internal combustion gas or diesel engine clean sheet designing 7

[nanokron]

ok I finally have a copy from John Manning’s book, Internal Combustion Engine Design, published by Ricardo, 2012. ISBN 978095732920-1

directly from Ricardo engineering


here's a few question that I still not fully understand especially concerning the "Cylinder Block and Cylinder head"

especially from the Sketch DRAWINGS to the Final detail BLUEPRINT DRAWINGS before the first procurement prototype engine

1) when designing an engine "cylinder block" DRAWINGS is there any parts of the engine assembly preliminary design DONE before the said cylinder block DRAFTTING Ex: Crankshaft, camshaft, ect .

2) the designing process of the cylinder block DRAWINGS generally does it start with "Bottom Up design" or "Top Down design".

3) in a cylinder block design preliminary DRAWINGS what are the block Features design DRAFTING sequences Ex: A) crankcase, B) cylinders layout, C) lower cylinder deck, D) water jacket, E) upper cylinder deck .

4) How does the interaction Between the different engineers and the draftsman Works? who will be in charge of the designed features?
of the specific engine part for a cylinder block DRAWINGS

5) at last all the above questions BUT for the "Cylinder Head" part

I am interested in the principle behind engine designing DRAWINGS only, not much in CAD or FEA and or CFD. I am just intrigue by the way they design major engine part like in the 50's, 60's and 70's drafting tables and slide rulers! BUT any computer related design subject still appreciated as a feedback casting and machining drawings both are in my field of interest

and if any GOOD publication of concern of the above subject and questions I'll be happy to source if I can get them

engine size mostly of my interest would be bellow 1000 CU-IN or about 17 liters in displacement gas or diesel ICE industrial or automotive from 1 to 8 cylinders either inline or v configuration

any reply appreciated

Steve

 

[GregLocock]

1) I'd be designing the rotating parts ahead of the big lump with holes in. But that's just me.

Cheers

Greg Locock


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[BrianPetersen]

First some general overall-assembly illustrations to get the concept on paper. Then rotating/reciprocating parts. Then cross-sectional assembly views. Then details of the components. Then off to the pattern-maker/toolmaker/machinist/"shop". Then, probably, back to the detailer to correct any errors or missing information or improvements from the shop as they attempted to do their work and needed more information (or made corrections) in order to do it. Then back to the assembly drawing for detailing. And probably back and forth a few times. After the prototype engine was built and tested, most certainly there would be more rounds of revisions - probably several through the process, as issues were discovered and resolved.

I never designed engines, but did design other mechanisms, and the beginning of my career was before the common and relatively inexpensive availability of CAD, and the above is generally how it happened.

This would have been before finite-elements methods and simulation were used to optimise every conceivable aspect of engine operation, performance, and weight before committing any design to metal.

I have two examples of a motorcycle whose design would have been done in the early to mid 1980s, and upon disassembly, it's quite apparent where they eliminated one crankcase bolt from the design but couldn't be bothered to update the design of the casting, and where they added two more ... the two whose bolt heads can't be accessed without first dismantling the entire top end of the engine even if said dismantling is not otherwise necessary ... you still have to do it, JUST to be able to get to the heads of those two infernal bolts. Descendents of that design stayed in production into the late 1990s.

 

[EHudson]

Greg is correct. Rotating and piston assemblies first.

Have the packaging requirements in mind. Engine design is all about packaging once you have in depth knowledge of the individual components (no small thing).

Pick a reasonable BMEP not something over the moon. Pick a reasonable piston speed and the bore and stroke.

It's just me, but I go for the easy part next, the piston pin. From the max predicted pressure and pin bearing pressure, design with bending bending and ovality limits in mind.

Then put a survivable top land and ring package on top the pin hole and begin on the skirt and rod design. (Gas engine pin diameters are about 1/4 of the bore and diesels about 1/3 give or take.)

