# straight 6



## sbdtasos (Jan 1, 2019)

hello to everyone and happy new year
new year new project is on the way
6 cylinder straight line
bore 24mm 
stroke 24mm


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## e.picler (Jan 1, 2019)

Looks really nice! Congratulations.
Having a 24mm bore seems to be a good size.

Edi


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## michelko (Jan 2, 2019)

Nice cant wait to see the build process
Happy new year


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## sbdtasos (Jan 5, 2019)

aluminium 7075 cylinder head ready
big piece near to 200mm lenght
working time near to 4,30 hours both pieces


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## CrashedAgain (Jan 5, 2019)

That is amazing work.  Almost makes me want to set up CNC......but I'm having too much fun making mistakes and scrapping parts "the old way".


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## mayhugh1 (Jan 5, 2019)

sbdtasos said:


> aluminium 7075 cylinder head ready
> big piece near to 200mm lenght
> working time near to 4,30 hours both pieces


Did you mean 430 hours?


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## e.picler (Jan 5, 2019)

Hi Sbdtasos!
Congratulations, it looks realy nice. For sure will be a great engine.

What CAD and CAM are you using?

Tks,
Edi


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## sbdtasos (Jan 6, 2019)

mayhugh1 said:


> Did you mean 430 hours?


Terry 4,30 for head and 3,30 for cylinder 
my mistake


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## ozzie46 (Jan 7, 2019)

I believe he means 4 hrs 30min. and 3 hrs 30 mins. 

Ron


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## sbdtasos (Jan 10, 2019)

engine block ready


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## michelko (Jan 10, 2019)

sbdtasos said:


> engine block ready
> View attachment 106651
> View attachment 106652
> View attachment 106653
> ...


Niiiccceee


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## sbdtasos (Jan 17, 2019)

cam lobes,distributor,timing belt tensioner ready


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## petertha (Jan 17, 2019)

Can you tell us a bit more about the valves. Are these just the guides for the valve stems to slide in & something different for the actual valve seat? Kind of hard to make out scale or how it integrates into head.


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## sbdtasos (Jan 18, 2019)

yes that is only the guides for the valves
as you will see on the photo i dont use valve seats
my engines work with this type with no failure


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## sbdtasos (Feb 4, 2019)

crank and rods ready


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## sbdtasos (Feb 16, 2019)

engine assembly


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## kuhncw (Feb 16, 2019)

That is a beautiful Inline Six!  Well done.

Chuck


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## mayhugh1 (Feb 16, 2019)

Beautifully executed. Great choice of finishes also. - Terry


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## FKreider (Feb 16, 2019)

Wow, fantastic work!

Are the distributor and exhaust pipes 3D printed?? Will they hold up to the head without melting?

Anxiously awaiting videos of it running!


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## sition (Feb 17, 2019)

wow, nice


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## sition (Feb 17, 2019)

Will different distances of carburetor intake pipe affect imbalance?


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## bobden72 (Feb 17, 2019)

How is the compressed air getting from the turbo to the carb inlet ?  Very nice work mind.  Ah just noticed the intercooler in front of the rad, all clear now.


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## ARUP (Feb 17, 2019)

Hi- beautiful work! Are any pictures available of the assembled crank shaft? The counterweights are 'full circle'?


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## Shopgeezer (Feb 17, 2019)

A mini turbo with intercooler! Thats amazing. Are both wheels straight vanes or did you manage to curve them?


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## kuhncw (Feb 18, 2019)

I would also like to see photos of your assembled crankshaft.

Thanks.

