Lets build an engine

Post here information about your own engineering projects, including but not limited to building your own car or designing a virtual car through CAD.
Mad_Scientist
0
Joined: 03 Aug 2014, 23:55

Lets build an engine

Post

assuming unlimited funds, lets talk about some of the materials you would use in a "f1 style engine" meaning this engine would be built for high rpm (16,000rpm non pneumatic valves) used with a high burn temperature exotic fuel..

my choices below

block - aluminum (or CGI when availible)
rods- high strength steel (some approaching or exceeding titanum specs now)
pistons - mmc aluminum
wrist pins - dlc coated titanium
rings - ductile iron (replaced after "x" hours)
valves - titanium alloy (intake) ceramic coated steel (exhuast) (not sure which allows here)
valve seats - highly conductive but "soft" beryllium allow
valve guides - tried and true ampco 45
headers - iconel

now its been a long time since i investigated the engine build i plan to move forward soon, but whats your take on these choices..

what would you do differently .. assuming no material bans

Lycoming
106
Joined: 25 Aug 2011, 22:58

Re: Lets build an engine

Post

You want a high-revving F1 style engine, but you don't want pneumatic valves?

+Mfg
0
Joined: 04 Aug 2014, 02:57

Re: Lets build an engine

Post

Mad_Scientist wrote:assuming unlimited funds, lets talk about some of the materials you would use in a "f1

my choices below
block - aluminum (or CGI when availible)
what would you do differently .. assuming no material bans
I would use additive manufacturing rather than casting to create a block that incorporates steel and/or Inconel liners directly into a super lightweight aluminum space frame structure with super thin walls.
The water/glycol cooling passages could even run through the honeycombed structure with heat exchange fins "printed" into place. Predict a 20 to 40% lighter weight than the current cast block with higher thermal efficiency (less fuel to carry).
Every other cast part in/on your mad scientist engine could see similar mods and savings.

Mad_Scientist
0
Joined: 03 Aug 2014, 23:55

Re: Lets build an engine

Post

+Mfg wrote:
Mad_Scientist wrote:assuming unlimited funds, lets talk about some of the materials you would use in a "f1

my choices below
block - aluminum (or CGI when availible)
what would you do differently .. assuming no material bans
I would use additive manufacturing rather than casting to create a block that incorporates steel and/or Inconel liners directly into a super lightweight aluminum space frame structure with super thin walls.
The water/glycol cooling passages could even run through the honeycombed structure with heat exchange fins "printed" into place. Predict a 20 to 40% lighter weight than the current cast block with higher thermal efficiency (less fuel to carry).
Every other cast part in/on your mad scientist engine could see similar mods and savings.

that does sound like a good idea. I do wonder though, what kind of heat cycling and tempering processes you would have to go through to achieve a similar strength as a cast part. I am familiar with laser sintering, and the parts are amazingly strong right out of the machine. is very expensive however... I had negated myself to using a printed sand casting which will also allow you to do some tricky things.

as pneumatic valves go, I would love to have them.. but in this particular engine I think a Mechanical system similar to what Ducati uses would be more appropriate. at any rate.. the Rev limit is 16,000 so I'm not sure either system is needed.

+Mfg
0
Joined: 04 Aug 2014, 02:57

Re: Lets build an engine

Post

I believe you are referring to laser melting rather than sintering process when looking for strong, out of the machine parts. Reaching the strength of castings is no longer a problem as some processes produce billet quality parts. Billet strength with NO molds and little post machining.
You eliminated the restrictions of regulations, correct? Let' print up a new engine optimized for each venue. V8, V6, V10, whatever. Can be done... If each could be tuned quickly enough.
Valve train??? Skip it all together and go to electromechanical actuators for the valves. Results in additional power, lower weight, and better fuel economy. (https://m.youtube.com/watch?v=ZYEjAv0hFug)

SlowSteve
1
Joined: 04 Aug 2014, 16:20

Re: Lets build an engine

Post

MadScientist,

I think you maybe have a few things to think about here - there is a lot of scope in your question.