Base the small end of the rod on pin bearing load and pin bosses in the piston and then base the width of the big end of the rod on the crankpin bearing limits and your estimated crankpin size. The crankpin is about 2/3'd of the bore diameter if you expect to slide the pistons in from the top with a straight cut rod cap. Is it a Vee or opposed engine? Make sure the bottom of the piston skirts don't hit one another in a Vee or the back of the opposite rod in an opposed layout. In line just need to clear crank bits and main bearing bosses.

Once you have a rod that seems to work put it in position every 10 degrees of crank rotation to generate an outline of the path the rod travels (banjo shape)so you can give it clearance to your block and cam if there is one in the block. Next decide on a bore spacing and layout a crankshaft. The preliminary crank design should take into account 1) bending stress 2) balance weights and 3) oil hole placement. Torsional stuff and oil film calculations come in later iterations.

Work out the main bearing caps and bolts next from the expected loads. You'll need a head bolt pattern. This may require a cylinder head design. It will surely require a good concept.

Next, I like to think about the core that will make the water jacket and how it will be supported in the foundry flasks. You will also have a water pump location in mind.

Maybe at this point you can pencil in your space claim for the block.

Don't expect your first try to be great. It takes practice but in time you'll get better.

 

[nanokron]

it is interesting to see the ping pong ball effect between different engineering department trying to figure out how the hell are all those parts going to fit together I am sure that there was plenty of Advils in reach to control head aches

so from what I understand is that the rotation/reciprocating mass parts are calculated and drawn BEFORE the stationary parts, so they can have the whole assembly drawings done when they can get all the parts to fit together INTERESTING INDEED!

now I have an idea why an engine program could take years to be develop a reliable engine in the slide rules, pencil and paper era

as I understand it seams that most preliminary calculation are done before the first detail drawings and are bases on ratios, from either bore to feature ratio and/or stroke to feature ratio for dimensions and stress factors

By the way is there any publication that details those process of design like SAE papers or books or what search engine term that would highlight this subject especially 60's and 70's era


Steve

 

[Lou Scannon]

No world class manufacturer is going to divulge their trade secrets in detail in real time or shortly after the fact. And once their competitors have figured out what they're up to there's little point in either of them publishing such information. What you're left with are fairly vague publications that are rich with claims and qualitative comparisons, and relatively devoid of specific design criteria. For instance, "American Iron, A History of the OHV V8 1961-70", by STS Press, 1999, which is a collection of papers published in SAE Transactions describing the design and development of significant OEM V8 engines in the named period, by the designers themselves.
At the end of the day, the only recipe for competitive design is hard won experience coupled with judicious assessment, comprehension, and digestion of what has gone before.

"Schiefgehen wird, was schiefgehen kann" - das Murphygesetz

 

[nanokron]

https://www.calum-douglas.com/design/

here's a good link that is of interest I might buy the book when it will be available

in that web page there's some really good info but does it have most of the answer that I am seeking for ?

the above link is there as an example of what I am interested in

publication based on the above example

I am aware that many engineers wont disclose much knowledge about the subject from what I understand it is almost a black art no joke

there's quite a few legacy engine parts blueprints on the net but to understand the sequence of the process to the design itself is somewhat

of a mystery don't forget there is about a couple hundreds of ICE engine manufacturers in the world so the info is there just real hard to get

sadly people like Leo Goosen , Giotto Bizzarrini and Mike Costin/Keith Duckworth just to name a few are all gone by now so engine designers

of those days that work on engine project development are really scarce so does the info


Steve

 

[GregLocock]

If modern engine design is anything like modern vehicle design then you spend at least a year with spreadsheets and little what-if studies (or even, heaven forbid, literature studies), and teardowns of older designs, before you really get a decent spec hammered together. Then you'd do the product development V.

Cheers

Greg Locock


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[CWB1]

Engine design is like any other complex engineering design - incremental over time. If the goal is to create a new engine, a small research team is going to identify a few critical features/improvements for an existing engine size/family, design/model/prototype a few parts, put them on an existing mule, and flog that engine on dyno to fully understand the effect of your changes and correlate them back to a combustion model. Once they have a promising set of improved parts, research throws it over the wall to the production teams and those part/system-specific specialists to further analyze, improve, and test that iron. Once those handful of parts appear production ready, a much larger team of part/system-specific specialists are going to each design their new part/system to fit the new engine's requirements, build a few prototypes, test, complete pilot runs, etc through the production process. I have worked on OE engine research and production component teams and can attest its a very long and complex process, starting with a few engineers assigned and ending with dozens.