Chuck


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## sbdtasos (Feb 18, 2019)

FKreider said:


> Wow, fantastic work!
> 
> Are the distributor and exhaust pipes 3D printed?? Will they hold up to the head without melting?
> 
> Anxiously awaiting videos of it running!



distributor cap is from derlin cnc machined and the exhaust pipes are from air contitioner copper pipe 8mm od 6mm id


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## sbdtasos (Feb 18, 2019)

mayhugh1 said:


> Beautifully executed. Great choice of finishes also. - Terry


thanks Terry
i admire also your work that is amazing


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## sbdtasos (Feb 18, 2019)

Shopgeezer said:


> A mini turbo with intercooler! Thats amazing. Are both wheels straight vanes or did you manage to curve them?


thanks both wheels are with curved fins


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## sbdtasos (Feb 18, 2019)

here is first start


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## bobden72 (Feb 18, 2019)

Lovely sounds as good as it looks.


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## e.picler (Feb 18, 2019)

Wonderfull, Marvellous!
Congratulations Sbdtasos. A piece of art.

Ansious to see it runing again.

Edi


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## michael-au (Feb 19, 2019)

nice looking engine, sounds good too


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## IgorW (Feb 19, 2019)

Amazing work! I hope its not too much to ask but would you like to share some details about the turbo? Are you planning on connecting it to the intake? I know its probably not going to make any boost at this scale but i still fancy the idea. Keep it up! Cheers!


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## stef110 (Feb 19, 2019)

super nice build!


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## ShopShoe (Feb 20, 2019)

That is wonderful: Both to look at and to listen to:

thank You for posting,

--ShopShoe


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## Johno1958 (Feb 20, 2019)

Nice and lumpy sound and a great build.
Cheers
John


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## popnrattle (Feb 21, 2019)

beautiful music to my ears. Thanks for posting.


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## Kenny Broomfield (Feb 22, 2019)

So newbie question. Is that a kit kit or barstock? Where did you find plans or supplies? Very nice work.


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## neil_1821 (Feb 23, 2019)

That’s absolutely beautiful, great craftsmanship and sounds as good as it looks. Were these built to plans or is it your own design?


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## sbdtasos (Feb 25, 2019)

neil_1821 said:


> That’s absolutely beautiful, great craftsmanship and sounds as good as it looks. Were these built to plans or is it your own design?


thanks for the goog words its my own design


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## neil_1821 (Feb 25, 2019)

sbdtasos said:


> thanks for the goog words its my own design



That’s even more impressive being your own design. I bet it was a huge relief when it fired up and sounded like that!

Would you ever consider making plans to sell or perhaps the 3D models? I’d suspect there would be a lot of interest from the modelling community.


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## sbdtasos (Mar 3, 2019)

Would you ever consider making plans to sell or perhaps the 3D models? I’d suspect there would be a lot of interest from the modelling community.[/QUOTE]

that is what i am doing wright now ,trying to print the parts with all dimenssions


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## Linton Evans (Mar 4, 2019)

sbdtasos said:


> Would you ever consider making plans to sell or perhaps the 3D models? I’d suspect there would be a lot of interest from the modelling community.



that is what i am doing wright now ,trying to print the parts with all dimenssions[/QUOTE]


Yes  _ I too totally agree - Would you consider making the 3D files available for purchase?? Thanks


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## Willyb (Sep 7, 2020)

sbdtasos said:


> hello to everyone and happy new year
> new year new project is on the way
> 6 cylinder straight line
> bore 24mm
> ...


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## Willyb (Sep 7, 2020)

Congratulations on selling your motor. I was wondering if you remember what camshaft timing you used? It sounds really nice. Planing on building an engine and would like something similar for the camshaft.
Cheers
Willy


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## sbdtasos (Sep 13, 2020)

Willyb said:


> Congratulations on selling your motor. I was wondering if you remember what camshaft timing you used? It sounds really nice. Planing on building an engine and would like something similar for the camshaft.
> Cheers
> Willy


this is my camshaft
intake open 40btdc
intake close 30abdc
exhaust open 30bbdc
exhaust close 40atdc


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## gbritnell (Sep 14, 2020)

You're intake timing is a little radical for a model engine. 
gbritnell


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## johwen (Sep 16, 2020)

