GX500 build

[Flyinhillbilly]

I couldn’t resist a test fit with the stock wrist pin since I knew there was only .005” difference, and it seems that I won’t have to wait for the reamer set to know what rod I need after all. It looks like it’ll be a stock length rod, and the piston will be going for a ride in my larhe.

 

[karl]

Wild, I like

 

[Functional Artist]

Nice work & very creative!

Someone says "you can't do that"
You says "I think, I just did!"

 

[Denny]

What are you going to do for a head gasket? Lapp head and deck, o ring or just pray to Jesus a gasket holds up.

 

[Flyinhillbilly]

What are you going to do for a head gasket? Lapp head and deck, o ring or just pray to Jesus a gasket holds up.

Custom copper gasket with an o ring.

 

[Flyinhillbilly]

The head is on its way to North Carolina to spend some quality time with Johnnie at Laid Back Racing.
He’s built several heads for my unlimited karts, and I’ve always been very happy with the results.

 

[Kartorbust]

So what kind of rpm you going to be seeing out of this realistically? You going to be able to raise the overall gear ratio because you have more torque to work with? This is just purely insane, hopefully you won't have any troubles staying out front of the pack.

 

[Denny]

He should be able to stay in front of lightning with that combination!

 

[Budget GoKart]

this is just one insane build

 

[Flyinhillbilly]

So what kind of rpm you going to be seeing out of this realistically? You going to be able to raise the overall gear ratio because you have more torque to work with? This is just purely insane, hopefully you won't have any troubles staying out front of the pack.

According to the math on mean piston speed I should be safe at 7500.
You’ve nailed my whole reason behind doing this with the RPM. My thought is that if I can make enough torque that I won’t have to rev the engine nearly as much, so it should last better.
I blew up 3 really nice small blocks this year and I believe that it was because we have to turn them 9-10k rpm to get the job done.

 

[Budget GoKart]

if its turning at 7500 rpm making probably around 50hp ish i think you shouldnt have a torque issue your gonna have to gear it to go stupid fast and its still just only gonna spin LOL

 

[Functional Artist]

Will this ultra custom engine still "qualify" for the kinda racing that you do?
...or are ya building this BEAST just ta see if ya can
...&/or ta see if "it" will work
...&/or ta see what "it" can/will do
...&/or is it just for fun"?

Your first "test ride" should be interesting

 

[Karts of Kaos]

wow this thing is going to be mean

 

[Kartorbust]

Will this ultra custom engine still "qualify" for the kinda racing that you do?
...or are ya building this BEAST just ta see if ya can
...&/or ta see if "it" will work
...&/or ta see what "it" can/will do
...&/or is it just for fun"?

Your first "test ride" should be interesting

If I recall, he races in the Unlimited series, so just about anything goes.

 

[Flyinhillbilly]

If I recall, he races in the Unlimited series, so just about anything goes.

Yep, unlimited modified.
I’m keeping it at 500cc so that it’ll still be legal for the unlimited all stars in case I want to race with them again.

 

[Flyinhillbilly]

if its turning at 7500 rpm making probably around 50hp ish i think you shouldnt have a torque issue your gonna have to gear it to go stupid fast and its still just only gonna spin LOL

I’m going to say 60+ on horsepower. I run a blend of 75%methanol and 25% nitromethane, and the fuel makes quite a bit of power on its own.
I’m thinking there will be a lot of throttle control involved in driving this one effectively.

 

[karl]

so I bought a 96mm piston for a zongshen 625cc.

Did you order it from Zongshen's site? If so, where did it ship from? Seems like it's the only way
to get your hands on the motor or parts as of now.

 

[Budget GoKart]

at this point the motor has as many ccs as some twins do. also since you two are the ones to ask if i where to do a high torque vtwin mower engine would two smaller carbs that are linked together make more torque and power with a long intake? or the stock carb with no governor?

 

[Kartorbust]

Did you order it from Zongshen's site? If so, where did it ship from? Seems like it's the only way
to get your hands on the motor or parts as of now.

Zongshen's site is the only place to at least get the complete engine and parts. VegasCarts seem to only have the billet connecting rod these days. https://zongshen.us/products/625cc-piston-rings-96mm-flat-top

 

[Flyinhillbilly]

Zongshen's site is the only place to at least get the complete engine and parts. VegasCarts seem to only have the billet connecting rod these days. https://zongshen.us/products/625cc-piston-rings-96mm-flat-top

I ordered it from the zongshen site, and it shipped out of Florida. I played with the idea of building a 625, but it wouldn’t have been legal for UAS.