Bronda engine

[KartFab]

So..................

I have this idea, and I'm sure others have had it as well.... 3 short paragraph ideas...(sorry fabroman, I'm gunna ruin this with bad grammar

Briggs 5 hp flathead: Good compact size, 'bulletproof' engine, crappy rusted metal gas tank/straw carb.

Honda carburetor: starts consistently, better on fuel, better all around in my opinion.

I have been contemplating removing a governor, and what better engine to do it with than a briggs 5 hp flathead?.... and I happen to have a gx160/200 carb as a spare and a good briggs engine with no tank/carb/air filter...

Here is where it gets interesting...

Briggs engine had an affair with the forbidden honda, and it's love child will be the Bronda engine:

Briggs flat head governor removed w/Honda gx 160/200 carb, and am external gas tank.

I haven't worked out the details yet, but my plan is to:

1) remove governor from briggs
2) fabricate a short carb adaptor one side mates w/briggs, and the other mates with the gx 160/200 carb
3) fabricate a choke lever retainer for the carb
4) fabricate a throttle mechanism to directly control the honda carb
5) some sort of honda performance adaptor intake filter?Might have to buy
6) fab an exhaust pipe, am thinking stainless.


Thoughts anyone?

 

[rmm727]

fully adjustable Tecumseh carbs will bolt up with an H35 Tecumseh intake thats had the bolt holes lightly slotted. Probably a better carb to be honest with you. I know most hate a Tec carb when its dirty. There is also a plastic Briggs intake for the flathead that will let you bolt up a Tec carb or a clone Mikuni. They are $30 on ebay.

 

[rmm727]

http://www.ebay.com/itm/321170563040?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

 

[KartFab]

I would totally buy it if I had made $30 on ebay, but I only made like $6.50 selling a nat gas adaptor to some random dude on ebay today.

I am sticking with the honda carb not because it's better than a Tecumseh (which it is, I don't hate Tecumseh, I loathe Tecumseh), but because I have one already. I want to do this on the cheap and want to go into DIY mode, rather than buy stuff.

 

[OzFab]

(sorry fabroman, I'm gunna ruin this with bad grammar

Wait, what? You make me sound like some kind of grammar nazi

That all sounds easy enough. From what I understand, the one thing most dislike about the 5hp B&S is the carb/tank setup so, by replacing it with a Honda carb, the biggest issue I see is making an adaptor, which is relatively simple really...

 

[directdrive]

https://www.youtube.com/watch?v=wu7GoTxQw8Q
Here's a video that shows a long runner intake. The carb. looks like a Mikuni. It's a pretty simple "affair", two home made flanges and a piece of tube.

 

[KartFab]

Just ordered:
12" of 7/8" 16 ga seamless 316 stainless tubing
1'x4"x 1/4" stainless plate, 304L

Ill be making the intake adaptor and header out of this. (i didn't measure the exhaust hole, but intake was a little bigger than 3/4", but both briggs and honda carbs sit right at 3/4" on the intake side of the carb... I think. (really close no matter how you look at it so it should work). I think the actual size of tubing should have been 18 gauge for it to mate perfectly with the intake side of the block, but the carb itself is at 3/4"... splitting hairs, I can always shave a little with my dremel to get a smooth transition between carb/intake/block.

 

[qtband]

I used copper pipe and 1" washers to make an adapter for a few bucks. Still running good!
http://www.diygokarts.com/vb/showthread.php?t=24022

 

[directdrive]

Bronda

I like this idea you have because you could also build an intake for a clone carb. Dirt cheap to buy and you can throw in an emulsion tube, jet it right and have a pretty good performer.
Home built headers are the way. The multiple stage ones are nice,but you can build one for way less.

 

[Doc Sprocket]

fully adjustable Tecumseh carbs will bolt up with an H35 Tecumseh intake thats had the bolt holes lightly slotted. Probably a better carb to be honest with you. I know most hate a Tec carb when its dirty. There is also a plastic Briggs intake for the flathead that will let you bolt up a Tec carb or a clone Mikuni. They are $30 on ebay.

I'm with you- I LIKE the old Series 1 Tec carbs. Good choice as far as OPE carbs go.

 

[KartFab]

What about the vent tube? (not sure about vocab) It is the tube that vents the air back into the air filter housing before the carb... make sense?

