# Motorcycle engine Stage 2



## Enginehead (Mar 12, 2022)

Designing an engine generally is extremely difficult at times. Making it roadworthy can be even worse depending on the country.


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## Enginehead (Mar 12, 2022)

I for instance work on a 1500ccm single cylinder, the C io 1500 P (H) 
OHV 4-Valve engine with a valvebridge-rocker assembly, with mechanical decompression for kickstart applications and automatic decompression for the electric starter.
I first based it on a cylinder and piston assembly from a Lycoming io 360 (Hence the io segment to its resemblance), but as in the end a screwed together lycoming head would be close to unchangable to a 4 valve system without damaging the cylinder whilst switching the head. So I returned to base on the pistons only. 

Theoretical Database:
Displacement: 1500ccm
Max. Hp.: 53Hp/4000 RPM. 
Max. Torque: 136Nm/3400 RPM
Coolant: Air/Oil cooling
Ignition: Dual Spark NGK BP6ES
Electronic Setup: Royal Enfield C500 EFI
Valve Setup: 4valve OHV with single Rockers (valvebridge) 
Fuel system: Electrionic fuel-injection dual setup. 
Starter: Kickstarter in the crankcase, E-Starter in the gearbox
Primary Drive: Duplex Chain with Compensation sprocket 
Secundary Drive: Simplex
Gearbox: Bakers 6 speed overdrive reverser. 

To be continued


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## stevehuckss396 (Mar 12, 2022)

This is a project you plan on building in the future?


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## Marmech (Mar 12, 2022)

If this is something you have in the works then keep us updated as it sounds like a decent project!

Good luck.

Mark


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## Enginehead (Mar 12, 2022)

It is a project I am trying to build as a sidecar motorcycle engine. I've been trying to upload some pictures to what i have so far but i think I'll need to do it via PC. 
Right now it is a solid edge folder full of parts, referencial parts and a few assemblies. 

The ruleset i have for it is:
It needs to fit in an already existent frame, which has been legally driven in the country (Austria, with the fitting papers), the engine needs to accommodate the standards of that particular motorcycle before it's stripped or even be better at it and many specialized parts need to be from official companies who do such for a living, otherwise it is even harder to legalize... And on some things i wouldn't dare to manufacture the parts for as long as i lack proper tooling.... Like casting... Especially with aluminum, as they have problems binding properly with the oxidization and the Heat treatment not to forget at that size often. 

The frame is from a Honda Shadow Vt1100 C2 ACE SC32 from 1996....it's my second motorcycle and it has plenty of kilometers on the engine. 
But we aren't here for the frame, now are we. 

The engine consists of 2 aluminum crankcases that take proper force from the engine. The main bearings are solid bronze bushings with a flangeside, which have slight oil groves on the vertical area and are faced center so the crankshaft is friction reduced. inner diameter 55mm H7. The crankshaft surface gets Maschined after the designated bushing bore with 0,05 +-0,005mm tol. standard. It has 2 opposing oil pocket dragg lines, which get milled in before the bore gets turned to precision. A fixation screw will destine the position of the groves in rotation vertically, as these also will be oil pockets for starting, to lessen the starting friction as much as possible. 
The crankshaft will be a 5 parter with billet parts, pressed and screwed into optimal position, which i still need to define as right now i have a placeholder crankshaft. 
I swear the next text will have a picture. 
The oil lining first goes through the pump (I'm still unsure if not to use a Honda Shadow vt1500 oil pump, or a suzi intruder....)
The oilpump bodies are in a modular casing, as otherwise i can't use any oilpump properly other than maybe one from a royal enfield. The oilpump is driven by a thin metal gear, that gets the rotation from the balancing shaft. 
After the oilpump there's the outside based fine thread oil filter, meterware, below the standing oil level so that the filter won't go dry when standing. It goes immediately through the crankcase going through the main bushings on both sides, also going through the oiling drills of the Crankshaft, then going out of the case to a bimetal spring valve via a coppertube (looseflange-threaded) , which engages the line to the oil cooler if the oil temperature goes beyond 95°C, plus/minus 2 degrees, before going into the aluminum cast enginehead, where it first travels in 2 holes parallel through he heat areas, before spilling through the rocker bushings and 2 sprinklers, one small one spraying the decompression lever and the other one spilling onto the pushrods, where they flow down the rod barrels, flowing back into the wet sump.


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## Longboy (Mar 12, 2022)

.....Kinda lost everyone with 1500CC's of single cylinder within a Honda frame. Send photos of your machine shop with engineering staff.


