Machined vs. CAST crankcase 3W/DA

[Highlights]

Zee man, you are absolutely correct. It was a long day yesterday and I ma not sure where my head was at.

What is your guys take on the differances between the two methods of knocking out a crankcase for many of the well known engines on the market?

I am aware of the differances. The Pros and cons. I have however seen some ugly photos of ZDZ where crankcases have suddenly blown apart. Voids often times are prevelant in cast parts. Anyone ever have any issues with 3W motors?
I generally prefer a machined part. With this being said 3W is a fine motor. Why aren't they machining?

Any thoughts?

[Highlights]

Anyone?

[Cracky]

Just to let you know, I moved this thread into the Gas Engines and Power forum.


in relation to your question. I would think that cast is a cheaper way to make them.

[Highlights]

Good work Crack man. I have gotten into the bad habit of dumping everything into the Clubhouse.

Yeah I agree with cast being cheaper for sure. Why the heck has 3W stuck with this type of manufacturing. Their engines (especially the CS series) are top shelf yet they use what is considered an inferior process of making their crancases.
Is this a poor assumption?

[Surly_Schmidt]

If done right there is nothing wrong with cast.

But it doesnt match the sexy look of a DA though.

[Craven]

Ever had sex with your DA?

[Highlights]

Craven dude, don't tell me........... the cast is a little rougher?

[Craven]

LOL.......That was for Surly Schmidt.

[Highlights]

Ah..... I see. I thought after his candid comment that maybe you were sharing a few secrets and asking if he'd actually ever tried it.


I am bulls$%^&ing of course.

Have a good one,

Highlights.

PS any comment on the crankcase itself though. You know being machined vs. cast? I am close to pushing the button on the new 3W 170TS SC.

[MikeC3D]

My thought's would be that the tolerence on moving parts would be much more precise on the machined parts versus cast. I would think that undo stress or loads on any void COULD be catostrofic, whether mach. or cast. Also I would think a machined part could be made lighter than cast in the process.

[Craven]

	Quote: Originally Posted by Highlights
	Ah..... I see. I thought after his candid comment that maybe you were sharing a few secrets and asking if he'd actually ever tried it. I am bulls$%^&ing of course. Have a good one, Highlights. PS any comment on the crankcase itself though. You know being machined vs. cast? I am close to pushing the button on the new 3W 170TS SC.

Sorry I'm an "idot" LOL

[btomlinson]

There are sever types of castings. Sand, Spin, Investment, Die etc.. Sand casting being the poorest quality. Spin castings are done by your auto wheel manufacturers and guarantee zero holes due to the centripetal force while casting..

One advantage for casting V/S machining from billet is the waste. A properly cast part of good quality should have zero pores. Once machined they will perform just as well as a billet component. The only down side castings is they are brittle and subject to crack if not properly designed

Cast parts can be machined every bit as close as a Billet part. All cast engine crankcases are machined internally

As for DA im not sure why the chose Billet over Castings. Perhaps it was the tooling cost which can easily run over 100K per component. and if you want to make a manufacturing change ,well get out your wallet. Im glad to see DA going with Billet. I think the material is 7075 Aluminum witch is a good strong Aircraft grade.


Most of your forgings are done with steel. Its common to forage crankshafts,Con rods etc..


Im outta breath...