Mix material engine block and sleeve?

[Mountain-god]

Hey

Does anyone know of any engines mixing materials - engine block and sleeve?

Specifically, I'm looking at building an engine with stainless steel cylinder sleeve and either aluminium or stainless steel block (where I prefer aluminium to reduce weight).

But I'm concerned at flex between the two materials - especially given their reaction to heat is a little different.

It maybe just a case of deciding how much flex and consequent wear is good enough for the benefit of reduced weight - or maybe a non-issue as the amount of material is so great (around the block) that flex just isn't an issue...

[sarnali2]

a stainless steel engine block would weigh a ton. Most m/c engines are aluminum crankcase, cylinder and heads with steel or nickasil liners in the cylinders and ribbing in the case's for reinforcement.

If you're talking about mixing casting and machining a one-off engine then I'm not sure anyone here can help.......Any mettalurgists in the house???

[pushrod]

I'd design the block to accept a sleeve. It's common practice to re-sleeve blocks, especially if said block is hard to replace, or the owner wants to keep that particular Serial Number.

[The_AirHawk]

Due to the weird thermal-expansion and wear characteristics, I'd stay-away from stainless steel for a liner. Either a ductile (cast) iron cylinder, or aluminium with a chromed or Nikasil-plated bore.

You should seek knowledgeable help with this project, as such items as piston side-clearances, piston-ring end-gaps, and piston-ring metallurgy will all vary depending-upon which cylinder material you choose.

For minimal development on a one-off engine, I would probably choose an iron liner, personally. Iron is very thermally-stable, reasonably wear-resistant and strong, fairly easy to cast, and is very machinable into intricate parts; as well as having established and predictable thermal-expansion characteristics.

[seruzawa]

Originally Posted by The_AirHawk

Due to the weird thermal-expansion and wear characteristics, I'd stay-away from stainless steel for a liner. Either a ductile (cast) iron cylinder, or aluminium with a chromed or Nikasil-plated bore.

You should seek knowledgeable help with this project, as such items as piston side-clearances, piston-ring end-gaps, and piston-ring metallurgy will all vary depending-upon which cylinder material you choose.

For minimal development on a one-off engine, I would probably choose an iron liner, personally. Iron is very thermally-stable, reasonably wear-resistant and strong, fairly easy to cast, and is very machinable into intricate parts; as well as having established and predictable thermal-expansion characteristics.

Or he could just watch "World's Fastest Indian" a few times.

[seruzawa]

Using stainless steel to build a block would trap the heat and that would result in seizures. As far as SS liners, it's been tried. It's not porous enough to hold the lubricating film of oil and once again you get seizures.

[longride]

Sounds like you are trying to reinvent the wheel. Good luck.

[mscuddy]

Use wood. A nice knotty pine works swell for cylinders and crankshafts, and Brazilian Iron Wood can be machined into crankcase halves and timing gears. Just stay away from termite infested areas like Compton or Lakewood. Steel and aluminum is so damaging to the environment, and causes global warming. Tinfoil is good for hats though, I'm wearing mine now!

[The_AirHawk]

Originally Posted by longride

Sounds like you are trying to reinvent the wheel. Good luck.

I recall a Kiwi who did just that roughly a decade and a half ago - and the fruit of his labours is still marveled-upon today.

Too bad he's no-longer around. Britten's designs were nothing if not "unique".

[The_AirHawk]

Originally Posted by mscuddy

Tinfoil is good for hats though, I'm wearing mine now!

Me Too!