I would like to not just dump the vent to the outside air, or some container....that would be my last resort. (what are the advantages/disadvantages to rerouting vs dumping the vent tube... considering I'm not going to be going crazy on this other than just removing governor/new intake/exhaust.

How could I attach a performance bolt on filter and the vent tube back into the carb?

I have thought about attaching the vent tube between the carb and the intake, but that is not done on all engines I have seen, all vent tubes have been vented to the area before the carb.

I thought about making a small spacer between the aftermarket air filter and the carb and tying a vent tube in there... which i will probably do unless its a bad idea?

The only problem i could see here is that air would travel faster after the air filter since is a smaller diameter hole... that would create a lower pressure in the vent tube hole, which means It would suck more crap air/oil from the vent tube... possibly?

Also, I havent bought a performance air filter/adapter yet, so I am still flexible on my air filter plans.

 

[Doc Sprocket]

Oviously, the crankcase needs to be vented. The reason it goes to the carb, is the EPA. You, however, can do whatever rubs your Buddah, as long as the vent remains open to atmosphere. I generally advise folks to top the tube with a cheapie automotive style inline fuel filter just to keep crap out of it, and call it good. In really high revving applications, some people route it to a (vented) catch can, as oil can end up getting chucked up the hose. If you with, you can put a dressy filter on it. I don't think I would advise venting it directly to the carb or inlet manifold as you were thinking. One, with the engine pulling a vaccuum, I can see the oil being sucked up the tube and into the intake. Two, any ingress of air from that system into the intake will play he// with your mixture.

 

[88nightrider]

I generally advise folks to top the tube with a cheapie automotive style inline fuel filter just to keep crap out of it, and call it good. In really high revving applications, some people route it to a (vented) catch can, as oil can end up getting chucked up the hose. If you with, you can put a dressy filter on it

Just be careful what type of filter you use.
On one of the forums for my bike, people have put on filters that kind of look like cone induction filters (just the look) on the engine/gearcase ventilation and had it clog up. And that is not something you want to happen!!!
But these engines can get up to about 9500 RPM. Much more risk of oil getting out the vent then.
On the old B&S engines the ventilation also kept the airfilter (sponge) moist with oil for it to work as intended.

 

[OzFab]

Another option is to attach a barb to the filter adaptor, as firemanjim did with his

 

[KartFab]

Ok I found some time to work on Mr Bronda.

Here is a sneak peek at the exhaust and intake. Still have to make them shiny/sand out the warping in the flanges, but the welding part is finished!

 

[2SlickNick]

I have yet to use the carb tank combo and already loath it. I too want a better carb. I am restoring a flat head too. Maybe I should just get a clone carb instead of a slide carb. Looks good cant wait to hear how it works. So I can follow suit.

 

[carter]

I don't think I would advise venting it directly to the carb or inlet manifold as you were thinking. One, with the engine pulling a vaccuum, I can see the oil being sucked up the tube and into the intake..

Very real problem. With my tecumseh's stock airbox this happened constantly and I'd have to replace filters once a month if not sooner because they were so fouled up with oil so badly, eventually I got tired of buying new air filters so I went with a higher performance intake adapter from BMI and a cone filter, I put a cheap inline fuel filter on my breather and it works just fine.

 

[KartFab]

BRONDA it all its glory! First it was governor removal, now its custom intake and exhaust. Next it will be bolted to something with wheels and direct throttle set up... That's the last small hurdle, but I think I have got a good plan for it!

Enjoy the video(s)! Give them a like/thumbs up in YouTube if you think someone else might benefit from them as well!

This first video below I create a custom intake and exhaust with my plasma, and TIG welder, then polish up the stainless steel and the engine fires up on the first pull!! (thanks Honda).

http://youtu.be/ixIyy4RCagM



This next one below is just re-jetting the carb for a #36 jet and a 140 emulsion tube. The 5 hp Flathead and the 212cc predator Honda clone have roughly the same displacement so I figured why not just use what they use on a clone? Seems to work out ok.

http://youtu.be/sufI8CzaWSs

 

[KartFab]

So what about these tachometer thingamabobs? How does one go about putting one on this engine?

 

[freakincage]

So what about these tachometer thingamabobs? How does one go about putting one on this engine?

The one I bought just had a wire that wrapped around the spark plug wire a few times. Tonight I have to post a bunch of pics in my Baja Revival thread, and the tach will be one of them.