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## Enginehead (Mar 12, 2022)

I and my friend are not machining it.
I do NOT have the tools for proper 3D or even 5D milling, which could be necessary for certain Parts, nor an NC lathe for that size. Although I would love to machine these parts by myself, I would never be able to drive it then. I let the parts manufacture. Especially since the TÜV-inspector is that hard of a convincable person. I design them and plan them in cooperation with a Civil technician in Wels, as much as an extra pair of eyes by the model engine manufacturer Ploberger, as much as parts of their manufacturing equipment needed for the job. Only thing I'll probably sit sideways on is about the honing as, dear lord I fear they have no honing tool of that size spectrum.
Followed by the Casting by the swiss foacas.
For smaller parts, that aren't incredibly relevant, like the gear position plate and the special bolts it needs, as much as special screws, that are otherwise not easy to come by or the exhaust piping and piping covers, from what is possible to manufacture by my friend and I on the engine itself. Most dirtywork will be on the motorcycle itself. I don't risk any chances for when driving. I can use my off time with the manual and NC steered machinery of the company i work in, but otherwise?
I'm letting them be produced after the design i work already 9 months on. I have a workshop with tools mainly for assembly and the basic handtool manufacturing.
You can have That picture latest tomorrow morning as i won't drive to it now as it's late.
In the meantime I'm here to show the planning of it, with its CAD files, also what I do have on hand is the candidate:
The left one of the two Honda Shadows is the lucky contestant.


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## Enginehead (Mar 12, 2022)

Dont mind the bags and the drawer, I'm moving soon


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## Enginehead (Mar 12, 2022)

Longboy said:


> .....Kinda lost everyone with 1500CC's of single cylinder within a Honda frame. Send photos of your machine shop with engineering staff.


Also, I can fully understand that I lost you on that part, Especially since it all doesn't sound too believable.
In fact, I rather doubt that I'll be taken serious with this project especially since it has an unbelievable cost. the calculation towards the engine alone resolve on around 8.000€, although I rather say 10.000€ as I'm optimisticly pessimistic about production goals.
I'll continue anyways.


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## Longboy (Mar 12, 2022)

Of course you can believe it that your credibility is non existent. Yer a little short on funding engineering and and tooling costs let alone acquisition and adaptation of like parts already in existence.  And you just want one prototype. There are no 1500 cc single cyl. gas engines. Take your show elsewhere.


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## Enginehead (Mar 12, 2022)

You are right, there. Are no 1500ccm thumpers in a motorcycle. The biggest seen in a motorcycle is a 2000ccm single cylinder petrol. 
And believe me, money is the last thing I'm concerned about. 
Anyway. Sure. I'll just stop posting.
Wish a pleasant time.


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## Steamchick (Mar 14, 2022)

Hi Engine head, Keep posting please, many of us I reckon will be interested in the obstacles you meet and overcome in this project. I learn from most who are ambitious and do things like you are attempting. It is through the experience and sharing that we all learn. So don't be put off by Longboy with his doubting Thomas attitude. None of us individuals represent the whole readership. We all choose to read the posts that interest us, and ignore that do not  hold our interest.
So, "My query": Plain bearings are not sympathetic to crank flexure. I experienced the large degree of crank flex under dynamic conditions when I wiped-out alternators on various regular motorcycle engines, while trying to fit better generators for better lighting.... The 1960s engines needed 0.004in clearance between the rotor and stator - outboard of he main crank bearing.  Later alternator parts (to mid-1970s) that were "interchangeable" and had higher outputs had 0.003, 0.0025 and 0.0015in clearances. On a Triumph 650 cc. twin (1962) I could just get away with 0.0025in clearance, but on a 1964 500cc Single I could only get away with 0.003in clearance. The main bearings on both engines were ball races, as plain bearings with suitable close clearances could not survive the crank-flex and consequential dynamic axial mis-alignment of the crank main-shafts. Car engines (e.g. 4-cyl 2 litre) with similar bore and stroke have a much larger main bearing size and consequential crank stiffness. 
So how are you designing the crank for the plain main bearings to are planning? Is it very stiff? Check main bearing sizes for a 9 litre 6-cylinder diesel truck engine and compare to yours? I am curious...
K2


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## Vietti (Mar 14, 2022)

Saw a YouTube video of a guy, Australian?, who built a v twin with aircraft cylinders, Mallard?  Any way it looks real cool and is ridable.  Hope some one can supply a link.  He built numerous other bikes with cylinders added etc.  Gifted builder.


