How to make my engine and more powerfull : LUSENET : Junkyard Wars : One Thread

Hi, Ive got a near new 5hp B&S Industrial plus motor (not the racing raptor version.) and I was wodering how i could supercharge or put a blower/turbo onto the motor with little modifications (no boring the head or any thing like that.) I like the hair dryer idea but the motor is worth a bit (in in New Zealand)and i dont want to take any major chances. If I stick a 12v leaf blower onto my 5hp briggs, how would i power it? mabye a 12 V battery? but how much would that weigh? 8+ kgs? ive heard that some of the briggs have a built in altenator (mine is the industrial version) so maybe that could keep a small 12V battery powered up. how would i do it all? If youve done it before or have an idea or somthing like that, big or small, please dont hesitate to send me an email ( ) or post a answer on this page. if you could help or send me some photos or projects that you have made i would extremely appreciate it. thanks heaps


-- Harrison (, July 21, 2003


Hey... I had an idea. You could use a blower motor from a heater motor(from an old ford or chevy car/truck). These blowers have a 2" output on them. They also run off of 12vdc. For powering it, check to see if your motor has an additional alternator wire under the flywheel. If it does, this should be 12vdc. If it doesn't, you can get a 12v lawnmower battery from Walmart or somewhere like that. Usually, 20.00 to 30.00. Even a motorcycle battery will work. With a fully charged battery, the run time should be a few hours. You can also go to a wrecking yard and get a heater switch from any old car to have variable speed control for the blower motor, or an old headlight switch from a Ford truck. The headlight switch has a dimmer for the dash lights that works great for a variable control. Let me know if this works! I've thought about doing this to the intake on my Mazda 626. I've seen kits for this application, so it should work.

-- brian lindley (, July 22, 2003.

brian lindley thanks for your answer! thats just what ill do. Howerver im in New Zealand , but im sure i can sort somthing out.

Thanks again brian, and good luck with your 626.


-- Harison (, July 22, 2003.

No problem... Since american cars are scarce over there, just look for any heater blower motor from an old car. You should be able to find one. Something else... the flywheel on your motor puts out a ton of air! The intake is around the pull start, and it pushes air across the head and block for cooling the motor. I had a flywheel cover that had a 2" hole in the side of it and it put out a very good volume of air! If you want a pic of the flywheel cover with the location of the hole, just let me know and I'll send a picture. This way, the air supply would be driven off the motor itself, not from an external source requiring 12vdc. Also, the higher rpm's, the more air required for the blower, so, the higher rpm's of the motor, the faster the flywheel fins turns, hence, more air is delivered! Hope this helps!

-- brian lindley (, July 22, 2003.

Forgot to add... This is the same principal as a blower, Like a B&M Blower on a Ford or Chevy big block! The only thing I would be worried about is blowing a head gasket, but its a 2min. job to replace and about $5.00 for the gasket. To me, it would be worth it to try. By the way... if you need parts for the motor, just about all internal parts on those 5hp are interchangeable through out many years! Try to find an old spare 5hp for future needed parts! You'll save a ton of cash as parts wear out!

-- brian lindley (, July 22, 2003.

I just wanted to contribute by saying that a 12V leaf blower will compress the air SOME because it's a centrifugal compressor basically. More than likely the blower motor from a vehicle will not be able to compress air, nor will a hair dryer. It's just not the right type of blower. One proven option is using a smog pump from any car you can find, preferably from a big V8 or equivalent. These are in essence a positive displacement supercharger just like the ones used on hipo vehicles. Just set it up on a belt drive from the motor, or maybe you could run it off the flywheel, and plumb the outlet into the carburetor. Be cautious about the belt/gear reduction on it and use a boost gauge to be sure you don't pass 8 psi (maybe less than that, it just depends)It could take as much as 12, 13, 14 psi but you're on your own ;). These engines have somewhere around 8:1 compression so it will take a considerable amount of boost. Also make sure you add fuel via the carburetor if possible or find another way to do so, perhaps you could seal the gas tank and pressurize it with boost pressure. Otherwise open the needle on bottom of the carb(it should have one there) until it smokes and tries to die and then close it just a tad. ALWAYS run rich on a forced induction motor. Good Luck!

-- John Lewis (, August 08, 2003.

It wont work you need the blower to suck throught the carb i already tried this and the air has more pressure than the fuel hence it impossible to deliver fuel. Or you could put a fuel pump on it.

-- weston (, September 13, 2003.

hey man put Nos brand super octain charger that you can get at any auto parts store mix it with the gas it adds like 2hp on a five horspower that is a lot! shot i can go 47-50 now

-- Rico munoz (, October 22, 2003.

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