Crankcase Casting wall thickness
Crankcase Casting wall thickness
(OP)
Hello Everyone,
I am new to this forum and design field as well.
How to calculate the wall thickness of crankcase or cylinder head casting.
Even cylinder head or crankcase design related document/web link will be appreciated.
I have searched on internet but could not found anything.
Thank You.
I am new to this forum and design field as well.
How to calculate the wall thickness of crankcase or cylinder head casting.
Even cylinder head or crankcase design related document/web link will be appreciated.
I have searched on internet but could not found anything.
Thank You.





RE: Crankcase Casting wall thickness
Bring your wallet.
The information you seek may not be available, even there, since there are commercial incentives to reveal nothing, or even to reveal misleading information.
You could probably learn a lot by sectioning and reverse engineering an existing engine in which you are interested.
You will probably need a big power hacksaw.
Mike Halloran
Pembroke Pines, FL, USA
RE: Crankcase Casting wall thickness
RE: Crankcase Casting wall thickness
Is there any design formulas?
RE: Crankcase Casting wall thickness
Vibration analysis (the shape and thickness of the crankcase is a factor in how much noise the engine makes)
Thermal analysis - avoiding large changes in thickness which could be fracture sites
Manufacturability - and in the case of sand casting, allowing for core shifting
And a healthy dose of experience.
RE: Crankcase Casting wall thickness
FEA yeah, but in the old days it was also and still can be trial and error, using stress coat and strain gauges.
Its not just a use this thickness or that thickness, its also what weight limits do you have and there maybe ribbing to add strength etc. I don't think there are any said calculations to find the perfect crankcase cross section. Way too many variables.
RE: Crankcase Casting wall thickness
However, I would point out that specifically with noise reduction, and I suspect torsional stiffness, some analysis shows that thin wall+webs is a worse solution than the same material spread out as a uniform plate.
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: Crankcase Casting wall thickness
As mentioned allow for core shift on the ports - the tighter you want the core prints, the more sand that will be scrubbed off when fitting cores - this will have to be flushed out into the risers or will cause you trouble. If you make them looser they will be easier fit, but may move or float until they contact core print registration.
If you are diecasting the blocks then you can go down to 4mm in most areas, but remember to use far less machining allowance since the strength of diecastings is mainly in the surface skin due to the chilling effect of the permanent steel mould. If you machine off too much of this chilled skin bad things will happen.
Brian,
(have put 200 heads + through a 40yr old power hacksaw and swore as many times more with mis-filled complex prototype CPS castings)
RE: Crankcase Casting wall thickness
Greg, I think if you went down to minimum feasible thickness, you would be denting the aluminium with any wayward blow from a hammer or even a spanner (wrench).
je suis charlie
RE: Crankcase Casting wall thickness
Thin walls and ribs may get you the strength and rigidity that is needed, but in some designs the thin panels have vibrated in the range that can be heard, and when the engine gets to a speed to excite that the noise can be very bad.
= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube
RE: Crankcase Casting wall thickness
My inaccurate check on a cast iron block Automotive gas engine. I'd say any minimum areas are maybe .25 thick that would be coolant jacket to outside. Case webs ? .375 or more in thin areas. Deck thickness over .5, Al head combustion chamber .4 to deck surface, Ports to outside wall about .22 . If manufactures released prints, a study of that would be helpful.
In the post above an F1 engine is going to be a trade off for weight and strength, and does not represent a very durable long lasting design, how many races did that particular engine have to last?
RE: Crankcase Casting wall thickness
Guys