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View Full Version : Pingpings or impact damage? Need some technical advice


404
18-06-2012, 06:52 PM
Hey crew,

So the other week I had to pull out of the Night race on the 5th of June because I popped a water hose and cooked my motor during the morning practice. So I have pulled the head and the head gasket had shreds of metal hanging off of it. On inspection the pistons looked okay with only a few small (1/5mm) ping pits on no 2,3 & 4 but no 1 has the following marks on it.

http://i15.photobucket.com/albums/a390/Catherine802/IMG_0754.jpg

http://i15.photobucket.com/albums/a390/Catherine802/IMG_0755.jpg

I think bits of the gasket got munched between the piston top and the head as the head also has these marks but the question remains...

Is it pingspings or impact damage?
TurboHead
18-06-2012, 07:09 PM
Wasn't sure from the first pic but 2nd is impact for sure. Bits have since gone through exhaust (check valves for damage).
Simon
18-06-2012, 07:32 PM
Pics of the head? More importantly, spark plug guides.
Could be spark plug electrode hitting the crown.
DISTRBD
18-06-2012, 07:49 PM
Magic1 can show you what a piston looks like from pingpingpingping
Joe
18-06-2012, 07:56 PM
Is it pingspings or impact damage?

Definitely caused by pingpingpingpings
joshg123
18-06-2012, 07:57 PM
Doesnt look like ping, more like something was flapping around, question is did the overheat pull the head from the block to allow the firing ring to break and flap about like that? or something along those lines.
404
18-06-2012, 08:18 PM
The electrode tip and plug is still in tact. There are similar marks on the head to match the piston marks. Will upload the other pictures later on tonight.
404
18-06-2012, 09:18 PM
Doesnt look like ping, more like something was flapping around, question is did the overheat pull the head from the block to allow the firing ring to break and flap about like that? or something along those lines.

I think you might be on the money with this one Josh. The no1 exhaust valves aren't damaged but they are the only ones that are discoloured brown. My guess would be that this piston had maybe blown through a small hole to bleed into the water jacket and then when it cooked at barbs it has taken the firing ring out and the rest followed suit? Will bring the head back to Perth for a hardness,skew & crack test...

http://i15.photobucket.com/albums/a390/Catherine802/IMG_0757.jpg

http://i15.photobucket.com/albums/a390/Catherine802/IMG_0758.jpg

http://i15.photobucket.com/albums/a390/Catherine802/IMG_0759-1.jpg
joshg123
19-06-2012, 06:43 AM
I dont know if its just the camera angle, but that chamber looks like its had water in it. So coolant has prob crossed over from the jacket in the block, taken the firing ring with it and started mushing in the quench area