Drilling holes on side of block?

[Dynoracecams]

I know this guy that took his briggs enigine and had it built. He bored it out and deck the block. Then he drilled a holl on the intake side on the carberator side of the valve i was wounder if anyone had any info on how it work and if i could do somthing to make it better

[oscaryu1]

What do you mean make it better? More power?

[Dynoracecams]

Yea like making it bigger or hooking nitrouse in it or somthing like that

[2or3wheels]

must be for injecting nitros?

[Jblankster]

i know wut its for, im going out now. no time to explain. ill be back!

[oscaryu1]

He was planning to either inject No2 through the port, or hook it up to a fuel pump... Like the Mikuni Fuel Pulse Pump. The pulse comes from the carburetor, which the pump then pumps gas into the carb...

[jr dragster Tyler]

He was planning to either inject No2 through the port, or hook it up to a fuel pump... Like the Mikuni Fuel Pulse Pump. The pulse comes from the carburetor, which the pump then pumps gas into the carb...
The pulse comes from the intake or the block breather.

[Jblankster]

^he said it. but i know some people even use the governor hole, or yes drill a hole in le side.

[oscaryu1]

Thanks for correcting me :)

Governor holes are fine (speaking about GX series). However, there's not always a gurantee of pulse, and there's a higher risk of oil going in there.

[jr dragster Tyler]

Yeah I agree with him THE best pulse is from the intake.

[oscaryu1]

There's no real use of a fuel pump if you're running a stock setup... Even with few modifications, a new jet would solve it...

[jr dragster Tyler]

There's no real use of a fuel pump if you're running a stock setup... Even with few modifications, a new jet would solve it...

Yes there is a need for a fuel pu
mp if the fuel tank is lower than the carb then you need somthing to bring the fuel to the carb.

[Jblankster]

^what he said. and in that case you can run a remote tank. which is cool :D

[oscaryu1]

If you're running a stock setup, I doubt you'll have a remote tank or a gas tank wayyyy below the carburetor.

[jr dragster Tyler]

It doesnt hav to be Wayyyy below the carb to need a pump. If the tank is 1 inch below the carb it NEEDS a pump.

[oscaryu1]

Look up some old Briggs engines. Carburetors, with fuel tanks bolted right next to the oil plugs... No pump either. Just a metal line running from the tank to the carburetor.

EDIT - Also look up some of those 3HP engines with the carburetor on one side of the engine, and the gas tank on the other side.

[Jblankster]

^im sure they had fuel pumps. theres no other way. i think at least, idk much about carbs.

[oscaryu1]

Sure... it was a plain carburetor...

No fuel pumps. Also, on my Briggs 3HP, the fuel pickup tube was around 4"-5" long.

Some carburetors don't need fuel pumps because they use a diaphram n' stuff...

[Jblankster]

oh yea those kind, you made it sound like they were on the other side of the **** engine.

on the 5hp flat heads have a diaphragm carb with a pickup tube, the air blowing over the tube creates a vacuum which pulls the gas into the carb. you can try it yourself with 2 straws

[oscaryu1]

oh yea those kind, you made it sound like they were on the other side of the **** engine.

on the 5hp flat heads have a diaphragm carb with a pickup tube, the air blowing over the tube creates a vacuum which pulls the gas into the carb. you can try it yourself with 2 straws

I know that. Pulsa-Jet on 3-5HP's and Vaccu-Jet or something for the 2HP's (very simple design)...

http://www.asecc.com/gallery/images/JCwmb.jpg

http://theepicenter.com/giffiles/tipoweek/briggs.gif

They were on the other side :biggrin5:

[ironman]

now thanks old school is that your s or just a picture you got

[Jblankster]

i have the one in the second pic, the gas line is still higher/same hight as the carb. so it flows into it still, the "pressure" of the gas is what brings it to the carb.

like a water tower in your town.

[jr dragster Tyler]

Well no matter if it has a pump, diamphram, or vacum thing its still a form of either sucking up or pumping the fuel in. It does magically flow in the carb uphill.

[crazycart]

The diaphram in the carb is pretty much a built in fuel pump.Why else would the carb have a diaphram??

[oscaryu1]

Some carburetors don't need fuel pumps because they use a diaphram n' stuff...

Hmm... sound familiar? :rolleyes:

And no, it isn't my engine. But you have to admit. She is a BEAUT!

[Russ2251]

Diaphragm carbs are not necessarily pumpers. Diaphragms replace floats and bowls primarily.

[oscaryu1]

Then it must be a miracle that that Briggs could suck gas up that much of line and run! The carburetor is too small to place a diaphram in anyways... and there's none in the tank/line...

[Russ2251]

There is a check valve built into fuel tank pick-up. Once the fuel flow starts, it does not run back into tank. Fuel line stays filled until it runs out of fuel. I have 3 Briggs engines that use this same fuel system and all work flawlessly. A 1936 model 'Y', 1938 model 'WM', and 1941 model 'WMB'. All are also kick start.

[oscaryu1]

That's what I was wondering about! Thank you!

[hickskateboarder]

when air flows thru the carb, it creates an area of low pressure. the higher air pressure outside (and hence, in the tank) pushes the gas up through the "tube" into the carb. the pressure of air (on average at sea level) is 14.7 psi, plenty enough to push gas up into ur carb. we figured out in physics that if you have a perfect vaccuum air pressure will push water straight up 10 meters. over 30 feet.