View Full Version : Can forged pistons be repaired?
Laine_16v
04-10-2009, 11:30
Hi,
Ive just split my engine apart after its failure to see the damage. The top of the pistons is slightly damaged, it probably has 20-30 small indentations and marks on it.
Is it possible to say fill this aluminium weld and then have the piston re-milled?
put some sugar on it , will be reet :P
Hi,
Ive just split my engine apart after its failure to see the damage. The top of the pistons is slightly damaged, it probably has 20-30 small indentations and marks on it.
Is it possible to say fill this aluminium weld and then have the piston re-milled?
Not weld them but if there is enough material on the tops and the pockets arnt damaged ?then you could get some milled off all the pistons. Its normal to do this to get exact compresions on race engines...
Whats engough material, i dont know but a good engine builder would :wink:
Any pics of offending actical ?
sideways danny
04-10-2009, 18:03
was this from a foreign object going down the trumpet? dont think I would taking into account the state of tune.
The pistons are drop forged, the repaired section wouldnt be. I think the difference in density of the two sections could in theory cause cracking. i wouldnt risk it.
The pistons are drop forged, the repaired section wouldnt be. I think the difference in density of the two sections could in theory cause cracking. i wouldnt risk it.
If its just the tops of the piston this wont be an issue at all but its all about maintaining suitable thickness in section. People in the know would know if its OK or not.
Some pics of the damaged ones would help....
"just" the top of the piston....Ie the hottest part?? I.e the area which is subject to quite large thermal variation/shock?
I think that anybody properly in the know would say "just fit new ones".
It really does depend on the damage as to whether welding would even be considered, milling could be an option, it just depends on the depth/ammount.
cliolord
04-10-2009, 19:43
Hi,
'Gaz' just split my engine apart after its failure to see the damage. The top of the pistons is slightly damaged, it probably has 20-30 small indentations and marks on it.
Is it possible to say fill this aluminium weld and then have the piston re-milled?
Ta Bud :wink: just run it, will be alreet. Bet it'll still run fine, sort the head mind 8)
bit of chewing gum and tin foil be reyt!
This thread is uselss without pics, matt brown says so too.
MatBrown
04-10-2009, 20:08
:matbrown:
Mat.
Laine_16v
11-11-2009, 12:15
Tada long awaited pics! I stripped the block yesterday, taken all the pistons out and spent about 1 minute cleaning / sanding the ****ed piston.
When i pulled hte piston out the top compression ring was shattered and chunks just fell out, the groove the ring sits in on the piston is not pinched though.
Can this be repaired?
PIcs in next post...
Laine_16v
11-11-2009, 12:19
http://i133.photobucket.com/albums/q51/laine_16v/SL370812.jpg
http://i133.photobucket.com/albums/q51/laine_16v/SL370813.jpg
http://i133.photobucket.com/albums/q51/laine_16v/SL370814-1.jpg
http://i133.photobucket.com/albums/q51/laine_16v/SL370814.jpg
Laine_16v
11-11-2009, 12:21
If you look closely in the first picture the piston skirt looks quite scuffed too, ****ed?
Laine_16v
11-11-2009, 12:37
http://www.honda-tech.com/showthread.php?t=1086914
Just found them in google, sounds identical piston to mine, so might be able to get a new one :S
all thats stamped on them is 'JE 83M'
Id fit new ones personally.
If you mill them you are going to have to deck the block.
Plus youve got the risk of tiny cracks already in the crown area...not worth the risk of it fracturing fully.
them slippers your mates wearing look class, can you get me a set? :D
sideways danny
11-11-2009, 14:48
that's way beyond use IMO
Id fit new ones personally.
If you mill them you are going to have to deck the block.
Plus youve got the risk of tiny cracks already in the crown area...not worth the risk of it fracturing fully.
Can you not just fit one new one ? As long as they are matched (potential machining of the new one to ensure balanced compression ratio) should be fine. Dont see why you would have to get 4 new ones....Know a few engines that have just damaged one piston and have just been replaced....
Laine_16v
11-11-2009, 18:26
I'd quite happily fit a new one.
But you try finding me a 'JE 83M' 11.5:1 piston for me ;)
Id fit new ones personally.
If you mill them you are going to have to deck the block.
Plus youve got the risk of tiny cracks already in the crown area...not worth the risk of it fracturing fully.
Can you not just fit one new one ? As long as they are matched (potential machining of the new one to ensure balanced compression ratio) should be fine. Dont see why you would have to get 4 new ones....Know a few engines that have just damaged one piston and have just been replaced....
As Elaine says, he has daft pistons, we had enough trouble getting new rings for it, let alone a single piece.
If it was an "easy" part then yes, just fitting one would be fine.
cliolord
11-11-2009, 19:37
Make a piston out of wood? Or do the bolt up next time Blaine :lol: NOW GET YOUR WALLET OUT AND LETS BUILD ONE FFS!
that looks one brutal piston to me , roughen the others
to match ,be reet :P
ohh wait ... BRUTAL !!! :P
Laine_16v
11-11-2009, 19:49
Cor shacks always around the corner with his hilarious commentary!
I had forged pistons in my F3P turbo,an number three cylinder kept oiling the plug.......found out piston had melted an pinched ring.
These pistons were from an original build done by, Prima Racing.
So i thought id ring em up and see how much for a set..............£750 :shock: :shock: i hasten to say i didnt buy them.
Dare i say,could 1 be made/machined from billet alloy to match?
Well the problem we had with Laines was they were an old item, so much so that JE didnt have a record of them. One could be made as a one off, probably costing £200 at a guess.
Justin..
12-01-2010, 19:55
Are forged pistons made of alloy then ?
Laine_16v
13-01-2010, 00:13
Are forged pistons made of alloy then ?
Dont quote me on this but off the top of my head they are made of drop forged alluminium.
FAO anyone interested, someone bought the pistons off me in the end and is having JE machine up a replacement pistons :)
Drop forged aluminium alloy yes.
The forgings are then machined from the billet to the final piston dimensions.
somewhere in the tread ive seen "problems to find piston rings" ?
when you have a problem in the near future, contact these guy's:
http://www.totalseal.com/
they made rings for my Arias and JE pistons for any application. Steel/ductile/cast iron/nickasil...no problem at all.
Laine_16v
16-01-2010, 14:54
Totalseal were my second option after finally getting them through JE direct.
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