Very radical timing as it will be hard to start and difficult to get to idle and a lumpy motor. I would suggest an Overlap of 20 degrees myself
Johwen


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## leerkracht (Sep 16, 2020)

Radical timing ? 
the effective timing of the camshaft you need to measure with the clearance from 0.05mm to 0.1mm , you have a lot les timing with these small lobes  (make an assembly  > inventor  and see the result with  different  clearences )


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## Willyb (Sep 16, 2020)

sbdtasos said:


> this is my camshaft
> intake open 40btdc
> intake close 30abdc
> exhaust open 30bbdc
> exhaust close 40atdcView attachment 119328


Hi sbdtasos
Thank you for making this information available. What idle rpm would you reliably get using this Camshaft timing?  Thanks again for the information.
Cheers
Willy


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## johwen (Sep 16, 2020)

It would depend on flywheel weight and inlet manifolding for even fuel distribution. It wouldn't be slow and if it was would be lumpy. I would open the the exhaust 45 BBDC and close 10 ATDC and Inlet open at 15BTDC and close 30ABDC. With good porting and valve shape would give a nice running engine and a slow idle speed. Hope this helps. John from down under


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## Willyb (Sep 16, 2020)

Hi John
I should have referred to the idle speed  "sbdtasos"  was getting in his video of Post #29.  Sorry.
In the Video, the motor seems to be idling quit slow for these Camshaft timings. I would guess between 1500 and 2000rpms?
Yes it's lumpy but that's expected. Starts very well also.
Interested in looking at the plans when available.

Thanks John and sbdtasos


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## JCSteam (Sep 17, 2020)

This is an awesome engine. Very nice work on the machining. The Turbo is especially interesting, not many seen on small engines. 

Regards
Jon


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## petertha (Sep 18, 2020)

leerkracht said:


> ...the effective timing of the camshaft you need to measure with the clearance from 0.05mm to 0.1mm , you have a lot les timing with these small lobes  (make an assembly  > inventor  and see the result with  different  clearences )



Hi leerkracht. I dont want to digress this post about cam design. I think I will make a new post on that subject because I have more questions.  But your comment caught my eye as I was just looking at this same aspect myself. Just to use this cam as an example, is this an appropriate method to determine 'true' cam timing considering clearance as you mention?

I took his drawing & replicated myself. It shows 156.2 deg of valve open duration just based on the cam geometry. But that is only theoretical, no clearance. If I draw a peripheral clearance circle of 0.10 mm around the center & look for the new intersection, it reduces the open duration to 126.4 deg. I have made myself a spreadsheet to evaluate cam timing for model engines and to use the plot visualization, I think what happens is the reduced duration due to clearance effect acts like the black arrows (shortens the bars). So overlap is also affected. I know this is simplistic because other geometry issues enter the picture. But I think I see what you are saying, a small amount of clearance has a magnified effect on small model cam profile.


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## leerkracht (Sep 19, 2020)

cam shaft info 

gr


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## johwen (Sep 19, 2020)

If you listen to the V/12, a lovely engine, at idle it is not smooth but it smooths out  when the revs rise and i guess it needs the power at at high revs. Also it is turbo'ed. You can change the power curve by changing valve timing. But the first decision is what will the engine be used for i.e. if you want a smooth running engine at low speed the timing is best set mildly on the other hand if it is a racing motor then more radical timing  is the way to go. Exhaust systems and inlet systems will also vary the power/torque curves John. from down under.


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## leerkracht (Sep 19, 2020)

the v12 of 180 ° runs uneven on idle  because   it was the first run  of this engine , so completely new and not yet properly settings of the carburator and run in  , now this engine runs very smoothly over the entire rev range.800-3600 rpm  under load of the 4 bladed prop   wiht a 3 blade or 2 blade prop  easyly   rise the rpm over 4000 

pictures of coversion the  v12 60°    from 3 single Super Tigre  carburators to  6 double home made immediately 500 rpm more

enjoy


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