HELP¡¡¡¡ DASA 16 mm

[meucarango]

This is the most destroyed

 

[waxhead]

OK thanks
So you are looking at physical damage there. the piston shows no sign of overheating etc.
So its not a tunning issue, its a clearance issue
What does the top of the exhaust port look like is there hammering marks from the piston smacking into it??
Have the power valves been clearanced correctly ???

 

[meucarango]

valves were machined (2 mm piston farther)

 

[waxhead]

Something is forcing that ring upwards as can been seen from the side pic
The only thing i can think of forcing the ring upwards is hitting something on the downwards stroke
Have a look and make sure the bottom of the exhaust port does not have a massive sharp edge on it thats catching the ring and tearing it off. ie not enough chamfer to push the ring back in

Seems like you have the power valve theory sorted then

 

[meucarango]

Have a look and make sure the bottom of the exhaust port does not have a massive sharp edge on it thats catching the ring and tearing it off.
1mm is Vicel after the second destruction

 

[waxhead]

I dont understand vicel ??
does this mean you have filed a 1mm chamfer on it ??

 

[wsuwrhr]

You verified the valve, when fully "closed", is 1 MM away from the piston?

Brian

valves were machined (2 mm piston farther)

 

[meucarango]

does this mean you have filed a 1mm chamfer on it ??
yes the entire exhaust

 

[meucarango]

You verified the valve, when fully "closed", is 1 MM away from the piston

2mm closed valves of the piston

 

[waxhead]

Ok well that would seem to stop that
And its not hitting the head. Have you checked the height that both pistons are coming to at tdc is the same. ie distance from top of cylinder

It would seem that the piston suffered from physical damage.
you have clearanced the power valves
you have put a decent chamfer on everything

im now wondering if it has a bent rod that pushing it hard up against the exhaust port
Is the exhaust port showing signs of damage at all

 

[meucarango]

perfectly aligned rods

 

[waxhead]

Ok im out
With out actually seeing it I cant offer any more suggestions

 

[wsuwrhr]

perfectly aligned rods

What is this picture showing?

I don't see any relevance.

 

[meucarango]

now I try to understand that all potential problems
I'm confused

 

[waxhead]

What is this picture showing?

I don't see any relevance.

I think he is trying to show that he has checked the pistons coming to tdc at the same height
The pics dont show that but I am guessing he has done it since he said perfectly aligned rods like he has checked them

 

[meucarango]

I think he is trying to show that he has checked the pistons coming to tdc

YES YES

 

[wsuwrhr]

I think he is trying to show that he has checked the pistons coming to tdc at the same height
The pics dont show that but I am guessing he has done it since he said perfectly aligned rods like he has checked them

With a mag base on an aluminum head?

All I can guess is the indicator went to zero?

Relative to what?

From one side to the next?

The second you move the base, there is nothing to check.

 

[wsuwrhr]

How else did you verify the rods are straight?

Brian

 

[meucarango]

How else did you verify the rods are straight
rods are recreated assure
I want to say is that post pistons reach top two

 

[ATS_Aaron]

I may have missed it before. But what fuel are you using?