# boxer engine



## sbdtasos (Dec 4, 2017)

after a long relaxing time i desided that is the time to start a new project.
i was thinking a lot time ago to byild a boxer engine.
so i start sketching 
engine 4 cylinder boxer 24mm bore 24mm stroke


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## Rudy (Dec 5, 2017)

Ambitious plans for sure. What will be your approach? Casting, manual milling, CNC? Have a soft spot for that construction. Resembles my Subaru Sti engine &#61514;


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## sbdtasos (Dec 7, 2017)

Rudy said:


> Ambitious plans for sure. What will be your approach? Casting, manual milling, CNC? Have a soft spot for that construction. Resembles my Subaru Sti engine &#61514;



solid block 7075 milling with cnc router
yes is very close to subaru engine


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## michelko (Dec 17, 2017)

Hi,
Nice design. Would like to know how the cams and the crank are lubricated?

Regards Michael


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## sbdtasos (Dec 26, 2017)

michelko said:


> Hi,
> Nice design. Would like to know how the cams and the crank are lubricated?
> 
> Regards Michael



with splash oiling method for the crank.
now for the camshafts i will oil them before start


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## sbdtasos (Feb 8, 2018)

View attachment IMG_20180208_114806.jpg
View attachment IMG_20180208_114815.jpg
View attachment IMG_20180208_114754.jpg
View attachment IMG_20180208_114740.jpg
View attachment IMG_20180208_130638.jpg


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## sbdtasos (Feb 8, 2018)

engine start


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## Cogsy (Feb 9, 2018)

I'll definitely be watching this one.


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## michael-au (Feb 9, 2018)

Looks good, I will be following along


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## sbdtasos (Feb 9, 2018)

cylinder head ready


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## sbdtasos (Feb 10, 2018)

crank case ready


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## Brian Rupnow (Feb 10, 2018)

Sdbtasos--that is a very interesting engine.---Brian


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## sbdtasos (Feb 12, 2018)

good progress today.finish cylinder head ,missing only valve guides.
cam holders,intake manifold


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## michael-au (Feb 12, 2018)

Just wondering if the you are going to make the plans for this engine available 

good workmanship by the way


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## michelko (Feb 13, 2018)

Nice intake manifold. how is it made?

Michael


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## sbdtasos (Feb 13, 2018)

michael-au said:


> Just wondering if the you are going to make the plans for this engine available
> 
> good workmanship by the way



thanks 
yes when i finish the engine the plans will be available


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## sbdtasos (Feb 13, 2018)

michelko said:


> Nice intake manifold. how is it made?
> 
> Michael



hello 
i use aluminium pipes 8mm od with 6mm id
i give them shape with this tool 

http://www.johnart.gr/Catalogue/index.php?main_page=product_info&products_id=5035

and welding together with this sticks

https://www.ebay.com/itm/ALUMINIUM-...518670?hash=item2a9d3b0a8e:g:bIYAAOSwd4tTwXpZ

also machine the ends


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## sbdtasos (Feb 15, 2018)

one distributor ready .also my head gaskets are ready


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## michael-au (Feb 16, 2018)

Will this engine be water cooled?


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## sbdtasos (Feb 16, 2018)

michael-au said:


> Will this engine be water cooled?



yes correct
the engine is water cooled


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## sbdtasos (Feb 16, 2018)

camshaft lobe ready
valve lifters shims
brass fitting on cam holders


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## sbdtasos (Feb 18, 2018)

pistons and pins ready


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## vederstein (Feb 18, 2018)

...the wonders of CNC....


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## sbdtasos (Feb 21, 2018)

crank ready


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## sbdtasos (Mar 4, 2018)

and we are very close


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## michael-au (Mar 4, 2018)

Looks fantastic nice work


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## michelko (Mar 5, 2018)

sbdtasos said:


> and we are very close



Hi
whats the yellow hose for? Looks like it´s going from the head to the carb?

Michael


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## sbdtasos (Mar 5, 2018)

michelko said:


> Hi
> whats the yellow hose for? Looks like it´s going from the head to the carb?
> 
> Michael



here is the correct possition for the yellow hose


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## sbdtasos (Mar 11, 2018)

and we have the first failure .the bearing of the conecting rod is broken 
i change it and try to start the engine again and the bearing again broke.i dont know the reason.now i have install brass bushes and i will see the results


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## michael-au (Mar 12, 2018)

Hope you get it sorted out, will be good to see it running


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## ninefinger (Mar 12, 2018)

My initial gut feel is that the ball bearing is undersized for the load.  Looking at full size applications - 2 stroke boat motors for one - I've seen needle roller bearings on the connecting rod big end. Even in modern car engines they are using babbit bearings as the load is quite high at this location in the engine.  I think you will find your brass bushes will serve well in this application.
Looking good - excited to see it run.

Good luck.
Mike


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## michelko (Mar 13, 2018)

I agree with Mike.  The bearing balls Look realy tiny.
Michael


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## Mechanicboy (Mar 13, 2018)

ninefinger said:


> Even in modern car engines they are using babbit bearings as the load is quite high at this location in the engine.
> 
> Mike



Mike, i am car mechanic and can tell you the babbit bearings is not longer in use in the modern car engines. Also we are using aluminium bearing alloys. The aluminium alloy bearing have wear resistance, high load-carrying capacity, fatigue strength, thermal conductivity, and excellent corrosion resistance, and low cost. The aluminium alloy bearing last long life up to 300 000 km to 400 000 km before the bearing is worned.   The world's highest mileage car, a 1966 Volvo P1800, has traveled more than 4,828,032 km (3,000,000 mi) on its original B18 engine.