This is very much an "Engineering" question, unlike a lot of this forum, which is more about "Science" or "Technology"- and therefore the main word is compromise.. Where do you want to compromise? That will affect all of your materials decisions.

For example - You have two different materials for Inlet and exhaust valves going into a third material of the headers, all with different coefficients of expansion. This is going to need some tuning - they will work best at certain temps and RPM ranges, and not others. Where do you want your scarfices to be? Will you give up some middle range torque for some top end RPM's?

Every time you mix two materials, you will have to make all of these choices. There is a lot of be said for using a single material throughout - for example Ti, but that also brings comprimises as well - depending on your desired outcomes it shows where the comprimises are made. When you know your comprimises you can select your materials... it has to be a "right to left" plan. Outcomes -> decisions -> comprimises -> materials.


But... if you're making a fantasy engine, why give yourself the limits that you have? A 2 stroke engine would have a lot of benefits over a 4 stroke - a lot more power per cc of capcity for one and a much higher rev range within practical engineering limits. If it only has to last race distance, why not use a Wankel engine? All the issues with them are down to trying to create longitevity - not an issue for a race distance. If you want efficiency and torque, then the Ilmoor double acting four stroke engine - they call it a "5 stroke" - has a huge amount of potential. Couple that with a CVT gearbox then you have some very.....different.... but potentially something game changing in a race powertrain.

When it comes to valve gear I agree with Lycoming. You could use Desmodronic, or any other positively closing valve gear - but what ever it is, you will be leaving a huge amount of power and flexibility on the table. From a race engine design point of view, there is nothing good about camshafts or desmo systems - they soak up a depressingly large fraction of available power, that could be going to the wheels, but more importantly they fix the timings of the valves. Pnumatics allow for entirely independent control of each valve, which brings with it a vast scope for tuning that is simply not possible with cams or gears.

Your point about Beryillium copper is interesting. I know that it's the "ideal" valve seat, but it's truely awful stuff to work with. Setting aside that it's lethally toxic to the people working it, it is also the single most awful to machine material I have ever encountered - it made me invent entire new swear words to express my rage with it. Your fabricators will be so angry having to work on it that they'll just go on strike.

Engine building is not like Aero design - more than anywhere else in a car - even painful areas like a gearbox and cooling systems- engine design is about choosing the least worst options, not the "best" options - for every element you optimise, you end up having to fight 10 new components that have been comprimised.

Steve

Mad_Scientist
0
Joined: 03 Aug 2014, 23:55

Re: Lets build an engine

Post

i think i should back up...

im starting with an engine block. that part i cant change, though i could machine one identical to it from a different material. lets just say the engine block is done.

most of my questions come in the form of "whats the best material to use?" i dont really worry about compromise. I want the best, and then ill make it fit. i understand the differences in thermal expansion between materials, but thats all simple to over come.

what this boils down to, is questions like.. should i use titanium for the valves, or nickelvac 800... should i use mmc for the pistons, or is 2318 now light enough (with the proper design)


i think i will end the thread here.. its very hard for me to explain to you guys what i need without making it public exactly what im doing. and in the racing circles im in, word travels fast and there is alot of people who copycat and have plenty of resources..

thanks for the help you have given.. i will look into the electronic valving

User avatar
flynfrog
Moderator
Joined: 23 Mar 2006, 22:31

Re: Lets build an engine

Post

You need some back ground is this a one pass drag engine or an endurance boat racing engine. If we are stuck with a stock block what block is it OHV or OHC. An f1 type engine is going to be very different depending on the car its in or the race distance expected engine life ect. What Hp figures are you looking for.

SlowSteve
1
Joined: 04 Aug 2014, 16:20

Re: Lets build an engine

Post

Mad_Scientist

I make a lot of engines - i.e I start with pen, paper and blocks of metal, lathes and Mills and after lots of cursing out pops an engine. I have worked with a lot of materials, including all of those you list in your first post, and used them all in engine builds.

