# Longboy's "SIDE SHAFTER" Model Gas Engine.



## Longboy (Feb 25, 2020)

If you look up "side shaft engine" on the internet, you get all your contemporary snow blower and rototiller utility engines displayed. For antique engines, the term refers to an external shaft driven by the crank to operate the valvetrain, provide ignition, drive a lube pump or engage a speed control governor. What if you laid out the crankshaft out to the side from a bank of vertical cylinders of a gas engine? 






Longboy's "Side Shafter" engine.......... starting this weekend!


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## minh-thanh (Feb 26, 2020)

Longboy !
Looking forward to your build.


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## Longboy (Feb 29, 2020)

A 4x4 inch aluminum angle piece gets cut back to a 3x4 inch piece.





In the vertical leg of the angle stock the web stub shafts will reside. The cylinders get the horizontal top side.





Cylinder boring shown from a previous engine.  A one inch bore to a 1.125 in. stroke for SIDE SHAFTER.


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## Longboy (Mar 1, 2020)

The brass bearing carriers installed for the crank webs. On each outboard end of the vertical face, a pair of aluminum blocks with their brass carriers for the crankshaft mount up to the framework.




I ordered some thin wall  half inch long Oilite bushings for all the bearing carriers. Seemed like they would do the job! It was later when tuning over the engine under compression with the drill....they were  not going to work for the kind of drive I'm using for SIDE SHAFTER. Seems like the internal clearance of these bushings to the shaft is just way too much. Not critical for the main shaft when spread out 8 inches from each other but for the stub shafts, they had to go. No shaft rocking in their carrier.




I replaced them all with R1810ZZ rollers, main shaft too......and the problem went away! There is no thrust movement in the stub shafts. Spacers and retainers on each side of the carriers ride on the inner bearing race


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## Longboy (Mar 3, 2020)

Box sections at each end supports the main angle piece.  A pair of 3/4 inch angles and flat bar stock tied into the vertical and bearing carrier.





The frame is complete in five pieces! With the frame's main vertical as SIDE SHAFT's backbone,  there will be no floor piece nor a longitudinal bar stock piece to complete another box with the main angle.





The bottom flat stock is cross slotted to give a positive lock in to the angle stock with one 6-32 screw from the bottom. Some rubber feet will find their way to each end.  Though it may look to be too short to support the cylinders, head and all its components without tipping to the left, to the right of the backbone go items to give a neutral left to right weight bias each side of the backbone.....including a flywheel!


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## Longboy (Mar 5, 2020)

Tecumseh points find themselves on on some flat stock to be bolted to the bearing carrier stock under the cam trigger on shaft to the inside of the frame member.









Automatic intake valves get their own assembly mounted to the cyl. head.  3/8 x 3/4 inch flat stock cage in the valve guides. Overlaid to each other with the o-ring seals and bolted together.


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## Longboy (Mar 7, 2020)

The radiators with their cyl. liners make the premier upon the deck of SIDE SHAFTER. Three 4-40 screws run up through the deck into the radiators.





The crank webs get dressed with their Traxxas drive members.





And the webs are balanced to the piston/rod assemblies. A brass counterweight will also be added to the backside.


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## Longboy (Mar 8, 2020)

Bringing the power strokes over to the crankshaft via the stub shafts are a pair of bevel gears. The drive being on the #4 cylinder as it is closest to the shaft bearing and carries the most load with the flywheel mounted.





Continuing the all star lineup of power distribution and allocation, cylinders 1 and 3 get some brass pulleys to turn the cooling fans. Now cylinder 2....was just too darn lazy to do anything for me!


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## awake (Mar 9, 2020)

Longboy, it is looking good! One thing I have been puzzling over: under each cylinder is a brass bearing with a short shaft. When I looked at the first picture in your last post, I think I now understand that at least one of these is geared from the crank shaft to bring the motion out to the side mounted cam shaft. But in the last picture above, it now is looking to me like each of these is geared to the crank shaft - is that correct? A very, very interesting design!


