5hp epoxy port

[Thepaetsguy]

I always looked at a 5hp intake port and figured fuel exits the carburetor and enters the stock intake port. Then has to slam the back of the intake port wall and I believe this could actually cause some fuel to fall out of the slip stream.

When the fuel falls out of the stream it pools in the bottom of the intake? And that pooled fuel would always just have to wait for the next intake stroke to even make it into the combustion chamber? (Those are questions I’m not sure if that’s true at all)


My thought process is add an epoxy ramp and close the port to a barrel. Give the fuel and air absolutely no where to go but the bottom of the intake valve waiting for it to open.

I have opened the port to the max before the epoxy. It‘s still a big port after the epoxy dried. I don’t see it being choked off. (Still mild cleanup work to be done)

 

[cl350rr]

As I understand it, you want to aim for uniform port cross section area throughout the port as any point where it opens to a larger area (like in the corners of the stock port) the fuel will drop out of suspension due to the change in velocity and the associated drop in pressure.

 

[Thepaetsguy]

With the little dimple of epoxy at the top it looks reminiscent of a 212cc’s port.

 

[Thepaetsguy]

This is a kohler 8hp that has the ramp from the factory.

 

[Thepaetsguy]

Finally dried enough to lightly sand on it.

Should I golf ball it? I’m gonna golf ball it

 

[Powerband83]

With the little dimple of epoxy at the top it looks reminiscent of a 212cc’s port. View attachment 328640 View attachment 328641

Not a bad start Mike. Many different options for epoxy on the market now days. On a 3 bolt block, many of us would use the nearest bolt hole as a guide for max bore when porting. The early 2 bolt blocks are great to practice on, so you're more comfortable modding a later raptor block down the road.
You know how a stock pulsa carb has that abrupt 90° bend? It really hinders power gains because the lack of velocity. The least amount of bends the better off one will be. A balance between flow/velocity plays a big role in gains, especially on a FH.

 

[Thepaetsguy]

Not a bad start Mike. Many different options for epoxy on the market now days. On a 3 bolt block, many of us would use the nearest bolt hole as a guide for max bore when porting. The early 2 bolt blocks are great to practice on, so you're more comfortable modding a later raptor block down the road.
You know how a stock pulsa carb has that abrupt 90° bend? It really hinders power gains because the lack of velocity. The least amount of bends the better off one will be. A balance between flow/velocity plays a big role in gains, especially on a FH.

Edit: I actually popped through the back of the top intake bolt hole. Got filled over with epoxy so not a problem. IT TOOK SO MUCH EPOXY. Like the stuff would shrink but it’s just I hogged the port out way bigger then it ever should have gone. So it needed a lot.

Also I have a two bolt intake apparently made by a guy named Otis paired with the intake boot from a Kawasaki klf185 bayou four wheeler is the ticket. I made one and will be hunting another billet wazoom intake to make another one of these soon.

 

[Thepaetsguy]

Some port work to document.

 

[Minimichael]

I always looked at a 5hp intake port and figured fuel exits the carburetor and enters the stock intake port. Then has to slam the back of the intake port wall and I believe this could actually cause some fuel to fall out of the slip stream.

When the fuel falls out of the stream it pools in the bottom of the intake? And that pooled fuel would always just have to wait for the next intake stroke to even make it into the combustion chamber? (Those are questions I’m not sure if that’s true at all)


My thought process is add an epoxy ramp and close the port to a barrel. Give the fuel and air absolutely no where to go but the bottom of the intake valve waiting for it to open.

I have opened the port to the max before the epoxy. It‘s still a big port after the epoxy dried. I don’t see it being choked off. (Still mild cleanup work to be done)
View attachment 328628 View attachment 328624 View attachment 328625 View attachment 328626 View attachment 328627

Nice eyebrow work. Nice flat-ish epoxy ramp, too. How about more pics from inside Otis?

 

[Thepaetsguy]

Nice eyebrow work. Nice flat-ish epoxy ramp, too. How about more pics from inside Otis?

I have no idea who Otis was. I think the people I talked to said his last name was marit and he was apparently like the best of the best

The only guy who could weld in a cam bearing and pass tech they said.


Todays job is drilling the epoxy ramp to get the valve guide back in sight.

 

[Thepaetsguy]

OFF topic I think I know how he did it! Took a rototiller extended PTO and milled the gear off and put it in the block backwards so the pto cam sticks out of the flywheel side of he block being used as a roll pin.

Tossed the arc racing cam bearing into a sleeve and grooved the bottom of the sleeve to fit flat against the case and welded it in place. Removed the bearing weld up the inside to set endplay and re-install the bearing.

I have a BUNCH of junk blocks a guy gave me and I have been playing around with it. Ordered some aluminum sleeves and an extended pto cam and such. If I ever get the perfect peices made up and fit right i can go to a local shop and have them weld everything in place.

 

[Thepaetsguy]

Good new everyone!: I drilled for the valve guide and got it perfectly.

Bad news for me specifically: I mixed the epoxy wrong and it sunk badly and will not harden. Coupled with me not having enough epoxy to fill the port in the first place means I wanna toss the whole block in the trash and move on to another project.

 

[Mark Brooks]

[QUOTE="Thepaetsguy, post: 1358260, member: ] I wanna toss the whole block in the trash and move on to another project.[/QUOTE]

Doesn't that go against your moniker? The "Pa everything is salvagable"

 

[Thepaetsguy]

[QUOTE="Thepaetsguy, post: 1358260, member: ] I wanna toss the whole block in the trash and move on to another project.

Doesn't that go against your moniker? The "Pa everything is salvagable" [/QUOTE]

Round two: FIGHT

All the epoxy is ground out. I ran some q-tips with polish down through the valve guide and lapped in a valve.

The moment I realized I did not mix enough epoxy to fill the whole port I should have stopped went and bought a couple big tubes and did it correctly the first time. I only have to be taught that lesson once.

I’ve done a few of these epoxy port ramps and they always worked out the first time.

 

[sparkwizard]

I keep a couple of the big pairs of JB Kwik. It sets faster, does not take 24 hours to set, so it doesn't drip and droop all over everything. According to the labels, is is about the same strength and heat resistance/ chemical resistance as the slow, messy JB Weld. I also keep the big tubes because I always mix too much because I can't keep messing around all day. On a good warm day, it starts to set in about 4 hours.

 

[Thepaetsguy]

Pictures of the last port epoxy I did the exhaust even got a small coat and a reducer.

One major thing I realized while reviewing pictures along with not enough epoxy I also packed the epoxy I did put in under the valve seat and I don’t know why I thought that would ever make a good ramp.

I need to have it above the valve seat like In the bottom picture that way I have a ton of extra to grind back to where I want it.

NOTED