Fruecrue 660 build thread

[Fruecrue]

The good;

 

[dall]

Very nice dave

 

[Fruecrue]

The bad;


I blew up @dall piston.
Hung a ring.
Learned a lesson.
Is there a prize for first saw blowed up?

 

[Termitebuffet]

Ugh

 

[dall]

is that the piston i sent dave ?

 

[Fruecrue]

I'm not out of the game.
Exhaust port obviously needs more arc anyway.
Stay tuned.
Still having fun for the record. I tend to push things too far. That's ok. I'm pretty good at dealing with it and bouncing back.
That original piston with the defect is on deck.

 

[Fruecrue]

is that the piston i sent dave ?

Yup.

 

[paragonbuilder]

View attachment 74600
I'm not out of the game.
Exhaust port obviously needs more arc anyway.
Stay tuned.
Still having fun for the record. I tend to push things too far. That's ok. I'm pretty good at dealing with it and bouncing back.
That original piston with the defect is on deck.

I like your attitude! I am much the same way. [emoji41]


Sent from my iPhone using Tapatalk

 

[MustangMike]

Ouch, that hurt just looking at it! I think the orig piston will be OK.

In your opinion, did the exhaust roof come to flat to begin with, or did you push it for performance sake?

I've got to admit, you got me nervous!

Good luck with the fix, hope your cylinder is OK!

 

[Deets066]

That was a flat roof....would've ran good I bet if it didn't hang

 

[Deets066]

The bad;

View attachment 74599
I blew up @dall piston.
Hung a ring.
Learned a lesson.
Is there a prize for first saw blowed up?

You definately get the prize for the first casualty

 

[drf256]

Uggh, again.

I thought your exhaust looked pretty darn good. The roof didn't look THAT flat, woulda been interesting to see it with the piston crown just below it before the mishap. Your chamfers look fine as well.

I guess we all win some and lose some with this obsession. You're taking it well.

 

[mdavlee]

Looks like it hung on the way down to me.

 

[Fruecrue]

Looks like it hung on the way down to me.

I agree.

 

[Brewz]

The exhaust didnt look that flat.
Nice and rounded out on the sides with good chamfer.
I'm calling ring cracked or piston had a fault.

 

[Brewz]

Top ring looks fine
Bottom ring was the culprit.

Its Dalls fault!

 

[Brewz]

How long did it run for before it went bang?
My pick is that the bottom ring cracked when installing the cylinder or soon after starting, then a piece pulled up to the top of the piston as it was heading down.

 

[Fruecrue]

She ran on and off 3 or 4 times.
Once without a muffler, maybe 2 minutes.
Checked and let cool- all good.
Did muffler mod, ran again, maybe 3 to 4 minutes, idle and light revs.
Put bar on, still warm, ran 1 or 2 minutes, tuning carb.
Then KABLOOEY. Stopped dead with a nasty ping. Was not revving hard at time of failure.

 

[Fruecrue]

Ouch, that hurt just looking at it! I think the orig piston will be OK.

In your opinion, did the exhaust roof come to flat to begin with, or did you push it for performance sake?

I've got to admit, you got me nervous!

Good luck with the fix, hope your cylinder is OK!

It was flat from the factory.
Roof might not have been the problem.

 

[Brewz]

The roof on the cross 660 cylinder I have here is very flat.
If I widened it I would be rounding it a touch.
Problem with that is the plated band