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## Longboy (Mar 10, 2020)

awake said:


> ....... motion out to the side mounted cam shaft. But in the last picture above, it now is looking to me like each of these is geared to the crank shaft - is that correct? A very, very interesting design!


Thanks awake.  You are somewhat on the right track. Let me give you a cryptic response! All four cylinders power the crankshaft through the bevel gears.....but the bevel gears are not connected to a cam shaft.


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## awake (Mar 10, 2020)

Ah, a mystery, is it? I look forward to seeing all revealed in the end!


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## Longboy (Mar 11, 2020)

A single piece cylinder head is bored into about 5/16 inch depth on 2 inch centers.









And I got a line up match upon the cylinders!





Sixteen 4-40 SS socketheads will draw down on the radiators.





One spark plug and one ex. valve in the chamber. A tapered cut around the circumference of the chamber for the O-ring seal and a push rod hole near the edge.





And on the top side some recessed boring for the rocker arm pedestals. At the sides,  porting for in./ex. flow.


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## Longboy (Mar 12, 2020)

All brass hardware to open up the exhaust valves.





All the holes and passage ways drilled in, a pattern milled across the head for the fins.


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## awake (Mar 12, 2020)

You are moving along quickly! Great progress, and great results.


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## Longboy (Mar 14, 2020)

Coming around the side of the rocker pedestal, the exhaust port to the outside.





SIDE SHAFTER will get a pair of brass, aluminum , copper mufflers. The brass tubes are end threaded and cross drilled to mount the mufflers and allow the gases to enter the copper canister.


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## Longboy (Mar 16, 2020)

The camshaft on the cylinder side of the backbone. Three bearings, roller behind the sprocket guard and a pair of brass bushings along the length. Individual lobes will be slid upon the shaft and locked in place with set screws.





20/40T MXL sprockets for the drive.





A pair of 24T MOD .5 brass bevel gears bring the the drive over to the distributor. The distributor shaft rises at an angle through the backbone to clear the forward frame box section.


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## Longboy (Mar 18, 2020)

The distributor perches atop the front box section. The U-joint gives a more favorable position near 45 degrees.  Available from vendors on Ebay.


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## awake (Mar 18, 2020)

Wow, you are making great progress! Looking good!


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## Longboy (Mar 19, 2020)

A pair of PVC bulkhead fittings form the shrouding for these 2 inch fans.  There is a pedestal mount under the hex, single 6-32 bolt through the top. 





Delrin pulley on shaft through the fan into a R166 roller bearing in pedestal.





There is enough room to place the O-ring belt between the pulley and points cam. The fans turn counter clockwise and push air across the radiators and the drive ratio is about 2.3:1.















   Come see this weekend's presentation of SIDE SHAFTER !!!


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## Longboy (Mar 21, 2020)

Welcome to my presentation of the Longboy SIDE SHAFTER engine.   





This build began the first week of November.





Engine completed the middle of February.





Side Shafter's unique features begin with an off set crankshaft parallel to the cylinders.





Made possible by gearing the four cylinders through their crank webs.










Atmospheric intake valve block.





Composite metals flywheel.





1 in. bore by 1.06 in. stroke......55cc's.      See it running!          Dave.


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## dozerdroid (Mar 21, 2020)

Thank you for sharing, super cool.


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## minh-thanh (Mar 21, 2020)

Congratulations !
I like the way you do the engine, make a the engine the way you want it
Thanks for sharing.


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## awake (Mar 22, 2020)

Longboy, I am speechless. What a concept, and what a wonderful result! Well done!!


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## Longboy (Mar 22, 2020)

Thanks awake!  The geared crank concept worked so well with my SUPER TEE triple that it was worth a look/see on another project for this year with SIDE SHAFTER.  I may come back to it with a different multi- cylinder layout in the future and maybe other modelers will try it.  Sure gives some interesting attentions and visuals to open crankshaft engines.