As to drafting and design, engines are like any other product today - top-down design, 3d models are master, engineers own the design, and drafties own the prints pursuant to both the engineer's and checker's approvals. OE engine prints tend to be VERY detail oriented with common layouts due to complexity, their drawing standards after often 1k+ pages to ensure that every detail of a 10-20 page block print is almost identical to every other block print corporate-wide.

 

[nanokron]

I do understand the production side of an engine department with goals, objectives and criteria to meet before the homologations
for production that I am aware of those issues my question pertains more to the sequence of event from the initial sketch drawing to the final first detail sets of drawings before the first prototype evaluation engine the first new born and before the second iteration of the said prototype I am more interested in the process of finding the steps involved for each of the parts but mostly the cylinder block
and cylinder head

one of the mystery question I do have when the rotating and reciprocating mass studies are done
does the CYLINDER HEAD DESIGN come first BEFORE the CYLINDER BLOCK DESIGN or are BOTH done silmultaneously ?

like in the cylinder head does the layout of the of the CYLINDER HEAD DECK GEOMETRIC PROJECTION comes first OR the one from the CYLINDER BLOCK ?

I know that the casting pattern makers and tool makers are deeply involved in that process with the help of a lots of advils for the head aches LOL

like I have in mind that the cylinder head deck is define first before anything else THAN the combustion chambers including valve seat size are define as the next step ,THAN third the in and ex ports layout, THAN fourth the intake and exhaust port flange pad location
and so on all base on the initial drafted sketch and feedback from engineering, tools and casting department

each of these features of a cylinder head must be define in some sort of a sequence like a base layout to start with

I know that it is mostly related to DRAFTING and ENGINEERING as question wise it just seams to be real hard to find info on the process I just hope I am not to redundant in my request and the capital letters are only there to highlight the specific term of my questions!


P.S. I am not trying to reinvent the world BUT just trying to understand how the world was reinvented

Steve

 

[GregLocock]

You'd design much of the head before the block. In a large organisation they'd be designed more or less simultaneously but the block would lead.

Of course in a large organisation there are other constraints on the design and it is likely the block machining line would affect the eventual design.

Cheers

Greg Locock


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[TugboatEng]

Back in the days of Charles Kettering, clean sheet engine design was done wirh single cylinder proof of design engines. The combustion side of engines was not well understood and much experimentation was required. Once a well functioning cylinder was developed the cylinder block and crankshaft could be built around it. I see the same being true for modern concepts such as HCCI. Cylinder blocks are a relatively mature technology but combustion still has much development ahead. Then again, Ford's 2.7 Ecotec has a very unique cylinder block design.

 

[nanokron]

and what about the cylinder head feature design in which sequence like A then B then C and so on ?

so I guess that the combustion chamber would be detail draw first then the ports positions then the cylinder block mounting bolt holes because the placement of the ports wont constraint with the mounting bolt and so on

it's sure that if you have an OHV design you have almost no choice to draw the block and head blueprints simultaneously
because than the valve-train assembly becomes a new constraint for designing the lifter box cavity location and head gasket

REALLY INTERESTING! . Now I can see that there's just so much allowed into a package with multitude of parts and constraint like stress analysis, flow dynamics, heat rejection, and on and on. WOW that must be real stressful especially when you have to
meet a time table requirement for the project to be within the management goals rewarding when you succeed but brutal for your career if you fail! one tiny mistake in the design and the company could loose a lot, because of miss management like the infamous CHEVROLET VEGA in the 70's that had aluminum bore engine that failed to perform as expected and put GM between a rock and a hard place

Steve

 

[TugboatEng]

The Vega engine itself was way ahead of it's time. Most of the big German manufactures started using Alusil blocks after the mid-1990's with good success. It seems the root cause of the Vega problems was a dysfunctional cooling system which exposed other weaknesses of the design.