I would say that I am fairly good at it - I can make a steam engine which handles a measurable 17,200PSI of chamber pressure, I can make 2 strokes which deliver 23,000 RPM and I can make fully functional minature jet turbine engines which will fly a hefty model - all of them on my own and starting the designs from a blank sheet of paper. I don't say this to show off - I say it to show you that I'm not an arm chair engineer and I'm here to help if you need it.

With that background you're comment about "I don't really worry about compromise" and "I understand the differences in thermal expansion and it's easy to over-come" suprised me a lot - either you are a genius who makes me feel stupid - because compromises and fit are two of the banes of my life - or you are about to spend a lot of money on something that will cause you a lot of swearing, or worse be flat out dangerous.

If you have the engine block, then a lot of your decisions have been made. Your bore x stroke is pretty much set. Your bearing points and bearing layouts. Your studding patterns. Your crank shaft lay out. This in turn will affect your valve choices, your lubrication choices..... etc etc etc

If you're block if fixed, then the question that you should be asking youself is "What do I need to do to extract the maximum power from this block". Then "What is the maximum power this block can handle" is the next question - which is a different question - you don't say anything about the block you have but, for example, a LOT will be determined by the webs around the shell bearings - you can use any material you like, but if there is a harmonic issue, you you just don't have enough meat in them to support the bearing torque, then the engine will pull itself to pieces even if you use the finest materials in the world. "Materials science" is NOT "Engineering". You're asking "Engineering" questions but looking for Materials Science answers.



If you want us to shout out the names of some funky materials then we can do that. tell us and we will provide you with a list of wonderful gubbins in the blink of an eye.
If you want actual input, then also shout out and we will try to add value and usefulness.
If this is just mental excerise, then all power to you.

But... please please please don't be in a position where you are spending your own money on this and asking questions like you are.

Steve

Lycoming
106
Joined: 25 Aug 2011, 22:58

Re: Lets build an engine

Post

If you already have a block, then why does your original post talk about engine block materials?

mike
2
Joined: 10 Jan 2006, 13:55
Location: Australia, Melbourne

Re: Lets build an engine

Post

I will go for
Block: adiabatic steel block engine with ceramic coating, compact and maintenance free
Crank: 3D printed multi-piece crank+ball bearing, reduce oil usage
Piston: 3D printed ceramic coated
Piston rings: ringless air-seal system, reduce friction and heat
The idea is to get close to adiabatic cycle to extract higher efficiency

zenji
0
Joined: 23 Sep 2013, 01:22
Location: Australia

Re: Lets build an engine

Post

I machined berrylium copper ages ago, it's poisonous, wear a dust mask, change the coolant and clean the tank afterwards.
Don't let the dusty fillings get in your eyes, it erodes your eyes lens.
Dummy run the titanium parts in your cnc with the first being low grade stainless to get used the toughness and tool erosion.

xxChrisxx
44
Joined: 18 Sep 2009, 19:22

Re: Lets build an engine

Post

Mad_Scientist wrote:i think i should back up...

what this boils down to, is questions like.. should i use titanium for the valves, or nickelvac 800... should i use mmc for the pistons, or is 2318 now light enough (with the proper design)
You are going about design all backwards.

You don't pick what you are going to make stuff from first. You work out what it needs to do, then how big you can make it. This then defines the strength of material you need.

Also, no one ever machines anything out of Inconel (or similar) unless they absolutely have to. It's expensive, and a total bitch to work with.

TurboLag
9
Joined: 02 Apr 2014, 10:13

Re: Lets build an engine

Post

No one on Split crankshaft on dual ball bearings? WPC treated wrist pins, piston skirts, cam lobes and valve stems? That alone should have a huge impact in drive and valvetrain losses..

mzivtins
9
Joined: 29 Feb 2012, 12:41

Re: Lets build an engine

Post

George75 wrote:Hello everybody,
I have 2 Hayabusa engines
could you suggest me somebody to make for me the common drive
in order to make them become V8?
or to provide me the plans of this part....
Hey George!

Give Radical engineering a call! i think they are quite famous for 'Busa engine and their 'Busa v8's!

http://www.radicalprecisioneng.com/