordschleife Master
These threads might be of interest to you:
http://speedtalk.com/forum/viewtopic...che+crankshaft
http://speedtalk.com/forum/viewtopic...che+crankshaft
You may want to get in touch with one of the members there, Jon Schmidt, who worked at Bryant early on making all sorts of racing crankshafts.
Edit: How about you make a crank like this?
http://speedtalk.com/forum/viewtopic...266354#p266354
http://speedtalk.com/forum/viewtopic...che+crankshaft
http://speedtalk.com/forum/viewtopic...che+crankshaft
You may want to get in touch with one of the members there, Jon Schmidt, who worked at Bryant early on making all sorts of racing crankshafts.
Edit: How about you make a crank like this?
http://speedtalk.com/forum/viewtopic...266354#p266354
Last edited by ptuomov; 10-23-2010 at 09:46 PM.
10-24-2010, 12:01 AM
#5
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Colin
I was thinking 4340 as per moldex why do you suggest 4130?
Ptuomov
Thats one funky looking crank. I like the idea of the hollow throws but how the heck do you balance the thing? How would you keep the hollow journals full of oil?
I was thinking 4340 as per moldex why do you suggest 4130?
Ptuomov
Thats one funky looking crank. I like the idea of the hollow throws but how the heck do you balance the thing? How would you keep the hollow journals full of oil?
10-24-2010, 12:38 AM
#6
Nordschleife Master
Sean,
use what you would like, I was more just joking around.
However there are some very nice chromolly cranks out there for some extreme performance engines.
use what you would like, I was more just joking around.
However there are some very nice chromolly cranks out there for some extreme performance engines.
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10-24-2010, 08:20 AM
#8
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Definitely 4340 VAR, not 4130. 300M material is even better if you need the strength/durability. See Crower cranks for some good reference material. There is a whole lot more to producing a crank than just picking the correct material and machining a blank.
Last edited by beentherebaby; 10-24-2010 at 08:41 AM.
10-24-2010, 09:13 AM
#9
Nordschleife Master
I think (but do not know) that the whole crank is gun drilled thru the mains and the crank pins / rod journals are drilled, too, but just from one side. Then, plugs made of lighter material are inserted into the holes. The crank pin plug is obviously missing. The oil passages are machined to the surface of the plugs. Among other things, this allows one to use lower oil pressure.
10-24-2010, 03:22 PM
#12
Three Wheelin'
This is a good chance for a flat plane crank!
You'd be the first and it would be a unique engine with a sound that stands out.
Of course you'd then want high compression, ample cams and ITBs. Build it to rev high with good rods and pistons. Might as well dry sump it and go racing too!
You'd be the first and it would be a unique engine with a sound that stands out.
Of course you'd then want high compression, ample cams and ITBs. Build it to rev high with good rods and pistons. Might as well dry sump it and go racing too!
10-24-2010, 05:52 PM
#13
Race Director
This is a good chance for a flat plane crank!
You'd be the first and it would be a unique engine with a sound that stands out.
Of course you'd then want high compression, ample cams and ITBs. Build it to rev high with good rods and pistons. Might as well dry sump it and go racing too!
You'd be the first and it would be a unique engine with a sound that stands out.
Of course you'd then want high compression, ample cams and ITBs. Build it to rev high with good rods and pistons. Might as well dry sump it and go racing too!
Seriously.....between the two of you....you could make this work.....Sean could make the parts and I have no doubts you could figure out the timing-cams....
However what is the advantage of a flat plane crank? I know Ferrari uses them?
Sean already has a great racing platform built too....just gotta work out the motor
10-24-2010, 06:18 PM
#14
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What is largest flat plane V8 engine? Latest Ferrari V8's are 4.5L. As flat V8 is like two inline 4 engines joint at crank they tend to shake like 4 cylinder engines. Since Porsche wanted to use balancer shafts in 2.5, 2.7 and 3L fours to keep vibration down I think flat 5L+ V8 is not best possible idea. Weight of the moving parts must be kept very small.
10-24-2010, 07:17 PM
#15
Nordschleife Master
That's the shape of counterweight that apparently deflects oil the best possible way. The best possible way in this case meaning minimizing the likelihood that oil "rebounds" back to the crank.