 

[nanokron]

yep the famous ford ECOBOOST with the oil pan covering half the cylinder block yep and interesting design no doubt

or the STYER M14 and M16 engine are Monoblock and quite an unusual but interesting design no less

here's a description

https://steyr-motors.com.au/technology/monoblock/

https://files.engineering.com/getfi...81df-4300-91fe-2692244e4679&file=untitled.png

https://files.engineering.com/getfi...-5644-473b-b1ad-ac448b20f02f&file=s-l1600.png

https://files.engineering.com/getfile.aspx?folder=e29f0ec3-fafc-4e4f-92ce-a85903c53fe3&file=bg2.png

https://files.engineering.com/getfile.aspx?folder=0f5af7cb-7891-4b7e-a207-af08ed1c5956&file=bg3.png

 

[nanokron]

yep those special developement engines are called "Mono-cylinder Test Rig" these engine are use for evaluation purpose only for updating emission certification on diesel or gas industrial engines General Electric use to have one at its R&D center in Nyskayuna NY
for evaluation homologation EMD has one too like caterpillar or any other engine manufacturer around the world F1 engine like Ferrari
used to have one to for there development of there 90's v12 and v10 F1 engines even the venerable 2 stroke Detroit diesel use to have a 1-71 engine ( made by the Cleveland diesel company a division of GM ) pretty uncommon these days but if you type it on google you will get pic and specs for it I have seen probably 4 or 5 of those at engine shows in running condition

Steve

 

[CWB1]

Going back to my previous post, engine design starts with a small group developing the core combustion hardware - combustion chamber/piston, valvetrain, and boost for a given bore, stroke, and rod length. Much of that work is still done with single cylinder research engines bc they're easy to remachine/relocate and replace major components, and you can easily control temperature and pressure of every fluid throughout the system. Once complete, translating that work into block and head castings is a lot of fairly straightforward design work as the previous team provides most of the necessary interfaces. The head and block guy fills in the blank around the previous team's hardware, shells it in CAD, runs a CFD on the resultant oil, cooling, and fuel passages, tweaks as necessary, analyzes the necessary joints, then runs a casting sim and reviews with the foundry to ensure castability/manufacturability. Like most engineering today, there really isn't nor does there need to be much/any interaction with the trades until you begin building prototypes.

 

[PJGD]

Agreed - in the case of diesel engines, the design starts with the combustion system and works outwards from there. Today, there are numerous subtle tweaks to the combustion chamber shape and proportions that are evaluated in the single cylinder engine to meet your pre-aftertreatment engine-out emission targets , since without the confidence of meeting emissions the engine will never be sold. In the pre-emissions era, the focus was just on power, fuel efficiency and manufacturing cost.

Once the combustion system has been settled, you now know the peak cylinder pressures that you have to design for, the location of the fuel injector (on-axis or side entry), the induction port shapes to get the required in-cylinder air motion, and the peak injection pressures which may impact your camshaft design and location if unit pumps/injectors are specified. Another early stage decision is whether to go with a slab cylinder head or individual unit heads as used by, for instance, Scania and MAN.

 

[nanokron]

so from what I understand for the cylinder head model drawings is first you start by modeling the combustion chamber and sparkplug location second you model the ports design(length, cross section and locations for both in and ex ) third you model the valves fourth you model the valve guides fifth the upper oil deck with all the features related to the valve train and so on till the last step
is the close all the external surfaces ( cylinder head external feature like valve cover pad the intake and exhaust ports pad flange
than the external surfaces ends. I think I begging to understand the sequence that leads to the finished part

Steve

 

[CWB1]

Essentially yes. Engine design is like any other complex design today - parametrically driven. For the rough initial design, in CAD I would float all of the internal components into position as well as some external bounding planes/surfaces based on the space-claim/package limitations, then just solidify the space in between to form the block and head.