Use a table ban saw to hack off the 340 piston crown .

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James Clews said:
Rat Bastid, how do you hold the piston skirts in a three jaw chuck without damaging them or even worse braking the skirts by tightening the chuck. and if you do not tighten it the piston will move around damaging it. Now it appears you have a lot more intelligence so tell me how you do it?
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I aint ratbastid , but I wrapped thy hemi pistons with thin brass sheet in a 4 jaw chuck...
 
polyjohn said:
This thread is all 'BACK TO FRONT'!

Its the 360 pistons that are too tall for the 340 block as I've 'BEEN THERE DONE THAT' myself.
The 340 guy bought cheap used forged 360 pistons for a 340 build.
Had to turn about 30 thou off them to get the compression right...

UTG would have used them as is a run some race gas lol...

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Thanks polyjohn....by the way, what's the measurements on old poly hemis? Anybody know? I think there was a 331 ci and I am thinking a 354?
 
Jessearent said:
Thanks polyjohn....by the way, what's the measurements on old poly hemis? Anybody know? I think there was a 331 ci and I am thinking a 354?
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You straighten us out polyjohn..so your saying I need some old forged 360 pistons .070 over for the .0.30 over bore 340 block I am looking at? And taking off bout 0.030 from the top is plauseable?
 
Jessearent said:
You straighten us out polyjohn..so your saying I need some old forged 360 pistons .070 over for the .0.30 over bore 340 block I am looking at? And taking off bout 0.030 from the top is plauseable?
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They do sit pretty far down in the hole stock.
 
AJ/FormS said:
Where are the rings gonna end up relative to the deck?
and will they survive there?
Recheck your math;
A friend of mine did this with used factory pistons, (don't know which ones) without spacers. It's been a strong street-runner nearly as long as mine has (since 1999)
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sounds promising
 
Don't think me stupid for asking this next question. ... Is mopars 4" crank measured by taking the .42" difference 4" - 3.58", is there only .21" throw added to the crank? Half on the top of the stroke and half at the bottom? or is all .42" added to crank equalling .84" if I measure bottom to top?
 
How's this... Best offer so far...
If you scrounge up the money to ship your pistons to me & back to you I'll mill them for free...

Just figure out an accurate number that you need taken off... If you prefer I have a band saw too.....


IMG_7657.jpg
 
Your not kidding? I already bought me a precision Chinese hack saw...just vise it in and bring down the blade. I need to get back home and do the measuring. Got me a set of trw L2405f...forged stock. I need the 4" crank now and will get the measurents...money and time....thanks for being on standby. Sincerely jj
 
1WildRT said:
How's this... Best offer so far...
If you scrounge up the money to ship your pistons to me & back to you I'll mill them for free...

Just figure out an accurate number that you need taken off... If you prefer I have a band saw too.....


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Looks like you're all set, just grab the belt sander with 16 grit.
Remember just hold it flat and level and move it slowly, let the paper do the work.
 
Jessearent said:
Your not kidding? I already bought me a precision Chinese hack saw...just vise it in and bring down the blade. I need to get back home and do the measuring. Got me a set of trw L2405f...forged stock. I need the 4" crank now and will get the measurents...money and time....thanks for being on standby. Sincerely jj
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add LOA( backwards) at the end of my name and send me ma...ling info .,....
 
Mtrhead said:
Hello fella just find an old guy with a mill in his garage and get the tops milled down...I'm having an old set of 12.5 trw's done now!!!
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Got me a generous offer from a fan. He said he would do it for free on his mill/lathe, whatever.
 
I save bout $500 by get the old trw set verses the custom kit pistons, and they are forged! Total for the set $313 out the door.
 
I PM'ed you shipping info,

I have a proper piston vise, I have a bridgeport mill & I have the skills to do the job properly... You need an accurate number & you need to be sure the amount you want taken off won't leave the dome to thin & subject to failure...
 
Darn, I hate thieves, shoot em on site. I tryed to fit a short block in the cab of my truck but could only fit me a 8 3/4 axle...gonna drop it off in the bed of my pickup when I get to the yard.

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