ARC rod copy for GX340/390/predator 420

[Edwin Spangler]

https://www.ebay.com/itm/406131589968

Rod looks decent enough. Bolt are questionable. Bearings are questionable.

-But Ill worry about those questions later if something blows up.

 

[Sparkwizard]

Looks good. Where did it come from? We have a 420 on a 73 Wheel Horse "mud kart" that might be fun with more RPM.

 

[Hellion]

Looks good. Where did it come from? We have a 420 on a 73 Wheel Horse "mud kart" that might be fun with more RPM.

He posted in Quick Bits about that rod but he didn’t mention the rod, just used a photo (which makes it hard as heck to search for). I recalled I pressed him to share the link. Starts here on post #1,989:

Quick Bits

No, just a common metric. My i.d. might be larger than it needs to be. But thats what trial and error is about. Anything will help. Im not looking for absolute quiet just not ear bleeding.

www.diygokarts.com

 

[Sparkwizard]

Thank you, Sir.

 

[Hellion]

Rod looks decent enough. Bolt are questionable. Bearings are questionable.

-But Ill worry about those questions later if something blows up.View attachment 163141View attachment 163147

Neat features with the scoop style dipper and the overall lightening milling. Those bearing shells do look questionable and look at little dinged up. Is there anything there that might catch the fingernail? Not sure if I am looking at manufacturing debris, swarf or dirty box (box debris).

The “12 point bolts” are odd. Does that take a special socket or your run-of-the-mill 12 point Crapsman?

 

[Whitetrashrocker]

The NR racing rod also has the 12pt bolts, but not the dipper scoop.

Edwin
Are you going to mic that rod or plasti-gauge it?

 

[Master Hack]

The “12 point bolts” are odd. Does that take a special socket or your run-of-the-mill 12 point Crapsman

The NR racing rod also has the 12pt bolts, but not the dipper scoop.

I got the ARC rod last year, it had both the dipper and 12 pt.
yeah a regular 12 pt socket will work.

 

[Master Hack]

But Ill worry about those questions later if something blows up

I would worry about those chinese bolts now while it only costs a few bux.
Chinese machining is improving, but the metalurgy is poor, im my opinion.

 

[panchothedog]

Rod looks decent enough. Bolt are questionable. Bearings are questionable.

-But Ill worry about those questions later if something blows up.View attachment 163137View attachment 163138View attachment 163139View attachment 163140View attachment 163141View attachment 163146View attachment 163147View attachment 163148View attachment 163149you.

What is the price difference between that and the ( real deal ) ARC rod? You could always buy some ARP bolts ( like the ones you get from ARC.) That is where a lot of the strength comes from. Regardless, it's got to be a lot better than the stock setup.

 

[Edwin Spangler]

The NR racing rod also has the 12pt bolts, but not the dipper scoop.

Edwin
Are you going to mic that rod or plasti-gauge it?

No measuring, just gonna run it. I got wayy too deep into some nonsense with the kart, that I should have waited for. Now it needs to be ready in a week when family comes to visit. Been out in the heat for a few days and I just want it back together. Im willing to learn a lesson.

 

[Edwin Spangler]

As for the bolts, those are getting replaced. They have threads peeling off. I even have to clean the threads in the rod because of this.

Theyre also just an 8mm 12pt. Lol this is funny... Just removing the rod cap, im starting to round off those bolt heads. This is with a SnapOn socket that fits PERFECTLY. It started to round it off and jammed about halfway around so I saved it at least. Dont know why that matters because theyre not even going in the bolt bucket.

 

[Edwin Spangler]

Neat features with the scoop style dipper and the overall lightening milling. Those bearing shells do look questionable and look at little dinged up. Is there anything there that might catch the fingernail? Not sure if I am looking at manufacturing debris, swarf or dirty box (box debris).

The “12 point bolts” are odd. Does that take a special socket or your run-of-the-mill 12 point Crapsman?

Yea, there was a gouge in each of the bearings but I think I smoothed them out ok-ish. Just used the dremel... (joking) Im gonna stop at a few stores today and see if anyone has some replacements.

 

[Hellion]

As for the bolts, those are getting replaced.

Noooooo! Just run it. I thought you're willing to learn a lesson? I’m joking. At minimum it must go together.

Just used the dremel... (joking)

The Dr. Emel felt pad and jeweler’s rouge wouldn’t be out of the question.... It should be fine as-is and wear-in on the harder forged crankshaft journal (right?)

 

[Edwin Spangler]

Couldnt find ARP bolts so I "tried" to use these bolts it came with. They torqued without rounding off so.. Success? Im satisfied with how they felt as they were getting torqued.

The bearings picked clean with my fingernail. Still a couple gouges but nothing catches.

Everything is going back together and turning smoothly.

-But my dumb*** forgot to order head gaskets so now Im waiting on those. You ever spend an hour looking for something you never ordered? I have a feeling Im not the only one.

Next update will either be a success story or it will be carnage pictures.