Super-Charged 2 Stroke Briggs Valve Operation

[Dirtpros]

isn't it a 4 stroke?

[ChargerMiles007]

@Dirtpros

It started out as a 4 stroke, but now it is a uniflow 2 stroke, both valves are for exhaust, and it has ports for inlet.

I have another one called the Jumo 205 type, it is a 2 srtroke that uses the pistons for valves.

All of my engines start out as 4 strokes, since they are cheap and plentiful here, plus Briggs buils good engines!

[Dylan464]

thats pree damn cool

[ChargerMiles007]

@Dylan464

Thanks, I am working on another similar supercharged engine using just the valves, and no inlet ports, I hope to have it going in perhaps a month.

[gokartspeeder]

So, the supercharger prepares a fuel/air mixture and forces it out into the intake via piston pressure and ti is opreated by a chainfrom the crankshaft of the one that auctually runs? Sorry if I misunderstood, im just trying to figure out how it works.

[ChargerMiles007]

@gokartspeeder

Yes, I think you understand it OK.

All the burning takes place in the engine with the blue cover. This type of engine needs to be force fed, or it won't run at all, it was easiest for me to build the piston type blower.

[david929190]

Why not take the flywheel off the supercharger engine so the two stroke has less work to do.

[ChargerMiles007]

@david929190

I actually did that when I first ran this engine 10 years ago. It worked OK that way, but I kept having chain drive issues (it would throw the chain off the supercharger), so I put the flywheel on it. Now I use it for the electric starter.

[bennydagerman]

was it a 4stroke u converted into a 2stroke?

[ChargerMiles007]

@bennydagerman

Yes, I build all of my FrankenBriggs engines from 4 stroke Briggs engines :)

[bennydagerman]

@bennydagerman respect to you i was about to call u out like everyone else,  that its a 4stroke till u demonstrated the ports in the cylinder wall, nice job!

[ChargerMiles007]

@bennydagerman

Thanks, glad the vid explains how this one really works, since it is a tricky one.

[MalliganTheUFO]

OMG!!!! Look at all the god damn DUMB people on here arguing that this is not a 2 stroke! ha ha ha ha. Although its not supercharged technically. I know your trying to keep the pulses timed but you could over drive the blower. or mount an sc14 to it :D You have done a great job building this!!!! Hmmm, mount an sc14 to the blower.... lol

[ChargerMiles007]

@MalliganTheUFO

Hey, glad to know that you understand what I have done here!

I guess most people are just not familiar with this type of engine.

Maybe I will take a regular L head Briggs, attach this "supercharger" and drop in a double lobbed 2 stroke cam. That would really blow their minds! Well at least they would be doing some Serious head scratching!

Geez, I could probably have that done in about 6 hours (the cam would take most of the time).

[MalliganTheUFO]

@ChargerMiles007 Im a fitter machinist and like to tinker away with engines and I do wonder.... How do you make your cams exactly?? Im guessing you have access to a camshaft grinder or something similar??

[ChargerMiles007]

@MalliganTheUFO

I wish I had access to a cam grinder!

I weld the extra metal on the lobes, then hand grind them using a combination of a pedastal grinder, a rotary grinder and a 5" disk grinder, as well as emery paper . Crude, but it works for these engines.

[MalliganTheUFO]

@ChargerMiles007 Ohhhh, the hard way! lol. Its pretty easy to make a cam shaft/profile grinder out of an old lathe. The hard way is still good enough for an engine like this though. You have some pretty good engine builds on your channel!

[ChargerMiles007]

@MalliganTheUFO

Thanks, I try to build mainly old designs from the past, using Briggs lawnmower engines.

I try to stay away from Brand X engines, since I don't want any surprise holes blown in the crankcase by the con-rod! A friend is trying to weld me up a high compression head, but there is a lot of grunge in the head metal.

[th19940305]

these are four stroke what dont you get about it they have oil dipsticks

[ChargerMiles007]

@th19940305

Yes, you are right, in that they started out as 4 stroke engines.

Now they are converted to a type of 2 stroke engine, that has oil in the crankcase, just like a 4 stroke. Similar to the old GMC 6-71 2 stroke diesel engines. Not all 2 strokes breath thru the crankcase, like LawnBoy lawnmowers, and chain saws.

The engines I build, are just very rare types, so you would probably never have seen one before. I saw the Junkers Jumo 205 at an airplane museum.

[th19940305]

@ChargerMiles007 so there running on 2stroke mix and if on reg gas they will score?

