$txt['youtube'] = 'YouTube'; $txt['youtube_invalid'] = '#Invalid YouTube Link#'; Es-Kape 1.0 upgrade to Briggs & Stratton Animal 206cc Kart Racking Engine

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Es-Kape 1.0 upgrade to Briggs & Stratton Animal 206cc Kart Racking Engine

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voipwell:
Mokai is bound by epa rules in engine selection.  But I would like 2.0 performance with 1.0 weight.  I picked the animal because of the torque chart.   The Subaru and Kholer peak horsepower is below 3600 rpm.  The peak torque even lower than that in the 2k range.  The animal has both it's torque and hp peaking in the 4-5k range peaking at 5k.  And,  it's built to withstand brutal beatings with racing parts designed to withstand up to 7500 rpm.  The coil limits the rpm to 6100 on the sealed racing version.  The unsealed animal can spin over 7500k.  I believe to 12k.  Sealed is a seal they put on the engine like the seal on your electric meter.  Sealed 206 engines can race in events that sanction sealed 206 engines. 

In the short year playing with Mokais,  my theory is they have enough hp but they could use more rpm. I believe it is not the jet loads on the engine preventing 1.0 subaru from going faster.  It is the ability to turn fast enough because of the engine design limit.  It simply can't bring it's 7 hp to the 4500 rpm party.   2.0 spins at 4550 at the impeller where 1.0 spins at about 4k.  Subaru spins that prop at 4k even though according to it's torque chart it is pushing the prop with 4 hp at that rpm.  The other 3 are being used to turn the engine that fast.  So, that rabbit hole led to the animal and other performance engines.

So i'm testing the theory that a 1.0 with 2.0 power at 1.0 weight would be a good companion to a 2.0. It may have more of the original skinny water advantages than beefy 2.0.

There are EPA options available like Tillotson, which are honda  clones with racing components.  They are advertised at 10 hp stock. 
But their peak HP occurs at the 4-5K range again so if subaru can do 18 with 3-4hp at 4k then imagine what animal at 4,600 will do on the same boat where 4600 would be it's intersection of torque and HP peaks.  I don't believe i should run the pump any faster than what Mokai runs the 2.0 pump at.  But,  since my 1.0 is not under warranty because i bought it used,  if i break it,  i pay for it.

The first step is to get the motor mounts on the animal.  They attach from the sides to the block using the side cover bolts instead of the bottom mounting bolts.  We'll have to see how things line up.  One thing to note,  i took the engine compartment to the kart shop to see if it would fit and the only problem looked like the valve cover touched the side of the engine compartment.  I saw a previous post on this forum where they heated up the plastic and bent it out a little bit with a 2x4.

Briggs also puts this engine in some snowmobiles.  And i saw a video where the guy mentions a low profile valve cover and bingo they make one so no clearance problem. 


I'm hoping this provides a path for Mokai owners that need to save 25 lbs to get their boat to plane.  The ones that don't care about planing are lucky and there are tons of uses for a slower mokai.  Mokai 2.0  appears to need to achieve 19-20 mph to plane for me and my wife.  She can get to 18 in 1.0 so just need to spin that impeller at the speed they are spinning 2.0 (4550) and should go about 27. 

happul3:

--- Quote from: voipwell on October 07, 2019, 07:51:56 PM --- Subaru spins that prop at 4k even though according to it's torque chart it is pushing the prop with 4 hp at that rpm.  The other 3 are being used to turn the engine that fast.  So, that rabbit hole led to the animal and other performance engines.


--- End quote ---

Are you looking at the right chart? The one I have for EX21D shows exactly 7hp max horsepower at 4000 rpms.

voipwell:
Is this the one you are looking at?  I marked it where 7 hp ends. 
The blue area is the recommended output range.  Those two points that are marked continuous output are the maximum torque at 3k and maximum hp at 3600.  They can say anything they want in the white area of the diagram regarding maximum but the we run our Mokai's at an rpm over 3600 which results in lost hp.  4.75 at 3600 and it looks like 2.5 hp at 4000.  Ever notice when the grate completely clogs the rpm is almost the same as when it is clear.  The motor is not under a huge load.  If it was there would be a significant rpm difference inside the water and outside the water.  I'd be glad to discuss the chart and how i may be misreading it but i looked at a lot of charts.  Look at this one for the animal.

Painlesstom:
This will be exciting to see. Hope you will post pics of your progress. I've been wanting to see what an animal motor would do in any of these hulls, but the 1.0 would be the best candidate for speed. Is your animal electric start with a charging system? That seems to be the limitation with RPM on a lot of these motors when a charging system is required, stock flywheels don't like to go past 4500 rpm. I think 5000 rpm would be the max I would push one. You should be fine if you can hit 4500 though, I hope you see that with a tight wear ring. 1.0 would be flying at that RPM.

voipwell:
The chart says maximum hp 7  rpm 4000 but they don't say maximum 7 hp at 4000 rpm.  They are  two separate items put on the same line i hope for saving space and not deceiving.  You would really believe that unless you looked at the torque chart.  It's a 7 hp motor that can't operate above 5 hp.  Even though it says recommended output range it still shows that the hp drops dramatically after 3600 rpm.  This is a fine point that i stumbled across by hearing the big difference in sound between the 1.0 and 2.0 in the 2.0 review video.  I always assumed it was 7 hp @ 4000 rpm until i really read about the relationship between torque and hp.  Then it became apparent what it would take to get 1.0 fast.  4500 rpm.  Subaru just can't spin that fast without load.

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