Are stock HP273 pistons forged or cast?

Posted By: toolmanmike

Are stock HP273 pistons forged or cast? - 09/13/09 04:28 AM

I have heard conflicting stories but have never seen anything in print. Are the factory 10.5:1 Hp273
pistons forged or cast? How heavy are they? Thanks, toolmanmike

Posted By: Rhinodart

Re: Are stock HP273 pistons forged or cast? - 09/13/09 04:33 AM

I have a couple 67 273 4-bbl engines apart and they are definitely forged and heavy! I also have a set of replacement forged pistons .030 over and they are real heavy!

Posted By: mr_340

Re: Are stock HP273 pistons forged or cast? - 09/13/09 05:42 AM

I never had a 235HP 273, but my old 2bbl 273 had really thick wall pins. I don't remember the pistons being overly heavy (by Chrysler standards), but the pin had about .300" thick wall. I think they did that to keep the same balance as a 318 piston and pin. It would make the assembly line easier if they could balance all the cranks the same.

Posted By: dart4forte

Re: Are stock HP273 pistons forged or cast? - 09/13/09 03:32 PM

Quote:

I have a couple 67 273 4-bbl engines apart and they are definitely forged and heavy! I also have a set of replacement forged pistons .030 over and they are real heavy!

Are you sure you don't have the L2222 TRW Forged pistons. Every HP 273 I've torn apart had the 10.5 cast piston. Also, there is a secret to lightening the HP piston. Also as a note: EGGE shows a 4 barrel piston with the L2222 part number. However, after calling them I find that the piston they offer is the cast replacement piston. Really hard to find forged pistons for the 273 without going with the major manufacturers since their pistons are custom made and run around $600-$800 a set.

Posted By: toolmanmike

Re: Are stock HP273 pistons forged or cast? - 02/06/10 04:47 AM

I bought a set of the Egge 10.5/1 pistons. They are cast and come with pins and clips. The +.030's are about 60 grams lighter than the stock standard bore slugs so I balanced the rotating assembly. They were all within a half a thousandth of the same size. Good stuff! Mike

Attached picture 5785649-09_24_0.JPEG

Posted By: RapidRobert

Re: Are stock HP273 pistons forged or cast? - 02/06/10 05:28 AM

they are cast and as said the pins are very heavy so the 273 piston/pin assy will weigh the same as the 318 piston/pin assy even w the smaller dia (& therefore lighter) 273 pistons so the balancing bobweight is the same.

Posted By: MrSixpack

Re: Are stock HP273 pistons forged or cast? - 02/06/10 01:42 PM

My 3 commando engines has cast pistons.

Posted By: jcc

Re: Are stock HP273 pistons forged or cast? - 02/06/10 04:56 PM

Quote:

I have a couple 67 273 4-bbl engines apart and they are definitely forged and heavy! I also have a set of replacement forged pistons .030 over and they are real heavy!

So when the time comes around to repbuild my 273, I don't care about the 318 bobweight issue, what lightweight piston options are out there, custom or off the shelf?

Posted By: John_Kunkel

Re: Are stock HP273 pistons forged or cast? - 02/06/10 10:07 PM

Quote:

I have a couple 67 273 4-bbl engines apart and they are definitely forged and heavy!

Got a pic of the underside?