[ChargerMiles007]

@th19940305

Actually, all my 2 stroke Briggs engines use regular 10W30 oil in the crankcase. I don't mix any oil with the gas.

[th19940305]

@ChargerMiles007 Let me get this right, your running it on reg gas and theres oil in the crankcase, then that would make it a four stroke. The piston moves up and down twice before it ignites correct?:

[ChargerMiles007]

@th19940305

Right, it runs on regular gas, oil in the crancase, BUT it fires everytime, so it is a 2 stroke. The camshafts on the supercharger and 2 stroke have double lobes, so valves open every revolution. Thats why I need the supercharger, since this type of 2 stroke won't feed itself air, it needs an air pump.

[MalliganTheUFO]

@th19940305 Lol! Look up the "Stihl 4-mix" Its a 4 stroke that has no dipstick.... It runs on 2 stroke fuel but it is a 4 stroke, it has no sump, no dipstick and no oil in the crank case whatsoever. So you cant judge an engine by its dipstick

[th19940305]

@MalliganTheUFO i know about the stihl 4 mix but briggs and stratton never made one like that

[MalliganTheUFO]

@th19940305 I was just making a reference to the fact that you cant assume an engine is a 4stroke because it has a dipstick. Briggs never made a 2 stroke like this one either......

[th19940305]

@MalliganTheUFO 4 mix doesnt have a dipstick so this is a 4 stroke right

[MalliganTheUFO]

@th19940305 No, 4 mix has no dipstick, but it is a 4 stroke. The engine in this video is a 2 stroke but has a dipstick. You cant judge an engine by the fact that it has a dipstick or not

[kollak01]

these are four stroke engines dip shit!

hence having valves!

[ChargerMiles007]

@kollak01

Now you look here DIP SHIT.

Yes, both of these engines started out a 4 strokes.

Expand your mind a bit to except the fact that 2 Stroke engines can have valves also. This one is a type of Uniflow 2 stroke.

Take a look into some of the 2 strokes with 4 valves per cylinder that almost made it into production in cars about 10 years ago.

[amfan12]

I want to do something similar, but use an automotive smog/AIR pump as a scavenge blower.

[ChargerMiles007]

@amfan12

Yes, that might work out. I haven't had much to do with smog pumps, so I am not sure.

[KrankieV2]

hey you could connect the scavenger pump to the monosupape and maybe then it would breathe well enough to make lots of power

[ChargerMiles007]

@KrankieV2

HeHeHe! Actally the 2 stroke here uses the Monosoupape block with its inlet ports and manifold! I just made a new 2 stroke camshaft :)

[rustyATV]

If I recall, this type of engine isn't considered to be Supercharged, since the compressor (or in this case, the other engine) is handling scavenging duties and is only moving an equivalent quantity of air.

[ChargerMiles007]

@rustyATV

Yes, you are technically correct, it should be called a Scavenger pump, but most people wouldn't have a clue what that meant!

I am building another one right now, based on the Jumo205 engine.

[NASTYTHEBOY]

thats cool :O

[ChargerMiles007]

@NASTYTHEBOY

Thanks for watching :)

[listepikster]

hope you get it running and put up a video of it running continiuosly :-)

[ChargerMiles007]

@listepikster

I will give it one more try, before I take it back apart.

This engine has always been a Fussy one, I guess I should have kept it running on the vid that it runs the longest on, but I was in a hurry to get to the Library to upload it. Now it doesn't want to stay running :((

This engine has a habit of shaking stuff loose though, it used to vibrate the chain drive sprockets right off the shafts! I solved that problem.

[More350Power]

Thanks for the vid! Now I understand the functionality once I see it. The possibilities with these small engine parts are endless

[stydel311]

lol, JB Weld is good for everything, right?

[NASTYTHEBOY]

@stydel311 HELLS TO THE YEAH! :D

ive heard of some guy that patched a scored cyinder block :O

[30GB]

make a supercharged 4 stroke

[ChargerMiles007]

@30GB

We have one ready to run, I show it in an earlier vid. My son that built it wants to run it soon, so he said last night :)

I actually removed it off this base to put this engine back together. I will try once more to get this engine to run for a minute or so, then I will put the SuperCharged 4 stroke back on the base.

[dc5000123]

Looks like the ratio is 1:1?

[ChargerMiles007]

@dc5000123

Yes it is a 1:1 ratio, as I want to keep the pressure pulse from the Blower timed right with when the inlet ports are open.