Looper exhaust porting

[Trommehinne]

Hello Captain. It is interesting following you, i have a 225 looper and i like how you do with your engine.
Hvor i Sverige holder du til? I live close to the Swedish border.
Hilsen Ketil.

[Captain75]

Hello Captain. It is interesting following you, i have a 225 looper and i like how you do with your engine.
Hvor i Sverige holder du til? I live close to the Swedish border.

Hilsen Ketil.

hej Ketil
jag bor i närheten av Stockholm
hälsningar Anders

[Captain75]

Slow progress is being made...
Pistons have got some dimples to help prevent scoring and better the lubrication.
Added lube holes for the wrist pins aswell.
Right now trying to get all pistons to weigh the same...

[Captain75]

Honing finished, first a round with stones, finished with 320grit ballhone. Fingers coped fine...
Now I am a bit worried that my wrist pins became to small after cleaning, I can easily put them in by hand, and they can almost "fall out" if you turn the piston sideways. Meter shows 0,03mm play between piston boss and wristpin.
Do I need to change?

[CNC_Guy]

That is .00112 In imperial if that helps anyone. .001 clearance would fall out easily.

[Captain75]

I know that They can't fall out due to the clips, it was just a way to describe the actual fit.

[CNC_Guy]

I just translated the amount of clearance for the non-metric.

[baja200merk]

You should be able to slide them in by hand. How did you clean them?

[Captain75]

I sat them one at the time in a machine like this, cleaned them while rotating at high speed, using 600grit wet paper...

[baja200merk]

I can measure a stock one when I get to shop later and maybe we can figure out how much you took off.

Worst case I have about 60 stock pins sitting in the scrap bucket, you can have 6 for free but shipping might cost more then new ones

[Captain75]

All of them about 0,944" some of them 0,9445" in the bearing area.
measurements taken with a digital caliper(couldn't get my micrometer to work properly)

[powerabout]

I think the pins are metric?

[Captain75]

I think the pins are metric?

They are probably 24mm from factory, I altered the scale in order to hopefully recieve answers from the US guys...
My pins measure appx 23,98mm, which according to my digital caliper, is the same as 0,944"
My concern is weather to much play can make the wristpins destroy the piston bosses?(make the hole oval)I don't think spinning pins would destroy the bosses, its the rapid direction changes that worrie me...

[Captain75]

All pistons ready, heavy ones goes with light rods...

Plugged the predrilled relief roles, reachable when motor is assembled, if I want them opened...

The three threaded exhaust relief holes on a newly painted lower unit...

Now I am just waiting for my new wristpins and upper crank bearing.

[racer]

Get the pistons to weigh the same the rods also putting the heavy pistons with light rods is not nearly as good as weigh matched parts. You will need the exhaust holes for it to idle without loading up, also helps low end throttle responce. Personaly I would remove the lower part of the can.