5HP briggs supercharged!

[Conker5295]

Hey guys i have been working on a 5 horsepower briggs engine for two days, gettin it back up and running. I'm also going to do allot of performance work to it. like port polish and all that good stuff. i have two of these motors and me and my brother are building them mostly for fun, not at our expense in any way. they were given to us along with the frame. and I know this is a long shot but we have ideas on how to put a 90's ford thunder bird supercharger on mine. is this even possible and would it just blow the head rite off? i know it is a long shot but just think about how fast that little cart would go. also if u have any suggestions on how to make these little engines get up and go. please feel free to say it.

 

[jman231994]

I dunno if this would work, but maybe you could gear down the supercharger so that it creates less pressure? I'm not entirely sure what would happen if you had it running at full speed, someone else probably will though

 

[Conker5295]

yeah i had that thought too, my idea was to run a torque converter and weld an extra pully to it, then have an extra belt running to the supercharger. it wont spin it at its full potential but it will get it going, and it wont tax the engine any spinning it cause it doesnt really take anything to turn it in the first place.

 

[christeeezy]

I think the friction from that big of a supercharger would negate any power gain you might achieve from it.

 

[Conker5295]

I think the friction from that big of a supercharger would negate any power gain you might achieve from it.

Im not saying your wrong but what u mean friction?

 

[christeeezy]

It is called "parasitic loss".

What that means is that it takes power from the engine to operate the supercharger, because the internals are not frictionless. Since the supercharger would be really big in relation to the 5hp Briggs, the power needed to operate the SC might be close to, or more than what the SC would create. For example:

Motor makes 5hp stock
Added supercharger takes 4hp to operate
Supercharger makes 4 or 5hp in return
Motor has a final outcome of 5 or 6hp.

This is the same thing that happens with drivetrains on cars, and is the reason you don't get the same horsepower numbers laid down to the wheels compared to at the motor's flywheel. The transmission, driveshaft(s), differential(s), axles and bearings, tire friction with the asphalt, all cause parasitic loss.

 

[Conker5295]

It is called "parasitic loss".

What that means is that it takes power from the engine to operate the supercharger, because the internals are not frictionless. Since the supercharger would be really big in relation to the 5hp Briggs, the power needed to operate the SC might be close to, or more than what the SC would create. For example:

Motor makes 5hp stock
Added supercharger takes 4hp to operate
Supercharger makes 4 or 5hp in return
Motor has a final outcome of 5 or 6hp.

This is the same thing that happens with drivetrains on cars, and is the reason you don't get the same horsepower numbers laid down to the wheels compared to at the motor's flywheel. The transmission, driveshaft(s), differential(s), axles and bearings, tire friction with the asphalt, all cause parasitic loss.

OH, ok i get what ur saying, so if i bore out the piston and sleave it, and some other preformance work u think it would still be pointless? Ive seeen these little motors be put up to 12 horsepower with some work. just an idea. not sure tho

 

[jman231994]

christeeezy is right that it might happen, however if its geared down you will have less of an issue. The problem with attaching it to the output of the torque converter is that supercharger speed wont be relative to the engine speed anymore because of the converter.....converting lol

 

[Conker5295]

christeeezy is right that it might happen, however if its geared down you will have less of an issue. The problem with attaching it to the output of the torque converter is that supercharger speed wont be relative to the engine speed anymore because of the converter.....converting lol

yes very true but if i get the rite pullys and get it to the rite RPMs ill be able to get the SC to the speed of my choosing. (for the most part)


THANK YOU ALL FOR THE INPUT

 

[christeeezy]

OH, ok i get what ur saying, so if i bore out the piston and sleave it, and some other preformance work u think it would still be pointless? Ive seeen these little motors be put up to 12 horsepower with some work. just an idea. not sure tho

If you fully build your motor with forged internals, stroked bore, flat top piston, agressive cams, etc, you might have enough power to somewhat more efficiently operate the SC.

But more importantly, the motor would be more tolerant to higher boost levels, meaning you wont have to tune down (put a bigger pulley on) the supercharger (as much). This *should* net you more power.

 

[Conker5295]

If you fully build your motor with forged internals, stroked bore, flat top piston, agressive cams, etc, you might have enough power to somewhat more efficiently operate the SC.

But more importantly, the motor would be more tolerant to higher boost levels, meaning you wont have to tune down (put a bigger pulley on) the supercharger (as much). This *should* net you more power.

Just rebuilt the engine today, it fires rite up. havent gotten a hold of a good torque converter yet tho. after i get that on im gonna start workin on a supercharger mount

Im gonna run the SC and see if it helps.