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## awake (Mar 23, 2020)

Aha! Now I will search for the SUPER TEE triple to see what you did there!


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## awake (Mar 24, 2020)

Longboy, after reading the SUPER TEE build, and this one, my mind is buzzing with possibilities ...


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## Longboy (May 7, 2020)

Looking at HMEM user "awake" and his Webster build. He made a carb from plans posted, developed by Chuck Fellows. I'm looking at them and started a quick project after hey/ nay the self made idea for a long time. I don't need the throttling valving as through the lean/ rich fuel feed........ will vary the RPM in a narrow but satisfactory range.






The SIDE SHAFTER now has the 4 inch steel flywheel. Slowed the engine down some. Trying this mixer on this engine as it is four cylinders and with the throttle open very slightly on the O.S carb here, the engine maxes out it's low RPM smooth threshold in the 1000RPM range. Conclusions and results of the home grown mixer to come.......


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## Brian Rupnow (May 7, 2020)

Lovely bit of work Longboy. Engine runs very well and shows a lot of dedication. A piece of engineering artwork!!---Brian


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## Longboy (May 8, 2020)

Brian Rupnow said:


> Lovely bit of work Longboy.................


Thanks Brian. Picked up a few ideas and methods over time here......some from your pages of know how!


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## doc1955 (May 8, 2020)

That is an interesting engine runs great. Very nice thanks for sharing!!


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## Longboy (May 9, 2020)

The fuel mixer works well. Swapped it between a twin and SIDE SHAFTER and got the same response.





I made a duplicate right away and tried out on another couple of twins. The venturi is 5/32in. bore. The brass air jet for this engine is drilled 1/8 in. currently. With the needle near closed it will start and idle around 1100 and through enrichment settles back to 700 and stalls. This 400 rpm move is all over in a quarter turn of the needle screw with the eighth incher.




Along with a couple fixed bore air jets I made a variable jet. 10-32 set screw restrictor under a 3/16 hole. I'll take the fixed bore as you only need the fuel screw to vary the engine speed and each engine has its own carb anyway. Let's see what it looks like running with the 5/32 inch air jet.


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## awake (May 9, 2020)

If I'm seeing right, it looks like you have only the needle adjustment, but no throttle - ?


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## Longboy (May 9, 2020)

awake said:


> If I'm seeing right, it looks like you have only the needle adjustment, but no throttle - ?


Yes. Fixed air jets and variable fuel.....no throttle.


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## Longboy (May 11, 2020)

Using model airplane carbs in the .15 size for most of my gas engines. They work fine in engines beyond their purposed thimble size displacement @ 15K RPM.  Adaptable for my purpose, the settings more than what I need. You play with the air throttle and fuel mix screws as well as set the position of the needle valve in the fuel jet.......can drive you nutz on a fresh engine you are trying to trouble shoot. Looking at most hit/miss engines with one valve fuel supply  mixers, sees to the needs of my steady idle, stationary industrial type models .

Some assumptions I made looking at the O.S. carb is the intake horn diameter. At about 5/16 inch and duplicated on my mixer. Fuel did not travel up the line too well.  Too large an air horn opening with no throttle provision......no vacuum.  Reduced to near the venturi bore as an air jet insert into the intake horn..........results turning very favorable. Seems that the air demand on models with intake port diameters close to the venturi bore can also be the intake horn diameter bore on a twin and quad cylinder engine running at similar idle speeds, 1000-1200rpm  in my evaluation of a couple of engines double the displacement from another. Also apparent that the venturi effect takes place beyond the carb body, at the air jet insert. Got a whole world of ambient atmospheric pressure starting there and your intake manifold plenum takes care of the other end of the process.





This basic fuel mixer is easy to make.  Single needle/seat fuel control. Fixed air jet insert into air horn control. Adapter to fit mixer to manifold.


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