Custom 70cc engine build

[Z.hb71]

?? cant have that....... what you using to seal the block Yama bond?
Dose the case close without the crank in?

Yes the cases close without the crank. I'm using the o ring groove with oring cord to seal the case shall I freeze the crank?

 

[DougStar]

Yes the cases close without the crank. I'm using the o ring groove with oring cord to seal the case

Just thinking out loud here ??? it's one of two things bearings are not in or the crank is not lined up

 

[Seandonato73]

When I go together with my saws I toss the case half in the oven at 300* for about 10 minuets and use freeze spray on the crank journals. Sometimes they fall right together with oit freezing them.

 

[Z.hb71]

When I go together with my saws I toss the case half in the oven at 300* for about 10 minuets and use freeze spray on the crank journals. Sometimes they fall right together with oit freezing them.

Ok thanks. I got both halves together but I'm Gunna take it back apart just to make sure it's sealing right, I don't want to end up doing this twice.

 

[1Coopgt]

Fingers crossed for you Z.

 

[Z.hb71]

Fingers crossed for you Z.

Thanks Coop ?

 

[crucialRC]

Same here brah.

 

[DougStar]

+1?

 

[Z.hb71]

Ok I need to ask something, I'm installing the piston circlip I'm wondering, there's a notch in my piston and my cir clip is almost a full circle with a break in in, do I have to line up the break in the circlip to the notch in the Piston?
Here is the circlip

thers the notch
And here is the circlip installed, as you can see the edge of the break in the clip is lined up with the edge of the notch, is this correct? I'm pretty sure it is, but just to be sure, don't want a clip flying out and fekin everything up

Edit: I hate to inform you guys, that this 70cc will not be done today or tomorrow or the next day, I have uncountered a issue were the crank is not allowed the go all the way to bdc becuase the piston hits a section of the crankcase, so the crankcase will need to be modified. I had no idea that this problem would arise becuase I have no means of testing this till today because I didn't have bearings in the case or was ready for the piston. ??????? so theres another week or 2 onto this whole ordeal.
Edit: ok maybe I have a plan, I'll buy a poopy $15 rotary tool and hit the case with it after I take it all apart, a very very very annoying delay and I should have checked it before it's half assembled.

 

[Seandonato73]

Give your circlip a turn so the edge doesn't line up with the cut out. I'll grab a pic from my engine later. Cooking right now. It really sucks that you encountered another issue!

 

[Z.hb71]

Give your circlip a turn so the edge doesn't line up with the cut out. I'll grab a pic from my engine later. Cooking right now. It really sucks that you encountered another issue!

Ok, I'll definitely appreciate a picture. Yeah this issues definitely sucks, especially because I have to remove literally everything from the engine (even bearings). Question, if I heat the case to 200-300 degrees to remove bearings, will it damage the bearings? I don't think so because the engine goes over 200 degrees running but just to be sure

 

[Seandonato73]

No they arnt sealed bearings. They should be fine. And here's your pic kinda a bugger to see but that's how I've always put that style in. Call me paranoid but I've never had a clip pop out putting them in that way.

 

[Polar_Bus]

The notch in the piston is only there so you have a recess to use a small tool to pry out and remove the circlip. Whenever you install circlips you always want the circlip notch to be a 12 oclock or 6 oclock . This is the best position to avoid circlip closure flex under peak rpm.

 

[DougStar]

Give your circlip a turn so the edge doesn't line up with the cut out. I'll grab a pic from my engine later. Cooking right now. It really sucks that you encountered another issue!

???? ah crap sorry Z

 

[Z.hb71]

???? ah crap sorry Z

Yeah it totally sucks, but, I'm trying to source me a rotary to, i don't care if it's disposable becuase I'm just tryna get running. Here's pics if you want


It's mostly the back corners, front is ok but extremely close
Question, what rotary tool bit can I use to grind this? A diamond bit? Carbide bit?? What?

 

[DougStar]

You get some cheap rotary tools??
Get something like this tungsten carbide
Once you have it In your tool it will eat the alloy?? don't press too hard

 

[Z.hb71]

You get some cheap rotary tools??View attachment 52413
Get something like this tungsten carbide
Once you have it In your tool it will eat the alloy?? don't press too hard

Ok thx. I'll try and pick up one from home Depot or something asap, wanna get it back together ( first time saying that LOL)

 

[mark35]

Bummer.. Can't you just take some from the piston to save taking the case apart again??

 

[Z.hb71]

Bummer.. Can't you just take some from the piston to save taking the case apart again??

I'm not sure about that. Won't it make it in balanced? I have no idea. Also I'll have to buy new cir clips if I do that. Becuase I've heard reusing circlips is a horrible idea because they can be fatuiged

 

[DougStar]

Buy new clips??