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## Vietti (Mar 14, 2022)

Found it.  The Flying Millyard.  He built 30 or so fascinating bikes including a v-twin Velocette.  Worth a look.  Google works too.


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## stevehuckss396 (Mar 14, 2022)

His name is Allen Millyard. He has been adding cylinders to bikes long before youtube was a thing. I am a subscriber to his page. 



			https://www.youtube.com/c/AllenMillyard


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## Enginehead (Mar 14, 2022)

Steamchick said:


> Hi Engine head, Keep posting please, many of us I reckon will be interested in the obstacles you meet and overcome in this project. I learn from most who are ambitious and do things like you are attempting. It is through the experience and sharing that we all learn. So don't be put off by Longboy with his doubting Thomas attitude. None of us individuals represent the whole readership. We all choose to read the posts that interest us, and ignore that do not  hold our interest.
> So, "My query": Plain bearings are not sympathetic to crank flexure. I experienced the large degree of crank flex under dynamic conditions when I wiped-out alternators on various regular motorcycle engines, while trying to fit better generators for better lighting.... The 1960s engines needed 0.004in clearance between the rotor and stator - outboard of he main crank bearing.  Later alternator parts (to mid-1970s) that were "interchangeable" and had higher outputs had 0.003, 0.0025 and 0.0015in clearances. On a Triumph 650 cc. twin (1962) I could just get away with 0.0025in clearance, but on a 1964 500cc Single I could only get away with 0.003in clearance. The main bearings on both engines were ball races, as plain bearings with suitable close clearances could not survive the crank-flex and consequential dynamic axial mis-alignment of the crank main-shafts. Car engines (e.g. 4-cyl 2 litre) with similar bore and stroke have a much larger main bearing size and consequential crank stiffness.
> So how are you designing the crank for the plain main bearings to are planning? Is it very stiff? Check main bearing sizes for a 9 litre 6-cylinder diesel truck engine and compare to yours? I am curious...
> K2


Thanks for that heads up there, it's really appreciated.

I really agree to to your claim of Roller bearings not being overruled by the bushing.

In fact the flying Millyard, the 5Liter V-Twin, has actual roller bearings. It is actually mainly the size needed to accomodate the same linear forces a bushing could, hence why these are preffered on rockier or generally bigger engines.These size issues easily were accomodated by the copper bushing, as much as it often more cost effective production.

I actually thought a lot about the decision of using bearings or bushings. The reason I more or less had to choose a copper bearing was, that the engne would have to overcome serious space issues. Not because of its height as luckily the frame goes deep into the tank and the new tank will be raised aboth by a certain bit, but, because of the valve system. Like Royal enfield, I use a very close aligned Cam system, to keep the engine at the same time as compact as possible.
Would I use anything bigger like a bearing, I'd run into space issues, as the cam gearing needs to be bigger aswell, as the mountings of the cam pin get dangerously close to the bushing already.

I actually had to look up the design of the Bonneville crankshafts as I wasn't looking that deep into them. I was actually surprised to see the crankshaft flywheels in the middle instead of the much more spread out heavier Sidelined or combined counterbalance. Meanwhile the single cylinder assembly has more crank flexing due to comparably more force being applied per stroke. The flex is considerably higher.
Thanks to my engine and its high force to overcome, I immediately went for quite stiff main journal sections. The Crankshaft falls small in diameter quite quickly though, as flywheel and cam-gearing don't need close to this stiff of an assembly. Especially since the gear setup plate and the friction tip of the crankshaft are encased by roller bearings.

But thanks to the "flywheel" at the counterweights it was necessary. And so far I get 50 to 75 mu clearance with heat expansion in mind.

Also what isn't actual on this picture is, that the main bushings don't have the high alloyed steel casings yet.


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## Enginehead (Mar 14, 2022)

stevehuckss396 said:


> His name is Allen Millyard. He has been adding cylinders to bikes long before youtube was a thing. I am a subscriber to his page.
> 
> 
> 
> https://www.youtube.com/c/AllenMillyard



Thank you Vietti and stevehuckss.
This british gentleman is an ace of his kind and a true demonstrator to what's possible.
Also an incredible design might be the NSU Bison 2000, the 2l thumper i mentioned early on.

Just what the Bison will never achieve is for example a legal license of roadworthyness in germany, where it was built. it was used for Race applications solely. Meanwhile I have no clue how Millyard got the 5l V2 onto the road. I have to close to fight with the TüV for allowing a different type of break line on my cruising Honda, as the standard rubber one is prone to massive breaking losses through expansion. Hence why I'm working with another citys' TüV.


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