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## Mechanicboy (Mar 13, 2018)

sbdtasos said:


> Use bronze instead brass, it will last much better. Brass is not solid as bronze. Make lubricating hole under the connecting rod where there is not pressure zone to be sure the bearing is well lubricated since you do not have oil canal inside the crankshaft to lubricate the connecting rod bearings and crank shaft bearings.


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## sbdtasos (Mar 13, 2018)

in all my engines i use bearings 6x10x3 on the rods with no faulier 
on this engine i use bearing 8x12x3,5 and i have this problems 
now i think that will be ok with the brass bushes
now i trying to start the engine but i have some issues
as you will se on video the engine start but stop after 2-3 seconds
when i close the carb with my finger the engine start but only for 2 - 3 seconds after is not starting 
i check the timming and i want everybodys opinion for that 
my camshaft timing at 40 before  tdc and close 30 after bdc for the intake 
and for the exhaust 30 before bdc and 40 after tdc
i check my camshaft and i want your opinions for my timminig if is ok or not 
cylinder 1 in -30 btdc +40 atdc 
              ex -30 bbdc+30 abdc
cylinder 2 in -25 btdc+45 atdc
              ex -35 bbdc +45 abdc
cylinder 3 in -40 btdc+35 atdc
              ex -30 bbdc+35 abdc
cylinder 4 in -40 btdc+30 atdc
              ex -30 bbdc+40 abdc
do you thing that this timinig is a problem?


[ame]https://www.youtube.com/watch?v=js5OguG-bLs&feature=youtu.be[/ame]


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## ninefinger (Mar 15, 2018)

What is your ignition timing like?  And what do you have for a flywheel?  Sounds like it might be either to aggressive ignition and/or too little flywheel to keep it going.


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## ninefinger (Mar 15, 2018)

Mechanicboy said:


> Mike, i am car mechanic and can tell you the babbit bearings is not longer in use in the modern car engines. Also we are using aluminium bearing alloys. The aluminium alloy bearing have wear resistance, high load-carrying capacity, fatigue strength, thermal conductivity, and excellent corrosion resistance, and low cost.



I use babbit bearings as a general description for hydrodynamic bearings of that type, not meant to imply the actual construction of the bearing itself.  
Basically an oil film bearing has a much higher load capacity than a ball bearing of the same outer / inner diameter and width.

Mike


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## sbdtasos (Mar 16, 2018)

ninefinger said:


> What is your ignition timing like?  And what do you have for a flywheel?  Sounds like it might be either to aggressive ignition and/or too little flywheel to keep it going.



90% ignition have problem
yes i know that engine looks like that have to much ignition timing
but is only 25 degrees btdc
i am waiting a new ignition and i will try again to start the engine


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## pp2076 (Mar 16, 2018)

sbdtasos said:


> and we have the first failure .the bearing of the conecting rod is broken
> i change it and try to start the engine again and the bearing again broke.i dont know the reason.now i have install brass bushes and i will see the results


Fake Chinese bearings perhaps?


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## sbdtasos (Mar 18, 2018)

pp2076 said:


> Fake Chinese bearings perhaps?



yes correct


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## sbdtasos (Mar 18, 2018)

i make a new test with a cdi from motor bike
the engine work very smooth 
i already order a new rcexl ignition 
here you can see the engine working with motor bike cdi

[ame]https://www.youtube.com/watch?v=3lNdRXjMYi0&feature=youtu.be[/ame]


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## michelko (Mar 19, 2018)

cool...
something flowen away at 0:20 What Diameter is the Distributor?
Do you have detailed pics of it? maybe a plan?

I am fighting with the ignition on my bugatti 8 Cylinder

http://www.modelenginemaker.com/index.php/topic,6848.0.html


Michael


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## sbdtasos (Mar 20, 2018)

michelko said:


> cool...
> something flowen away at 0:20 What Diameter is the Distributor?
> Do you have detailed pics of it? maybe a plan?
> 
> ...



hello 
that flowen part was a piece of steel that need for the hall sensor to give signal 
gistriutor is 40 mm 
i can send you the sketch if you want
nice thread your engine


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## nparmley (Sep 2, 2019)

Awesome looking build. Have you finished?


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## sbdtasos (Sep 12, 2019)

nparmley said:


> Awesome looking build. Have you finished?


yes  engine finished and sold


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## nparmley (Jan 20, 2020)

With the pistons looking like they are directly opposite of each other, what does the crank look like? Does the engine use a typical crank of 4 connecting rods to 4 separate crank lobes, or is it 2 lobes?


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## sbdtasos (Jan 21, 2020)

nparmley said:


> With the pistons looking like they are directly opposite of each other, what does the crank look like? Does the engine use a typical crank of 4 connecting rods to 4 separate crank lobes, or is it 2 lobes?


yes correct 
cylinders are directly oppostite and crank is with 2 lobes


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## bluejets (Jan 21, 2020)

Called forked rods. Other option is offset big ends.


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## ldsgeek (Jan 22, 2020)

sbdtasos said:


> yes correct
> cylinders are directly oppostite and crank is with 2 lobes


That's more properly termed a horizontally opposed engine or a 180 degree V, since the pistons are on the same crank pin. A boxer has each pair of pistons moving toward TDC at the same time. This cancels out the tendency for the engine to try to rotate about the axis perpendicular to both the crank centerline and the cylinder bores. VW, Porsche, BMW motorcycles and Subaru are boxers. Ferrari made several 180 degree 12 cylinders which were not boxers (opposing pistons shared a crank pin).


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## Brian Rupnow (Jan 22, 2020)

That particular rod configuration is called 'Knife and fork' .


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